Defence Science Journal
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Performance Analysis of One Model of Communication and Information System in Military Operation
Get PDFThis paper presents a model of communication and information system in military operations. Here OPNET MODELER simulation package is applied because it is suitable for network modelling, topology and capacity planning. Simulation of different types of IP traffic and monitor their performance to optimise the functionality of network elements, management performance network applications, and as well as in research and development of new network technologies. Application of the method of mass service are determined by the capacity needed for voice transmission on the links in the model and using the OPNET MODELER simulation program are analysed performance modeled communication information system in data transmission. The results of the simulation are presented through target the service settings: workload links communication and information system, e-mail download response time, http page download response time and packet loss in data transfer. The aim of the research has shown that modeled communication information system with defined elements (nodes), the capacity of links (according to the specification of telecommunication devices) and defined traffic can respond to the requirements of command forces in the military operation in terms of telecommunication service. The results of the analysed service target parameters show that modeled communication and information system provides an efficient flow of information and the tra nsfer of voice and IP data for the needs of command and control in military operations
A Novel Method to Develop High Fidelity Laser Sensor Simulation Model for Evaluation of Air to Ground Weapon Algorithms of Combat Aircraft
Get PDFSuccessful release of any air to ground weapon from a combat aircraft is determined based on the positional parameters received from the sensors and the mission cues. Laser designated pod is one of the most sought weapon sensor, which gives the accurate data for Air to Ground weapon aiming. Laser designated pod being hardware intensive system, works with real world environment, it increases the development and integration effort towards finalising the weapon aiming algorithms and also pilot vehicle interface requirements. A novel method using mathematical models and the atmospheric error models is proposed to develop a high fidelity laser designated pod simulation model for functional and performance evaluation of weapon algorithms. The factors affecting the weapon trajectory computations are also considered in the sensor model outputs. The sensor model is integrated in the high fidelity flight simulator, which consists of both aircraft and Real world systems either as actual or simulated for close loop pilot evaluation. The behaviour of the sensor model is cross validated and fine-tuned with the actual sensor output and confirmed that the developed laser designated pod sensor simulation model meets all the requirement to test the air to ground weapons in the flight simulator
Fast 3D Integrated Circuit Placement Methodology using Merging Technique
Get PDFIn the recent years the advancement in the field of microelectronics integrated circuit (IC) design technologies proved to be a boon for design and development of various advanced systems in-terms of its reduction in form factor, low power, high speed and with increased capacity to incorporate more designs. These systems provide phenomenal advantage for armoured fighting vehicle (AFV) design to develop miniaturised low power, high performance sub-systems. One such emerging high-end technology to be used to develop systems with high capabilities for AFVs is discussed in this paper. Three dimensional IC design is one of the emerging field used to develop high density heterogeneous systems in a reduced form factor. A novel grouping based partitioning and merge based placement (GPMP) methodology for 3D ICs to reduce through silicon vias (TSVs) count and placement time is proposed. Unlike state-of-the-art techniques, the proposed methodology does not suffer from initial overlap of cells during intra-layer placement which reduces the placement time. Connectivity based grouping and partitioning ensures less number of TSVs and merge based placement further reduces intra layer wire-length. The proposed GPMP methodology has been extensively against the IBMPLACE database and performance has been compared with the latest techniques resulting in 12 per cent improvement in wire-length, 13 per cent reduction in TSV and 1.1x improvement in placement time
Modified Low Rank Approximation for Detection of Weak Target by Noise space Exploitation in Through Wall Imaging
Get PDFLow dielectric materials referred as weak targets are very difficult to detect behind the wall in through wall imaging (TWI) due to strong reflections from wall. TWI Experimental data collected for low dielectric target behind the wall and transceiver on another side of the wall. Recently several researchers are using low-rank approximation (LRA) for reduction of random noise in the various data. Explore the possibilities of using LRA for TWI data for improving the detection of low dielectric material. A novel approach using modification of LRA with exploiting the noise subspace in singular value decomposition (SVD) to detect weak target behind the wall is introduced. LRA consider data has low rank in f-x domain for noisy data, local windows are implemented in LRA approach to satisfy the principle assumptions required by the LRA algorithm itself. Decomposed TWI data in the noise space of the SVD to detect the weak target adaptively. Results for modified LRA for detection of weak target behind the wall are very encouraging over LRA
Ballistic Protection of Military Shelters from Mortar Fragmentation and Blast Effects using a Multi layer Structure
Get PDFIn addition to its usage as a top attack ammunition in the battle field against troops, 120 mm mortar bomblethas been recently used in the terror attacks against military shelters and civil constructions. This research studiesthe protection of vehicle and personnel military shelters against mortar fragmentation warhead projectile and it’sdestroying effects. The mortar warhead threat combines both blast load and ballistic fragment penetration effects. Composite structure layers are proposed herein to be integrated with concertina walls to achieve full protection against the mortar projectile destroying effects. The current paper investigates the ability of the proposed layers to stop the mortar’s fragments and to mitigate its blast load. The velocity and the mass distribution of the produced projectile fragments were estimated using Split-X software. Besides, the ability of the proposed protection layers to stop the fragments and mitigate the blast wave was evaluated using AUTODYN hydrocode. A static firing test was then performed to validate the theoretical results and verify the effectiveness of the proposed protection added layers. The current study showed that the proposed composite layers are sufficient to protect the military shelters from the mortar’s destroying ballistic effects
Behavioural Fault tolerant control of an Omni directional Mobile Robot with Four mecanum Wheels
Get PDFThis paper analyses the four-mecanum wheeled drive mobile robot wheels configurations that will give near desired performance with one fault and two faults for both set-point control and trajectory-tracking (circular profile) using kinematic motion control scheme within the tolerance limit. For one fault the system remains in its full actuation capabilities and gives the desired performance with the same control scheme. In case of two-fault wheels all combinations of faulty wheels have been considered using the same control scheme. Some configurations give desired performance within the tolerance limit defined while some does not even use pseudo inverse since using the system becomes under-actuated and their wheel alignment and configurations greatly influenced the performance
Selection of Core shell Material based Electromagnetic Wave Absorbers in 2 to18 GHz using TOPSIS and VIKOR Ranking Methods
No full textElectromagnetic (EM) wave has become an integral part of this electronics dominated era with extensive application in wireless communication, health care, and military applications. This has led to the development of EM wave absorbers for camouflaging the military warheads from the enemy radar tracking systems. The development of these absorbers requires considerable resources viz. time, energy, raw materials and cost. This creates a need for selection of a better absorber from the existing ones rather than the development of a new one to save the valuable resources. The judicious selection of an efficient microwave absorber requires ranking the existing absorbers based on selection criteria. For the first time, an attempt has been made to apply the concept of multi-criteria decisionmaking methods viz. VIKOR and TOPSIS in ranking the microwave absorbers. Core-shell materials provides enhanced EM wave attenuation owing to their hierarchical composite structure which provides a better approach to tune the dielectric and magnetic properties of the composite for obtaining good impedance matching resulting into enhanced absorption. In the present work, magnitude of minimum reflection co-efficient value, absorber thickness, deviation from the central frequency (i.e. 10 GHz) and -10 dB bandwidth have been selected as the criteria for judiciously selecting suitable core-shell based EM wave absorbers in 2-18 GHz. The selected criterion has been assigned distinct weights using Analytic Hierarchy Process (AHP). The AHP derived weights have been employed in TOPSIS and VIKOR analysis for the absorbers ranking and selection
Standoff Detection and Identification of Explosives and Hazardous Chemicals in Simulated Real Field Scenario using Time Gated Raman Spectroscopy
Get PDFThe detection of hazardous chemicals, explosives, improvised explosive materials, energetic materials and their associated compounds for security screening, forensic applications and detection of unexploded ordnance is an active area of research. The results based on comprehensive experimental study and performance of time gated Raman spectroscopy (TGRS) for stand-off detection of explosives and hazardous chemicals under realistic scenario are presented. Representative results drawn from the experimental study for detection of explosives and hazardous chemicals in simulated real field scenario are given
Recent Advancements in Study of Effects of Nano Micro Additives on Solid Propellants Combustion by Means of the Data Science Methods
Get PDFThe efforts of Russian-Indian research team for application of the data science methods, in particular, artificial neural networks for development of the multi-factor computational models for studying effects of additive’s properties on the solid rocket propellants combustion are presented. The possibilities of the artificial neural networks (ANN) application in the generalisation of the connections between the variables of combustion experiments as well as in forecasting of “new experimental results” are demonstrated. The effect of particle size of catalyst, oxidizer surface area and kinetic parameters like activation energy and heat release on the final ballistic property of AP-HTPB based propellant composition has been modelled using ANN methods. The validated ANN models can predict many unexplored regimes, like pressures, particle sizes of oxidiser, for which experimental data are not available. Some of the regularly measured kinetic parameters extracted from non-combustion conditions could be related to properties at combustion conditions. Results predicted are within desirable limits accepted in combustion conditions
Selection of Pressure Angle based on Dynamic Effects in Asymmetric Spur Gear with Fixed Normal Contact Ratio
Get PDFAsymmetric spur gears are finding application in many fields including aerospace propulsion and automobile which demand unidirectional or relatively higher load on one side of the gear flank. Design intend to maximise the load carrying capacity of the drive side of asymmetric gear by increasing the pressure angle is achieved at the expense of coast side capacity. Multiple solution for coast to drive side pressure angle exist for a given contact ratio and each of these have relative merits and demerits. In the present work asymmetric spur gears of theoretically equal contact ratio as that of corresponding symmetric gears are selected to investigate the change in gear tooth static transmission error and dynamic behaviour with coast and drive side pressure angle. Study shows that dynamic factor of normal contact ratio asymmetric spur gears below resonance speed are relatively lower than corresponding symmetric gears of same module, contact ratio, number of teeth, coast side pressure angle and fillet radii. Results also show that, coast and drive side pressure angle can be suitably selected for a given contact ratio to reduce the single tooth and double tooth contact static transmission error and dynamic factor of asymmetric spur gears