Earticle

The demands for high speed applications are growing at a faster rate. To meet theserequirements, 4G technologies are being used nowadays. COFDM based WiMax is the outcome in this direction which promises to cater these high speed and high quality applications. Worldwide Interoperability for Microwave Access (WiMax) is an IEEE 802.16 standard-based broadband wireless access (BWA) technology which employsCoded orthogonal frequency division multiplexing access (COFDM). This paper analyses Bit Error Rate for WiMax based COFDM system with QPSK modulation scheme under various channel conditions like AWGN, Rayleigh, Rician and Nakagami-m. It has been observed that performance of Nakagami fading channel is better than other fading channels.

Churn prediction is an important task for Customer Relationship Management (CRM) in telecommunication companies. Accurate churn prediction helps CRM in planning effective strategies to retain their valuable customers. However, churn prediction is a complex and challenging task. In this paper, a hybrid churn prediction model is proposed based on combining two approaches; Neighborhood Cleaning Rules (NCL) and Particle Swarm Optimization (PSO). NCL is applied in the preprocessing stage for handling the imbalanced churn data; and eliminating outliers and unrepresentative data. In the next stage, a Constricted PSO is applied for developing the final prediction model. The developed model is evaluated and compared with a baseline PSO model. The proposed hybrid model is compared also with Artificial Neural Networks (ANN) and Decision trees (DT) models which are traditional and common approaches used in the literature for churn prediction. The experimental results show that the proposed hybrid model outperforms the baseline PSO model, ANN and DT in terms of accuracy and actual churn rate.

Interleukin–17E (also known as Interleukin–25) is the distinct member of Interleukin–17 cytokine family, induces the expression of IL–4, IL–5 and IL–13. Economical production of interleukin – 17E has lot of importance in the current day research in several clinical applications. The objective of the study was to optimize the physico–chemical parameters i.e., dissolved oxygen (DO) and nutritional factors i.e., carbon, nitrogen and phosphate sources on production of Interleukin–17E using industrially important salt inducible Escherichia coli GJ1158. The expression levels were not increased beyond 30 % DO in batch fermentation, but expression levels were increased beyond 30 % DO in fed-batch fermentation. The threshold level of dissolved oxygen ranges was 50 % in respect to the IL–17E production. Pulses of nutritional factors i.e., glucose, yeast extract and K2HPO4 enhanced the expression levels in fed batch fermentation at 40 % and 50 % dissolved oxygen ranges. When OD600 of the culture reaches to 74 in fed batch fermentation, culture was induced with 100 mM sterile NaCl and further incubated for next 15 hr. Purification was carried out using Ni – NTA spin column. A final concentration of 98 mg/L of purified IL–17E was obtained using cost effective medium viz., modified M9ON medium. The IL–17E thus produced is tested for its activity. In this study, fed-batch fermentation emphasizes the highest concentration of codon optimized recombinant human interleukin–17E using salt inducible expression host till to date, which manages to satisfy the industrial and clinical requirements.

The objective of this study is to use a Fuzzy Analytic Hierarchy Process (Fuzzy AHP) and geographical mapping models using Geographical Information System (GIS) to locate the most appropriate sites for solar energy farms in Shodirwan region in Iran. GIS interpolation showed that annual solar insolation in Shodirwan is very good and can be used for potential solar farm locations. The average of solar insolation in the region is 5.12 kWh/m2/day annually. Results showed that 18.25% of the Shodirwan area is exploitable as solar farms. With a conversion efficiency of 10% and area factor of 70%, annual electricity production for the exploitable area is roughly 16100 GWh. Land suitability analysis for solar farms implementation was carried out and overlay results obtained from the analysis of the resultant maps showed that 13.98% and 3.79% of the total land area demonstrate high and good suitability levels, respectively. The total electricity generation potential from both highly and good suitability levels in Shodirwan region was about 15,690 GWh annually.

This paper presents the non-linear control of an induction motor (IM). The objective of nonlinear control is to can control separately flux and the speed, several techniques of control are used for (IM), The technique of control oriented flux (FOC) whichpermits the decoupling between input and output variables, so (IM) is assimilate to continuous current motor , this method has a problem is how exactly oriented the axis d on the flux .However, feedback linearization amounts to cancelling the nonlinearities in a nonlinear system so that the closed- loop (CL) dynamics is in a linear form . A goal of feedback linearizationis to can controlled separately flux and the speed ,the motor model is strongly nonlinear then it’s composed to the autonomous and mono- variables too under systems so every under system presented an independence loop of control for each variables is given . We proposed the MRAS (system adaptive reference model) for speed and rotor fluxobserver.

Turbine blades of a gas turbine are responsible for extracting energy from the high temperature, high pressure gases. These blades are operated at elevated temperatures in aggressive environments and are subjected to large centrifugal forces. As many as 42 percent of the failures in gas turbine engines were only due to blading problems and the failures in these turbine blades can have dramatic effect on the safety and performance of the gas turbine engine. In this research paper, an attempt has been made to analyze the failure of gas turbine blade through Mechanical analysis. The blade under investigation belongs to a 30 MW gas turbine engines used in marine applications and is made of Nickel-Base superalloys. Before failure, the turbine blade was operated for about 10000 hours while its service life was expected to be around 15000 hours. Mechanical analysis has been carried out assuming that there might be failure in the blade material due to blade operation at elevated temperature and subjected to large centrifugal forces. The gas turbine blade model profile is generated by using CATIA V5R21software. The turbine blade is analyzed for its thermal as well as structural performance. It was observed that there was no evidence of rubbing marks on the tip section of turbine blade indicating the elongation of the blade is within the safe limit. Maximum stresses and strains are observed near to the root of the turbine blade and upper surface along the blade roots. Maximum temperatures are observed at the blade tip sections and minimum temperature at the root of the blade. Temperature distribution is decreasing from the tip to the root of the blade section. The temperatures observed are below the melting temperature of blade material.

In day today life we frequently come across some minor incidents occurring in case of two- wheeler. This includes problems like damage to various two wheeler parts because of vehicle slipping, collapsing, and minor dash or due to impact of heavy weight. In such cases the handle of vehicle deforms or undergoes buckling/bending. this dissertation aims at studding the deformation taking place due to buckling by analyzing the stresses and reducing this stresses by making modification in dimensions or by changing material properties of handlebar.