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The Matter of Decision-Making Control Over Operation Processes of Marine Power Plant Systems with the Use of their Models in the form of Semi-Markov Decision-Making Processes
PublikacjaThe article presents the possibility to control the real operation process of an arbitrary device installed in the marine power plant based on the four-state semi-Markov process, being the model of the process, which describes the transition process of operational states of the device and the transition process of its technical states. All these states are precisely defined for the ship main engine (SG). A hypothesis is proposed...
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Acoustic imaging of selected areas of Gdansk Bay with the aid of parametric echosounder and side-scan sonar
PublikacjaThe article presents and analyses the data recorded during sounding of the Gdansk Bay seabed with the aid of a parametric echosounder and a side-scan sonar. The accuracy of seabed structure examination, as a condition for obtaining valuable results, requires correct configuration of echolocation devices and proper calibration of peripheral devices, such as the survey unit geographical position sensor – GPS, the navigation unit,...
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Buckling and shape control of prestressable trusses using optimum number of actuators
PublikacjaThis paper describes a method to control the nodal displacement of prestressable truss structures within the desired domains. At the same time, the stress in all members is unleashed to take any value between the allowable tensile stress and critical buckling stress. The shape and stresses are controlled by actuating the most active members. The technique considers the members’ initial crookedness, residual stresses, and slenderness...
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Local buckling of thin-walled channel member flange made of aluminum alloy
PublikacjaThe paper deals with local stability of the thin-walled compressed flange of channel columns and beams made of aluminum alloy. The aim of paper is to find critical stress of local buckling of the flange member taking into account the web-flange interaction in linear and nonlinear elastic range of the member material. The governing differential equation of the problem is derived with aid of the principle of stationary total potential...
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Rapid Yield Estimation and Optimization of Microwave Structures Exploiting Feature-Based Statistical Analysis
PublikacjaIn this paper, we propose a simple, yet reliable methodology to expediteyield estimation and optimization of microwave structures. In our approach,the analysis of the entire response of the structure at hand (e.g., $S$-parameters asa function of frequency) is replaced by response surface modeling of suitablyselected feature points. On the one hand, this is sufficient to determinewhether a design satisfies given performance specifications....
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On forced vibrations of piezo-flexomagnetic nano-actuator beams
PublikacjaThe effect of excitation frequency on the piezomagnetic Euler-Bernoulli nanobeam taking the flexomagnetic material phenomenon into consideration is investigated in this chapter. The magnetization with strain gradients creates flexomagneticity. We couple simultaneously the piezomagnetic and flexomagnetic properties in an inverse magnetization. Resemble the flexoelectricity, the flexomagneticity is also size-dependent. So, it has...
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An optimal form of the finite element mass matrix in the analysis of longitudinal vibrations of rods
PublikacjaIn this paper, an attempt is made to find the optimal form of the mass matrix of a rod finite element, which allows one to obtain the smallest errors in the longitudinal frequency determination of natural vibrations of any boundary conditions within the whole range of determined frequencies. It is assumed that the mass matrix can be treated as a linear combination of the consistent and diagonal matrices. Based on analytical considerations,...
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An analysis of observability and detectability for different sets of measured outputs - CSTR case study
PublikacjaA problem of proving the observability/detectability at a given measured output for non-linear biochemical systems has been addressed in this paper. A theory of indistinguishable state trajectories has been used to prove the properties of the observability or detectability of this system. It is related to taking system dynamics into consideration depending on initial conditions and the impact of inputs taking into account a given...
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Impact of Geometrical Imperfections on Estimation of Buckling and Limit Loads in a Silo Segment Using the Vibration Correlation Technique
PublikacjaThe paper examines effectiveness of the vibration correlation technique which allows determining the buckling or limit loads by means of measured natural frequencies of structures. A steel silo segment with a corrugated wall, stiffened with cold-formed channel section columns was analysed. The investigations included numerical analyses of: linear buckling, dynamic eigenvalue and geometrically static non-linear problems. Both perfect...
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Superconductivity in the superhard boride WB4.2
PublikacjaWe show that the superhard boride WB4.2 is a superconductor with a Tc of 2.05(5) K. Temperature-dependent magnetic susceptibility, electrical resistivity, and specific heat measurements were used to characterize the superconducting transition. The Sommerfeld constant γ for WB4.2 is 2.07(3) mJ mol−1 K−2 and the ΔC/γTc=1.56, which is somewhat higher than what is expected for weakly coupled Bardeen–Cooper–Schrieffer type superconductors....
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Sensor Position Estimation Method for IoT Using Mobile Reference Node
PublikacjaThe paper proposes an innovative method of locating objects for the Internet of Things (IoT). The proposed method allows the position of a fixed measuring sensor (MS) to be estimated using one mobile base station with a known position moving around the MS. The mathematical analysis of the method, and three algorithms — Newton’s (NA), gradient descent (GD) and genetic (GA) — for solving the system of non-linear positional equations...
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Analogues of trypsin inhibitor SFTI-1 modified in the conserved P1′ position by synthetic or non-proteinogenic amino acids retain their inhibitory activity
PublikacjaA series of linear and monocyclic (with a disulfide bridge only) analogues of trypsin inhibitor SFTI-1 modified in the P-1 and/or P-1' positions were synthesized by the solid-phase method. In the substrate specificity P-1 position, Phe or N-benzylglycine (Nphe) were introduced, whereas the conserved Ser6 in Bownam-Birk (BBI) inhibitors was replaced by Hse (L-homoserine), Nhse [N-(2-hydroxyethyl)glycine], Sar, and Ala. Kinetic studies...
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Measurements of Dispersed Phase Velocity in Two-Phase Flows in Pipelines Using Gamma-Absorption Technique and Phase of the Cross-Spectral Density Function
PublikacjaThis paper concerns the application of the gamma radiation absorption method in the measurements of dispersed phase velocity in two-phase flows: liquid–gas flow in a horizontal pipe- line and liquid–solid particles in a vertical pipe. Radiometric sets containing two linear 241Am gamma radiation sources and two NaI(Tl) scintillation detectors were used in the research. Due to the stochastic nature of the signals obtained from the...
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Buckling of simplified models of silo with corrugated walls and vertical stiffeners
PublikacjaThe paper deals with buckling of cylindrical silos composed of corrugated sheets and vertical stiffeners (columns). Comprehensive finite element analyses were carried out for a perfect silo by means of a linear buckling approach. Corrugated walls were simulated as an equivalent orthotropic shell and vertical thin-walled columns as beam elements. Calculations for perfect silos with different numbers of columns made it possible to...
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Fractional differential equations with causal operators
PublikacjaWe study fractional differential equations with causal operators. The existence of solutions is obtained by applying the successive approximate method. Some applications are discussed including also the case when causal operator Q is a linear operator. Examples illustrate some results.
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The Complexity of Zero-Visibility Cops and Robber
PublikacjaIn this work we deal with the computational complexity aspects of the zero-visibility Cops and Robber game. We provide an algorithm that computes the zero-visibility copnumber of a tree in linear time and show that the corresponding decision problem is NP-complete even for the class of starlike graphs.
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Assessment of the Impact of GNSS Processing Strategies on the Long-Term Parameters of 20 Years IWV Time Series
PublikacjaAdvanced processing of collected global navigation satellite systems (GNSS) observations allows for the estimation of zenith tropospheric delay (ZTD), which in turn can be converted to the integrated water vapour (IWV). The proper estimation of GNSS IWV can be affected by the adopted GNSS processing strategy. To verify which of its elements cause deterioration and which improve the estimated GNSS IWV, we conducted eight reprocessings...
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Highly selective impedimetric determination of Haemophilus influenzae protein D using maze-like boron-doped carbon nanowall electrodes
PublikacjaThis study reports a novel impedimetric immunosensor for protein D detection in purified and bacterial (Haemophilus influenzae, Hi) samples. The detection was based on antigen recognition by anti-protein D antibodies (apD) immobilised at the maze-like boron-doped carbon nanowall electrodes (B:CNW). The B:CNW electrodes were synthesised, and their surface was characterised by scanning electron microscopy (SEM) and X-ray photoelectron...
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Resource productivity and environmental degradation in EU-27 countries: context of material footprint
PublikacjaThis study explores the relationship between the resource productivity and environmental degradation in European Union-27 countries. This study tests this relationship in context of high, moderate, and low material footprint sub-samples; these samples are formed utilizing the expectation–maximization machine learning algorithm. Using the panel data set of EU-27 countries from 2000 to 2020, linear and non-linear autoregressive distributed...
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On unique kinematics for the branching shells
PublikacjaWe construct the unique two-dimensional (2D) kinematics which is work-conjugate to the exact, resultant local equilibrium conditions of the non-linear theory of branching shells. Several types of junctions are described. For each type the explicit form of the principle of virtual work is derived.
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GreedyMAX-type Algorithms for the Maximum Independent Set Problem
PublikacjaA maximum independent set problem for a simple graph G = (V,E) is to find the largest subset of pairwise nonadjacent vertices. The problem is known to be NP-hard and it is also hard to approximate. Within this article we introduce a non-negative integer valued functionp defined on the vertex set V(G) and called a potential function of agraph G, while P(G) = max{vinV(G)| p(v)} is called a potential of G. For any graph P(G) <= D(G),...
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Collaborative Delivery by Energy-Sharing Low-Power Mobile Robots
PublikacjaWe study two variants of delivery problems for mobile robots sharing energy. Each mobile robot can store at any given moment at most two units of energy, and whenever two robots are at the same location, they can transfer energy between each other, respecting the maximum capacity. The robots operate in a simple graph and initially each robot has two units of energy. A single edge traversal by an robot reduces its energy by one...
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Generalized Dobrushin Coefficients on Banach Spaces
PublikacjaThe asymptotic behavior of iterates of bounded linear operators (not necessarily positive), acting on Banach spaces, is studied. Through the Dobrushin ergodicity coefficient, we generalize some ergodic theorems obtained earlier for classical Markov semigroups acting on L1 (or positive operators on abstract state spaces).
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The effect of anionic surfactant concentration on activated sludge condition and phosphate release in biological treatment plant
PublikacjaThis paper discusses the influence of a wide range of anionic surfactant concentrations on activated sludge. Linear alkylbenzene sulphonate (LAS) was chosen as an example of a commonly used anionic surfactant. The fate of the surfactant during biological treatment of wastewater was tested. The effect of surfactant on glucose and starch removal was studied.
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Job-related emotions and job burnout among civil servants: examining the shape of the relationship in cross-sectional and longitudinal models
PublikacjaWstęp: Związek pozytywności, czyli proporcji między pozytywnymi a negatywnymi emocjami, z wypaleniem zawodowym może przybierać kształt krzywoliniowy. Ponadto z perspektywy teoretycznej jest to relacja przyczynowo - skutkowa, w której pozytywność jest proksymalnym, a wypalenie – dystalnym wymiarem dobrostanu zawodowego. Dotychczasowe badania były jednak prowadzone najczęściej w planie poprzecznym i testowały relacje prostoliniowe....
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Signal Reconstruction from Sparse Measurements Using Compressive Sensing Technique
PublikacjaThe paper presents the possibility of applying a new class ofmathematical methods, known as Compressive Sensing (CS) for recovering thesignal from a small set of measured samples. CS allows the faithful recon-struction of the original signal back from fewer random measurements bymaking use of some non-linear reconstruction techniques. Since of all thesefeatures, CSfinds its applications especially in the areas where, sensing is...
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Predicting the seismic collapse capacity of adjacent SMRFs retrofitted with fluid viscous dampers in pounding condition
PublikacjaSevere damages of adjacent structures due to structural pounding during earthquakes have emphasized the need to use some seismic retrofit strategy to enhance the structural performance. The purpose of this paper is to study the influence of using linear and nonlinear Fluid Viscous Dampers (FVDs) on the seismic collapse capacities of adjacent structures prone to pounding and proposing modification factors to modify the median...
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Acoustic heating produced in the boundary layer
Publikacja: Instantaneous acoustic heating of a viscous fluid flow in a boundary layer is the subject of investigation. The governing equation of acoustic heating is derived by means of a special linear combination of conservation equations in the differential form, which reduces all acoustic terms in the linear part of the final equation but preserves terms belonging to the thermal mode. The procedure of decomposition is valid in a weakly...
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Hazardous material-related propagation of the effects of train accidents in the subgrade
PublikacjaA large part of the transport of hazardous materials is carried out by rail. Therefore, the security of these transports is becoming increasingly important. Every catastrophe involving dangerous materials has a negative impact on the participants of the incident and the surrounding environment, because its range is generally not local. It follows that in the event of a catastrophe, its effects should be minimized and remediation...
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Assessment of Subsoil Subsidence Under the Railway Surface with the Use of Fuzzy Sets
PublikacjaThe cause of the subsidence of the railway track is the subsidence of the track bed itself and it is often related to the subsidence of the subsoil. Such settlement leads to: uneven longitudinal railways and track twist. These phenomena have a negative impact on the comfort and safety of driving, and in extreme cases lead to a train derailment. It has been shown that the magnitude of these settlements is determined by many parameters...
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On thermal stability of piezo-flexomagnetic microbeams considering different temperature distributions
PublikacjaBy relying on the Euler–Bernoulli beam model and energy variational formula, we indicate critical temperature causes in the buckling of piezo-flexomagnetic microscale beams. The corresponding size-dependent approach is underlying as a second strain gradient theory. Small deformations of elastic solids are assessed, and the mathematical discussion is linear. Regardless of the pyromagnetic effects, the thermal loading of the thermal...
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Chromium-Catalyzed CO2–Epoxide Copolymerization
PublikacjaIminopyrrole, aminopyrrole, and aminophosphine ligands were complexed with various chromium sources, producing eight complexes that were tested for their catalytic behavior toward epoxide–CO2 copolymerization. As elucidated by MALDI-TOF-MS, copolymerizations afforded polycarbonates and poly(ether-carbonates) exhibiting linear or cyclic topologies.
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Equitable colorings of some variation of corona products of cubic graphs
PublikacjaThe problem of determining the value of equitable chromatic number for multicoronas of cubic graphs is studied. We provide some polynomially solvable cases of cubical multicoronas and give simple linear time algorithms for equitable coloring of such graphs which use almost optimal number of colors in the remaining cases.
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Viability of decisional DNA in robotics
PublikacjaThe Decisional DNA is an artificial intelligence system that uses prior experiences to shape future decisions. Decisional DNA is written in the Set Of Experience Knowledge Structure (SOEKS) and is capable of capturing and reusing a broad range of data. Decisional DNA has been implemented in several fields including Alzheimer’s diagnosis, geothermal energy and smart TV. Decisional DNA is well suited to use in robotics due to the...
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Using FreeFEM open software for modelling the vibrations of piezoelectric devices
PublikacjaModelling vibrations of piezoelectric transducers has been a topic discussed in the literature for many decades. The first models - so-called one-dimensional - describe the vibrations only near operating frequency and near its harmonics. Attempts to introduce two-dimensional models were related to the possibility of one transducer working at several frequencies, including both thickness vibrations and those resulting from the transducer...
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The new investing effectiveness evaluation multi-criteria method in modern supply systems
PublikacjaThe important problem in the processes of modelling and programming the development of sustainable energy sector is the multi-criteria manner of assessing the effectiveness of investments. The goal of this paper is to show how to take into account the impact of investments in multidimensional modelling decision-making processes. This goal can be achieved through the development, presentation, and use of a new multi-criteria method...
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Particle Filter Modification using Kalman Optimal Filtering Method as Applied to Road Detection from Satellite Images
PublikacjaIn the paper recursive state estimation approach is presented as applied to satellite images. Especially, a model of dynamic systems of the non-linear and non-Gaussian systems is presented, and finally the Kalman filter and particle filter and an integration of both is figured out. Special attention is paid to the application for satellite image analysis.
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Derivation of motor mean phase currents in PMSM drives operating with low switching-to-fundamental frequency ratio
PublikacjaPulse width modulation (PWM) of inverter output voltage causes the waveforms of motor phase cur-rents to consist of distinctive ripples. In order to provide suitable feedback for the motor current con-trollers, the mean value must be extracted from the currents’ waveforms in every PWM cycle. A com-mon solution to derive the mean phase currents is to sample their value at the midpoint of a symmetrical PWM cycle. Using an assumption...
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Two-Rate Based Low-Complexity Variable Fractional-Delay FIR Filter Structures
PublikacjaThis paper considers two-rate based structures for variable fractional-delay (VFD) finite-length impulse response (FIR) filters. They are single-rate structures but derived through a two-rate approach. The basic structure considered hitherto utilizes a regular half-band (HB) linear-phase filter and the Farrow structure with linear-phase subfilters. Especially for wide-band specifications, this structure is computationally efficient...
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Example of tension fabric structure analysis
PublikacjaThe aim of the work is to examine two variants of non-linear strain-stress relations accepted to description of architectural fabric. Discussion on the fundamental equations of the dense net model, used in description of coated woven fabric behaviour is presented. An analysis of tensile fabric structures subjected to the dead load and initial pretension is described.
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Local variance factors in deformation analysis of non-homogenous monitoring networks
PublikacjaThis paper proposes a modification of the classical deformation analysis algorithm for non-homogeneous (e.g. linear-angular) monitoring networks. The basis for the proposed solution is the idea of local variance factors. The theoretical discussion was complemented with an example of its application on a simulated horizontal monitoring network. The obtained results confirm the usefulness of the proposed solution.
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On a Recurrence Arising in Graph Compression
PublikacjaIn a recently proposed graphical compression algorithm by Choi and Szpankowski (2012), the following tree arose in the course of the analysis. The root contains n balls that are consequently distributed between two subtrees according to a simple rule: In each step, all balls independently move down to the left subtree (say with probability p) or the right subtree (with probability 1p). A new node is created as long as...
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Testing Stability of Digital Filters Using Multimodal Particle Swarm Optimization with Phase Analysis
PublikacjaIn this paper, a novel meta-heuristic method for evaluation of digital filter stability is presented. The proposed method is very general because it allows one to evaluate stability of systems whose characteristic equations are not based on polynomials. The method combines an efficient evolutionary algorithm represented by the particle swarm optimization and the phase analysis of a complex function in the characteristic equation....
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Noncentrosymmetric Triangular Magnet CaMnTeO6: Strong Quantum Fluctuations and Role of s0 versus s2 Electronic States in Competing Exchange Interactions
PublikacjaNoncentrosymmetric triangular magnets offer a unique platform for realizing strong quantum fluctuations. However, designing these quantum materials remains an open challenge attributable to a knowledge gap in the tunability of competing exchange interactions at the atomic level. Here, a new noncentrosymmetric triangular S = 3/2 magnet CaMnTeO6 is created based on careful chemical and physical considerations. The model material...
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Acoustic heating produced in the thermoviscous flow of a bingham plastic
PublikacjaThis study is devoted to the instantaneous acoustic heating of a Bingham plastic. The model of the Bingham plastic's viscous stress tensor includes the yield stress along with the shear viscosity, which differentiates a Bingham plastic from a viscous Newtonian fluid. A special linear combination of the conservation equations in differential form makes it possible to reduce all acoustic terms in the linear part of of the final equation...
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Efficiency of acoustic heating produced in the thermoviscous flow of a fluid with relaxation
PublikacjaInstantaneous acoustic heating of a fluid with thermodynamic relaxation is the subject of investigation. Among others, viscoelastic biological media described by the Maxwell model of the viscous stress tensor, belong to this type of fluid. The governing equation of acoustic heating is derived by means of the special linear combination of conservation equations in differential form, allowing the reduction of all acoustic terms in...
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Core-Shell Nanoparticles with Hyperbranched Poly(arylene-oxindole) Interiors
PublikacjaCore-shell type star polymers composed of poly(tert-butyl acrylate) (poly(t-BuA)) arms and 100% hyperbranched poly(arylene-oxindole) interiors were synthesized via the "core-first" method. Atom transfer radical polymerization of t-BuA initiated by 2-bromopropionyl terminal groups of the hyperbranched core was applied for the synthesis of the stars. The resultant star structures were characterized by gel permeation chromatography...
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Acoustic heating produced in the thermoviscous flow of a Bingham plastic
PublikacjaThis study is devoted to the instantaneous acoustic heating of a Bingham plastic. The model of the Bingham plastic's viscous stress tensor includes the yield stress along with the shear viscosity, which differentiates a Bingham plastic from a viscous Newtonian fluid. A special linear combination of the conservation equations in differential form makes it possible to reduce all acoustic terms in the linear part of of the final equation...
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Investigation of the 16-year and 18-year ZTD Time Series Derived from GPS Data Processing
PublikacjaThe GPS system can play an important role in activities related to the monitoring of climate. Long time series, coherent strategy, and very high quality of tropospheric parameter Zenith Tropospheric Delay (ZTD) estimated on the basis of GPS data analysis allows to investigate its usefulness for climate research as a direct GPS product. This paper presents results of analysis of 16-year time series derived from EUREF Permanent Network...
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Stability and load bearing capacity of a braced truss under upward wind loading
PublikacjaThe paper is focused on the numerical and experimental investigation of stability of a steel truss under upward wind loading. The structure was stiffened by elastic braces situated at the top and bottom chord. Usually the lateral (translational) brace stiffness is considered. However, the rotational stiffness of braces caused by interaction between torsional stiffness of the truss top chord and bending stiffness of the roof elements...