Electrical and Electronics

This paper discusses the ways for maintaining high availability of a system in order to keep high reliability figure. In doing so, the basic principles of reliability are discussed. Since good maintenance practice enhances availability, some important topics on maintenance management are also discussed. At the end recommendations are made on how to keep a system in a high availability state.

Positioning of nodes in ad hoc networks of vehicles in recent years is an interesting subject for research, helps to build the topologic map for car. It also provides information about places close to the car. For the open wireless communication and mobility with high -speed for a large number of vehicles, in inter- vehicle communication, authentication message, integrity and privacy of the car have been identified as the main security requirements. In this study, methods for vehicle location privacy is proposed, which include: define a switch pair and a number alias for vehicles, vehicle grouping,, select the leader for groups and finally use of several RSUs. At the end of the study, the proposed method is simulated using NS2 software, and some critical parameters of the network, are examined to see the effect of the proposed method on the network.

Differential Power Analysis (DPA) has been shown to be an effective attack in cryptographic systems capable of revealing secret data by measuring power consumption. Recent DPA resistant circuits / logics incur severe penalties in terms of area and power. This paper proposes the design of a secure logic family for DPA resistant cryptographic devices. Here the power consumption is insensitive to unbalanced load conditions thus adopting a semi-custom design flow without any constraint on the routing of the complementary wires. The proposed logic is based on a novel encoding concept where the information is represented in time domain rather than in the spatial domain as in standard dual-rail logic. In this paper, a logic family exploiting the proposed concept is simulated to show power consumption independent of the processed data and routing capacitances. It also shows an optimistic improvement in the energy consumption balancing and area reduction.

Edge truncated slot Aperture microstrip patch antenna for dual frequency operation is investigated in this paper. A simple microstrip edge fed has been used to feed the antenna and a quarter wave length transformers is used for impedance matching. The size of the antenna is reduced by 25.4% when compare to conventional square patch antenna. Design concepts with feeding methods are given along with simulated results. The antenna is showing a gain of 5.9db and a return loss of less than -10dB with VSWR<2 at both resonating frequencies.

This paper presents a multiple description coding method for HD image. The proposed method is bases on the SPIHT algorithm which provides high image compression ratio. The algorithm based on wavelet transforms and Wavelet-based compression provides multi-resolution hierarchical characteristics. This proposed method also uses poly phase sampling technique to generate multiple descriptions. The technique reduces the transmission error and memory required for storing HD images. The proposed method proved higher performances in terms of PSNR when compared to the standard SPIHT. The graph of PSNR versus BER is given in the experimental results.

Over the last three decades of the 20th century, gross domestic product per capita, exponential growth in mobile technology and population growth were the main drivers of increases in global warming and climate change. Industrial revolution and electronics, information and communication technology products have altered the landscape of modern society in countless ways, in office, at home and on mobility. However, they have created and added a new source of heat generation and emission into environment due to consumer electronics products. In spite of recent studies indicating possible threats to global climate, there is no long term data available on the amount of heat generated, emitted and dissipated into environment by cell phones. The aim of this research work is to experimentally measure the heat generated by cell phones during on(sleep/Idle) mode, Rx and Tx modes. The experiments were conducted using specially fabricated four decimal digit temperature measurement test instrument. Population and cell phones projections for India, China, USA and the whole world were also included in this research work for 2050. An attempt is made to indicate amount of heat generated, emitted and dissipated into environment by India, China, USA and entire world by cellular mobiles at present and projections for 2050.

A new model of fractal geometry for microstrip patch antenna is presented in this paper. The current fractal structure is implemented on patch aperture by placing slots in a systematic order. A commercial substrate material of RT-duroid is chosen with dielectric constant of 2.2 and loss tangent of 0.009. The dimension of the patch aperture is 56.7X42.9 mm. The simulated results show that the antenna is resonating at 2.6 GHz and 2.8 GHz, which comes under Wi-Fi application and a very good performance, is observed with respect to impedance bandwidth return loss, field distributions and radiation pattern.

Array patterns depends on type of elements, spacing between the elements and length of the array etc., conventionally elements are spaced at ?/2 in an array. However, in this paper we are made to generate the normalized radiation patterns for different spacing and different types of elements. It has been possible to control the radiation pattern by controlling the spacing between the elements. The arrays considered contain non-identical elements with non-uniform spacing. The results are useful for design of arrays to produce low side lobes for EMI suppression.

This paper investigtaes a comparative evaluation of carrier-based pulsewidth modulation (CB-PWM) methods devoted to the control of a B3-VSI, also known delta inverter, feeding an open-loop induction motor (IM) drives. Four CB-PWM methods namely: (i) sinusoidal PWM (SPWM), (ii) third-harmonic injection PWM (THI-PWM), (iii) optimal PWM (OPT-PWM), and (iv) space-vector PWM (SV-PWM) are analytically presented in order to control a delta inverter. The performance of the CB-PWM methods under consideration are firstly presented and therefore their control performances are analyzed and compared based on simulation and experimental results. The comparison is achieved by an investigation of the total and partial harmonic distortion ratios of the IM stator phase currents.

This research paper portrays the automatic energy management system. Solar energy is used as alternate renewable energy and the energy obtained from solar energy can be directly utilized as dc supply for handling dc machines. The DC power is further converted to AC with the help of inverter. This process takes place automatically with the help of advanced microcontroller. The microcontroller is programmed in such a way to detect the kind of power supply needed for machines (i.e.) whether AC or DC supply. If there is no need of power supply to the machines solar energy can be directly stored in the battery for later use. This technique is applicable for both in residential and industries purpose. For the implementation of the system PIC microcontroller is used and simulation is done by Keil C µ Vision 4 software is applied for different mode of operations. In order to reduce the bus bars and wastage of power, this system provides a solution to operate efficiently into different modes. The result of our research idea will be done in Keil C software.