Response of a Stretched String Subjected to a Moving Mass

In this paper, the dynamics of a taut horizontal string with a constant velocity moving mass including its rotary inertia, is modelled. The equation of motion is solved using Galerkin’s approach, employing appropriate comparison functions. A discontinuity or jump in the trajectory of the mass has been established when the mass is about to leave the string. The consideration of rotary inertia in the model is found to affect the spatial location of the jump in the trajectory of the moving mass

A High Performance Parallel Approach to Delay Sum Beamformer in a Homogeneous Multicore Environment

A Cache-Aware Beamformer (CABF) algorithm for the DAS beamformer in a homogeneous multicore processor environment is presented. The context of the proposed algorithm is established by discussing the case for a refined multicore implementation of the beamformer algorithm for a sonar application. The algorithm is designed, implemented, and compared to a regular pthread multicore implementation and a standard OpenMP-based implementation, using arithmetic intensity as the metric. FMA implementations of the algorithms are carried out, and the CABF algorithm is shown to achieve a better arithmetic intensity. A 6000-element array is designed with a simultaneous forming of 200 beams to test the efficacy of cabf in a multicore platform. The results show a 73 % increase in GFLOPS for FMA operations. The performance of the beamformer algorithm for different data sizes is studied, and on average, a 36 % improvement in computational performance is achieved compared to the OpenMP-based implementation

Novel Selective Maintenance Approach to Ensure Mission Reliability of Armored Vehicles Considering Multiple Deployment Roles in Distinct Operating Profiles

Given the gravity of the element of surprise in modern warfare, military forces worldwide are constantly attempting to achieve and maintain operational readiness of their critical military equipment. Selective Maintenance (SM) is considered an effective approach for achieving system operational readiness. Effective use of the SM approach for military equipment requires considering various military-specific factors such as multiple deployment roles, distinct operating profiles, human reliability, and the use of refurbished or non-OEM spares. This makes the SM approach for military systems very challenging. This paper presents an approach that formulates the SM problem intending to achieve and maintain the required level of operational readiness for predefined future missions from a military viewpoint. This approach employs a novel methodology that estimates the mission reliability of military equipment while modeling the combined impact of several important military-specific factors. This complex yet necessary integration of various military-specific factors makes the present approach accurate and apt to the exact modus operandi of the armed forces. The developed approach is demonstrated for the maintenance of armored vehicles deployed on distinct missions under different operating conditions. Numerical investigations illustrate the efficacy of the present approach and highlight its advantages over the conventional maintenance approach

Unscented Kalman Filters Integrated with Deep Learning Approaches for Active Sonar Based 2D Underwater Target Tracking

This manuscript proposes a new approach to track 2D targets using a combination of machine learning algorithms and the Unscented Kalman filter (UKF). The approach makes use of active sonar sensors to measure range and bearing, which are used to predict the target’s course and speed. So far in the literature of target tracking, researchers assumed covariance matrix of the noise in sonar measurements. In this manuscript, it is tried to estimate the same using deep learning algorithms. The Machine Learning algorithms, such as multilayer perceptron, convolutional neural network, long-short term memory, and gated recurrent unit, are employed to approximate the covariance of the noise in the input measurements. Simultaneously, the Unscented Kalman Filter (UKF) is utilised to mitigate the noise in the measurements and to estimate the position and speed of the target. The results are quantified through Monte Carlo simulations in a simulated underwater environment. The measurements are assumed to conform to a normal Gaussian distribution with a mean of zero. The findings indicate that LSTM has superior performance compared to the other models. Nevertheless, it is important to note that the results are constrained in their applicability due to the restricted set of variables employed for training the machine learning models

Fractal Inspired Hybrid Microstrip Patch Antenna for Surveillance Drone Applications

          Drone based surveillance and communication systems are playing a vital role in modern days for both military and civilian applications. Antennas with low profile, smaller size, and light weight are essential for the realization of these systems. A novel fractal-inspired hybrid microstrip patch antenna realized with Sierpinski gasket fractal slots cut in the radiating patch along with corresponding ground structure simultaneously defected with Sierpinski carpet fractal slots is reported for the first time. The antenna resonates at 2.4 GHz with a measured return loss of 17 dB, gain of 7 dB and measured 3 dB beamwidth is of the order of 70 deg. The current approach leads to the size reduction of the antenna to the extent of 55% in comparison to standard radiating patch antenna resonating at the same frequency. The fractal-inspired hybrid microstrip patch antenna is a promising candidate for drone-based surveillance and communication applications owing to its miniaturization and good directional radiation properties

Advances in Solid Mechanics and Composites

Applied mechanics is a scientific discipline that focuses on the study of various laws of mechanics and their application in solving engineering problems. The Indian Society for Applied Mechanics (ISAM) organizes conferences focused on various areas of applied mechanics, encompassing solid mechanics, fluid mechanics, and biomechanics. The fifth Indian Conference on Applied Mechanics (INCAM-2022) was jointly organized by the Department of Mechanical Engineering, National Institute of Technology (NIT) Jamshedpur, and ISAM during November 11-13, 2022 at Jamshedpur in India. It provided a technical platform for researchers and academicians to present their research work and discuss the broad field of applied mechanics........

A Comprehensive Review of Dimensionality Reduction Techniques for Real time Network Intrusion Detection with Applications in Cybersecurity

This paper reviews popular signature and anomaly-based intrusion detection systems (IDS). Dimensionality reduction techniques (DRT) are used to increase the efficiency of such systems for real-time operation. Autoencoder-based IDS is rapidly gaining in popularity, primarily due to its inherent ability to denoise data and reduce dimensionality. In addition to the efficiency, we also look at the classification techniques used by various authors, and the overall impact of a model in terms of performance metrics. This article is written for novices in cybersecurityto get a jumpstart on the latest IDS algorithms. The purpose is to give useful insights into the broad and progressive view of various techniques in wide use, expose high-impact future research areas and to summarize classic IDS methods and feature selection techniques

Radiation Behavior of Synthesized LiTi Ferrite Based Microstrip Antenna in X Band

The paper comprehensively explores the development, characteristics, and antenna applications of lithium titanium (LiTi) ferrite. Utilising a solid-state reaction technique, the study examines the substrate’s electrical, magnetic, and structural properties in detail. Additionally, it assesses the far-field radiation patterns of a magnetically-biased LiTi ferrite-based antenna. Key findings point to a noticeable reduction in mutual coupling and radiated power, along with an isotropic redistribution of minor side lobes. Comparative analysis with RT-duroid substrates in X band frequency spectrum highlights the LiTi ferrite-based antenna’s remarkable 62.85 % miniaturization and consistent directivity, along with a superior quality factor. These findings emphasise LiTi ferrite’s potential for compact, high-performance applications in demanding environments. LiTi ferrite’s advantages in miniaturisation and stability position it for specific applications, despite trade-offs in bandwidth, gain, and impedance compared to RT-duroid substrates

Effect of Thermodiffusion on Non Premixed Flame in MILD Regime Using a Modified Reacting Solver

Numerical simulations for moderate and intense low oxygen dilution (MILD) combustion with essential solvers and detailed mechanisms involve more complications and computational time. Various advanced combustion modeling techniques have recently been developed to study MILD combustion characteristics. However, every combustion model has specific issues predicting the temperature and emissions of the MILD combustion flames. The diffusive nature of the MILD flame is considered, and individual Lewis numbers are investigated on a non-premixed flame. The current study analyzes the methane/hydrogen flame propagation with different Lewis number combinations in a hot co-flow environment.Individual Lewis numbers for methane and hydrogen are investigated from stochiometric to ultra-rich mixtures in non-premixed flames. Several numerical simulations are performed in the OpenFOAM9 environment using a modified EDC model with tuned turbulence and combustion model constants. The numerical simulation results with hydrogen and methane Lewis numbers of 0.4 and 0.9, respectively, show promising agreement with the experimental findings of Dally et al. [1]. Various combustion parameters are studied with different CH4 and H2 Lewis number combinations. In addition, the unity Lewis number case is simulated and compared to the situations that are taken into consideration

Performance Evaluation of DGNSS Receiver for Dynamic Military Applications

In military applications, a highly accurate and precise navigation system is necessary for some ground-based combat system applications to navigate the vehicle and mark the location of the fuses and pickets laid by the mobile equipment. Few companies across the globe have developed expertise in manufacturing Global Navigation Satellite System (GNSS) receivers with Real Time Kinematics (RTK) capability along with integrated INS. On mobile equipment, it is not always possible to precisely place the Differential GNSS (DGNSS) antenna and GNSS receiver at the point for which the data needs to be marked. For such applications, lever arm calculation needs to be implemented. Also, due to uneven terrain conditions and slopes, the vehicle undulates up to 10o about its longitudinal and transverse axis. This dynamic condition induces considerable errors in the actual data. During the fuse laying process, there is also a continuous requirement for real-time location data in the GNSS-denied environment for a short period. INS was integrated with the GNSS receiver. We discuss test methodology for GNSS receiver performance evaluation. Experimentations were performed, taking into consideration these requirements. Data collected are also analyzed and discussed. Test results confirmed that the module is accurate with an accuracy of a few centimeters