Search
Search results for: high availability
-
Implementation of failover and load balancing algorithms in SIP PBX High Availability system
PublicationGoal of the project was to design a High Availability SIP VoIP system that guarantees access to additional services like auto-attendent and automatic call distribution. The realization of the project required system to have load balancing and failover algorithms implemented. From the end users’ point of view the whole system had to figure as a single element. After taking under consideration the known methods of implementations...
-
Enhancing Availability for Critical Services
PublicationTraditional approaches to provide classes of resilient service take the physical network availability as an input and then deploy redundancy and restoration techniques at various layers, often without full knowledge of mappings between layers. This makes it hard (and often inefficient) to ensure the high availability required by critical services which are typically a small fraction of the total traffic. Here, the innovative technique...
-
Providing Differentiated Levels of Service Availability in VANET Communications
PublicationInter-vehicle communications seems to be a promising remedy not only for a number of road-safety issues, but also to improve the efficiency of road traffic, as well as to support the on-board infotainment applications. However, it often encounters disruptions due to high mobility of vehicles causing frequent failures of communication links. In this paper, we utilize the idea of multipath vehicle-to-vehicle routing to provide protection...
-
Accuracy and Availability of EGNOS - Results of Observations
PublicationAccording to SBAS concept the user should receive timely the correct information about the system integrity and corrections to the pseudoranges measurements, which leads to better accuracyof coordinates. In theory the whole system is permanently monitored by RIMS stations, so it is impossible to deliver the faulty information to the user. The quality of the system is guaranteed inside the border of the system coverage however in...
-
The importance and availability of marine certified reference materials
PublicationTraceability and reliable results are the two pillars of analytical methods; certified reference materials (CRMs) meet this requirement. ISO 17034:2016 credentials provide brief information on general requirements for the competence of Reference Material Producers (RMPs). The different types of CRMs have been produced in recent years for chemical analysis in food, water, soil, and sediment matrices in recent years. This review...
-
Urban Freight Transport Demand Modelling and Data Availability Constraints
PublicationThe paper provides a review of urban freight transport demand modelling approaches confronted with constrains regarding adequate data provision from a perspective of the local authorities. Demand estimation models has been selected as a reference because they are the most representative in terms of inclusion of urban freight indicators which can be transformed into a decision-support tool for evaluation of freight measures. The...
-
Impact of Cyclist Facility Availability at Work on the Number of Bike Commuters
PublicationThe article describes the results of research designed to establish whether cycle provision can influence the number of employees commuting by bike. To that end, employee surveys were conducted in three IT companies in 2012 and 2016. The questionnaire asked about travel behaviour and what the staff thought about their company’s provision of cyclist facilities. Since 2012 each of the companies has moved its head office and the...
-
A graph coloring approach to scheduling of multiprocessor tasks on dedicated machines with availability constraints
PublicationWe address a generalization of the classical 1- and 2-processor unit execution time scheduling problem on dedicated machines. In our chromatic model of scheduling machines have non-simultaneous availability times and tasks have arbitrary release times and due dates. Also, the versatility of our approach makes it possible to generalize all known classical criteria of optimality. Under these stipulations we show that the problem...
-
Binder availability and blending efficiency of reclaimed asphalt: A state-of-the-art review
Publication -
Using Probabilistic Availability Measures for Predicting Targeted Attacks on Network Nodes
Publication -
Network Protection Against Node Attacks Based on Probabilistic Availability Measures
Publication -
Phosphorus concentration and availability in raw organic waste and post fermentation products
PublicationThe aim of the study was to determine the mobility of phosphorus forms in raw organic waste and from the solid and liquid fractions of digestate. To achieve the purpose of this study, the components (including livestock manure, agricultural waste, food waste, sewage sludge) and their post fermentation products were considered. Subsequently, the effect of the fermentation process on the mobility of phosphorus forms in post-fermentation fractions...
-
Comparison of selected algorithms for scheduling workflow applications with dynamically changing service availability
PublicationThis paper compares the quality and execution times of several algorithms for scheduling service based workflow applications with changeable service availability and parameters. A workflow is defined as an acyclic directed graph with nodes corresponding to tasks and edges to dependencies between tasks. For each task, one out of several available services needs to be chosen and scheduled to minimize the workflow execution time and...
-
Lipid oxidation and lysine availability in Atlantic mackerel hot smoked in mild conditions.
PublicationZawartość nadtlenków w wędzonych makrelach była o 50% mniejsza, a liczba anizydynowa 2,5 razy większa niż w surowych rybach. Przechowywanie ryb wędzonych w temp. +2C nie wpłynęło na zawartość produktów utlenienia lipidów. Zawartość dostępnej lizyny była podobna w surowych i wędzonych rybach. Skóra ryb wędzonych zawierała 2 razy więcej fenoli niż tkanka mięśniowa.
-
Lipid oxidation and lysine availability in smoked Atlantic mackerel fillets and Baltic sprats.
PublicationNie wykazano korelacji między stopniem utlenienia lipidów a ich zawartością w rozmrożonych filetach makreli. Gorące i zimne wędzenie nie wływało na liczbę nadtlenkową w mięsie filetów makreli, natomiast w mięsie wędzonych szprotów była ona znacznie mniejsza niż w rybach surowych. Wędzenie nie powodowało obniżenia dostępnej lizyny, chociaż liczba anizydynowa zwiększyła się dwukrotnie w wędzonych filetach makreli i czterokrotnie...
-
Chromatic Scheduling of 1- and 2-Processor UET Tasks on Dedicated Machines with Availability Constraints
Publication -
Chromatic scheduling of 1- and 2-processor uet tasks on dedicated machines with availability constraints.
PublicationRozważono uogólnienie klasycznego szeregowania jednostkowych zadań jedno- i dwuprocesorowych na maszynach dedykowanych. Przyjęty model pozwala na naturalne wprowadzenie wszystkich klasycznych kryteriów optymalizacyjnych dla harmonogramów. Zaproponowano algorytmy wielomianowe dla systemów rzadkich.
-
An Analysis of External Finance Availability on SMEs’ Decision Making: A Case Study of the Emerging Market of Poland
Publication -
Integrating heterogeneous systems with high-dependability requirements by means of web services
PublicationWeb services are commonly used on boundaries of heterogeneous components in Service Oriented Architecture (SOA) as they provide a universal communication channel not bound to any particular programming language or run-time platform. This paper describes how web services can be used to integrate heterogeneous systems which serve purposes requiring high dependability, reliability and availability. Examples of such systems include...
-
Improvement in clinical symptoms in patients with the first episode of psychosis is associated with a decrease in systemic nitric oxide availability. A pilot study
Publication -
Time series analysis and impact assessment of the temperature changes on the vegetation and the water availability: A case study of Bakun-Murum Catchment Region in Malaysia
PublicationThe Bakun-Murum (BM) catchment region of the Rajang River Basin (RRB), Sarawak, Malaysia, has been under severe threat for the last few years due to urbanization, global warming, and climate change. The present study aimed to evaluate the time series analysis and impact assessment of the temperature changes on the vegetation/agricultural lands and the water availability within the BM region. For this purpose, the Landsat data for...
-
Editorial for the special issue on advances in forward and inverse surrogate modeling for high-frequency design
PublicationThe design of modern‐day high‐frequency devices and circuits, including microwave/RF, antenna and photonic components, historically has relied on full‐wave electromagnetic (EM) simulation tools. Initially used for design verification, EM simulations are nowadays used in the design process itself, for example, for finding optimum values of geometry and/or material parameters of the structures of interest. In a growing number of...
-
High precision and accuracy using low cost GNSS receivers and supporting technologies
PublicationThis chapter focuses on methods and techniques of positioning, based on the highly accurate and precise Global Navigation Satellite System (GNSS), which are available at a relatively low price. In this context, a comparison of different positioning methods provided by the free and open source software (FOSS) package called RTKLIB is given. Other aspects related to price reduction are also considered, including availability and...
-
GNSS INVENTORY OF HISTORIC NARROW-GAUGE RAILWAY LINE IN KOSZALIN UNDER EXTREMELY UNFAVORABLE MEASUREMENTS CONDITIONS FROM THE POINT OF VIEW OF SATELLITE SIGNALS AVAILABILITY
PublicationA team of academic researchers from the Gdańsk University of Technology, Gdynia Maritime University and the Polish Naval Academy have been working since 2009 on the methodology of using active GNSS geodetic networks for geodetic inventory of railways and on adapting this measurement technique for designing geometric layouts of railway and tram lines. Over the years, the team tested a variety of configurations of receivers and settings...
-
Decentralized control of a different rated parallel UPS systems
PublicationThe paper presents the single phase uninterruptible power supply (UPS) system with galvanic separated DC-AC-DC-AC converters operating in parallel. The CAN physical layer based system of communication between converters has been developed and applied, which allow to utilize a decentralized master-slave control providing high availability factor of the whole UPS system. The control system of particular converters has been developed...
-
In situ synthesis of micro-plastics embedded sewage-sludge co-pyrolyzed biochar: Implications for the remediation of Cr and Pb availability and enzymatic activities from the contaminated soil
Publication -
Testing the Positioning Accuracy of GNSS Solutions during the Tramway Track Mobile Satellite Measurements in Diverse Urban Signal Reception Conditions
PublicationMobile Global Navigation Satellite System (GNSS) measurements carried out on the railway consist of using satellite navigation systems to determine the track geometry of a moving railway vehicle on a given route. Their purposes include diagnostics, stocktaking, and design work in railways. The greatest advantage of this method is the ability to perform measurements in a unified and coherent spatial reference system, which...
-
New Simple and Robust Method for Determination of Polarity of Deep Eutectic Solvents (DESs) by Means of Contact Angle Measurement
PublicationThe paper presents a new method for evaluating the polarity and hydrophobicity of deep eutectic solvents (DESs) based on the measurement of the DES contact angle on glass. DESs consisting of benzoic acid derivatives and quaternary ammonium chlorides–tetrabutylammonium chloride (TBAC) and benzyldimethylhexadecylammonium chloride (16-BAC)—in selected molar ratios were chosen for the study. To investigate the DESs polarity, an optical...
-
A Theoretical and Experimental Study of Moderate Temperature Alfa Type Stirling Engines
PublicationThe Stirling engine is a device that allows conversion of thermal energy into mechanical energy with relatively high efficiency. Existing commercial designs are mainly based on the usage of high temperature heat sources, whose availability from renewable or waste heat sources is significantly lower than that of moderate temperature sources. The paper presents the results of experimental research on a prototype alpha type Stirling...
-
International Conference on Availability, Reliability and Security
Conferences -
Wstępne wyniki badań dostępności sieci ASG-Eupos podczas inwentaryzacji trasy kolejowej Kościerzyna - Kartuzy = Preliminary research results of ASG-Eupos network availability during surveying of Kościerzyna-Kartuzyrailway route
PublicationW artykule przedstawiono wyniki pomiarów dostępności określonej wartości błędu współrzędnych, wyznaczonych przy wykorzystaniu sieci ASG-EUPOS, uzyskane podczas pomiarów inwentaryzacyjnych testowego odcinka linii kolejowej. Pomiary z wykorzystaniem4 odbiorników GNSS przeprowadzono w miesiącu lutym bieżącego roku na odcinku trasy kolejowej Kościerzyna - Kartuzy. Program badań zakładał montaż, na pokładzie platformy kolejowej napędzanej...
-
Iterative learning approach to active noise control of highly autocorrelated signals with applications to machinery noise
PublicationThis paper discusses the design and application of iterative learning control (ILC) and repetitive control (RC) for high modal density systems. Typical examples of these systems are structural and acoustical systems considered in active structural acoustic control (ASAC) and active noise control (ANC) applications. The application of traditional ILC and RC design techniques, which are based on a parametric system model, on systems...
-
Active Control of Highly Autocorrelated Machinery Noise in Multivariate Nonminimum Phase Systems
PublicationIn this paper, a novel multivariate active noise control scheme, designed to attenuate disturbances with high autocorrelation characteristics and preserve background signals, is proposed. The algorithm belongs to the class of feedback controllers and, unlike the popular feedforward FX-LMS approach, does not require availability of a reference signal. The proposed approach draws its inspiration from the iterative learning control...
-
How to Sort Them? A Network for LEGO Bricks Classification
PublicationLEGO bricks are highly popular due to the ability to build almost any type of creation. This is possible thanks to availability of multiple shapes and colors of the bricks. For the smooth build process the bricks need to properly sorted and arranged. In our work we aim at creating an automated LEGO bricks sorter. With over 3700 different LEGO parts bricks classification has to be done with deep neural networks. The question arises...
-
Integration of inertial sensors and GPS system data for the personal navigation in urban area
PublicationGPS and Inertial Navigation Systems (INS) have complementary properties and they are therefore well suited for integration. The integrated solution offers better long-term accuracy than a stand-alone INS and better integrity, availability and continuity or a stand-alone GPS receiver, making it suitable for demanding applications. The complementary features of INS and GPS are the main reasons why integrated GPS/INS systems are becoming...
-
Data Integration from GPS and Inertial Navigation Systems for Pedestrians in Urban Area
PublicationThe GPS system is widely used in navigation and the GPS receiver can offer long-term stable absolute positioning information. The overall system performance depends largely on the signal environments. The position obtained from GPS is often degraded due to obstruction and multipath effect caused by buildings, city infrastructure and vegetation, whereas, the current performance achieved by inertial navigation systems (INS) is still...
-
Pathways of nitrogen compounds depletion in hybrid constructed wetlands
PublicationHybrid Constructed Wetlands are composed of two or more filters with mixed flow direction of sewage. Apparently in the HCWS the benefits of both types of bed are merged, resulting in better effluent quality (organic and nitrogen componds removal). Such heterogeneous environment creates possibilities for different ways of nitrogen "disappearing". The objective of the present study was to compare the removal of nitrogen with accompanying...
-
THE COST ANALYSIS OF CORROSION PROTECTION SOLUTIONS FOR STEEL COMPONENTS IN TERMS OF THE OBJECT LIFE CYCLE COST
PublicationSteel materials, due to their numerous advantages - high availability, easiness of processing and possibility of almost any shaping are commonly applied in construction for carrying out basic carrier systems and auxiliary structures. However, the major disadvantage of this material is its high corrosion susceptibility, which depends strictly on the local conditions of the facility and the applied type of corrosion protection system....
-
Molywood: streamlining the design and rendering of molecular movies
PublicationMotivation High-quality dynamic visuals are needed at all levels of science communication, from the conference hall to the classroom. As scientific journals embrace new article formats, many key concepts – particularly in structural biology – are also more easily conveyed as videos than still frames. Notwithstanding, the design and rendering of a complex molecular movie remain an arduous task. Here, we introduce Molywood, a robust...
-
A study of nighttime vehicle detection algorithms
Open Research DataThis dataset is from my master's thesis "A study of nighttime vehicle detection algorithms". It contains both raw data and preprocessed dataset ready to use. In the pictures below you can see how images were annotated.
-
Polymer biodegradable coatings as active substance release systems for urological applications
PublicationCatheter-associated urinary tract infections are the result of catheterization of the bladder. The risk of infection is directly proportional to the length of the bladder catheterization. Bacteria cells have the ability to adhere and create the biofilm on the surface of catheter materials. Bacteria’s biofilm is an extremely beneficial environment of existence for microorganisms. Microorganisms that are an integral part of the biofilm...
-
ENERGY EFFICIENT AND ENVIRONMENTALLY FRIENDLY HYBRID CONVERSION OF INLAND PASSENGER VESSEL
PublicationThe development and growing availability of modern technologies, along with more and more severe environment protection standards which frequently take a form of legal regulations, are the reason why attempts are made to find a quiet and economical propulsion system not only for newly built watercraft units, but also for modernised ones. Correct selection of the propulsion and supply system for a given vessel affects significantly...
-
Modeling nutrient removal and energy consumption in an advanced activated sludge system under uncertainty
PublicationActivated sludge models are widely used to simulate, optimize and control performance of wastewater treatment plants (WWTP). For simulation of nutrient removal and energy consumption, kinetic parameters would need to be estimated, which requires an extensive measurement campaign. In this study, a novel methodology is proposed for modeling the performance and energy consumption of a biological nutrient removal activated sludge system...
-
Performance Analysis and Quantification of BeiDou Navigation Satellite System (BDS-3)
PublicationPositioning, Navigation, and Timing (PNT) information play a vital role in everyday life of common persons. People greatly rely on Global Navigation Satellite System (GNSS)-enabled applications for navigation to reach their desired destination. However, GNSS navigation performance is highly degraded in urban environments due to the high probability of signal interruption, multipath (MP), and/or non-line-of-sight (NLOS) signal...
-
Thematic Areas in the Polish Countryside and Their Role in Local Development
PublicationThe article defines the phenomenon of space thematisation with regards to rural areas in Poland. The typology of thematic spaces and criteria of their comparative description have been proposed. Thematic villages, home gardens, amusement parks and housing estates have been distinguished. They have been compared in terms of spatial availability, the degree of user participation and the commercial vs. non-commercial creation purpose....
-
MCSA with Normalized Triple Covariance as a bearings diagnostic indicator in an induction motor
PublicationStatistics of bearing failures in induction motors indicate, that they constitute more than 40% of IM damage, therefore bearing diagnosis is very important. Vibration methods for bearing diagnostics have one major disadvantage - they require the availability of the machine for sensors installation. This is the reason for seeking new methods based on motor supply current analysis. Diagnosis of induction motors, conducted remotely...
-
Detection and Mitigation of GPS Spoofing Based on Antenna Array Processing
PublicationIn this article authors present an application of spatial processing methods for GPS spoofing detection and mitigation. In the first part of this article, a spoofing detection method, based on phase delay measurements, is proposed. Accuracy and precision of phase delay estimation is assessed for various qualities of received signal. Spoofing detection thresholds are determined. Efficiency of this method is evaluated in terms of...
-
Using FreeFEM open software for modelling the vibrations of piezoelectric devices
PublicationModelling 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...
-
Dimethyl ether (DME) as potential environmental friendly fuel
PublicationIn recent years, there has been a growing interest in replacing petroleum fuels with so-called second generation environmental friendly fuels. Compared to traditional petroleum fuels dimethyl ether (DME) could be used as a clean high-efficiency compression ignition fuel with reduced particulate matter (PM), sulfur oxides (SOx), hydrocarbons (HC), carbon monoxide (CO) as well as combustion noise. Compared to some of the other leading...
-
Ranking of Generation Source Locations by a Hybrid Multi-Criteria Method
PublicationThe paper presents a ranking of the locations of eight renewable energy sources (RES) made using a hybrid multi-criteria analysis method. The method is a combination of the analytical hierarchical process (AHP) method and numerical taxonomy. The considered generating sources, i.e. solar plants, biogas plants, and wind farms are sources that will significantly contribute to implementing the provisions of the energy and climate package...