Search results for: quantile regressions
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The Effect of Protrusions on the Initiation of Partial Discharges in XLPE High Voltage Cables
PublicationThis 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...
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Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
PublicationThe acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining...
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Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
PublicationThe acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining...
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Expert systems in quality control of manufacturing processes
PublicationThe paper deals with quality control in conditions of computer integrated manufacturing (CIM). It shows that quality of material stream items have to be analyzed on every stage of manufacturing process. Collecting and analyzing quantity of data with usage of expert systems make it possible to create a system for coordination of cell's work. The system contains error recovery algorithm and adaptive control subsystem based on fuzzy...
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Combinated treatment of landfill leachates with wastewater in a sequencing batch reactor (SBR)
PublicationSanitary landfill leachates are treated usually by multistage systems using physical, chemical and biological processes. One of the most economic and efficient method is combined treatment of landfill leachates with municipal wastewater in a sequencing batch reactor (SBR. The main advantage of such co-treatment is that landfill leachates variability (in quality and quantity) do not influence the effectiveness of biological processes....
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On the Usefulness of the Generalised Additive Model for Mean Path Loss Estimation in Body Area Networks
PublicationIn this article, the usefulness of the Generalised Additive Model for mean path loss estimation in Body Area Networks is investigated. The research concerns a narrow-band indoor off-body network operating at 2.45 GHz, being based on measurements performed with four different users. The mean path loss is modelled as a sum of four components that depend on path length, antenna orientation angle, absolute difference between transmitting...
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Efficiency of gas detection algorithms using fluctuation enhanced sensing
PublicationEfficiency of various gas detection algorithms by applying fluctuation enhanced sensing method was discussed. We have analyzed resistance noise observed in resistive WO3- nanowires gas sensing layers. Power spectral densities of the recorded noise were used as the input data vectors for two algorithms: the principal component analysis (PCA) and the support vector machine (SVM). The data were used to determine gas concentration...
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Towards rainfall interception capacity estimation using ALS LiDAR data
PublicationIn this study we develop a spatial model for interception capacity of vegetation based on LiDAR data. The study is conducted in the natural wetland river valley dominated meadows, reeds and small bushes. The multiple regression model was chosen to relate the field measurements of interception capacity and LiDAR statistics at 2m grid. The optimal model was chosen by stepwise selection and further manual variables selection resulting...
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Driving the Image of an Electricity Supplier through Marketing Activities
PublicationThe aim of this study is to determine how marketing actions undertaken within the marketing mix by electricity providers influence their image. Referring to the Stimulus-Organism-Response (SOR) theory, research hypotheses were formulated, and a regression model was constructed, assuming positive impacts of selected marketing actions of electricity providers on their image. A quantitative approach was employed to test the research...
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Advanced sensitivity analysis of the impact of the temporal distribution and intensity of rainfall on hydrograph parameters in urban catchments
PublicationKnowledge of the variability of the hydrograph of outflow from urban catchments is highly important for measurements and evaluation of the operation of sewer networks. Currently, hydrodynamic models are most frequently used for hydrograph modeling. Since a large number of their parameters have to be identified, there may be problems at the calibration stage. Hence, sensitivity analysis is used to limit the number of parameters....
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GVC and wage dispersion. Firm-level evidence from employee-employer database
PublicationResearch background: Wage inequalities are still part of an interesting policy-oriented research area. Given the developments in international trade models (heterogeneity of firms) and increasing availability of micro-level data, more and more attention is paid to wage differences observed within and be-tween firms. Purpose of the article: The aim of the paper is to address the research gap concerning limited cross-country evidence...
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An experimental study of high-hydrogen welding processes
PublicationThis paper presents investigation results of determination of the diffusible hydrogen content in deposited metal obtained by means of two most often used methods-the glycerin method and the mercury method. Relation has been defined between results of those methods in the area characteristic of low-hydrogen as well as high-hydrogen welding processes. Relations available in the literature do not include the diffusible hydrogen content...
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Magnetic-field-induced electric quadrupole moments for relativistic hydrogenlike atoms: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function
PublicationWe consider a Dirac one-electron atom placed in a weak, static, uniform magnetic field. We show that, to the first order in the strength of the external field, the only electric multipole moments, which are induced by the perturbation in the atom, are those of an even order. Using the Sturmian expansion of the generalized Dirac-Coulomb Green function we derive a closed-form expression for the electric quadrupole moment induced...
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Comprehensive two dimensional gas chromatography coupled with mass spectrometry as tool for characterization of the main pollutants present in atmospheric air in Gdansk
PublicationNowadays, the technique that is commonly used to identify and quantify the chemical compounds in gas sample is gas chromatography. The separation resolution in gas chromatography can be improved by applying the modulation technique. In this paper present is the most important information regarding the pollutants present in atmospheric air. The areas in which the tests were carried out are one of the largest industrial zones in...
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Reject water and landfil leachate treatment with hydrophyte method - preliminary results
PublicationTreatment of landfill leachate (LL) and reject water (RWC) from dewatering of digested sludge in WWTPs have become one of the actual problems. Treatment of both types of wastewater is in many cases very costly and difficult due to quality and quantity fluctuations in time as well as high concentrations of specific pollutants. In case of our investigation the TSS concentration in RWC was two times higher than in LL. The shere of...
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Optimizing control by robustly feasible model predictive control and application to drinking water distribution systems
PublicationThe paper considers optimizing Model Predictive Control (MPC) for nonlinear plants with output constraints under uncertainties. Although the MPC technology can handle the constraints in the model by solving constraint model based optimization task, satisfying the plant output constraints under the model uncertainty still remains a challenge. The paper proposes Robustly Feasible MPC (RFMPC), which achieves feasibility of the outputs...
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Attenuation of Hyperglycemia in Diabetic Rats Assisted by Immobilized Probiotic in Sodium Alginate
PublicationDiabetes mellitus type 2 (DM2) is the most common chronic disease worldwide, characterized mainly by increased glucose concentration in the blood and affecting several organs’ functionality. The daily consumption of probiotic bacteria can help control diabetes and reduce the damage caused. Cell immobilization techniques are a powerful tool that provides physical cell protection to such probiotic bacteria against gastrointestinal...
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Estimation of the Ultimate Strength of FRP Strips-to-Masonry Substrates Bond
PublicationFiber-Reinforced Polymers (FRP) were developed as a new method over the past decades due to their many beneficial mechanical properties, and they are commonly applied to strengthen masonry structures. In this paper, the Artificial Neural Network (ANN), K-fold Cross-Validation (KFCV) technique, Multivariate Adaptive Regression Spline (MARS) method, and M5 Model Tree (M5MT) method were utilized to predict the ultimate strength of...
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Enhancing women’s engagement in economic activities through information and communication technology deployment: evidence from Central–Eastern European countries
PublicationThis study takes a macro perspective to examine the associations between the economic deployment of information and communication technology (ICT), women’s labor market participation, and economic growth in Central–Eastern European countries between 1990 and 2017. We use data extracted from World Bank Development Indicators, World Development Reports, and the World Telecommunication/ICT Indicators Database. Our methodological framework...
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The analysis of firms’ involvement in internationalisation and determinants of its intensity – an analysis for developing and post-transition economies
PublicationThe study presents the empirical analysis of firms’ involvement in different forms of internationalisation: export, indirect export, import, indirect import and finally simultaneous exporting and importing. The analysis is based on firm-level data from the World Bank Enterprise Survey (March 2017 release). The empirical part is divided into two stages. Firstly account is taken of firms’ heterogeneity and then a Melitz type analysis...
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Cargo ships heat demand - operational experiment
PublicationThe paper presents the results of an experiment conducted on two cargo ships – a 5300 TEU container with a steam heating system and a 7500 dwt general cargo ship with a thermal oil system. On both ships research has been carried out using specially designed measuring equipment. After gathering data about flow velocity and temperatures (steam/ cooling water/ thermal oil/ seawater/ outside air), calculations have been done, resulting...
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Comparison of the Effectiveness of Health Systems in The European Countries-Two-Stage DEA Model
PublicationThis article compares the efficiency of health systems in selected European countries using two-stage data envelopment analysis (DEA), based on data from the EUROSTAT database. In the first step, DEA efficiency scores were calculated for health care systems and, subsequently, the external variables describing lifestyle were used to calculate the truncated regression. Health care resources (physicians, nurses, hospital beds, financial...
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Global sensitivity analysis of membrane model of abdominal wall with surgical mesh
PublicationThe paper addresses the issue of ventral hernia repair. Finite Element simulations can be helpful in the optimization of hernia parameters. A membrane abdominal wall model is proposed in two variants: a healthy one and including hernia defect repaired by implant. The models include many uncertainties, e.g. due to variability of abdominal wall, intraabdominal pressure value etc. Measuring mechanical properties with high accuracy...
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Reduced-cost constrained miniaturization of wideband antennas using improved trust-region gradient search with repair step
PublicationIn the letter, an improved algorithm for electromagnetic (EM)-driven size reduction of wideband antennas is proposed. Our methodology utilizes variable-fidelity EM simulation models, auxiliary polynomial regression surrogates, as well as multi-point response correction. The constraint handling is implicit, using penalty functions. The core optimization algorithm is a trust-region gradient search with a repair step added in order...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublicationThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublicationThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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Determination of API content in a pilot-scale blending by near-infrared spectroscopy as a first step method to process line implementation
PublicationNear infrared (NIR) spectroscopy was used for estimation of powder blend homogeneity and manufacturing control of a medicinal product powder mixture containing active pharmaceutical ingredient (API). Aiming at initiating a Process Analytical Technology (PAT) activity, the first step was a stationary mode atline evaluation. In this, the content of pharmaceutical active compound in the powder mixtures intended to the direct tabletting...
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BLOOD PRESSURE ESTIMATION BY MEANS OF A JOINT IMPEDANCE– PHOTOPLETYSMOGRAPHIC METHOD
PublicationThe knowledge of patient’s day to day blood pressure changes is invaluable to physicians for both diagnostics and health monitoring reasons. Constant observation of the pressure throughout a day would provide even more valuable clinical information. A convenient non-invasive methods of blood pressure estimation for monitoring purposes are widely proposed. This work shows a statistical approach to...
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Experience with instantiating an automated testing process in the context of incremental and evolutionary software development
PublicationThe purpose of this article is to present experiences from testing a complex AJAX-based Internet-system which is under development for more than five years. The development process follows incremental and evolutionary lifecycle model and the system is delivered in subsequent releases. Delivering a new release involves both, the new tests (related to the new and/or modified functionalities) and the regression tests (after their...
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Measurement of benzene concentration in urban air using passive sampling
PublicationAbstract The concentration of benzene in urban air in theTri-City area of Poland (Gdańsk-Sopot-Gdynia, andTczew) was assessed using diffusive passive samplers (Rad-iello). Samples were collected during a four-year monitoringcampaign (2007-2010) at selected monitoring stations man-aged by the Agency of Regional Air Quality Monitoring inthe Gdańsk Metropolitan Area (ARMAAG) Foundation.The performance of the passive samplers was investigatedin...
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Working Conditions in Global Value Chains: Evidence for European Employees
PublicationThis article investigates a sample of almost nine million workers from 24 European countries in 2014 to conclude how involvement in global value chains (GVCs) affects working conditions. We use employer–employee data from the Structure of Earnings Survey merged with industry-level statistics on GVCs based on the World Input-Output Database. Given the multidimensional nature of the dependent variable, we compare estimates of the...
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Multi-pulse VSC arrangements with coupled reactors
PublicationThis paper presents a novel approach to the multipulse VSC (Voltage Source Converter) arrangements based on several conventional inverter modules connected in parallel by using coupled reactors. This solution reduces the THD of the output voltage, despite the low switching frequency of transistors. The advantage of the proposed solution is also a relatively small rated power of the reactors. Proposed new arrangements for different...
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Hybrid Modulation for Modular Voltage Source Inverters with Coupled Reactors
PublicationThis paper proposes and discusses a concept of a hybrid modulation for the control of modular voltage source inverters with coupled reactors. The use of coupled reactors as the integrating elements leads to significant reduction in the size and weight of the circuit. The proposed modulation combines novel coarsely quantized pulse amplitude modulation (CQ-PAM) and innovative space-vector pulse width modulation (SVPWM). The former...
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On power stream in motor or drive system
PublicationIn a motor or in a drive system the quantity of power increases in the direction opposite to the direction of power flow. Energy losses and energy efficiency of a motor or a drive system must be presented as functions of physical quantities independent of losses. Such quantities are speed and load. But the picture of power stream in a motor or in a drive system is presented in the literature in the form of traditional Sankey...
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Web Services Integration with Regard to the Metrics of Data Believability
PublicationThe paper is concerned with estimating the believability of data acquired from web services. In the paper, a new method for believability estimation is introduced. The method is designed for integrating web services. The believability estimation is based on the following metrics: quantity, reputation, approval, independence, traceability, maturity, authority and objectivity. In the method, data trustworthiness is determined by...
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Modelling of joining route segments of differential curvature
PublicationThe paper presents a new general method of modelling route segments curvature using differential equations. The method enables joining of route segments of different curvature. Transitional curves of linear and nonlinear curvatures have been identified in the case of joining two circular arcs by S-shaped and C-oval transitions. The obtained S-shaped curves have been compared to the cubic C-Bezier curves and to the Pythagorean hodograph...
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Technology convergence and digital divides. A country-level evidence for the period 2000–2010
PublicationThe paper, mostly empirical in nature, investigates issues on cross-national new information and communication technologies (ICTs) adoption patterns and growth directions. In the period of 2000–2010, a great number of countries underwent substantial changes on the field of ICTs implementation. Many of them made a great “jump” starting with almost “zero level” of ICTs adoption in the year 2000 and during the ten- year period were...
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The Rayleigh model of the multipath fading channel
Open Research DataThe dataset contains the results of simulations that are part of the research on modelling the multipath fading in the communication channel. The Rayleigh fading envelope is generated using the Monte-Carlo simulation (MCS) in the LabVIEW programming environment.
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The α-µ model of the multipath fading channel
Open Research DataThe dataset contains the results of simulations that are part of the research on modelling the multipath fading in the communication channel. The envelope of the α-µ fading process is generated using the Monte-Carlo simulation (MCS) in the LabVIEW programming environment.
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Intermolecular Interactions as a Measure of Dapsone Solubility in Neat Solvents and Binary Solvent Mixtures
PublicationDapsone is an effective antibacterial drug used to treat a variety of conditions. However, the aqueous solubility of this drug is limited, as is its permeability. This study expands the available solubility data pool for dapsone by measuring its solubility in several pure organic solvents: N-methyl-2-pyrrolidone (CAS: 872-50-4), dimethyl sulfoxide (CAS: 67-68-5), 4-formylmorpholine (CAS: 4394-85-8), tetraethylene pentamine (CAS:...
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Quantum mechanical which-way experiment with an internal degree of freedom
PublicationFor a particle travelling through an interferometer, the trade-off between the available which-way information and the interference visibility provides a lucid manifestation of the quantum mechanical wave-particle duality. Here we analyse this relation for a particle possessing an internal degree of freedom such as spin. We quantify the trade-off with a general inequality that paints an unexpectedly intricate picture of wave-particle...
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Iterative Global Sensitivity Analysis Algorithm with Neural Network Surrogate Modeling
PublicationGlobal sensitivity analysis (GSA) is a method to quantify the effect of the input parameters on outputs of physics-based systems. Performing GSA can be challenging due to the combined effect of the high computational cost of each individual physics-based model, a large number of input parameters, and the need to perform repetitive model evaluations. To reduce this cost, neural networks (NNs) are used to replace the expensive physics-based...
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Wpływ udziału użytkownika na jakość użytkową w projektach informatycznych.
PublicationArtykuł przedstawia wyniki badań przeprowadzonych wśród 30 uczestników projektów informatycznych, reprezentujących różnorodne przedsiębiorstwa. Uzyskane dane zostały poddane analizie ilościowej z wykorzystaniem metody chi^2, której zadaniem było ocena stopnia korelacji występującego pomiędzy udziałem użytkowników końcowych, a jakością użytkową produktu. Wyniki badań skupiają się wokół poszukiwań rozwiązania problemu określanego...
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Global value chains and wages under different wage setting mechanisms
PublicationThis study examines whether, and how, differences in wage bargaining schemes shape the relationship between global value chains (GVCs) and the wages of workers while considering both GVC participation and position in GVC. Our dataset is derived from the European Structure of Earnings Survey (SES), containing employee–employer data from 18 European countries, merged with sectoral data from the World Input-Output Database (WIOD)....
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A breath of fresh air - social cognitive career theory in studying entrepreneurial intentions
PublicationA pinch of robustness and a pinch of freshness create an interesting story. That is why this study focuses on entrepreneurial intentions from an alternative theoretical perspective in an underexplored context. In this paper, it is argued that social cognitive career theory is relevant to the study of individual entrepreneurial cognition and behaviour, and it offers a solid framework in entrepreneurship research. This paper expands...
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INTERNAL DETERMINANTS OF FIRMS’ INNOVATIVENESS
PublicationThis article presents an analysis of the determinants of a firm’s innovativeness deriving from its internal potential and characteristics. The analysis is based on research carried out on 1355 firms that applied for public subsidies from the Innovative Economy Operational Program in 2014. The methods applied are logit regression, comparative analysis and literature review. The analysis is structured ac- cording to Bielski’s model...
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SENSITIVITY ANALYSIS IN THE REHABILITATION OF HISTORIC TIMBER STRUCTURES ON THE EXAMPLES OF GREEK CATHOLIC CHURCHES IN POLISH SUBCARPATHIA
PublicationThis work concerns structural and sensitivity analysis of carpentry joints used in historic wooden buildings in south-eastern Poland and western Ukraine. These are primarily sacred buildings and the types of joints characteristic for this region are saddle notch and dovetail joints. Thus, in the study the authors focus on these types of corner log joints. Numerical models of the joints are defined and finite element simulations...
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Method of selecting the LS-SVM algorithm parameters in gas detection process
PublicationIn this paper we showed the method of resistive gas sensors data processing. The UV irradiation and temperature modulation was applied to improve gas sensors’ selectivity and sensitivity. Noise voltage across the sensor’s terminals (proportional to its resistance fluctuations) was recorded to estimate power spectral density. This function was an input data vector for LS-SVM (least squares – support vector machine) algorithm, which...
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Performance and Power-Aware Modeling of MPI Applications for Cluster Computing
PublicationThe paper presents modeling of performance and power consumption when running parallel applications on modern cluster-based systems. The model includes basic so-called blocks representing either computations or communication. The latter includes both point-to-point and collective communication. Real measurements were performed using MPI applications and routines run on three different clusters with both Infiniband and Gigabit Ethernet...
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Comparison of bacterial production in the water column between two Arctic fjords, Hornsund and Kongsfjorden (West Spitsbergen)
PublicationBacterial production and the accompanying environmental factors were measured in the water columns of two Arctic fjords during the cruise in July and August 2013. Water samples were collected at six stations located in the central part of Hornsund and Kongsfjorden. In Hornsund, where average water temperatures were 1.25-fold lower than in Kongsfjorden, the bacterial production was twice as high (0.116 ± 0.102 vs 0.05 ± 0.03 mg...