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Search results for: pahs
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Melatonin: A Cutaneous Perspective on its Production, Metabolism, and Functions
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On the synthesis of coupled-lossy resonator filters with unloaded quality factor control
PublicationA technique for fast synthesis of coupling matrix low-pass prototypes of generalized Chebyshev bandpass filters with lossy resonators is presented in this paper. The coupling matrix is found by solving a nonlinear least squares problem based on zeros and poles of filter's transfer functions. Additional constraints are introduced that allow one to control the level of unloaded quality factor of resonators.
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Contaminants in airport runoff water in the Vicinities of Two International Airports in Poland
PublicationThe general aim of the study was to evaluate environmental quality associated with the operations (combustion of fuels, cleaning of aircraft and airport aprons, aircraft, ground vehicle maintenance and repairs, fuelling operations, de/anti-icing operations) of international airports located in central and northern of Poland. These two monitoring areas were set up to monitor PAHs, PCBs, formaldehydes, phenols, detergents (cationic,...
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Contaminants in airport runoff water
PublicationDespite the many positives ensuing from the rapid expansion of the air transport sector, airport operations as a whole are a substantial source of environmental pollution.Increases in aviation developments have serious consequences on the surrounding air, soil and water bodies like lakes, rivers and ground water. The present work deals with the determination of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls...
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Employing flowgraphs for forward route reconstruction in video surveillance system
PublicationPawlak’s flowgraphs were utilized as a base idea and knowledge container for prediction and decision making algorithms applied to experimental video surveillance system. The system is used for tracking people inside buildings in order to obtain information about their appearance and movement. The fields of view of the cameras did not overlap. Therefore, when an object was moving through unsupervised areas, prediction was needed...
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Problem of inconsistent and contradictory judgements in pairwise comparisonmethod in sense of AHP
PublicationThe aim of this paper is to show the relationship between inconsistent and contradictory matrices of data obtained as a result of the pairwise comparison of factors in the sense of the Analytic Hierarchy Process. The consistency check is performed to ensure that judgements are neither random nor illogical. This paper shows that even if a matrix will pass a consistency test successfully, it can be contradictory. Moreover an algorithm...
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Laser Beam as a Precision Tool to Increase Fatigue Resistance in an Eyelet of Undercarriage Drag Strut
PublicationThe article contains the results of tests on a laser-processed eyelet of undercarriage drag strut to increase its fatigue strength. Laser processing concentrated on both sides around the hole of eye for connecting the undercarriage drag strut caused that the material in this area withstood more than twice the number of load cycles established for this material. In order to determine the reasons for the increase in fatigue strength,...
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Integracja systemów diagnostycznych w radiologii.
PublicationElektroniczne wytwarzanie, składowanie oraz prezentacja danych medycznych staje się coraz częściej koniecznością dyktowaną zarówno aspektami jakości i bezpieczeństwa jak i warunkami ekonomicznymi. W artykule omówiono wymagania oraz proces integracji systemów diagnostycznych (PACS) i prezentacyjnych w radiologii. Rozpatrzono przykładowe studium przypadku dla Zakładu Radiologii AMG w Gdańsku.
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KASKADA Platform in Cloud Environment
PublicationKASKADA is a computing platform for developing and running services and applications oriented to multimedia processing and data streaming. A solution for serving the platform in the PaaS model is presented. The paper briefly describes the software for creating the private cloud environment based on the OpenStack software. The coud has been deployed to a supercomputer working in C2 NIWA at the Gdansk University of technology. This...
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Modelling of Mechanical Behaviour of High-Frequency Piezoelectric Actuators Using Bouc-Wen Model
PublicationThe paper presents the application of a modified, symmetrical Bouc-Wen model to simulate a mechanical behaviour of high-frequency piezoelectric actuators (PAs). In order to identify parameters of the model, a two-step algorithm was utilized. In the first stage, the mechanical parameters were identified by taking into account their bilinear variability and using a square input voltage waveform. In the second step, the hysteresis...
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Bondage number of grid graphs
PublicationThe bondage number b(G) of a nonempty graph G is the cardinality of a smallest set of edges whose removal from G results in a graph with domination number greater than the domination number of G. Here we study the bondage number of some grid-like graphs. In this sense, we obtain some bounds or exact values of the bondage number of some strong product and direct product of two paths.
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Dynamic ranking of cloud providers
PublicationThe paper focuses on how to create an effective dynamic ranking service for IaaS,PaaS and SaaS cloud providers. It considers building of a quality model for thispurpose along with definition of quality measurement procedures. The paper discussesseveral techniques known from already existing price comparison engines that couldbe modified and adopted for comparison of cloud providers. Furthermore, a tech-nique for filtering measured...
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Experimental generation of complex noisy photonic entanglement
PublicationWe present an experimental scheme based on spontaneous parametric down-conversion to produce multiple-photon pairs in maximally entangled polarization states using an arrangement of two type-I nonlinear crystals. By introducing correlated polarization noise in the paths of the generated photons we prepare mixed-entangled states whose properties illustrate fundamental results obtained recently in quantum information theory, in particular those...
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A new quantum-inspired approach to reduce the blocking probability of demands in resource-constrained path computation scenarios
PublicationThis article presents a new approach related with end-to-end routing, which, owing to quantum-inspired mecha-nisms of prediction of availability of network resources, results in improved blocking probability of incoming requests to establish transmission paths. The proposed scheme has been analyzed for three network topologies and several scenarios of network load. Obtained results show a significant (even twofold) reduction of...
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Selected concentration techniques for gas chromatographic analysis of environmental samples
PublicationThe paper describes the role and tasks of environmental analysis and monitoring. It emphasises the leading role played by gas chromatography, especially when coupled with suitable sample preparation. This is demonstrated by some literature evidence and mainly by the author's original work on the design of sample preparation apparatus and development of GC-based methods of determination of a wide variety of organic pollutants in...
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All-gather Algorithms Resilient to Imbalanced Process Arrival Patterns
PublicationTwo novel algorithms for the all-gather operation resilient to imbalanced process arrival patterns (PATs) are presented. The first one, Background Disseminated Ring (BDR), is based on the regular parallel ring algorithm often supplied in MPI implementations and exploits an auxiliary background thread for early data exchange from faster processes to accelerate the performed all-gather operation. The other algorithm, Background Sorted...
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Determination of flavanols by liquid chromatography with fluorescence detection. Application to the characterization of cranberry-based pharmaceuticals through profiling and fingerprinting approaches
PublicationIn this work, a new method based on reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection (FLD) was established for the determination of catechins and related oligomeric proanthocyanidins (PACs) in cranberry-based pharmaceuticals. Compounds were recovered by liquid extraction using methanol/water/hydrochloric acid (60:39:1, v:v:v) as the extraction solvent. The chromatographic separation was carried...
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Low-Voltage LDO Regulator Based on Native MOS Transistor with Improved PSR and Fast Response
PublicationIn this paper, a low-voltage low-dropout analog regulator (ALDO) based on a native n-channel MOS transistor is proposed. Application of the native transistor with the threshold voltage close to zero allows elimination of the charge pump in low-voltage regulators using the pass element in a common drain configuration. Such a native pass transistor configuration allows simplification of regulator design and improved performance,...
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Sample Rate Conversion Based on Frequency Response Masking Filter
PublicationThe sample rate conversion with high resampling ratios requires low-pass digital filters with very narrow transition band which results in high computational complexity and makes filter design problematic. Therefore in this work we propose to use the FRM method, which breaks the filter with a narrow transition band into a group of filters with reduced design requirements. These decreases the number of non-zero coefficients and...
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Comparison of centralized and decentralized preemption in MPLS networks
PublicationPreemption is one of the crucial parts of the traffic engineering in MPLS networks. It enables allocation of high-priority paths even if the bandwidth on the preferred route is exhausted. This is achieved by removing previously allocated low-priority traffic, so as enough free bandwidth becomes available. The preemption can be performed either as a centralized or a decentralized process. In this article we discuss the differences...
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Multimedia in teaching economics and management in higher education.
PublicationNowadays, the use of multimedia teaching materials at universities makes a standard practice. However their saturation is still quite low comparing to the expectations of students - the main consumers of the information contained therein. This article will present the results of research conducted among students of Management and Engineering Management carried at the Technical University of Gdańsk. Some students of Computer Science...
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Vision-based motion analysis of kitesurfer
PublicationKitesurfing is a relatively recent phenomenon with raising popularity worldwide – a recently developed extreme water sport considered a high-risk injury sport. It combines elements of several other sports, in particular sailing, surfing, windsurfing, wakeboarding, and snowboarding. The main purpose of authors’ research in the present paper is to use a vision system technique for measuring a kitesurfer’s body movements in order...
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The equivariant spectral flow and bifurcation of periodic solutions of Hamiltonian systems
PublicationWe define a spectral flow for paths of selfadjoint Fredholm operators that are equivariant under the orthogonal action of a compact Lie group as an element of the representation ring of the latter. This G-equivariant spectral flow shares all common properties of the integer valued classical spectral flow, and it can be non-trivial even if the classical spectral flow vanishes. Our main theorem uses the G-equivariant spectral flow...
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Automatic system for measuring shifts and deformation of dental prostheses
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Application of Closed Circuit Television for Highway Telematics
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Analysis of false alarm causes in video fire detection systems
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Problems of diagnosing fire alarm systems in transport facilities
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Transmission system model in the track-vehicle relationship based on Long Term Evolution technology
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Reliability And Maintenance Analysis Of CCTV Systems Used In Rail Transport
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Electromagnetic Interference Issue in Safety Systems Applied at Airports
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Effects of independent magnetic fields in the very low frequency range elf generated by selected elements of an electric traction unit on the ambient environment and electronic systems
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Teaching methodology of the diagnosing process on the example of the fire alarm system
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Modeling of the denture’s elastic base
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Methodology of testing positive attitudes to electrostatic discharges — measuring position
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Minimizing the Impact of Electromagnetic Interference Affecting the Control System of Personal Rapid Transit in the Context of the Competitiveness of the Supply Chain
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The Issue of Operating Security Systems in Terms of the Impact of Electromagnetic Interference Generated Unintentionally
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Reliability and operating properties of the electronic safety system used for unintended electromagnetic radiation sources
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Load path sensitivity and multiaxial fatigue life prediction of metals under non-proportional loadings
PublicationEngineering components often operate under complex loadings, in which the variable amplitude multiaxial stresses are raised by geometric discontinuities including holes, grooves, fillets and shoulders, etc. Besides, the non-proportional loading will lead to the rotation of maximum principal stress/strain and additional fatigue damage of structural elements in service. Consequently, the multiaxial and non-proportional loading have...
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Modeling nitrous oxide production by a denitrifying-enhancedbiologically phosphorus removing (EBPR) activated sludge in thepresence of different carbon sources and electron acceptors
PublicationIn this study, the IWA Activated Sludge Model No. 2d (ASM2d) was expanded to identify the most important mechanisms leading to the anoxic nitrous oxide (N2O) production in the combined nitrogen (N) and phosphorus (P) removal activated sludge systems. The new model adopted a three-stage denitrification concept and was evaluated against the measured data from one/two-phase batch experiments carried out with activated sludge withdrawn...
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Efficiency of landfill leachate treatment in a MBR/UF system combined with NF, with a special focus on phthalates and bisphenol A removal
PublicationIn this study, a pilot-scale membrane bioreactor (MBR) was operated at a municipal solid waste plant (MSWP) to treat a mixture of landfill leachates (LLs) obtained from modern (MP-LLs) and previous (PP-LLs) waste cells. The MBR unit combined anoxic and aerobic zones with external ultra- and nanofiltration (MBR/UF and MBR/UF/NF, respectively). In addition to the removal of macropollutants, special attention was given to phthalates...
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Hydrophobic deep eutectic solvents as “green” extraction media for polycyclic aromatic hydrocarbons in aqueous samples
PublicationThe paper presents novel nonionic and hydrophobic deep eutectic solvents which were synthesized from natural compounds, i.e., thymol, ±camphor, decanoic and 10-undecylenic acids. Fundamental physicochemical properties of the synthesized deep eutectic solvents were determined, followed by their application as extractants in ultrasound-assisted dispersive liquid-liquid microextraction to isolate and enrich polycyclic aromatic hydrocarbons...
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Subharmonic solutions for a class of Lagrangian systems
PublicationWe prove that second order Hamiltonian systems with a potential of class C1, periodic in time and superquadratic at infinity with respect to the space variable have subharmonic solutions. Our intention is to generalise a result on subharmonics for Hamiltonian systems with a potential satisfying the global Ambrosetti-Rabinowitz condition from [P. H. Rabinowitz, Proc. Roy. Soc. Edinburgh Sect. A, 114 (1990), 33-38]. Indeed, we weaken...
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Operational causes of fatigue failures within the passages of gas turbine engines
PublicationThe short profile of a fatigue wear process of gas turbine engine's constructional elements has been introduced in the article. The primary causes of a fatigue cracks formation within the mechanical system as well as within the passages of the engine have been showed. Especial attention was devoted to the low-cycle fatigue, what is associated with unsteady thermal-flow processes being worked out in the passages.The selected damages...
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PHASE OBJECT OBSERVATION SYSTEM BASED ON DIFFRACTION PHASE MICROSCOPY
PublicationIn the paper authors present a special measurement system for observing phase objects. The diffraction phas microscopy makes it possible to measure the dimensions of a tested object with a nanometre resolution. To meet this requirement, it is proposed to apply a spatial transform. The proposed setup can be based either on a two lenses system (called 4 f ) or a Wollaston prism. Both solutions with all construction aspects are described...
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Parallelization of Compute Intensive Applications into Workflows based on Services in BeesyCluster
PublicationThe paper presents an approach for modeling, optimization and execution of workflow applications based on services that incorporates both service selection and partitioning of input data for parallel processing by parallel workflow paths. A compute-intensive workflow application for parallel integration is presented. An impact of the input data partitioning on the scalability is presented. The paper shows a comparison of the theoretical...
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Modelling Long‐Term Transition from Coal‐Reliant to Low‐Emission Power Grid and District Heating Systems in Poland
PublicationEnergy systems require technological changes towards climate neutrality. In Poland, where the power system is dominated by outdated coal-fired power plants, efforts to minimize the environmental impact are associated with high costs. Therefore, optimal paths for the development of the energy sector should be sought in order to achieve ambitious long-term strategic goals, while minimizing the negative impact on the consumers’ home...
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The Mechanism of a Retro-Diels–Alder Fragmentation of Luteolin: Theoretical Studies Supported by Electrospray Ionization Tandem Mass Spectrometry Results
PublicationThe mechanisms of retro-Diels–Alder fragmentation of luteolin are studied theoretically using the Density Functional Theory method (B3LYP hybrid functional) together with the 6-311++G(d,p) basis set and supported by electrospray ionization tandem mass spectrometry (ESI-MS) results. The reaction paths leading to the formation of 1,3A and 1,3B fragment ions observed as the main spectral features in the ESI-MS spectrum are described...
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Investigation into MPI All-Reduce Performance in a Distributed Cluster with Consideration of Imbalanced Process Arrival Patterns
PublicationThe paper presents an evaluation of all-reduce collective MPI algorithms for an environment based on a geographically-distributed compute cluster. The testbed was split into two sites: CI TASK in Gdansk University of Technology and ICM in University of Warsaw, located about 300 km from each other, both connected by a fast optical fiber Ethernet-based 100 Gbps network (900 km part of the PIONIER backbone). Each site hosted a set...
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Influence of laser processing of the low alloy medium carbon structural steel on the development of the fatigue crack
PublicationThe paper contains the results of the structural analysis, hardness tests and fatigue tests conducted for the medium carbon structural steel with low content of Cr and Ni after its processing with CO2 laser beam. Pre-cracks were made in the round compact tension (RCT) specimen used for fatigue test. Next, four paths, parallel to each other, were melted on both sides of the samples using a laser beam. The paths were perpendicular...
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The Maslov index and the spectral flow—revisited
PublicationWe give an elementary proof of a celebrated theorem of Cappell, Lee and Miller which relates the Maslov index of a pair of paths of Lagrangian subspaces to the spectral flow of an associated path of self-adjoint first-order operators. We particularly pay attention to the continuity of the latter path of operators, where we consider the gap-metric on the set of all closed operators on a Hilbert space. Finally, we obtain from Cappell,...