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APPLICATION AND EVALUATION OF THE GLEAMS MODEL TO A CATTLE GRAZING PASTURE FIELD IN NORTH ALABAMA

  • Kang, M. S.;P. prem, P.-Prem;Yoo, K. H.;Im, Sang-Jun
    • Water Engineering Research
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    • v.5 no.2
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    • pp.55-68
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    • 2004
  • The GLEAMS (Groundwater Loading Effects of Agricultural Management System, version 3.0) water quality model was used to predict hydrology and water quality and to evaluate the effects of soil types from a cattle-grazed pasture field of Bermuda-Rye grass rotation with poultry litter application as a fertilizer in North Alabama. The model was applied and evaluated by using four years (1999-2002) of field-measured data to compare the simulated results for the 2.71- ha Summerford watershed. $R^2$ values between observed and simulated runoff, sediment yields, TN, and TP were 0.91, 0.86, 0.95, and 0.69, respectively. EI (Efficiency Index) of these parameters were 0.86, 0.67, 0.70, and 0.48, respectively. The statistical parameters indicated that GLEAMS provided a reasonable estimation of the runoff, sediment yield, and nutrient losses at the studied watershed. The soil infiltration rates were compared with the rainfall events. Only high intensity rainfall events generated runoff from the watershed. The measured and predicted infiltration rates were higher during dry soil conditions than wet soil conditions. The ratio of runoff to precipitation was ranging from 2.2% to 8.8% with average of 4.3%. This shows that the project site had high infiltration and evapotranspiration which generated the low runoff. The ratio of runoff to precipitation according to soil types by the GLEAMS model appeared that Sa (Sequatchie fine sandy loam) soil type was higher and Wc (Waynesboro fine sandy loam, severely eroded rolling phase) soil type relatively lower than the weighted average of the soil types in the watershed. The model under-predicted runoff, sediment yields, TN, and TP in Wb (Waynesboro fine sandy loam, eroded undulating phase) and Wc soil types. General tendency of the predicted data was similar for all soil types. The model predicted the highest runoff in Sa soil type by 105% of the weighted average and the lowest runoff in Wc soil type by 87% of the weighted average

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Structural Characterization and Dielectric Studies of Superparamagnetic Iron Oxide Nanoparticles

  • Sivakumar, D.;Naidu, K. Chandra Babu;Nazeer, K. Prem;Rafi, M. Mohamed;kumar, G. Ramesh;Sathyaseelan, B.;Killivalavan, G.;Begam, A. Ayisha
    • Journal of the Korean Ceramic Society
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    • v.55 no.3
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    • pp.230-238
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    • 2018
  • Superparamagnetic iron oxide nanoparticles (SPIONs) have been prepared without using surfactants to assess their stability at different time intervals. The synthesized particles were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, ultraviolet-visible-near infrared spectroscopy, and energy dispersive spectroscopy. Field emission scanning electron microscopy and high-resolution transmission electron microscopy images of the samples were also investigated. The average particle size was measured to be 12.7 nm even in the polydispersed form. The magnetic and dielectric characteristics of the $Fe_3O_4$ nanoparticles have also been studied and discussed in detail.

A Note on Computing the Crisp Order Context of a Fuzzy Formal Context for Knowledge Reduction

  • Singh, Prem Kumar;Kumar, Ch. Aswani
    • Journal of Information Processing Systems
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    • v.11 no.2
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    • pp.184-204
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    • 2015
  • Fuzzy Formal Concept Analysis (FCA) is a mathematical tool for the effective representation of imprecise and vague knowledge. However, with a large number of formal concepts from a fuzzy context, the task of knowledge representation becomes complex. Hence, knowledge reduction is an important issue in FCA with a fuzzy setting. The purpose of this current study is to address this issue by proposing a method that computes the corresponding crisp order for the fuzzy relation in a given fuzzy formal context. The obtained formal context using the proposed method provides a fewer number of concepts when compared to original fuzzy context. The resultant lattice structure is a reduced form of its corresponding fuzzy concept lattice and preserves the specialized and generalized concepts, as well as stability. This study also shows a step-by-step demonstration of the proposed method and its application.

Back EMF Design of an AFPM Motor using PCB Winding by Quasi 3D Space Harmonic Analysis Method

  • Jang, Dae-Kyu;Chang, Jung-Hwan;Jang, Gun-Hee
    • Journal of Electrical Engineering and Technology
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    • v.7 no.5
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    • pp.730-735
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    • 2012
  • This paper presents a method to design the waveform of a back electromotive force (back EMF) of an axial flux permanent magnet (AFPM) motor using printed circuit board (PCB) windings. When the magnetization distribution of permanent magnet (PM) is given, the magnetic field in the air gap region is calculated by the quasi three dimensional (3D) space harmonic analysis (SHA) method. Once the flux density distribution in the winding region is determined, the required shape of the back EMF can be obtained by adjusting the winding distribution. This can be done by modifying the distance between patterns of PCB to control the harmonics in the winding distribution. The proposed method is verified by finite element analysis (FEA) results and it shows the usefulness of the method in eliminating a specific harmonic component in the back EMF waveform of a motor.

Identification of 18 flutter derivatives by covariance driven stochastic subspace method

  • Mishra, Shambhu Sharan;Kumar, Krishen;Krishna, Prem
    • Wind and Structures
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    • v.9 no.2
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    • pp.159-178
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    • 2006
  • For the slender and flexible cable supported bridges, identification of all the flutter derivatives for the vertical, lateral and torsional motions is essential for its stability investigation. In all, eighteen flutter derivatives may have to be considered, the identification of which using a three degree-of-freedom elastic suspension system has been a challenging task. In this paper, a system identification technique, known as covariance-driven stochastic subspace identification (COV-SSI) technique, has been utilized to extract the flutter derivatives for a typical bridge deck. This method identifies the stochastic state-space model from the covariances of the output-only (stochastic) data. All the eighteen flutter derivatives have been simultaneously extracted from the output response data obtained from wind tunnel test on a 3-DOF elastically suspended bridge deck section-model. Simplicity in model suspension and measurements of only output responses are additional motivating factors for adopting COV-SSI technique. The identified discrete values of flutter derivatives have been approximated by rational functions.

Somatic Embryogenesis in a Range of Genotypes and Genetic Stability of the Plants Derived from Somatic Embryos Using Morphological and RAPD Markers in Sweet Potato

  • Sharma, Sonali Dixit;Ghosh, Sangeeta Ahuja;Mandal, Binay Bhushan;Srivastava, Prem Shanker
    • Journal of Plant Biotechnology
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    • v.6 no.2
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    • pp.119-124
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    • 2004
  • For long-term conservation of germ plasm, somatic embryos of sweet potato are important because shoot tips are not amenable to liquid nitrogen storage. Somatic embryos from different genotypes were used for induction of somatic embryogenesis in a large number of genotypes. Somatic embryogenesis was induced on 2,4-D medium in all the 11 genotypes, collected from geographically distinct locations. Genetic fidelity of the regenerated plants was confirmed by morphological and RAPD markers.

Numerical and theoretical modelling of low velocity impact on UHPC panels

  • Prem, Prabhat R.;Verma, Mohit;Ramachandra Murthy, A.;Rajasankar, J.;Bharatkumar, B.H.
    • Structural Engineering and Mechanics
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    • v.63 no.2
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    • pp.207-215
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    • 2017
  • The paper presents the studies carried out on low velocity impact of Ultra high performance concrete (UHPC) panels of size $350{\times}350{\times}10mm^3$ and $350{\times}350{\times}15mm^3$. The panels are cast with 2 and 2.5% micro steel fibre and compared with UHPC without fiber. The panels are subjected to low velocity impact, by a drop-weight hemispherical impactor, at three different energy levels of 10, 15 and 20 J. The impact force obtained from the experiments are compared with numerically obtained results using finite element method, theoretically by energy balance approach and empirically by nonlinear multi-genetic programming. The predictions by these models are found to be in good coherence with the experimental results.

Application of artificial neural network for determination of wind induced pressures on gable roof

  • Kwatra, Naveen;Godbole, P.N.;Krishna, Prem
    • Wind and Structures
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    • v.5 no.1
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    • pp.1-14
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    • 2002
  • Artificial Neural Networks (ANN) have the capability to develop functional relationships between input-output patterns obtained from any source. Thus ANN can be conveniently used to develop a generalised relationship from limited and sometimes inconsistent data, and can therefore also be applied to tackle the data obtained from wind tunnel tests on building models with large number of variables. In this paper ANN model has been developed for predicting wind induced pressures in various zones of a Gable Building from limited test data. The procedure is also extended to a case wherein interference effects on a gable roof building by a similar building are studied. It is found that the Artificial Neural Network modelling is seen to predict successfully, the pressure coefficients for any roof slope that has not been covered by the experimental study. It is seen that ANN modelling can lead to a reduction of the wind tunnel testing effort for interference studies to almost half.