bluuebunny/crossref_metadata_2025_split huggingface dataset:
Finite element analysis for airfield asphalt pavements rutting prediction
Authors: Leonardi G. 
Published: June 2015

Abstract
This paper presents a numerical study of an aircraft wheel impacting on a flexible pavement. The proposed three dimensional model simulates the behaviour of flexible runway pavement during the landing phase. This model was implemented in a finite element code in order to investigate the impact of repeated cycles of loads on pavement permanent deformation.
In the model a traditional multi-layer pavement structure was considered. In addition, the asphalt layer (HMA) was assumed to follow an elasto-viscoplastic behaviour.
The results demonstrate the capability of the model in predicting the permanent deformation distribution in the asphalt layer
On simplified forms of the fractional-order backward difference and related fractional-order linear discrete-time system description
Authors: Ostalczyk P. 
Published: June 2015

Abstract
In this paper three simplified forms of the fractional-order (FO) backward difference (BD) are proposed and analysed. Due to time and frequency characteristics criteria parameters of simplified forms of the FOBDs are chosen. Applications of the simplified forms of the FOBDs diminish a number of multiplications and additions needed to evaluate the FOBD. This is very important in real-time microprocessor calculations. It is proved that in a discrete state-space description of a fractional-order system one should correct the input matrix with simplified forms of the FOBD. Investigations are supported by two numerical examples
Assessment of Polish Power System angular stability based on analysis of different disturbance waveforms
Authors: Pruski P. , Paszek S. 
Published: June 2015

Abstract
The paper presents investigation results concerning assessment of the Polish Power System (PPS) angular stability based on power system state matrix eigenvalues associated with electromechanical phenomena, when using the angular stability factors calculated on the basis of these eigenvalues. The eigenvalues were calculated by analysis of the disturbance waveforms of the instantaneous power, angular speed and power angle of synchronous generators in PPS generating units when taking into account introduction of a disturbance to different units. There was assumed a disturbance in the form of a rectangular pulse introduced to the voltage regulation system of a generating unit. There was also analysed the effect of the duration of the introduced test disturbance on the calculation results of the eigenvalue influencing the measurement waveforms of the instantaneous power of generating unit no 5 in Rybnik Power Plant. The method for eigenvalue calculations used in the investigations consists in approximation of the disturbance waveforms in particular generating units with the use of the waveforms being a superposition of the modal components associated with the searched eigenvalues. The hybrid optimisation algorithm being a serial combination of the genetic and gradient algorithms was used for computations
Determining selected diesel engine combustion descriptors based on the analysis of the coefficient of variation of in-chamber pressure
Authors: Bąkowski A. , Radziszewski L. 
Published: June 2015

Abstract
This paper presents a method that uses the coefficient of variation (COV) of pressure in a diesel engine combustion chamber to determine the crank angle degree (CAD) for which the heat release rate (HRR) reaches the maximum value. The COV was proposed for determining the point corresponding to the angle of start of combustion (SoC). Regression models were fit with these descriptors for the engine powered by diesel, biodiesel or a combination of both, operating under full- or part- load conditions. The uncertainty parameter in these models was determined. Good agreement between the experimental results and the literature data shows the validity of the analysis
Finite-time stability and stabilization of singular state-delay systems using improved estimation of a lower bound on a Lyapunov-like functional
Authors: Stojanovic S.B. , Debeljkovic D.Lj. , Antic D.S. 
Published: June 2015

Abstract
In this paper, the problems of finite-time stability and stabilization for a class of singular time-delay systems are studied. Using the Lyapunov-like functional (LLF) with (exponential or power) weighting function and a new estimation method for the lower bound on LLF, some sufficient stability conditions are introduced. It is shown that the weighting function significantly reduces the conservatism of the stability criteria in comparison to estimation of the lower bound on LLF without this function. To solve the finite-time stabilization problem, a stabilizing linear state controller is designed by exploiting the cone complementarity linearization algorithm. Two numerical examples are given to illustrate the effectiveness of the proposed method
The new, parametrised IPTV Model for Determining the Quality in the IPTV Service
Authors: Uhl T. , Jürgensen H.S. 
Published: June 2015

Abstract
This paper describes a new measurement method for determining the quality of the IPTV (Television over IP) service. This method uses the latest IPTV Model and is one of a number of parameter-based measuring techniques (offline operation, i.e. without intrusive measurement). It delivers results that come very close to those of the corresponding Perceptual Evaluation of Video Quality (PEVQ) curves. The method is quickly and easily implemented - one of the great advantages of using this method to measure QoS
Surface and subsurface flow in eucalyptus plantations in north-central Portugal
Authors: Boulet Anne-K. , Prats Sergio A. , Malvar Maruxa C. , González-Pelayo Oscar , Coelho Celeste O.A. , Ferreira Antonio J.D. , Keizer Jan J. 
Published: June 2015

Abstract
In the Baixo Vouga region of north-central Portugal, forests occupy half of the territory, of which two thirds are Eucalypts plantations. The hydrological implications of this large-scale introduction of eucalypt are unknown and the aim of this exploratory study, realized in the Caramulo Mountains, was to describe overland flow (OLF), subsurface flow (SSF) and stream flow (Q) in a catchment dominated by Eucalyptus plantations. The main conclusions are that annual OLF rate is low, spatially heterogeneous between 0.1% and 6% and concentrated during the wet season as saturation excess, particularly as return flow. Infiltration-excess OLF due to the strong soil water repellence (SWR) is dominant during dry season, but produces residual runoff amount. SSF is the principal mechanism of runoff formation. It originates from matrix flow and pipe flow at the soil-bedrock interface, principally during the wet season. Matrix flow is correlated with soil moisture (SM) content, with a threshold of 25 %. Pipe flow starts with saturation of soil bottom but without saturation of the entire soil profile, due to a large network of macropores. Stream flow response is highly correlated with matrix flow behaviour in timing and intensity. SWR induces a very patchy moistening of the soil, concentrates the fluxes and accelerates them almost 100 times greater than normal percolation of the water in the matrix.
Rainfall estimation from in situ soil moisture observations at several sites in Europe: an evaluation of the SM2RAIN algorithm
Authors: Brocca Luca , Massari Christian , Ciabatta Luca , Moramarco Tommaso , Penna Daniele , Zuecco Giulia , Pianezzola Luisa , Borga Marco , Matgen Patrick , Martínez-Fernández José 
Published: June 2015

Abstract
Rain gauges, weather radars, satellite sensors and modelled data from weather centres are used operationally for estimating the spatial-temporal variability of rainfall. However, the associated uncertainties can be very high, especially in poorly equipped regions of the world. Very recently, an innovative method, named SM2RAIN, that uses soil moisture observations to infer rainfall, has been proposed by Brocca et al. (2013) with very promising results when applied with in situ and satellite-derived data. However, a thorough analysis of the physical consistency of the SM2RAIN algorithm has not been carried out yet. In this study, synthetic soil moisture data generated from a physically-based soil water balance model are employed to check the reliability of the assumptions made in the SM2RAIN algorithm. Next, high quality and multiyear in situ soil moisture observations, at different depths (5-30 cm), and rainfall for ten sites across Europe are used for testing the performance of the algorithm, its limitations and applicability range.
SM2RAIN shows very high accuracy in the synthetic experiments with a correlation coefficient, R, between synthetically generated and simulated data, at daily time step, higher than 0.940 and an average Bias lower than 4%. When real datasets are used, the agreement between observed and simulated daily rainfall is slightly lower with average R-values equal to 0.87 and 0.85 in the calibration and validation periods, respectively. Overall, the performance is found to be better in humid temperate climates and for sensors installed vertically. Interestingly, algorithms of different complexity in the reproduction of the underlying hydrological processes provide similar results. The average contribution of surface runoff and evapotranspiration components amounts to less than 4% of the total rainfall, while the soil moisture variations (63%) and subsurface drainage (30%) terms provide a much higher contribution. Overall, the SM2RAIN algorithm is found to perform well both in the synthetic and real data experiments, thus offering a new and independent source of data for improving rainfall estimation, and consequently enhancing hydrological, meteorological and climatic studies.
Impact of conservation practices on runoff and soil loss in the sub-humid Ethiopian Highlands: The Debre Mawi watershed
Authors: Dagnew Dessalegn C. , Guzman Christian D. , Zegeye Assefa D. , Tibebu Tigist Y. , Getaneh Menelik , Abate Solomon , Zemale Fasikaw A. , Ayana Essayas K. , Tilahun Seifu A. , Steenhuis Tammo S. 
Published: June 2015

Abstract
In response to the continually increasing sediment concentrations in rivers and lakes, the Ethiopian government is leading an effort where farmers are installing soil and water conservation measures to increase infiltration and reduce erosion. This paper reports on findings from a four year study in the 95 ha Debre Mawi watershed where under the government led conservation works, mainly terraces with infiltration furrows were installed halfway in the period of observation. The results show that runoff volume decreased significantly after installation of the soil and water conservation practices but sediment concentration decreased only marginally. Sediment loads were reduced mainly because of the reduced runoff. Infiltration furrows were effective on the hillsides where rain water could infiltrate, but on the flat bottom lands that become saturated with the progress of the monsoon rain, infiltration was restricted and conservation practices became conduits for carrying excess rainfall. This caused the initiation of gullies in several occasions in the saturated bottomlands. Sediment concentration at the outlet barely decreased due to entrainment of loose soil from unstable banks of gullies in the periodically saturated bottom areas. Since most uphill drainage were already half filled up with sediments after two years, long term benefits of reducing runoff can only be sustained with continuous maintenance of uphill infiltration furrows.
Identification of prevailing storm runoff generation mechanisms in an intensively cultivated catchment
Authors: Zumr David , Dostál Tomáš , Devátý Jan 
Published: June 2015

Abstract
The fact that flash floods initiated in arable catchments are often accompanied by massive sediment and nutrient loads often leads to the assumption that surface runoff is the principle pathway by which runoff reaches watercourses. On the basis of an evaluation of several rainfall-runoff events in a representative agricultural catchment, we show that runoff from cultivated land may be generated in a way similar to that seen on forested slopes, where shallow subsurface runoff is the predominant pathway by which runoff makes its way to watercourses in most runoff events. To identify the predominant runoff pathway, we employed a combination of turbidity measurements and stream discharge data. Suspended sediment flux, a newly introduced index representing the ratio between precipitation duration and total sediment yield, and direction of the discharge-turbidity hysteresis loops were proposed as reflective indicators of the frequency of runoff via different pathways.
In our study, most of the events initiated by rainstorms of various intensities and durations resulted in rapid increases in stream discharge. Although we observed temporal variability of topsoil properties attributable to seasonal weather changes and agricultural activities, e.g. bulk density and porosity, runoff generation was mainly driven by precipitation characteristics and the initial catchment saturation.
The role of station density for predicting daily runoff by top-kriging interpolation in Austria
Authors: Parajka Juraj , Merz Ralf , Skøien Jon Olav , Viglione Alberto 
Published: June 2015

Abstract
Direct interpolation of daily runoff observations to ungauged sites is an alternative to hydrological model regionalisation. Such estimation is particularly important in small headwater basins characterized by sparse hydrological and climate observations, but often large spatial variability. The main objective of this study is to evaluate predictive accuracy of top-kriging interpolation driven by different number of stations (i.e. station densities) in an input dataset. The idea is to interpolate daily runoff for different station densities in Austria and to evaluate the minimum number of stations needed for accurate runoff predictions. Top-kriging efficiency is tested for ten different random samples in ten different stations densities. The predictive accuracy is evaluated by ordinary cross-validation and full-sample crossvalidations. The methodology is tested by using 555 gauges with daily observations in the period 1987-1997. The results of the cross-validation indicate that, in Austria, top-kriging interpolation is superior to hydrological model regionalisation if station density exceeds approximately 2 stations per 1000 km2 (175 stations in Austria). The average median of Nash-Sutcliffe cross-validation efficiency is larger than 0.7 for densities above 2.4 stations/1000 km2. For such densities, the variability of runoff efficiency is very small over ten random samples. Lower runoff efficiency is found for low station densities (less than 1 station/1000 km2) and in some smaller headwater basins.
Using thermal tracers to estimate flow velocities of shallow flows: laboratory and field experiments
Authors: Lima Rui L.P. de , Abrantes João R.C.B. , Lima João L.M.P. de , Lima M. Isabel P. de 
Published: June 2015

Abstract
Accurate measurement of shallow flows is important for hydraulics, hydrology and water resources management. The objective of this paper is to discuss a technique for shallow flow and overland flow velocity estimation that uses infrared thermography. Laboratory flumes and different bare, vegetated and paved field surfaces were used to test the technique. Results show that shallow flow surface velocities estimated using thermal tracers and infrared technology are similar to estimates obtained using the Acoustic Doppler Velocimeter; similar results were also obtained for overland flow velocity estimates using thermography, here comparing with the dye tracer technique. The thermographic approach revealed some potential as a flow visualization technique, and leaves space for future studies and research.
Examination of aerial diatom flushing across watersheds in Luxembourg, Oregon and Slovakia for tracing episodic hydrological connectivity
Authors: Pfister Laurent , Wetzel Carlos E. , Martínez-Carreras Núria , Iffly Jean François , Klaus Julian , Holko Ladislav , McDonnell Jeffrey J. 
Published: June 2015

Abstract
Hydrological processes research remains a field that is severely measurement limited. While conventional tracers (geochemicals, isotopes) have brought extremely valuable insights into water source and flowpaths, they nonetheless have limitations that clearly constrain their range of application. Integrating hydrology and ecology in catchment science has been repeatedly advocated as offering potential for interdisciplinary studies that are eventually to provide a holistic view of catchment functioning. In this context, aerial diatoms have been shown to have the potential for detecting of the onset/cessation of rapid water flowpaths within the hillslope-riparian zone-stream continuum. However, many open questions prevail as to aerial diatom reservoir size, depletion and recovery, as well as to their mobilisation and transport processes. Moreover, aerial diatoms remain poorly known compared to freshwater species and new species are still being discovered. Here, we ask whether aerial diatom flushing can be observed in three catchments with contrasting physiographic characteristics in Luxembourg, Oregon (USA) and Slovakia. This is a prerequisite for qualifying aerial diatoms as a robust indicator of the onset/cessation of rapid water flowpaths across a wider range of physiographical contexts. One species in particular, (Hantzschia amphioxys (Ehr.) Grunow), was found to be common to the three investigated catchments. Aerial diatom species were flushed, in different relative proportions, to the river network during rainfall-runoff events in all three catchments. Our take-away message from this preliminary examination is that aerial diatoms appear to have a potential for tracing episodic hydrological connectivity through a wider range of physiographic contexts and therefore serve as a complementary tool to conventional hydrological tracers.
Kalman Filter or VAR Models to Predict Unemployment Rate in Romania?
Authors: Simionescu Mihaela 
Published: June 2015

Abstract
This paper brings to light an economic problem that frequently appears in practice: For the same variable, more alternative forecasts are proposed, yet the decision-making process requires the use of a single prediction. Therefore, a forecast assessment is necessary to select the best prediction. The aim of this research is to propose some strategies for improving the unemployment rate forecast in Romania by conducting a comparative accuracy analysis of unemployment rate forecasts based on two quantitative methods: Kalman filter and vector-auto-regressive (VAR) models. The first method considers the evolution of unemployment components, while the VAR model takes into account the interdependencies between the unemployment rate and the inflation rate. According to the Granger causality test, the inflation rate in the first difference is a cause of the unemployment rate in the first difference, these data sets being stationary. For the unemployment rate forecasts for 2010-2012 in Romania, the VAR models (in all variants of VAR simulations) determined more accurate predictions than Kalman filter based on two state space models for all accuracy measures. According to mean absolute scaled error, the dynamic-stochastic simulations used in predicting unemployment based on the VAR model are the most accurate. Another strategy for improving the initial forecasts based on the Kalman filter used the adjusted unemployment data transformed by the application of the Hodrick-Prescott filter. However, the use of VAR models rather than different variants of the Kalman filter methods remains the best strategy in improving the quality of the unemployment rate forecast in Romania. The explanation of these results is related to the fact that the interaction of unemployment with inflation provides useful information for predictions of the evolution of unemployment related to its components (i.e., natural unemployment and cyclical component).
Is Trust in Banks in Slovenia Put to the Test?
Authors: Taškar Beloglavec Sabina , Šebjan Urban 
Published: June 2015

Abstract
The question of the banking system’s stability in connection to trust since the 2008 crisis has been the subject of many debates seeking to find permanent solutions to banking system problems, as the current situation affects bank customers’ behavior. This article examined trust in banks during the financial crisis and offers, via demographic variables, explanations as tow whether or not customers tend to withdraw their deposits during a crisis. The results contribute to banks’ decision-making regarding deposits management and understanding customers’ behavior, especially during a crisis. The results show a negative relationship between trust and deposit withdrawal intention, where gender and education level play an important role.
Composite processing and property evaluation of far-infrared/electromagnetic shielding bamboo charcoal/phase change material/stainless steel elastic composite fabrics
Authors: Huang Chien-Lin , Huang Yu-Tien , Li Ting-Ting , Chiang Chia-Hsuan , Lou Ching-Wen , Lin Jia-Horng 
Published: June 2015

Abstract
This study aims to fabricate far-infrared (FIR)/electromagnetic shielding composite fabric and its composite yarn. Five types of composite yarns with different sheath components were made by using bamboo charcoal (BC) fibers, phase change material (PCM) roving and stainless steel (SS) fibers via a ring spinning frame, and then fabricated into five elastic warp-knitted fabrics with different weft yarns using a crochet knitting machine. The mechanical properties of different constituents of composite yarns and their fabrics, as well as FIR emissivity and electromagnetic shielding effectiveness (EMSE) of resulting fabrics were evaluated. The results show that BC/SS composite yarns and their fabricated warp-knitted fabrics display the highest tensile strength. Warp-knitted fabrics containing BC fibers possess the highest FIR emissivity. EMSE of the fabricated warp-knitted fabrics improves proportionally with the number of the lamination layers. The resulting multifunctional elastic knitted fabrics apply as athletic clothing, underwear, socks, protective or healthcare products in the future.
The recognition of transient compressional fault slow−slip along the northern shore of Hornsund Fjord, Sw Spitsbergen, Svalbard
Authors: Stemberk Josef , Briestenský Miloš , Cacoń Stefan 
Published: June 2015

AbstractThis paper presents the results of direct 3−D fault displacement monitoring along the northern shore of Hornsund Fjord, SW Spitsbergen, Svalbard. The fault displacements have been recorded using three permanently installed optical−mechanical crack gauges since 2009. The monitoring data from all three sites provided evidence for a remarkable slip event that lasted from September 2011 to May 2012. The cause is discussed in some detail with consideration given to both exogenic (temperature changes, surface processes) and endogenic processes (isostatic rebound and regional seismicity). It is proposed that transient fault slips recorded had a tectonic origin and were caused by approximately W−E oriented compression corresponding to regional compression in the Svalbard area.
New records of driftwood lichens in the Kaffiøyra Plain (NW Spitsbergen, Svalbard)
Authors: Węgrzyn Michał , Wietrzyk Paulina , Adamska Edyta , Nicia Paweł 
Published: June 2015

AbstractThis paper refers to lichen biota growing on driftwood in the Kaffiøyra Plain (NW Spitsbergen, Svalbard). The presented list of 25 lichenized fungi includes both the eurytopic, accidental, typical, and stenotopic species. Taxa that belong to the last two groups can be considered as lignicolous. This study confirms the existence of a specific group of lichen species, for which the driftwood is a main substrate in the Arctic. Additionally, five lichen species new for the whole Svalbard were recorded, namely: Candelariella coralliza, Elixia flexella, Lecanora saligna, Lecidea plebeja, and Xylographa sibirica.