Journal of Electrical & Electronic Systems

In this work a new method of signature recognition with neural network is proposed. The features are extracted from two raw databases of ATVS signature database: one consisting of 25 signature samples of 350 persons and other 46 signatures of 25 persons. The features include 9 features computed by DS Guru and HN Prakash and proposed features are no of pen downs, magnitude of average velocity, magnitude of average acceleration and length to height ratio. Signature features are pre-processed with a scaling method and brought to a value having same decimal point. A feed forward neural network is trained using back propagation learning method. With each features removed, an accuracy rate is calculated to check the feature which will be better for signature verification. Accuracy of recognition up to 98% and 89% are obtained using signature samples of 10 persons from each database respectively.

Hard switching specifies the stressful switching behavior of the controlled switches. During the turn-off and turn-on processes, the power electronic device has to withstand high current and voltage simultaneously, resulting in high stress and switching losses. The switching loss is directly proportional to the switch frequency, thus reducing the maximum switch frequency of the power electronic converter. The concept was to incorporate resonant tanks in the converters to create oscillatory (usually sinusoidal) voltage and/or current waveforms, so the zero current switching (ZCS) or zero voltage switching (ZVS) conditions can be achieved for the power control switches. The Soft-switched power converters are generally utilizing the resonance condition. Resonance condition is generally occurred just during the turn-off and turn-on processes, so as to create ZCS and ZVS across each switch. The Regulated three and five multiple-output dc-dc converter under zero-voltage switching (ZVS) condition is proposed. The converter is consists of three outputs altogether. With the help of two asymmetric half bridge converters, the first and second outputs are controlled. Based on the phase shift between two asymmetric half bridge converters, the third output is controlled. At high switching frequency, these multiple-output dc–dc converters can give higher efficiency. The various stages of operation, soft switching condition and controlling schemes are also explained. A closed loop and open loop control techniques of the three multiple output converter is explained.

The signal based hospital communication system is focused at enhancing effective communication and monitoring of patients by the health officer within the premises of the hospital. It is simple in design, effective and serviceable with the wired logic approach while the use of radio waves for the final link was avoided because of the inherent danger to human health. The various units consisting of power supply, multivibrators, logic gates and indicating system for lighting were designed to specification putting in mind the relevance and availability of parts. The prototype was constructed and testing was made contiguous to the hospital situation.

Space-time block codes alone generally have little or no coding gain. To extract coding gain, space-time block codes have been previously concatenated with an outer trellis to generate simple and powerful codes, recognized as superorthogonal codes. That work has two main themes: it explores methods and algorithms that generate coding gain in block codes exclusive of a trellis, as glowing as improve the coding gain in the presence of a trellis. At what time an external trellis is obtainable, our results simplify the super-orthogonal codes by finding new code supersets and corresponding set partitioning, resulting in improved coding gain. New algorithms are developed to efficiently build trellises for various full-rate MIMO codes, for that reason they extend the concept of trellis-block MIMO coding beyond orthogonal and quasi-orthogonal codes. In the absence of a trellis, a technique called single-block coded modulation is proposed to improve the coding gain of all varieties of space-time block codes. In that thesis they discuss coded modulation schemes designed for multiple antenna wireless channels without information of the channel at the transmitter. Space-time coding reduces the detrimental effect of channel fading. The space-time receiver takes advantage of diverse propagation paths between transmits and receive antennas to improve the performance of wireless communication. It contains a literature survey of the recent developments in MIMO signaling. The main types of spacetime codes are block and trellis codes. Space-time block codes (STBC) operate on a block of input symbols, producing a matrix output. Space-time block codes do not generally provide coding gain. Their main feature is the provision of diversity with a very simple decoding scheme. Concatenation of orthogonal space-time block codes (OSTBC) with an outer trellis has led to simple and powerful codes, known as super-orthogonal codes or STB-TCM.

The ARM7 controller is used in many applications. In this paper it is used as the core controller, to control the entire vehicle. A voice recognition module will be used for human interaction with the vehicle. This module will be at the transmitter side i.e. with the person, which gives the desired commands. The controller used at the transmitter side is PIC controller. This signal will be received by the controller at the receiver end placed on the vehicle for controlling. In controlling mainly four operations will be performed i.e. forward, stop, left, right in this prototype. To provide safety IR sensors will be used which gives feedback at the receiver end whenever there is any obstacle. For real time operation μcos-ii will be used to enhance the performance of system.

Optical thin film can control the reflection, refraction and transmission of specific wavelength of electromagnetic radiation and have numerous applications such as reflector, anti-reflector, attenuator, photovoltaic cell and refractor in the electromagnetic radiation spectrum. To perform the particular function for which they are designed, precise control of various film parameters such as thickness, composition, roughness, uniformity is necessary. Silicon dioxide, Zinc oxide, Zinc telluride are the most promising materials in optoelectronic and optical applications in the visible region as well as in the infrared and UV region. In this research, the optical properties such as spectral reflectance and transmittance of nano-scale optical thin films have been studied and analyzed for those materials on different substrates to obtain the optimal configuration for the best performance. To obtain this, the equations of reflectance and transmittance for thin film have been derived, then simulated and visualized by Matlab code. By changing film materials, substrates and film thickness, transmittance and reflectance characteristics have been observed and analyzed. The result showed that the reflectance and transmittance characteristics of optical thin film are strongly dependent on the wavelength of electromagnetic spectra. The film and substrate materials are very effective on the reflectance and transmittance characteristics of the optical thin films. It is also found that the reflectance and transmittance characteristics are greatly affected by film thickness. This research work will benefit and enhance the value of nano coating technology to determine the best thin film/substrate configuration in the development of micro- and nano optoelectronic devices.

Energy efficiency is one of the most important design goals for wireless sensor networks (WSNs). To this effect, clustering is mostly used to prolong the lifetime of WSNs. In this study, we propose a new energy efficient (EE) clusteringbased protocol for single-hop, heterogeneous WSNs. The proposed protocol uses channel state information (CSI) in the selection process of Cluster Heads (CHs). It is shown through simulations in MATLAB that the proposed protocol has 1.62 to 1.89 times better stability period than that of a well-known protocols including LEACH, DEEC, and SEP.

Tellurium has gained significant attention due to its photoconductivity, piezoelectricity, and thermo conductivity properties. The aim of this study was to evaluate the effect of biofield energy treatment on thermal, physical and atomic properties of tellurium powder. The tellurium powder was equally divided in two parts: control and treated (T). The treated part was subjected to Mr. Trivedi’s biofield energy treatment, whereas the control part was remained untreated. Subsequently, the control and treated samples were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy. The DSC data showed that latent heat of fusion was decreased by 14.13, 21.90, and 5.55% in treated samples T1, T2, and T3, respectively as compared to the control. However, the melting temperature did not show any change in treated samples as compared to the control. The TGA data showed that the peak width (difference in onset and endset) was increased from 213.67°C (control) to 234.82°C in treated tellurium sample. Besides, XRD results exhibited an alteration in lattice parameter, unit cell volume, density, atomic weight and nuclear charge volume of the treated tellurium powder as compared to the control. In addition, the crystallite sizes were significantly changed on crystalline plane (102) and (110) as 146.05→48.67 nm and 63.01→88.21 nm, respectively in the treated tellurium. The FT-IR spectra did not show any significant change in absorption frequencies in treated sample as compared to the control. Therefore, DSC, TGA and XRD data suggested that Mr. Trivedi’s biofield energy treatment has significantly altered the thermal and physical properties of tellurium powder. Thus, biofield energy treatment could be applied to modulate the thermal and physical properties in semiconductor and chalcogenide glass industries.