The current issue of the IETE Journal of Research (Vol.63, No.1, January–February 2017) contains 14 articles. These articles present on-going research and developments taking place in the broad areas of Electromagnetics, Biomedical Engineering, Electrical Engineering, Microelectronics, Computer Science and Communication Engineering.
The paper ‘Computation of capacitance matrix of orbiting space-craft bodies’, gives the analysis for computing the capacitance matrix and charge distribution of a space-craft using the method of moments. This is useful in studies for charging of orbital spacecraft due to space plasma that may affect on-board electronics. The analysis is compared with data from literature for standard geometric shapes of bodies.
In the paper ‘Extracting salient features for EEG based diagnosis of Alzheimer disease using support vector machine classifier’, different features are analyzed for the diagnosis of Alzheimer's disease and using them as biomarkers. The features are based on spectral, wavelet and complexity based methods and the study is done on an experimental database. The performance of these features in classification using support vector machines is discussed in the paper.
The paper titled ‘Implementation of fractal geometry to enhance the bandwidth of CPW fed printed monopole antenna’ presents a plus shaped fractal microstrip patch antenna geometry fed by a coplanar waveguide. The purpose is to enhance the impedance bandwidth. Various aspects such as width of the fractal slot, gap between feed strip and ground plane, and length and width of coplanar ground plane has been considered in the simulation studies. The paper gives the results of experiments performed on the fabricated antenna and their comparisons with simulations.
The next paper on ‘Internet of Things based free learning system: Performance evaluation and communication perspective’, is about creating e-learning environment using the available learning resources. It assumes that the resources can be accessed without human intervention using IoT system that is controlled autonomously. An architecture consisting of smart classrooms and virtual labs using constraint application protocol and IoT framework is presented for this purpose. The feasibility of such a system is demonstrated through simulation studies.
The next paper on ‘Local oscillator phase noise model for EVM estimation and optimization’, gives a local oscillator phase noise model for a RF transceiver. The local oscillator is based on type II charge pump phase locked loop. The oscillator is studied for carrier to phase noise ratio and error vector magnitude. Numerical simulations and experimental tests on a RF transceiver chip are described.
In the paper on ‘Modelling and numerical analysis of a novel wave energy converter’, a method for extracting marine energy through offshore wave energy harvesting is presented through numerical studies. The design is based on a floating type wave energy converter with buoyancy material. Electrical power is provided through a wind turbine inside with the movement of air inside the device from one chamber to another and without outside atmosphere interactions.
The paper titled ‘NAP: A nonlinear analytical hypergraph partitioning method’, presents a hypergraph partitioning method based on nonlinear programming. The partitioning method is useful in applications such as VLSI physical design and formal verification, data mining, sparse matric multiplication. The problem is formulated analytically and solved using conjugate gradient method of optimization. The given method is compared with Chaco for benchmark problems and in terms of cuts for graph samples.
The following paper on ‘New algebraic activation function for multilayered feed forward neural networks’, gives a parametric algebraic activation function for artificial neural networks. It belongs to a family of S-curves and satisfies the properties of activation functions. It has been used on resilient propagation algorithm that is a learning technique used in feed forward artificial neural networks. The activation function has been compared with other activation functions using benchmark datasets in terms of number of epochs and testing error.
The paper titled ‘Simulation of a new technique for vibration tests based upon active vibration control’, presents a technique for generating desired transient vibrations in a structure. Finite element model is used to reduce the first three vibration modes of a cantilevered plate that is instrumented with piezoelectric sensor and actuator patches. Optimal tracking control is used to vibrate a cantilevered plate according to the desired decay curves. Simulation results are presented to show the efficacy of the technique.
The paper titled ‘Q-learning based optimized routing in biomedical wireless sensor networks’, presents a routing method for sensed information from an individual node to a remote health care station in a biomedical wireless sensor network. Such a network can be attached with an individual and communicate with remote healthcare node. The routing method has been studied in simulation setup.
The next paper ‘Quadratic optimal control with disturbance attenuation for uncertain continuous-time T-S fuzzy systems’, presents a method to synthesize non-parallel-distributed-compensation fuzzy controller to achieve objectives of prescribed disturbance attenuation level for uncertain Takagi-Sugeno fuzzy system and minimization of a quadratic integral performance index. The fuzzy system is transformed into a constrained optimization problem. A design problem of a nonlinear mass-spring-damper mechanic system is used to demonstrate the application of the method.
The paper ‘Short-term congestion management by strategic application of FACTS devices and demand response programs under contingency conditions’, presents the use of Flexible Alternating Current Transmission System (FACTS), Demand Response (DR) programs, and Generation Redispatch (GR) for congestion management and minimization of operation costs under contingency conditions in power systems. The paper presents the approaches to be prioritized in different contingencies. The method is studied on IEEE 14-bus and IEEE 30-bus test systems.
The following paper titled ‘Stabilization of the two-axis gimbal system based on an adaptive fractional-order sliding-mode controller’, presents an adaptive fractional-order sliding-mode controller in the azimuth and elevation axes for stabilization of a two-axis gimbal platform when torque disturbances are present. The paper presents numerical simulation studies to demonstrate the robustness of the control approach against moments products variations.
The final paper on ‘Synthetic grounded lossy inductance simulators using single VDIBA’ gives two circuit realizations for actively variable simulated lossy inductors that are simple and resistor less. The structure uses a single active element in the form of voltage differencing inverting buffered amplifier (VDIBA), one grounded capacitor and one electronic MOS resistor. One topology is for serial inductance while the second topology is for parallel inductance simulation. The non-ideal analyses of transfer gain and parasitic elements of VDIBA are presented along with simulation performance on TSMC 0.25 um CMOS technology.