bluuebunny/crossref_metadata_2025_split huggingface dataset:
Successive Interference Cancellation for DS-Optical PPM-CDMA Systems
Authors: Alsowaidi N. , Eltaif Tawfig , Mokhtar M. R. 
Published: July 2016

AbstractIn this paper we introduce a successive interference cancellation (SIC) scheme for direct sequence optical code division multiple access (DS-OCDMA) systems using pulse position modulation (PPM). Considering double-padded modified prime code (DPMPC) as a signature sequence code, results show that the system has better performance in terms of both capacity and bit error rate (BER) as compared to the one without cancellation scheme, where the system with SIC scheme can support up to 88 users while the system without SIC scheme can support only 38 users at similar BER=10
Secured Hash Based Burst Header Authentication Design for Optical Burst Switched Networks
Authors: Balamurugan A. M. , Sivasubramanian A. , Parvathavarthini B. 
Published: July 2016

AbstractThe optical burst switching (OBS) is a promising technology that could meet the fast growing network demand. They are featured with the ability to meet the bandwidth requirement of applications that demand intensive bandwidth. OBS proves to be a satisfactory technology to tackle the huge bandwidth constraints, but suffers from security vulnerabilities. The objective of this proposed work is to design a faster and efficient burst header authentication algorithm for core nodes. There are two important key features in this work, viz., header encryption and authentication. Since the burst header is an important in optical burst switched network, it has to be encrypted; otherwise it is be prone to attack. The proposed MD5&RC4-4S based burst header authentication algorithm runs 20.75 ns faster than the conventional algorithms. The modification suggested in the proposed RC4-4S algorithm gives a better security and solves the correlation problems between the publicly known outputs during key generation phase. The modified MD5 recommended in this work provides 7.81 % better avalanche effect than the conventional algorithm. The device utilization result also shows the suitability of the proposed algorithm for header authentication in real time applications.
Analysis of DWDM System Using DPSK Modulation Technique with Raman–EDFA Hybrid Optical Amplifier
Authors: Gill Manveer Singh , Dewra Sanjeev 
Published: July 2016

AbstractThis paper evaluates the performance of differential phase shift keying (DPSK) optical system based on Raman–erbium-doped fiber amplifier (EDFA) hybrid optical amplifier (HOA) is obtained at 64×20 Gbps with 0.1 THz channel spacing. A DPSK signal with bit rate of 20 Gbps is transmitted up to 210 km at 0 dBm signal input power and up to 166 km at –10 dBm signal input power with acceptable quality factor and bit error rate (BER). It is also found that the transmission distance up to 264 km has been covered at 10 dBm signal input power using Raman–EDFA HOA.
Quality Analysis in Phase Modulated Radio over Fiber in WDM/DWDM Network
Authors: Sahoo S. , Kiran K. V. , Kumar V. , Yadav D. , Barpanda N. K. , Das Santos Kumar 
Published: July 2016

Abstract
There has been increasing demand for connection setup with a higher quality of service (QoS) in WDM/DWDM networks, especially in fields like radio over fiber, where phase modulation affects the link quality. Hence to meet guaranteed QoS in a phase modulated link, the effects of phase modulation on link quality are very much needed. The link quality is termed as quality factor (Q-factor). The primary objective is to use effectively the connections available to optimize the computed number of connections and reduce the blocked connections but at the same time guaranteeing QoS as per client’s need. The analysis has been done by taking care of routing and wavelength assignment (RWA) techniques. The performance analysis is presented in terms of blocking probability.
Homogenizing surface pressure time-series from
operational numerical weather prediction models
for geodetic applications
Authors: Dobslaw H. 
Published: July 2016

Abstract
Global surface pressure grids from 14.5 years
of 6-hourly analyses out of both the operational ECMWF
weather prediction model and ERA-Interim are mapped
to a common reference orography by means of ECMWF’s
mean sea-level pressure diagnostic. The approach reduces
both relative biases and residual variability by about one
order of magnitude and thereby achieves a consistency
among both data sets at the level of about 1 hPa. Remaining
differences rather reflect temperature biases and also
resolution limitations of the reanalysis data set, but are not
anymore related to the local roughness in orography or to
changes in the spatial resolution of the operational model.
The presented reduction method therefore allows to obtain
surface pressure time series with the long-time consistency
of a reanalysis from an operational numerical weather
model with much higher resolution and much shorter latency,
making the results suitable for geodetic near realtime
applications requiring continuously updated time series
that are homogeneous over many years.
Measurement of turbulent flow in a narrow open channel
Authors: Sarkar Sankar 
Published: July 2016

Abstract
The paper presents the experimental results of turbulent flow over hydraulically smooth and rough beds. Experiments were conducted in a rectangular flume under the aspect ratio b/h = 2 (b = width of the channel 0.5 m, and h = flow depth 0.25 m) for both the bed conditions. For the hydraulically rough bed, the roughness was created by using 3/8″ commercially available angular crushed stone chips; whereas sand of a median diameter d50 = 1.9 mm was used as the bed material for hydraulically smooth bed. The three-dimensional velocity components were captured by using a Vectrino (an acoustic Doppler velocimeter). The study focuses mainly on the turbulent characteristics within the dip that were observed towards the sidewall (corner) of the channel where the maximum velocity occurs below the free-surface. It was also observed that the nondimensional Reynolds shear stress changes its sign from positive to negative within the dip. The quadrant plots for the turbulent bursting shows that the signs of all the bursting events change within the dip. Below the dip, the probability of the occurrence of sweeps and ejections are more than that of inward and outward interactions. On the other hand, within the dip, the probability of the occurrence of the outward and inward interactions is more than that of sweeps and ejections.
Identifying the relationships of climate and physiological responses of a beech forest using the Standardised Precipitation Index: a case study for Slovakia
Authors: Vido Jaroslav , Střelcová Katarína , Nalevanková Paulína , Leštianska Adriana , Kandrík Radoslav , Pástorová Alena , Škvarenina Jaroslav , Tadesse Tsegaye 
Published: July 2016

Abstract
The paper presents relationship between the Standardised Precipitation Index (SPI) and physiological responses of individual trees in a beech stand using an example of an experimental plot in Bienska valley (Zvolen, Slovakia). SPI is a widely used tool for monitoring both short-term and long-term droughts, and for the assessments of drought impacts on agriculture. Due to the complex ecosystem bonds, monitoring of drought in forests often requires a sophisticated technological approach. The aim of the paper was to correlate the SPI on the physiological responses of trees that were recorded during the performed physiological research (sap flow, and stem circumference increment) at the site in the growing seasons (May to September) of the years 2012-2014. The results revealed a relationship between the index and the physiological responses, although the problem with the impact of other environmental factors has also come up. The secondary correlation, in which soil water potential that significantly affects physiological responses of forest tree species was used as a dependent variable, showed a tighter relationship with the SPI. We found the highest correlation between the soil water potential and the values of SPI aggregated for five weeks. This indicates that the beech forest has a five week resistance to drought stress. The results also enable simple monitoring of the initiation of the drought stress by applying SPI for five weeks.
Interpretation of ponded infiltration data using numerical experiments
Authors: Dohnal Michal , Vogel Tomas , Dusek Jaromir , Votrubova Jana , Tesar Miroslav 
Published: July 2016

Abstract
Ponded infiltration experiment is a simple test used for in-situ determination of soil hydraulic properties, particularly saturated hydraulic conductivity and sorptivity. It is known that infiltration process in natural soils is strongly affected by presence of macropores, soil layering, initial and experimental conditions etc. As a result, infiltration record encompasses a complex of mutually compensating effects that are difficult to separate from each other. Determination of sorptivity and saturated hydraulic conductivity from such infiltration data is complicated. In the present study we use numerical simulation to examine the impact of selected experimental conditions and soil profile properties on the ponded infiltration experiment results, specifically in terms of the hydraulic conductivity and sorptivity evaluation. The effect of following factors was considered: depth of ponding, ring insertion depth, initial soil water content, presence of preferential pathways, hydraulic conductivity anisotropy, soil layering, surface layer retention capacity and hydraulic conductivity, and presence of soil pipes or stones under the infiltration ring. Results were compared with a large database of infiltration curves measured at the experimental site Liz (Bohemian Forest, Czech Republic). Reasonably good agreement between simulated and observed infiltration curves was achieved by combining several of factors tested. Moreover, the ring insertion effect was recognized as one of the major causes of uncertainty in the determination of soil hydraulic parameters.
Rainfall timing and runoff: The influence of the criterion for rain event separation
Authors: Molina-Sanchis Isabel , Lázaro Roberto , Arnau-Rosalén Eva , Calvo-Cases Adolfo 
Published: July 2016

Abstract
Rain is not uniform in time and space in semiarid areas and its distribution is very important for the runoff process. Hydrological studies usually divide rainfall into events. However, defining rain events is complicated, and rain characteristics vary depending on how the events are delimited. Choosing a minimum inter-event time (MIT) is a commonly used criterion. Our hypothesis is that there will be an optimal MIT that explains the maximum part of the variance of the runoff, with time to runoff used as a surrogate. The objective is to establish a procedure in order to decide upon this optimal MIT. We developed regressions between time to runoff (T0) and three descriptive variables of rain. Our results show that the optimum MIT is 1 hour, which seems to be the minimum period of time required for water in larger macropores to drain and sufficiently modify the effect of antecedent soil moisture on the runoff generation process. Rain events are classified into three significantly different groups: (1) large and intense rains, (2) light rains on wet soil, and (3) light rains on dry soil. Intense rains produce most of the runoff, but there were significant differences between small events in the runoff generated. Of rain events, 63.75% are single-tip events, and many could be dew.
Modeling of sand-water slurry flow through horizontal pipe using CFD
Authors: Kumar Gopaliya Manoj , Kaushal D.R. 
Published: July 2016

Abstract
The paper presents three-dimensional CFD analysis of two-phase (sand-water) slurry flows through 263 mm diameter pipe in horizontal orientation for mixture velocity range of 3.5-4.7 m/s and efflux concentration range of 9.95-34% with three particle sizes viz. 0.165 mm, 0.29 mm and 0.55 mm with density 2650 kg/m3. RNG k-ε turbulence closure equations with Eulerian multi-phase model is used to simulate various slurry flows. The simulated values of local solid concentration are compared with the experimental data and are found to be in good agreement for all particle sizes. Effects of particle size on various slurry flow parameters such as pressure drop, solid phase velocity distribution, friction factor, granular pressure, turbulent viscosity, turbulent kinetic energy and its dissipation have been analyzed.
Modelling free surface flow with curvilinear streamlines by a non-hydrostatic model
Authors: Zerihun Yebegaeshet T. 
Published: July 2016

Abstract
This study addresses a particular phenomenon in open channel flows for which the basic assumption of hydrostatic pressure distribution is essentially invalid, and expands previous suggestions to flows where streamline curvature is significant. The proposed model incorporates the effects of the vertical curvature of the streamline and steep slope, in making the pressure distribution non-hydrostatic, and overcomes the accuracy problem of the Saint-Venant equations when simulating curvilinear free surface flow problems. Furthermore, the model is demonstrated to be a higher-order one-dimensional model that includes terms accounting for wave-like variations of the free surface on a constant slope channel. Test results of predicted flow surface and pressure profiles for flow in a channel transition from mild to steep slopes, transcritical flow over a short-crested weir and flow with dual free surfaces are compared with experimental data and previous numerical results. A good agreement is attained between the experimental and computed results. The overall simulation results reveal the satisfactory performance of the proposed model in simulating rapidly varied gravity-driven flows with predominant non-hydrostatic pressure distribution effects. This study suggests that a higher-order pressure equation should be used for modelling the pressure distribution of a curvilinear flow in a steeply sloping channel.
Hydraulic characteristics and sediment generation on slope erosion in the Three Gorges Reservoir Area, China
Authors: Qian Feng , Cheng Dongbin , Ding Wenfeng , Huang Jiesheng , Liu Jingjun 
Published: July 2016

Abstract
Hydrological processes play important roles in soil erosion processes of the hillslopes. This study was conducted to investigate the hydrological processes and the associated erosional responses on the purple soil slope. Based on a comprehensive survey of the Wangjiaqiao watershed in the Three Gorges Reservoir, four typical slope gradients (5°, 10°, 15°and 20°) were applied to five rainfall intensities (0.6, 1.1, 1.61, 2.12 and 2.54 mm·min-1). The results showed that both surface and subsurface runoff varied greatly depending on the rainfall intensity and slope gradient. Surface runoff volume was 48.1 to 280.1 times of that for subsurface runoff. The critical slope gradient was about 10°. The sediment yield rate increased with increases in both rainfall intensity and slope gradient, while the effect of rainfall intensity on the sediment yield rate was greater than slope gradient. There was a good linear relationship between sediment yield rate and Reynolds numbers, flow velocity and stream power, while Froude numbers, Darcy-Weisbach and Manning friction coefficients were not good hydraulic indicators of the sediment yield rate of purple soil erosion. Among the three good indicators (Re, v and w), stream power was the best predictor of sediment yield rate (R2 = 0.884). Finally, based on the power regression relationship between sediment yield rate, runoff rate, slope gradient and rainfall intensity, an erosion model was proposed to predict the purple soil erosion (R2 = 0.897). The results can help us to understand the relationship between flow hydraulics and sediment generation of slope erosion and offer useful data for the building of erosion model in purple soil.
Vertical and lateral soil moisture patterns on a Mediterranean karst hillslope
Authors: Canton Yolanda , Rodríguez-Caballero Emilio , Contreras Sergio , Villagarcia Luis , Li Xiao-Yan , Solé-Benet Alberto , Domingo Francisco 
Published: July 2016

Abstract
The need for a better understanding of factors controlling the variability of soil water content (θ) in space and time to adequately predict the movement of water in the soil and in the interphase soil-atmosphere is widely recognised. In this paper, we analyse how soil properties, surface cover and topography influence soil moisture (θ) over karstic lithology in a sub-humid Mediterranean mountain environment. For this analysis we have used 17 months of θ measurements with a high temporal resolution from different positions on a hillslope at the main recharge area of the Campo de Dalías aquifer, in Sierra de Gádor (Almería, SE Spain). Soil properties and surface cover vary depending on the position at the hillslope, and this variability has an important effect on θ. The higher clay content towards the lower position of the hillslope explains the increase of θ downslope at the subsurface horizon throughout the entire period studied. In the surface horizon (0-0.1 m), θ patterns coincide with those found at the subsurface horizon (0.1-0.35 m) during dry periods when the main control is also exerted by the higher percentage of clay that increases downslope and limits water depletion through evaporation. However, in wet periods, the wettest regime is found in the surface horizon at the upper position of the hillslope where plant cover, soil organic matter content, available water, unsaturated hydraulic conductivity (Kunsat) and infiltration rates are higher than in the lower positions. The presence of rock outcrops upslope the θ sampling area, acts as runoff sources, and subsurface flow generation between surface and subsurface horizons also may increase the differences between the upper and the lower positions of the hillslope during wet periods. Both rock and soil cracks and fissures act disconnecting surface water fluxes and reducing run-on to the lower position of the hillslope and thus they affect θ pattern as well as groundwater recharge. Understanding how terrain attributes, ground cover and soil factors interact for controlling θ pattern on karst hillslope is crucial to understand water fluxes in the vadose zone and dominant percolation mechanisms which also contribute to estimate groundwater recharge rates. Therefore, understanding of soil moisture dynamics provides very valuable information for designing rational strategies for the use and management of water resources, which is especially urgent in regions where groundwater supports human consume or key economic activities.
Design of a new hybrid artificial neural network method based on decision trees for calculating the Froude number in rigid rectangular channels
Authors: Ebtehaj Isa , Bonakdari Hossein , Hossein Zaji Amir , Hin Joo Bong Charles , Ab Ghani Aminuddin 
Published: July 2016

Abstract
A vital topic regarding the optimum and economical design of rigid boundary open channels such as sewers and drainage systems is determining the movement of sediment particles. In this study, the incipient motion of sediment is estimated using three datasets from literature, including a wide range of hydraulic parameters. Because existing equations do not consider the effect of sediment bed thickness on incipient motion estimation, this parameter is applied in this study along with the multilayer perceptron (MLP), a hybrid method based on decision trees (DT) (MLP-DT), to estimate incipient motion. According to a comparison with the observed experimental outcome, the proposed method performs well (MARE = 0.048, RMSE = 0.134, SI = 0.06, BIAS = -0.036). The performance of MLP and MLP-DT is compared with that of existing regression-based equations, and significantly higher performance over existing models is observed. Finally, an explicit expression for practical engineering is also provided.
Fungal pathogens and antagonists in root-soil zone in organic and integrated systems of potato production
Authors: Lenc Leszek , Kwaśna Hanna , Jeske Małgorzata , Jończyk Krzysztof , Sadowski Czesław 
Published: July 2016

AbstractOccurrence of culturable Fungi and Oomycota in root-soil habitat of potato cv. Owacja in organic and integrated production systems at Osiny (northern Poland) was compared in 2008-2010. The densities of both pathogens were significantly greater in the organic system. The eudominant fungal taxa (with frequency > 10% in at least one habitat) included species of Fusarium + Gibberella + Haematonectria, Penicillium, Phoma and Trichoderma. The dominant taxa (with frequency 5-10%) included species from 13 genera. In the rhizoplane, rhizosphere and non-rhizosphere soil, the total density of potential pathogens was greater in the integrated system, and of potential antagonists in the organic system. Among eudominant and dominant pathogens, Fusarium oxysporum and Gibellulopsis nigrescens occurred at greater density in the integrated system and Haematonectria haematococca and Phoma spp. in the organic system. Among eudominant antagonists, Trichoderma species occurred at greater density in the organic system. The organic system provided more disease suppressive habitat than the integrated system. The occurrence of brown leaf spot and potato blight was however similar in both systems. The mean yield of organic potatoes (24.9 t · ha-1) was higher than the mean organic potato yield in Poland (21.0 t · ha-1) and similar to the mean in other European countries (Germany 25.1 t · ha-1, Great Britain 25.0 t · ha-1). The organic system, based on a 5-year rotation, with narrow-leafed lupin, white mustard and buckwheat as a cover crop, inorganic fertilization based on ground rock phosphate + potassium sulphate, and biological and chemical control of insects and diseases (Bacillus thuringiensis ssp. tenebrionis + copper hydroxide + copper oxychloride), may be recommended for use in central Europe.
Model based decision support system of operating settings for MMAT nozzles
Authors: Fritz Bradley Keith , Czaczyk Zbigniew , Hoffmann Wesley Clint 
Published: July 2016

Abstract
Droplet size, which is affected by nozzle type, nozzle setups and operation, and spray solution, is one of the most critical factors influencing spray performance, environment pollution, food safety, and must be considered as part of any application scenario. Characterizing spray nozzles can be a timely and expensive proposition if the entire operational space (all combinations of spray pressure and orifice size, what influence flow rate) is to be evaluated. This research proposes a structured, experimental design that allows for the development of computational models for droplet size based on any combination of a nozzle’s potential operational settings. The developed droplet size determination model can be used as Decision Support System (DSS) for precise selection of sprayer working parameters to adapt to local field scenarios. Five nozzle types (designs) were evaluated across their complete range of orifice size (flow rate*) and spray pressures using a response surface experimental design. Several of the models showed high level fits of the modeled to the measured data while several did not as a result of the lack of significant effect from either orifice size (flow rate*) or spray pressure. The computational models were integrated into a spreadsheet based user interface for ease of use. The proposed experimental design provides for efficient nozzle evaluations and development of computational models that allow for the determination of droplet size spectrum and spraying classification for any combination of a given nozzle’s operating settings. The proposed DSS will allow for the ready assessment and modification of a sprayers performance based on the operational settings, to ensure the application is made following recommendations in plant protection products (PPP) labels.