Indian Institute of Technology Mandi
Mandi, India
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Dutt V.,Indian Institute of Technology Mandi | Ahn Y.-S.,Carnegie Mellon University | Gonzalez C.,Carnegie Mellon University
Human Factors | Year: 2013

Objective: To determine the effects of an adversary's behavior on the defender's accurate and timely detection of network threats. Background: Cyber attacks cause major work disruption. It is important to understand how a defender's behavior (experience and tolerance to threats), as well as adversarial behavior (attack strategy), might impact the detection of threats. In this article, we use cognitive modeling to make predictions regarding these factors. Method: Different model types representing a defender, based on Instance-Based Learning Theory (IBLT), faced different adversarial behaviors. A defender's model was defined by experience of threats: threat-prone (90% threats and 10% nonthreats) and nonthreat-prone (10% threats and 90% nonthreats); and different tolerance levels to threats: risk-averse (model declares a cyber attack after perceiving one threat out of eight total) and risk-seeking (model declares a cyber attack after perceiving seven threats out of eight total). Adversarial behavior is simulated by considering different attack strategies: patient (threats occur late) and impatient (threats occur early). Results: For an impatient strategy, risk-averse models with threat-prone experiences show improved detection compared with risk-seeking models with nonthreat-prone experiences; however, the same is not true for a patient strategy. Conclusions: Based upon model predictions, a defender's prior threat experiences and his or her tolerance to threats are likely to predict detection accuracy; but considering the nature of adversarial behavior is also important. Application: Decision-support tools that consider the role of a defender's experience and tolerance to threats along with the nature of adversarial behavior are likely to improve a defender's overall threat detection.Copyright © 2012, Human Factors and Ergonomics Society.

Pathak H.,Indian Institute of Technology Mandi
Theoretical and Applied Fracture Mechanics | Year: 2017

In the present technological scenario, functionally graded materials (FGMs) are being introduced by scientific community for a wide range of effective engineering applications especially in aerospace, nuclear reactor, bio-medical and military uses. Safety and long service life of engineering components made from FGMs are one of the major objectives of engineering design process. The prediction of fracture behaviour is quite essential for safe designing of such critical components. In this work, three dimensional quasi-static fatigue crack growth has been studied in FGMs. Effects of material gradient (due to FGMs nature) have been investigated in detail. Both crack growth contours and fatigue lives are studied with reference of material heterogeneity (FGMs). Detailed analyses are presented in the form of fracture toughness, crack growth contours and fatigue life cycles. Numerical results are presented for cyclic thermal and mechanical loading environments. The variation in the material properties for FGM has been modelled by exponential law. The solution methodology has been implemented in coupled finite element (FE) and extended element free Galerkin (XEFG) approach. Few planar and non-planar crack geometries are simulated to check robustness and accuracy of the proposed technique. It has been shown that employed computational approach provides accurate fracture studies and crack growth predictions for three-dimensional functionally graded materials. © 2017 Elsevier Ltd.

Chauhan A.,Indian Institute of Technology Mandi | Vaish R.,Indian Institute of Technology Mandi
Materials and Design | Year: 2013

The paper deals with the hard coating material selection using various multi-criteria decision making approaches. Large number of materials has stimulated intense research in the field of material selection. Various quantitative decision making approaches are employed to select hard coating material selection. Technique for order preference by similarity to ideal solution (TOPSIS) is used for ranking these materials. Material selection charts (Ashby approach) is used to select hard coating materials. Pareto-optimal hard coating materials are determined for trade-off between hardness (H), H/E and H3/E2 (E: Young's modulus). Hierarchical clustering is used to classify hard coating materials under study. Pearson correlation coefficients are calculated between the materials properties under study which can be integrated with materials informatics for rapidly screening and designing materials. © 2012 Elsevier Ltd.

Abbas S.,Indian Institute of Technology Mandi
Computers and Mathematics with Applications | Year: 2011

In this paper we discuss the existence and uniqueness of a pseudo almost automorphic solution of an integro-differential equation in a Banach space X. We achieve our results using the methods of fractional powers of operators and the Banach fixed point theorem. These results are new and complement the existing ones. © 2011 Elsevier Ltd. All rights reserved.

Thakur M.,Indian Institute of Technology Mandi
Journal of Computational Science | Year: 2014

In this paper a new genetic algorithm is developed to find the near global optimal solution of multimodal nonlinear optimization problems. The algorithm defined makes use of a real encoded crossover and mutation operator. The performance of GA is tested on a set of twenty-seven nonlinear global optimization test problems of variable difficulty level. Results are compared with some well established popular GAs existing in the literature. It is observed that the algorithm defined performs significantly better than the existing ones. © 2013 Elsevier B.V.

Diwaker,Indian Institute of Technology Mandi
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2014

The electronic, NMR, vibrational, structural properties of a new pyrazoline derivative: 2-(5-(4-Chlorophenyl)-3-(pyridine-2-yl)-4,5-dihydropyrazol-1-yl) benzo[d]thiazole has been studied using Gaussian 09 software package. Using VEDA 4 program we have reported the PED potential energy distribution of normal mode of vibrations of the title compound. We have also reported the 1H and 13C NMR chemical shifts of the title compound using B3LYP level of theory with 6-311++G(2d,2p) basis set. Using time dependent (TD-DFT) approach electronic properties such as HOMO and LUMO energies, electronic spectrum of the title compound has been studied and reported. NBO analysis and MEP surface mapping has also been calculated and reported using ab initio methods. © 2014 Elsevier B.V. All rights reserved.

Chakraborty A.,Indian Institute of Technology Mandi
Molecular Physics | Year: 2011

Nonadiabatic tunnelling in an ideal one-dimensional semi-infinite periodic potential system is analysed using our model. Using our simple analytically solvable model it is shown that an ideal one-dimensional semi-infinite periodic potential system can be thought as a model of molecular switch. The method is applicable to those systems where Green's function for the motion in the absence of coupling is known. The method has been applied to the problem where motion takes place on parabolic potentials, for which analytical expression of Green's function can be found. © 2011 Taylor & Francis.

Chauhan A.,Galgotias University | Vaish R.,Indian Institute of Technology Mandi
Materials and Design | Year: 2012

Material selection is an important task because large numbers of competitive materials are available for various technological applications. Numerous material selection techniques are reported whereas most of the techniques are knowledge based and require performance indices for material selection. In this context, Ashby approach is one of the efficient methods which rely on performance indices of materials in specific application. However Multiple attribute decision making (MADM) approaches do not require exact physical relation for material selection. We have investigated micro-electromechanical system's (MEMS) material selection using MADM approaches and compared their results with that of Ashby approach. Almost similar materials ranking indicates that MADM approaches are also efficient and ease to apply without any prior mathematical calculation for materials properties-application relation. © 2012 Elsevier Ltd.

Chauhan A.,Galgotias University | Vaish R.,Indian Institute of Technology Mandi
Materials and Design | Year: 2012

A large number of magnetic materials have been fabricated and found to be promising for their technological applications. However, it is difficult to select an optimal material (for technological application) because of the conflicting tradeoffs between their properties. In this context, the screening of magnetic materials is an important task. In this article, an attempt has been made to select the soft and hard magnetic materials using Multiple Attribute Decision Making (MADM) approach. VlseKriterijumska Optimizacija I Kompromisno Resenje (VIKOR) and Technique for order preference by similarity to ideal solution (TOPSIS) methods (MADM techniques) are employed to evaluate the relative ranking of these materials understudy. The relative weights for the different attributes (properties) are calculated using Shannon's entropy method. It is found that (Supermalloy, Magnifer 7904) (79Ni-15Fe-5Mo-0.5Mn) and Ferrite 4 (sintered) (SrO-6Fe2O3) are the optimal materials among studied soft and hard magnetic materials, respectively. Hierarchical clustering is used to classify magnetic materials under study. Pearson correlation coefficients are calculated between the attributes under study. © 2011 Elsevier Ltd.

Chiral N-salicyl-β-amino alcohol Schiff bases are important ligands widely employed in asymmetric catalysis. These are referred to as 'tridentate salen ligands' and are considered as a member of the well-known 'privileged ligands' group. The desire to understand the roles of weak non-covalent interactions in catalysis has greatly expanded the scope of structural studies on catalytic complexes. This review focuses on the structural and supramolecular features of the metal complexes derived from chiral N-salicyl-β-amino alcohol Schiff base ligands. Metal complexes of varying nuclearities, such as, mono-, di-, tri- and tetra-nuclear complexes, have been reported from this group of ligands. The geometries of the metal centers present in these complexes vary from tetrahedral, square-planar, square-pyramidal, octahedral to trigonal prismatic. The available structural data clearly indicate the coordination versatility of this group of ligands towards various metal ions. In addition, these complexes exhibit a variety of weak bonding interactions leading to the formation of supramolecular structures such as helices, 1-D chains, 3-D networks, etc. in solid state. The articles discussed here highlight the competence of chiral N-salicyl-β-amino alcohol Schiff base ligands to support various structural and supramolecular features in their complexes, but the role of these features in determining their catalytic efficiencies have not yet been studied in detail. We believe that the present review may inspire many such studies in future. © 2013 Elsevier B.V.

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