A Fuzzy Associative Classification with Evolutionary Algorithm based Rule Selection
Authors: D. Sindhu Bairavi, Prof. R. Sumathi, P. Dhana Lakshmi
Abstract
FRBCS suffers from exponential growth of the fuzzy rule search space when the number of patterns and/or variables be-comes high. This growth makes the learning process is more difficult and, in most of the cases, it leads to problems of scalability (in terms of the time and memory consumed) and/or complexity (with respect to the number of rules obtained and the number of variables included in each rule).FARC method for high-dimensional problems, this is based on three stages to obtain an accurate and compact fuzzy rule-based classifier. This FARC method limits the order of the associations in the association rule extraction and considers the use of subgroup discovery, this is based on an improved weighted relative accuracy measure to preselect the most interesting rules before a genetic post processing process for rule selection and parameter tuning.
A High Boost DC–DC Converter for Distributed Generation System
Authors: Revathi V T, Muhammedali Shafeeque K
Abstract
High boost dc-dc converters are usually used as the front-end converters to step from low voltage to high voltage which re-quires a large conversion ratio, high efficiency and small volume. To improve the conversion efficiency and achieve a high step-up voltage gain, many step-up converters have been proposed. A high step-up voltage gain can achieved by the use of switched-capacitor and voltage-lift techniques. However, the switch will suffer high charge current and conduction loss. This paper proposes a novel high step-up ratio and clamp mode converter to achieve high step-up voltage gain and high efficiency. The proposed converter adds two capacitors and two diodes on the secondary side of the coupled inductor to achieve a high step-up voltage gain. The coupled inductor can charge the two capacitors in parallel during the switch-o period and discharge them in series during the switch-on period. However, the leakage inductor of the coupled inductor may cause high power loss and high voltage spike on the switch. Thus, a passive clamping circuit is needed to clamp the voltage level of the main switch and to recycle the energy of the leakage inductor. The switch with low resistance is adopted to reduce the conduction losses. Also, the reverse-recovery problems of the diodes are alleviated thus improving the efficiency further. The operating principle and the steady state analyses are discussed in detail. Finally, a prototype circuit with 24-V input voltage, 450-V output voltage and 200-W output power is implemented in the laboratary to verify the performance of the proposed converter. The experimental results have conformed that high efficiency and high step-up voltage gain can be achieved. The voltage on the main switch is clamped at 84-V.
A Four Quadrant control Strategy for BLDC motor Using dSPIC
Authors: Junaid Bin Muhammed, Nizam V.N
Abstract
BLDC Motors are permanent magnet Synchronous motors. The stator is having control windings and the rotor is having the permanent magnets. So the construction is like a DC motor turned inside out. When the back EMF goes higher than the supply voltage, it can be functioned like an alternator as the load will feed the supply side. The motor can be controlled in all the four quadrant of a speed torque plane without any energy lose. Control is done by dSPIC. Four Quadrant operations come when the motor is allowed to rotate in both clockwise and counter-clockwise direction. Whenever there is a change in direction, back EMF goes higher than the supply side voltage, it is called the regeneration mode. The two motoring and two regeneration interval comprises the Four quadrant. This paper intends to save and reuse of regenerated electrical energy. The energy at the regeneration interval is stored in the supply side battery which can be used further instead of wasting as heat at the load
Stability-Indicating RP-HPLC Method for the Simultaneous Estimation of Efavirenz, Tenofovir and Emtricitabine in Pharmaceutical Formulations
Authors: PSRCHNP Varma D, A Lakshmana Rao
Abstract
A simple, precise and rapid HPLC method has been developed for the simultaneous determination of Efavirenz, Tenofovir and Emtricitabine in pharmaceutical dosage form. The method was carried out using Zorbax C8 column (150 mm x 4.6 mm, 5 µm) and mobile phase comprised of mixture of dilute orthophosphoric acid solution pH 2.4±0.02 as buffer and acetonitrile in the ratio of 70:30 v/v and degassed under ultrasonication. The flow rate was 1.0 mL/min and the effluent was monitored at 252 nm. The retention times of Efavirenz, Tenofovir and Emtricitabine were 1.81 min, 2.80 min and 7.30 min respectively. The method was validated in terms of linearity, precision, accuracy, specificity, limit of detection, limit of quantitation and by performing recovery study. Linearity was in the range of 600.13 to 1800.39 µg/mL for Efavirenz, 300.54 to 900.44 µg/mL for Tenofovir and 200.46 to 601.38 µg/mL for Emtricitabine respectively. The percentage recoveries of all the three drugs were ranging from 98.2 to 101.9 for Efavirenz, 99.7 to 101.9 for Tenofovir and 98.7 to 101.6 for Emtricitabine respectively from the tablet formulation. The proposed method is suitable for the routine quality control analysis of simultaneous determination of Efavirenz, Tenofovir and Emtricitabine in bulk and pharmaceutical dosage form.
A Concise Review on Introduction to Hydrological Models
Author: Aparajita Singh
Abstract
In recent scenario of rapid urbanization and industrialization causes various changes in our natural resources like air, water, soil etc. Various problems are caused due to these changes such as drought, frequent floods, pollution, change in climate, loss of biodiversity, extinction of many varieties of flora and fauna, land use and land cover changes, degradation of land and many more. Various researches are carried out to on the topics to comate the impact of these physical changes regarding our natural resources. So there is need of reliable hydrological model which will give more compatible results with the observed parameters. It is not always true that a complex hydrological model give the more accurate output. So there was an argued that even the use of complex models does not provide better results. This paper is regarding various hydrological models, their classification and short description about them.