Faculty Publications
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Item Comparison of two near-field blast vibration estimation models: A theoretical study(CRC Press, 2012) Arora, S.; Murmu, P.; Dey, K.Blast-induced rock damage has been directly related to blast vibration by many researchers. The common measurement of blasting vibration is in terms of peak particle velocity (PPV). The levels of peak particle velocity at which the rock damage occur are termed as threshold levels of PPV for rock damage. As rock damage is a phenomena occurring very close to the blast holes (<1 m), the peak particle velocity levels at the point of damage cannot be measured directly. Thus, the threshold levels of peak particle velocity for rock damage are estimated by using different near-field blast vibration estimation models. These models essentially use the vibration predictors established from the vibration measurements taken at a safe distance. The most common two techniques of near-field vibration estimation models are the mathematical summation of peak particle velocity resulting from the elemental charge column and the integrated peak particle velocity for the charge length i.e., zero to charge height. However, till date the scope of application of near-field estimation models is limited to single-hole blast only. This paper incorporates a review of the near-field blast-vibration estimation models. Apart from this, an extension of a near-field vibration estimation model for a row of periphery holes is also presented. A theoretical comparison is also made in between single-hole model and row of holes model for estimating the threshold peak particle velocity levels for overbreak in a drift. Similarly, the damage profiles for both the cases are also developed and presented. © 2013 by Taylor & Francis Group, LLC.Item Comparison of two near-field blast vibration estimation models: A theoretical study(2013) Arora, S.; Murmu, P.; Dey, K.Blast-induced rock damage has been directly related to blast vibration by many researchers. The common measurement of blasting vibration is in terms of peak particle velocity (PPV). The levels of peak particle velocity at which the rock damage occur are termed as threshold levels of PPV for rock damage. As rock damage is a phenomena occurring very close to the blast holes (?1 m), the peak particle velocity levels at the point of damage cannot be measured directly. Thus, the threshold levels of peak particle velocity for rock damage are estimated by using different near-field blast vibration estimation models. These models essentially use the vibration predictors established from the vibration measurements taken at a safe distance. The most common two techniques of near-field vibration estimation models are the mathematical summation of peak particle velocity resulting from the elemental charge column and the integrated peak particle velocity for the charge length i.e., zero to charge height. However, till date the scope of application of near-field estimation models is limited to single-hole blast only. This paper incorporates a review of the near-field blast-vibration estimation models. Apart from this, an extension of a near-field vibration estimation model for a row of periphery holes is also presented. A theoretical comparison is also made in between single-hole model and row of holes model for estimating the threshold peak particle velocity levels for overbreak in a drift. Similarly, the damage profiles for both the cases are also developed and presented. © 2013 Taylor & Francis Group.Item Performance comparison of executing fast transactions in bitcoin network using verifiable code execution(IEEE Computer Society help@computer.org, 2013) Singh, P.; Chandavarkar, B.R.; Arora, S.; Agrawal, N.In this paper, we study Bitcoin network for electronic cash transactions, and compare the extension to the BTCs network which inculcates provision of executing fast transactions with greater security and assurance with the former method of Proof-Of-Work for executing transactions. Above milestones are achieved by introducing the concepts of mutual trust and verifiable code execution between the payer and the payee in the network. Our work proposes a significant modification of the Pioneer model to provide a two-party trust framework for Bitcoin transactions; considerably faster compared to the generic trust platform of Bitcoin networks based on slow proof-of-work. The scheme proposed can promote the use of Bitcoin transactions in real life scenarios, where fast transactions are desirable due time constraints between the payment and the service. © 2013 IEEE.Item Adaptive Selection of Cryptographic Protocols in Wireless Sensor Networks using Evolutionary Game Theory(Elsevier B.V., 2016) Arora, S.; Singh, P.; Gupta, A.J.Game theory applies to scenarios wherein multiple players with contrary motives contend with each other. Various solutions based on Game theory have been recently proposed which dealt with security aspects of wireless sensor networks (WSNs). However, the nodes have limited capability of rationality and evolutionary learning which makes it unfavorable to apply conventional game theory in WSNs. Evolutionary Game Theory (EGT) relies on bounded rationality assumption which is in harmony with the wireless sensor networks characteristics. Based on EGT, authors propose an adaptive security model for WSNs for the selection of cryptographic protocols during runtime. The authors formulate this selection in WSNs with the help of an evolutionary game to obtain the evolutionarily stable strategy (ESS) for the system. In this model, the sensor nodes dynamically adapt their defensive strategies to attain the most efficient defense, corresponding to the attackers' varied strategies. Further, the simulations convey that the proposed system converges rapidly to the Evolutionary Stable Strategy. Not only the system converges, but also forms a stable system which was verified by deliberately destabilizing the system. Results show that the nodes quickly return to ESS even after perturbation. © 2016 The Authors.Item Adaptive Selection of Cryptographic Protocols in Wireless Sensor Networks using Evolutionary Game Theory(Elsevier B.V., 2016) Arora, S.; Singh, P.; Gupta, A.J.Game theory applies to scenarios wherein multiple players with contrary motives contend with each other. Various solutions based on Game theory have been recently proposed which dealt with security aspects of wireless sensor networks (WSNs). However, the nodes have limited capability of rationality and evolutionary learning which makes it unfavorable to apply conventional game theory in WSNs. Evolutionary Game Theory (EGT) relies on bounded rationality assumption which is in harmony with the wireless sensor networks characteristics. Based on EGT, authors propose an adaptive security model for WSNs for the selection of cryptographic protocols during runtime. The authors formulate this selection in WSNs with the help of an evolutionary game to obtain the evolutionarily stable strategy (ESS) for the system. In this model, the sensor nodes dynamically adapt their defensive strategies to attain the most efficient defense, corresponding to the attackers' varied strategies. Further, the simulations convey that the proposed system converges rapidly to the Evolutionary Stable Strategy. Not only the system converges, but also forms a stable system which was verified by deliberately destabilizing the system. Results show that the nodes quickly return to ESS even after perturbation. © 2016 The Authors.Item A mathematical model for estimating peak particle velocity in a space between two adjacent blast holes(2011) Arora, S.; Dey, K.Peak particle velocity (PPV) generated in blasting is accepted as a measure of rock and structural damage PPV is measured using a seismograph at a distance from the blast face to keep the instrument safe As the distance between the blast point and seismograph (point of interest) is significantly larger than the length of explosive charge column, the explosive column placed in the blast hole is considered as a point charge. Blast-induced rock damage occurs very close to the blast hole and therefore the charge length cannot be ignored. Thus, estimating the damaged zone by extrapolating far-field observations yields inaccurate results. In this paper, a mathematical model is developed for estimation of near-field PPV considering the effect of charge length in the hole. In the proposed model, effect of an elemental charge in the charge column is calculated and then summed up for the whole charge column of two adjacent holes. Apart from this it also takes into account the direction of blast waves originating from the blast holes. The proposed model is also tested for a field trial.