The limited reserves of fossil fuels and global environmental concerns over their use for electric power generation had augmented the attention in the exploitation of renewable energy resources. In particular, rapid advances in wind-turbine generator and photovoltaic technologies have brought opportunities for the utilization of wind and solar resources for electric power generation world-wide. Moreover, the economic aspects of these technologies are now adequately hopeful to also justify their use in small-scale stand-alone applications for residential use. If the development of a computer-based approach for evaluating the general performance of standalone hybrid wind-PV generating systems are analyzed and their results are reached to the common consumer with the economical analysis so that these systems can made more popular. In this paper a simulation approach has been suggested for designing Off-grid homes. Hourly average of wind speed/solar radiation data from the site is taken for the generating unit and the anticipated load data are used to predict the general performance of the generating system. The excess wind/solar-generated power, when available, is used to supply the power to the grid. Simulation studies were carried out using HOMER software. Simulation results will be given for performance evaluation of a standalone hybrid wind-PV generating unit for a residential house assumed to be located in a remote area which is analyzed as connected with grid and without connected to grid. Finally, the results obtained and methods are suggested to enhance the performance of the proposed model.

A coplanar waveguide fed asymmetric ground frequency reconfigurable antenna is designed and analyzed in this paper. The proposed antenna is occupying the compact dimension of 50X45X1.6 mm on FR4 substrate with dielectric permittivity 4.4. The designed antenna is operating in the wideband from 2 to 5.8 GHz with coverage in applications like Bluetooth, LTE, Wi-Fi and WLAN. The reconfigurable nature of the antenna is analyzed with the switching of PIN diodes placed on the antenna structure. The on and off conditions of the diodes D1 and D2 providing switching between the LTE, Wi-Fi and WLAN bands with good impedance matching. The advantage of PIN diodes includes high power handling capability, very low driving voltage and extremely low cost. Here the switch placement and control/biasing strategies depend on the type of the switch and the topology of the antenna. The prototyped antenna with biasing is providing excellent correlation with High Frequency Structure Simulator (HFSS) and Computer Simulation Technology (CST) simulation results. The reconfigurability of the antenna and its parametric optimization is analyzed and presented in this work.

This article presents the design and analysis of frequency tunable circular monopole antenna with notch band characteristics. The proposed antenna consisting of slots on the radiating element to attain notch bands in the ultra wideband (UWB). The dimensions of the slots are properly adjusted and optimized to obtain the desired band rejection response. Two PIN diodes are connected between stubs and the feed line to obtain the tenability in the notch bands. The switching operation between the diodes, controlling the length of the radiating structure and intern affecting the reconfigurable behaviour in the antenna. The overall dimension of the antenna is very compact and occupying around 44X40X1.6 mm on FR4 substrate with dielectric constant 4.4 and loss tangent 0.02. The proposed antenna initially notching WiMAX and WLAN operating bands of 3.1-3.7 GHz and 5.1-5.8 GHz and frequency tenability is analyzed with diodes switching condition to notch other communication application bands. The simulation results of reflection coefficient, radiation patterns and gain obtained from CST microwave studio and real-time measurements from prototyped antenna demonstrates the excellent working characteristics of the notch band antenna with tunable behaviour.

No abstract

Abstract:We propose a new lifetime model, called the Odd Generalized Exponential Type-I Generalised Half Logistic Distribution (OGET-IGHLD).We obtain some of its mathematical properties. We made an attempt to study some structural properties of the new distribution. The Maximum Likelihood method is used for Estimating the model parameters and the Fisher's information matrix is also derived. We illustrate the applications with generalised data.Keywords: Type-I Generalised Half Logistic Distribution, Hazard Function, Moments, Quantile, Maximum Likelihood, Estimation, Information Martix. Introduction:In life testing and reliability studies a combination of monotone and constant failure rates over various segments of the range of lifetime of a random variable is known as a bathtub or a non-monotone failure rate. In the biological and engineering sciences there are situations of non-monotone failure rates available to model such data; a comprehensive narration of the models is given in Rajarshi &Rajarshi (1988). Mudholkar, et al. (1995) presented an extension of the Weibull family that contains unimodel distributions with bathtub failure rates and also allows for a broader class of monotone hazard rates; they named their extended version the Exponentiated Weibull Family. Gupta and Kundu (1999)  and the corresponding probability distribution may be termed exponentiated or generalized versions of F(x).This generalization is adapted to the half logistic distribution and the resulting model is considered in this study. A half logistic model obtained as the distribution of an absolute standard logistic variate is a probability model of recent origin (Balakrishnan, 1985). Some well-known generators are the Marshall-Olkin generated (MO-G) by Marshall and Olkin (1997), The properties of Exp-G distributions have been studied by many authors in recent years, see Mudholkar and Srivastava (1993).There are always urge among the researchers for developing new and more flexible distributions. As a result, many new distributions have come up and studied. Recently, Tahir et al. (2015) propose a new class of distributions called the odd generalized exponential (OGE) family and study each of the OGE-Weibull (OGE-W) distribution, the OGE-Fréchet (OGE-Fr)distribution and the OGE-Normal (OGE-N) distribution. These models are flexible because of the hazard shapes: increasing, decreasing, bathtub and upside subset of down bathtub. A random variable X is said to have generalized exponential (GE) distribution with parameters α, β if the cumulative distribution function (CDF) is given by