The design and performance of different nanoelectronic binary multipliers

Journal of Computational Electronics - The design and performance of digital binary multipliers built using different types of nanoelectronic devices are investigated herein. Designs for...     

Path planning in GPS-denied environments via collective intelligence of distributed sensor networks

This paper proposes a framework for reactive goal-directed navigation without global positioning facilities in unknown dynamic environments. A mobile sensor network is used for localising regions of interest for path planning of an autonomous mobile robot. The underlying theory is an extension of a generalised gossip algorithm that has been recently developed in a language-measure-theoretic setting. The algorithm has been used to propagate local decisions of target detection over a mobile sensor network and thus, it generates a belief map for the detected target over the network. In this setting, an autonomous mobile robot may communicate only with a few mobile sensing nodes in its own neighbourhood and localise itself relative to the communicating nodes with bounded uncertainties. The robot makes use of the knowledge based on the belief of the mobile sensors to generate a sequence of way-points, leading to a possible goal. The estimated way-points are used by a sampling-based motion planning algorithm to generate feasible trajectories for the robot. The proposed concept has been validated by numerical simulation on a mobile sensor network test-bed and a Dubin’s car-like robot.     

LMI-based LSVF control of a class of nonlinear systems with parametric uncertainty: an application to an inverted pendulum system

This work centres around the stabilisation of a nonlinear system containing parametric uncertainty using a new Control Lyapunov Function (using Lie derivatives) which comes up with a linear matrix inequality-based design. The paper has three major contributions. The first one is an extension of a theorem proposed to find the convex-concave bounds of nonlinear function towards robustness. With some restrictions in the structure of the uncertainty, the theory developed here may be applied to find out the bounds of any nonlinear function with uncertainty. The next one is the main contribution of this paper in which the form of the control law obtained is linear and has several advantages from a practical point of view over almost all other nonlinear control techniques. The third one is the expansion of the proposed control scheme towards underactuated systems. To show the effectiveness of the proposed theory the controller design is attempted for both the traditional cart inverted pendulum and the more complex mobile wheeled inverted pendulum model.     

Trinary magnitude comparator using SLM based Savart plate

The demand of present technology inviting the popularity of multivalued optical computation system to coup up with the latest scenario of ultrahigh processing speed and handling large amount of data The magnitude comparator is the heart of the arithmetic and logic unit (ALU) in any logical processing and computing system. In this paper, a trinary magnitude comparator circuit has been proposed and implemented with modified trinary number (MTN) system. Optical tree architecture (OTA) of the proposed circuit has been realized reasonably using Savart plate and spatial light modulators (SLM). A simulation algorithm has also been developed and implemented to prove the authenticity of the proposed circuit through the simulation.     

Space‐time analysis of energy localization: A Poynting flow perspective with applications to pattern reconfigurable dipoles

In this paper, we explore the dynamics of electromagnetic energy, especially in the near‐field region of radiating antennas, from a fundamental perspective (ie, no limitations on antenna shape and nature of excitation signal) and identify some key future research directions. First, we provide a comprehensive critique of the frequency‐domain reactive energy and circuit‐theoretic Q‐factor based approach, which is predominantly adopted in literature. In this way, we emphasize on the importance of adopting a general time‐domain approach to characterize the near‐field electromagnetic energy of arbitrary antennas. Next, we revisit the inherent ambiguities associated with the Poynting power‐flux term in the context of electromagnetic energy, and point out the nonuniqueness of the reactive energy, conventionally obtained by subtracting the far‐field radiation density from the total electromagnetic energy density around antennas. Furthermore, we discuss the concept of Poynting localized energy and its potential integration with FDTD techniques, and investigate its space‐time behavior for a Yagi‐Uda principle based pattern reconfigurable dipole system.     

A Hybrid Offline-Online Approach to Adaptive Downlink Resource Allocation Over LTE

Radio resource management mechanisms in current and future wireless networks is expected to face an enormous challenge due to the ever increasing demand for bandwidth and latency sensitive applications on mobile devices. This is because an optimal resource allocation scheme which attempts to multiplex the available bandwidth in order to maximize Quality of service (QoS), will pose an exponential computational burden at eNodeB. In order to minimize such computational overhead, this work proposes a hybrid offline-online resource allocation strategy which effectively allocates all the available resources among flows such that their QoS requirements are satisfied. The flows are firstly classified into priority buckets based on real-time criticality factors. During the offline phase, the scheduler attempts to maintain the system load within a pre-specified safe threshold value by selecting an appropriate number of buckets. This offline selection procedure makes use of supervisory control theory of discrete event systems to synthesize an offline scheduler. Next, we have devised an online resource allocation strategy which runs on top of the offline policy and attempts to minimize the impact of the inherent variability in wireless networks. Simulation results show that the proposed scheduling framework is able to provide satisfactory QoS to all end users in most practical scenarios.      

Optimizing MapReduce for energy efficiency

The efficient use of energy is essential to address concerns of cost and sustainability. Many data centers contain MapReduce clusters to process Big Data applications. A large number of machines and fault tolerance capabilities make MapReduce clusters energy inefficient. In this paper, we present a Configurator based on performance and energy models to improve the energy efficiency of MapReduce systems. Our solution is novel as it takes into account the dependence of the performance and energy consumption of a cluster on MapReduce parameters. While this dependence is known, we are the first to model it and design a Configurator to optimize these parameter settings for maximizing the energy efficiency of MapReduce systems. Our empirical evaluations show that the Configurator can result in up to 50% improvement in the energy efficiency of typical MapReduce applications in two architecturally different clusters.     

Influence of combined electromagnetohydrodynamics on microchannel flow with electrokinetic effect and interfacial slip

We investigate analytically the combined consequences of electromagnetohydrodynamic forces and interfacial slip on streaming potential mediated pressure-driven flow in a microchannel. Going beyond traditional Debye–Hückel limit, we first derive a closed-form analytical solution for velocity field by considering nonlinear electrical potential distribution, wall slip effects, externally imposed transverse magnetic field, and laterally applied electric field in the plane of flow. The effects of electrical double-layer (EDL) formation and the consequent interfacial phenomena are critically examined under such situations. An expression for induced streaming potential in the microchannel is deduced considering EDL formation and the consequences of finite conductance of the immobilized Stern layer. This simplified analytical expression is later on critically assessed against three-dimensional simulation paradigm of streaming potential mediated flows, which is a first effort of this kind. We demonstrate that flow rate increases progressively with increasing surface potential and eventually approaches to a limiting value. Combination of electromagnetohydrodynamic effect with liquid slip is shown to amplify the flow rate, even at lower values of surface potential. Our study brings out the possibility of achieving an optimum flow rate by judicious application of combined electromagnetohydrodynamics. The present analysis has significant consequence in the design of advanced microfluidic devices with improved efficiency and functionality.     

Error probability independent delay analysis of single electronics circuits

This study based on Poisson process and orthodox theory of single electron tunneling for the first time proposes an error probability independent delay model for delay calculation of single electronics circuits, involving multiple tunneling events. The Poisson process assumes that the tunneling events are independent of each other, but in real single electronics circuits they are correlated through space and time, so this effect has been considered and included in the proposed model. The dependence of tunneling rates on the logic transition is thoroughly investigated. Finally, the model is applied to different logic gates, and the result is compared with the well known Monte Carlo approach to prove the accuracy of the proposed model.     

The role of yield stress on cracked thin panels of aluminum alloys repaired with a fRP patch

The aim of this study was to explore the effect of the yield stress of the cracked thin panels of aluminum alloys panel, repaired with one sided fiber reinforced polymer (FRP) patch, on the performance of the repair. Various different grades of aluminum alloys with thickness in the range of 1–1.3 mm were used as the skin material. The numerical simulation of the experimental results was done through ANSYS 15.0, using a cohesive zone material model (CZM model) at the interface of the skin and the patch. The effect of the far field applied stress was analyzed to simulate the initiation and the separation of the patch. In all the six cases, undertaken in this study, the patch separation occurred when the applied stress exceeded the yield stress of the skin by a small percentage. Even in the thinnest patch with its stiffness ratio of 0.28, the patch separated when the applied stress exceeded the yield strength of the skin material. In all the cases, the shear stress at the interface caused the slippage between the patch and the skin at the leading edge of the patch.