Approximated fuzzy logic controlled shunt active power filter for improved power quality

Shunt active power filters have been widely used for power quality improvement. With the advancement in artificial intelligence techniques, the applications of fuzzy logic‐based control systems have increased manifolds. This paper proposes a reduced rule fuzzy logic controller (FLC) in the voltage control loop of a shunt active power filter (APF), which is approximating a conventional large rule FLC. The difference between the controlled outputs of two controllers is compensated by proposed compensating factors. The dynamic response and harmonic compensation performance of proposed 4‐rule approximated fuzzy logic controller (AFLC) is compared with 25‐rule FLC. A three‐phase shunt APF is used for harmonic and reactive power compensation. The proposed scheme is tested with randomly varying single and multiple non‐linear loads. The simulation results presented under transient and steady‐state conditions confirm that the proposed 4‐rule AFLC efficiently approximates the 25‐rule FLC. The proposed control methodology takes less computational time and computational memory as the numbers of rules are reduced significantly.     

Impact of variational assimilation of MODIS thermodynamic profiles in the simulation of western disturbance

The present study was carried out to examine the impact of temperature and humidity profiles from the Moderate Resolution Imaging Spectroradiometer (MODIS) on the numerical simulation of western disturbance (WD) using the three-dimensional variational (3D-Var) assimilation technique in the nonhydrostatic version of the Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) fifth-generation Mesoscale Model (MM5). The WD that affected northwest India during 8–11 February 2007 was chosen for the numerical simulations. The results show that there are large differences between the initial meteorological fields from the National Center for Environmental Prediction (NCEP) analysis (without satellite data; control experiment (CNT)) and the optimal initial conditions (with MODIS data; experiment (EXP)). The optimal initial condition showed that MM5 3D-Var had produced an analysis that fit the MODIS observations very well. The assimilation of the MODIS temperature and moisture profiles did not show much impact on the track of the WD but, more importantly, it showed evidence of impacting the rainfall intensity prediction by retarding the incorrect prediction of intense rainfall. The root mean square difference (RMSD) in predicted rainfall from EXP was lower than from CNT. The assimilation of MODIS data also showed a positive impact on the temperature prediction.     

Linear-code multicast on parallel architectures

Parallel architectures involve communication with the aim of fast receiving of complete information at each node. Several architectures have been proposed to overcome the problem of high communicational and computational time complexity for transferring and receiving information. To reduce the complexity of such communication, we have implemented Linear Network Coding (LNC) in the parallel environment. For verification of our approach, we have considered some parallel architecture for implementing network coding approach and examined our results on these networks in a generic environment. We have formulated a standard approach for parallel networks, showing that by applying this approach effect of faulty nodes, information size and communication complexity exponentially decreases with code length.     

Experimental validation of control rod related perturbations of moderator regions in an SCWR-like fuel lattice

Two different types of perturbations of an SCWR-like fuel lattice have been investigated experimentally in the central test zone of the PROTEUS zero-power research reactor at the Paul Scherrer Institute in Switzerland. In each case, a campaign of high-resolution gamma-ray spectroscopy measurements was carried out on 34 fuel pins of the test lattice. In the first case, the test lattice was perturbed by inserting aluminum rods into the four central moderator regions, while in the second case, the perturbation was affected using steel absorber rods (instead of aluminum). The derived reaction rates are the capture rate in ²³⁸U (C₈) and the total fission rate (F_tot), as also the reaction rate ratio C₈/F_tot. Each of these has been mapped on the lattice and compared to calculated results from whole-reactor Monte Carlo simulations with MCNPX. Excellent agreement has been obtained, for both perturbed lattices, between the calculated and experimental distributions of C₈, F_tot and C₈/F_tot. Considering that control rods in an SCWR assembly are foreseen to be inserted into the central moderator regions, these results may be considered as generic validation of Monte Carlo simulations for the two different types of lattice perturbations which inserted control rods imply, viz. moderator displacement and strong neutron absorption.In a second step, calculated C₈, F_tot and C₈/F_tot distributions for the two perturbed lattices (as well as for the unperturbed lattice) have been compared, at assembly level, between MCNPX and the deterministic LWR lattice code CASMO-4E. In the case of the unperturbed lattice, as well as for the lattice with steel rods, the agreement between the codes is found to be within ～1% for all pins and each reaction rate. However, for the lattice with aluminum rods, i.e. the case with mainly just moderator displacement involved, CASMO overestimates the reaction rates in the vicinity of the perturbations by up to 2–3%, when employing the standard input options. The reason for this discrepancy has been found to be the leakage treatment, which uses the fundamental-mode buckling applied in a homogenized sense across the lattice. In this way, global leakage gradients get averaged out over the entire assembly. The optional input card BZ2 for CASMO resolves this problem, and the codes then agree within 1% even for the aluminum case.     

Simultaneous Determination of Metronidazole Benzoate Methylparaben, and Propylparaben by High-Performance Liquid Chromatography

The simultaneous determination of metronidazole benzoate (MB), methylparaben (MP), and propylparaben (PP) in an oral suspension formulation was developed using high-performance liquid chromatography (HPLC). The method was developed using a Novapak C₁₈ (3.9 × 150 mm, 4 μm) column, methanol-water (50:50, v/v) as the mobile phase and an ultraviolet (UV) detector at 254 nm. The peak area response versus concentration was linear in a concentration range from 40 to 400 μg/ml of MB, 0.8 to 8.0 μg/ml of MP, and 0.2 to 2.0 μg of PP. The correlation coefficients were 0.9997 for MB, 0.9987 for MP, and 0.9983 for PP, with relative standard errors of 1.12%, 1.28%, and 1.67%, respectively.     

Sources of elastic deformations in steel frame and framed-tube structures: Part 2: Detailed subassemblage models

This paper examines the accuracy of a set of equations for computing Displacement Participation Factors (DPFs) for beam-column subassemblages of steel moment resisting frame buildings. These factors allow the analyst to determine how the entire subassemblage or individual components of a subassemblage contribute to a given structural displacement. Additionally, the component’s contribution to displacement may be evaluated in terms of sources of axial, flexural, or shear deformation.When applied to a set of 12 isolated subassemblages, it was shown in Part 1 of the paper that deformations in the beam-column joint are very significant, and that flexural deformation in the joint, which is often ignored, should be considered in all analyses. The total displacement predicted through the use of the DPFs correlates extremely well with the results of detailed three dimensional finite element analyses of the same subassemblages. However, it was also shown that there is considerable uncertainty in the bending moments and moments of inertia that are used to compute joint flexural deformations.The objective of this paper, which is the second part of a two-part paper, is to further investigate the accuracy of the DPF expressions developed in Part 1. This is done by computing DPFs from the results of detailed three dimensional finite element analysis, and comparing these to those computed through the use of the simple expressions.The results of the analysis show that the joint flexural deformations are accurately predicted by the simple DPF expressions, but that this accuracy arises from compensating “errors” in the simplified analysis. It is also shown that the use of beam flange continuity plates has a marginal effect on computed displacements. The paper ends with recommendations for using the simplified expressions for computing subassemblage deformations, and for including such deformations in structural analysis of steel frame and tube structures.     

On the dispersion equation of Love waves in a porous layer

Summary The paper is concerned with the propagation of Love waves in a porous layer over an inhomogeneous half-space due to a point source. The dispersion equation for Love waves in a porous layer has been derived. The effects of porosity and inhomogeneity in the half-space have been shown graphically on the dispersion curves. The theory pointed out by Biot for the porous medium has been applied to solve the problem with the help of Green's function technique.With 4 Figures     

Cost analysis of a two unit priority standby system with imperfect switch and arbitrary distributions

This paper deals with cost analysis of a single server two-unit (one priority and the other ordinary) cold standby system with two modes—normal and total failure. A switch is used to operate the standby unit (ordinary) and it works successfully with known probability p( = 1 ? q). Priority unit gets preference both for operation and repair. Failure and repair time distributions are arbitrary. System fails when switch or both the units fail totally. The system is observed at suitable regenerative epochs in order to obtain reliability characteristics of interest to system designers and operations managers. Explicit results for the exponential time distributions have been obtained in particular cases.