Wyniki wyszukiwania dla: VOIP
-
Analiza danych osobowych przetwarzanych w systemach telekomunikacyjnych klasy IP PBX oraz metod ich anonimizacji za pomocą systemów SBC
PublikacjaOpisano wyniki realizacji pracy, dotyczącej analizy systemu telekomunikacyjnego, opartego na technologii VoIP, pod względem wymagań prawnych powstałych wraz z wejściem w życie przepisów Ogólnego Rozporządzenia o Ochronie Danych Osobowych (RODO). Przedstawiono wyniki analizy przykładowego systemu IP PBX Asterisk oraz wykorzystywanego w nim protokołu sygnalizacyjnego SIP, w kontekście przetwarzania danych osobowych, a także metody...
-
Analiza systemów współpracy Gatekeeperów.
PublikacjaReferat obejmuje zagadnienia związane z zapewnieniem współpracy pomiędzy gatekeeperami pracującymi w systemie VoIP działającym w oparciu o zbiór zaleceń ITU-T H.323. Zaprezentowano podstawowe topologie pracy gatekeeperów. Uwzględniono omówienie pojęć związanych z alternatywnymi gatekeeperami. Przedstawiono wykorzystywaną implementację gatekeepera, modele laboratoryjne i przyjęte scenariusze. Omówiono wyniki badań i dalsze prace...
-
Geo-location of the commune of an IP user
PublikacjaThis paper describes a system of geo-location of an IP user that would enable VoIP users to call 112. Basic requirement is fast (under 50ms) determination of the commune of the subscriber. To obtain as accurate information as possible aggregation of several methods was proposed: using a database of locations of IP ranges created by specialized companies, traceroute using history of user locations to assume his current one.It is...
-
Usługi Third Party Call Control zrealizowane z wykorzystaniem oprogramowania Open Source
PublikacjaKoncepcja sieci NGN zakłada otwartość na usługi udostępniane użytkownikom (abonentom). Jej realizacja wymaga ulokowania tej funkcjonalności w zewnętrznych elementach w stosunku do sieci telekomunikacyjnej udostępniającej usługi przenoszenia. Jednym z rozwiązań jest serwer Third Party Call Control (3PCC) w którym można ulokować scenariusze sterowania przebiegiem połączenia. W artykule przedstawiono i omówiono projekt, wykonany w...
-
Fracture Areas Quantitative Investigating of Bending-Torsion Fatigued Low-Alloy High-Strength Steel
PublikacjaIn this study, the impact of pseudo-random non-proportional bending-torsion fatigue loadings proportion on the fatigue life and the fracture surface topography was analyzed. Investigation was carried out for 24 specimens made of S355J2 steel with 11 different ratios of maximum stresses λ. For these cases, after the fatigue tests, the surface topography measurements were carried out using an optical profilometer, using the focus...
-
Determining QoS in the Video Telephony Service in an IP Environment
PublikacjaIP networks are indispensable nowadays. They are among the most efficient platforms. The constantly growing number of users and new services in these networks - the largest being the Internet - requires a good quality of any application used.Determining the QoS in real-time services is particularly important. This work is dedicated to exactly this aspect of the real-time service Video Telephony over IP (VToIP). First, the ITU-T...
-
Deep compaction control of sandy soils
PublikacjaVibroflotation, vibratory compaction, micro-blasting or heavy tamping are typical improvement methods for the cohesionless deposits of high thickness. The complex mechanism of deep soil compaction is related to void ratio decrease with grain rearrangements, lateral stress increase, prestressing effect of certain number of load cycles, water pressure dissipation, aging and other effects. Calibration chamber based interpretation...
-
Wykorzystanie uczelnianej infrastruktury telekomunikacyjnej i informatycznej do realizacji sieci następnej generacji
PublikacjaW pracy przedstawiono możliwości wykorzystania uczelnianych infrastruktur telekomunikacyjnych i informatycznych dla konwergencji technologii, usług i sieci. Scharakteryzowano etapy i wariantowość rozwiązań dla osiągnięcia stanu pełnej konwergencji. Przedstawione rozwiązania i koncepcje poparte są wynikami prac uzyskanymi w ramach grantu rozwojowego realizowanego na Wydziale ETI Politechniki Gdańskiej (R0205103). W ramach grantu...
-
A hybrid speech codec employing parametric and perceptual coding techniques
PublikacjaW referacie przedstawiono hybrydowy kodek mowy dla zastosowan w komunikacji VoIP wykorzystujący kodowanie parametryczne i percetualne. Sygnał mowy jest dzielony na składowe dźwięczne, które podlegają kodowania perceptualnemu, składowe bezdźwięczne, które kodowane są metodą parametryczną oraz transjenty, które nie są kodowane żadną stratną metodą. Dodatkowo przedstawiono architekturę kodeka, w której perceptualnie kodowana i przesyłana...
-
Applications of permeability, oedometer and direct shear tests to the sand mixed with waste tire crumb
PublikacjaThe amount of the used waste rubbers in the world has been increasing every year, and their utilization, become a major environmental problem worldwide. The present experimental work has been performed to investigate the influence of rubber inclusion on the behavior of a sand. Geotechnical properties of the sand, and sand with tire crumb at various ratios mixtures (0%, 2.5%, 7.5%, and 15%) were investigated through a series of...
-
Grade of service determination methodology in IP networks with SIP protocol
PublikacjaAlthough Grade of Service is very important in VoIP providers evaluation, We wasn't able to find any paper regarding the topic of measuring GoS variables for IP networks utilizing SIP, which are defined like for PSTN/ISDN/GSM networks (post-selection delay, answering delay, release delay, or probability of end-to-end blocking). Due to the lack of research in this field, it was necessary to start from defining measures and cover...
-
Wytwarzanie oprogramowania protokołu SIP dla urządzenia z systemem typu embedded w środowisku Linux
PublikacjaW pracy został zawarty opis procesu wytwarzania oprogramowania protokołu SIP dla potrzeb urządzenia z systemem typu embedded, którym był Abonencki Terminal Kablowy ATK DGT 7410. Na początku referatu przedstawiono obserwowane obecnie trendy rozwojowe w metodologii i sposobie wytwarzania oprogramowania wykorzystywanego w sieciach telekomunikacyjnych VoIP. Następnie przedstawiono krótki opis urządzenia ATK i podano uproszczony algorytm...
-
Architektura DiffServ w środowisku Linux
PublikacjaW artykule przedstawiono problem realizacji mechanizmów obsługi dla domeny DiffServ w środowisku Linux. Następnie scharakteryzowano założenia do projektu i omówiono realizację modelu takiej domeny, na którym wykonano szereg badań parametrów jakości obsługi klas ruchu typu Expedited Forwarding (EF) i Best Effort (BE). Wyniki wykazały, że mechanizmy oferowane w środowisku Linux spełniają wymagania co do jakości dla obsługi tych klas...
-
Radioisotope measurement of selected parameters of liquid-gas flow using single detector system
PublikacjaTo determine the parameters of two-phase flows using radioisotopes, usually two detectors are used. Knowing the distance between them, the velocity of the dispersed phase is calculated based on time delay estimation. Such a measurement system requires the use of two gamma-ray sealed sources. But in some situations it is also possible to determine velocity of dispersed phase using only one scintillation probe and one gamma-ray source....
-
Micro-modelling of shear localization during quasi-static confined granular flow in silos using DEM
PublikacjaThe paper deals with the quasi-static confined flow of cohesionless sand in a plane strain model silo with parallel walls and a slowly movable bottom. Numerical modelling was carried out by the discrete element method (DEM) using spheres with contact moments to approximately capture a non-uniform shape of sand particles. Different initial void ratios of sand and silo wall roughness grades were employed. Regular triangular grooves...
-
Investigation of Acoustic Properties of Poroelastic Asphalt Mixtures in Laboratory and Field Conditions
PublikacjaMeasures for the improvement of acoustic conditions in the vicinity of roads include the construction of pavement structures with low-noise surfaces with optimal macrotexture and the highest possible sound absorption coefficient. Laboratory evaluation of acoustic properties of a designed asphalt mixture before its placement in the pavement is a good solution. Currently, the most popular method for the determination of the sound...
-
Propagation Characteristics of Partial Discharges in an Oil-Filled Power Transformer
PublikacjaPower transformers are among the most important assets in the power transmission and distribution grid. However, they suffer from degradation and possible faults causing major electrical and financial losses. Partial discharges (PDs) are used to identify the insulation health status and their degradation level. PDs are incipient, low-magnitude faults caused by localized dielectric breakdown. Those activities emit signals in many...
-
Ocena jakości synchronicznych kanałów TDM emulowanych w sieci dostępowej wykorzystującej Ethernet
PublikacjaRozpowszechnienie Ethernetu powoduje eliminowanie rozwiązań typowych dla sieci TDM, z synchronizacją na poziomie bitów. Sieć NGN obok usług VoIP zakłada też realizację usług "konserwatywnych", dla których jest wymagana synchronizacja bitowa pomiędzy stroną nadawczą i odbiorczą, poprzez sieć komunikacyjną. Gdy wykorzystanie istniejącej wcześniej sieci TDM staje się nieopłacalne, rozwiązaniem jest użycie emulowanych kanałów o stałej...
-
The model of end-to-end call setup time calculation for Session Initiation Protocol
PublikacjaEnd-to-end call setup delay is one of the most important grade of service (GoS) parameters for VoIP networks with Session Initiation Protocol (SIP). A typical subscriber wants to have a connection established as soon as possible. From the operator's perspective call setup time is also crucial because he needs to know how probability of successful packet transmission on SIP links is related to a call setup delay. Then he can make...
-
Sposób i układ tłumienia echa akustycznego w terminalu VoIP
Wynalazki -
SkinDepth - synthetic 3D skin lesion database
Dane BadawczeSkinDepth is the first synthetic 3D skin lesion database. The release of SkinDepth dataset intends to contribute to the development of algorithms for:
-
Engineering TADF, Mechanochromism, and Second Harmonic Up- conversion Properties in Regioisomeric Substitution Space
PublikacjaThis research article explores the distinct TADF efficiency of three donor-acceptor based regio-isomers: DPAOCN (ortho- isomer), DPAMCN (meta-isomer), and DPAPCN (para-isomer). DPAPCN exhibits maximum TADF efficiency in both solution and solid-state with an impressive reverse inter-system crossing (RISC) rate of ~ 106 s-1; the underlying cause being the minimum singlet-triplet splitting energy or ∆EST and maximum SOC (spin-orbit...
-
Group-9 Transition-Metal Suboxides Adopting the Filled-Ti2Ni Structure: A Class of Superconductors Exhibiting Exceptionally High Upper Critical Fields
PublikacjaTi2Ni and the related η-carbide structure are known to exhibit various intriguing physical properties. The Ti2Ni structure with the cubic space group Fd3̅m is surprisingly complex, consisting of a unit cell with 96 metal atoms. The related η-carbide compounds correspond to a filled version of the Ti2Ni structure. Here, we report on the structure and superconductivity in the η-carbide-type suboxides Ti4M2O with M = Co, Rh, and Ir....
-
Analysis and interpretation of radiometric signals in a liquid-gas bubble flow
PublikacjaThe article presents the analysis of signals from a radiometric system consisting of two scintillation probes and two gamma radiation sealed sources. Calculations and interpretation were carried out for the bubble flow of the water-air mixture in the horizontal pipeline. The analysis of the obtained signals was done in time and frequency domain. In the frequency domain, a range of usable frequencies was identified, which were associated...
-
EVALUATION OF LIQUID-GAS FLOW IN PIPELINE USING GAMMA-RAY ABSORPTION TECHNIQUE AND ADVANCED SIGNAL PROCESSING
PublikacjaLiquid-gas flows in pipelines appear in many industrial processes, e.g. in the nuclear, mining, and oil industry. The gamma-absorption technique is one of the methods that can be successfully applied to study such flows. This paper presents the use of thegamma-absorption method to determine the water-air flow parameters in a horizontal pipeline. Three flow types were studied in this work: plug, transitional plug-bubble,...
-
Signal Processing in the Investigation of Two-phase Liquid-gas Flow by Gamma-ray Absorption
Publikacjan this paper, the use of the gamma-absorption method applied in the investigation of the two-phase liquid-gas flow in the pipeline is described. An example of its application to the air transported by water in a horizontal pipeline is evaluated. In the measurements, Am-241 radioactive sources and probes with Nal (Tl) scintillation crystals have been used. The signals from the radiometric set were used to determine the velocity...
-
SUMMER SCHOOL OF ENGLISH 2024
Kursy Online -
Modelowanie i ograniczanie skutków ataków uzurpacji uprawnień w systemach teleinformatycznych wspierających różnicowanie poziomu QoS
PublikacjaW wieloagentowych systemach teleinformatycznych pracujących w paradygmacie Klient-Serwer i wspierających różnicowanie poziomu QoS poważnym zagrożeniem są ataki uzurpacji uprawnień metodą Fałszywego VIPa. Ich celem jest zapewnienie Klientowi nienależnie wysokiego poziomu QoS, co powoduje nadużycie zasobów Serwera i szkody dla innych Klientów. W referacie podjęto próbę sforma-lizowania modelu takich ataków oraz zaproponowa-no obustronnie...
-
The correlation of fractal dimension to fracture surface slope for fatigue crack initiation analysis under bending-torsion loading in high-strength steels
PublikacjaIn this study, the fractal dimension of fatigue fracture surfaces is investigated in order to find an alternative failure loading indicator. Some of many metrological factors are generalized by reducing the fracture surface structure to one factor and develop an entire fracture surface procedure by analyzing the impact of surface slope and calculation resolution. Three notched geometries are studied under cyclic bending-torsion:...
-
Ewolucyjny rozwój uczelnianej infrastruktury komunikacyjno-informacyjnej na potrzeby e-uczelni
PublikacjaStosowane i proponowane rozwiązania w obszarze technologii informacyjnych stwarzają szerokie możliwości w rozwoju i wdrażaniu systemów komunikacyjno-informacyjnych wspomagających i usprawniających specyficzną działalności uczelni a szczególnie wspierających e-Uczelnię. Wymaga to jednak wprowadzenia zmian w infrastrukturze technicznej i organizacji pracy. W artykule rozpa-trzono możliwości wykorzystania uczelnianych infrastruktur...
-
The Effect of Protrusions on the Initiation of Partial Discharges in XLPE High Voltage Cables
PublikacjaThis paper is focusing on 3D Finite Elements Analysis (FEA) based modelling of protrusions as defects or imperfections in the XLPE high voltage cable. This study is aiming to examine the impact protrusions have on the initiation of partial discharges. Spherical and ellipsoidal protrusions with different sizes at the conductor screen of the high voltage cable is an essential content of this paper. In addition, a spherical gas-filled...
-
Development of polyurethanes for bone repair
PublikacjaThe purpose of this paper is to review recent developments on polyurethanes aimed at the design, synthesis, modifications, and biological properties in the field of bone tissue engineering. Different polyurethane systems are presented and discussed in terms of biodegradation, biocompatibility and bioactivity. A comprehensive discussion is provided of the influence of hard to soft segments ratio, catalysts, stiffness and hydrophilicity...
-
MECHANICAL PROPERTIES OF BOTTOM ASH – DREDGED MATERIAL MIXTURES IN LABORATORY TESTS
PublikacjaBottom ash from EC Gdańsk and dredged material taken from the mouth of The Vistula were mixed to form an engineering material used for dike construction. Mixtures with different bottom ash content were tested in laboratory to determine its basic physical and mechanical properties. The optimum bottom ash–dredged material mixture, built in the corps of the test dike, contains 70% of ash. The optimum bottom ash content in the mixture...
-
Fracture surface topography investigation and fatigue life assessment of notched austenitic steel specimens
PublikacjaThe objectives of this study were to investigate the fracture surface topography of X8CrNiS18-9 austenitic stainless-steel specimens for different loadings and notch radii and to supplement the knowledge about the fracture mechanisms for fatigue performance. Cases with three different values of the notch radius ρ and the stress amplitude σa were analysed. The fracture topographies were quantified by the areas over their entire...
-
Design of poroelastic wearing course with the use of direct shear test
PublikacjaPoroelastic Road Surfaces (PERS) are characterized by porous structure with at least 20% of air void content and stiffness almost 10 times lower than typical asphalt course. Such properties enable noise reduction up to 12 dB in comparison to SMA 11 mixture. However, the main disadvantage of previously used poroelastic mixtures, based on resin type binders, was their low durability, which resulted in raveling and delamination from...
-
Application of the Mathar method to identify internal stress variation in steel as a welding process result
PublikacjaThe paper deals with the method to identify internal stresses in two-dimensional steel members. Steel members were investigated in the delivery stage and after assembly, by means of electric-arc welding. In order to perform the member assessment two methods to identify the stress variation were applied. The first is a non-destructive measurement method employing local external magnetic field and to detecting the induced voltage,...
-
Detailed experimental investigations on frictional pressure drop of R134a during flow boiling in 5 mm diameter channel: The influence of acceleration pressure drop component =Études expérimentales détaillées sur la chute de pression frictionnelle du R134a lors de l'ébullition en écoulement dans un canal de 5 mm de diamètre : influence de la composante d'accélération de la chute de pression
PublikacjaThis article presents detailed two-phase diabatic pressure drop data for refrigerant R134a at a saturation pressure of 5.5 bar corresponding to the saturation temperature of 19.4 °C. Study cases have been set for a mass flux varying from 100 to 500 kg m−2 s−1. The obtained data are used as a validation of the void fraction literature models, a set of graphs shows comparisons, for a representative set of experimental conditions,...
-
Experimental investigation on straight and u-bend double tube heat exchanger with active and passive enhancement methods
PublikacjaAuthors in this work want to demonstrate the possibility to increase the heat transfer efficiency by using simple wire coil inserts to create turbulent flow in the boundary layer as well as air blowing into the annulus of the pipe. In the study, Wilson plot approach was applied in order to estimate heat transfer coefficients for all heat exchanger (HX) configurations. The study focuses on experimental values of heat transfer coefficient...
-
Ways of Harmonising Polish Competition Law with the Competition Law of the EU
PublikacjaThis article discusses the harmonisation of laws within the EU focusing on the specific ways of achieving an approximation of the Polish legal system with European competition law. It identifies and gives an overview of three specific ways of harmonising national laws with EU antitrust provisions: (1) spontaneous (or bottom-up) harmonisation; (2) judicial harmonisation and; (3) legislative harmonisation by means of EU Directives....
-
Hybrid all-cellulose reinforcement in polypropylene matrix biocomposites for injection moulding - influence of particle geometry and volume fraction on hybrid effect
PublikacjaThe presented study is focused on evaluation of influence of reinforcement volume fraction and geometry on the occurrence of positive hybrid effect by the hybridisation of man-made cellulose fibres (rayon viscose) with cellulose microparticle fillers applied in polypropylene matrix. Four volume fractions of reinforcement were used at 1:1 combination of short man-made cellulose fibres with cellulose microfillers of different aspect...
-
Wpływ mikrosfer-frakcji odpadów paleniskowych na mikrostrukturę i wybrane właściwości uzytkowe
PublikacjaIn this study, the microspheres samples were collected from national power station „Dolna Odra”. In this study, the following materials were used: Portland cement class 32,5R and aggregates of 2-8 and 8-16 fractions and natural sand with a maximum grain size of 2 mm and water. Concrete mixtures were made with microspheres additions of 15%, 25% and 40%. A constant water to binder ratio (w/b) of 0,52 was used throughout the investigation....
-
Modelling of shear zones during quasi-static granular silo flow using material point method (MPM)
PublikacjaThe paper focuses on confined silo flow of cohesionless sand. The problem considered is a quasi-static flow in a plane strain model silo with parallel walls simulated with the material point method (MPM). The simulation used a non-local hypoplastic constitutive model. Initially, the paper validated the implemented numerical approach with basic element tests and a plane strain compression test. The subsequent MPM calculations for...
-
Shear band evolution phenomena in direct shear test modelled with DEM.
PublikacjaA direct shear test is widely used in the geotechnical engineering field. It is an easy and quick test to measure the shear properties of soil. This test often replaces more expensive and difficult tri-axial shear test. Despite that the direct shear test is known and used for a long time, it is still not well investigated at the grain scale. This paper deals with the micro behaviour of the cohesionless sand inside the direct shear...
-
Simulations of hydro-fracking in rock mass at meso-scale using fully coupled DEM/CFD approach
PublikacjaThe paper deals with two-dimensional (2D) numerical modelling of hydro-fracking (hydraulic fracturing) in rocks at the meso-scale. A numerical model was developed to characterize the properties of fluid-driven fractures in rocks by combining the discrete element method (DEM) with computational fluid dynamics (CFD). The mechanical behaviour of the rock matrix was simulated with DEM and the behaviour of the fracturing fluid flow...
-
Experimental validation of pressure drop models during flow boiling of R134a – effect of flow acceleration and entrainment
PublikacjaA crucial step to assure proficient work of power and process apparatus is their proper design. A wide array of those devices operates within boiling or condensation of the working fluid to benefit from high heat transfer rates. Two-phase flows are associated with high heat transfer coefficients because of the latent heat of evaporation and high turbulence level between the liquid and the solid surface. Predicting heat transfer...
-
Numerical Simulation of Catastrophic Flood: the Case Study of Hypothetical Failure of the Bielkowo Hydro–Power Plant Reservoir
PublikacjaThe numerical modeling of flood wave propagation following the hypo-thetical breaks of the embankments of the Bielkowo hydro–power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland have been presented. The results of computations were used to estimate the parameters of the flood waves, which are indispensable for the flood zone determination and mapping and then for the flood risk analysis. When estimating...
-
Artificial Intelligence Technologies in Education: Benefits, Challenges and Strategies of Implementation
PublikacjaSince the education sector is associated with highly dynamic business environments which are controlled and maintained by information systems, recent technological advancements and the increasing pace of adopting artificial intelligence (AI) technologies constitute a need to identify and analyze the issues regarding their implementation in education sector. However, a study of the contemporary literature reveled that relatively...
-
Tyre/road noise reduction of poroelastic road surface tested in a laboratory
PublikacjaA so-called poroelastic road surface (PERS) is being developed in Europe. This contains a large percentage of rubber particles mixed with hard aggregate (stone and sand) and bound with polyurethane. This gives high air void content (around 30 %), high elasticity and smooth texture, all of which should give low noise properties. Inthis experiment anominally 30 mm thick sample of PERS was mounted on a steel drum. Various car tyres...
-
Aplikacje i usługi a technologie sieciowe
PublikacjaObserwując tempo rozwoju technologii sieciowych oraz usług i aplikacji stajemy przed ogromnym dylematem jak wykorzystać istniejące możliwości by modernizować wybrane usługi i aplikacje zgodnie z ciągle zmieniającymi się potrzebami użytkowników. Bardzo często sygnalizowane nowe technologie czy aplikacje mają jednak czysto charakter biznesowy podporządkowany prawom marketingu i nie wnoszą wielu istotnych zmian. Dlatego jest ważne...
-
Unfolding new values in the landscape of conflict
PublikacjaThe main objective of the paper is to investigate how the conflict quality of landscape can be used as its asset and potential for creating new values. Like mediation between different overlapping archaeologies offers a basis for the perception of place in the chronology of time, the mediation between conflicted areas creates a capacious zone for enhancing the unique quality of landscape in its architectural, social, cultural and...