(SoE) School of Engineering

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

Lock-in thermography is increasingly becoming popular as a non-destructive testing technique for defect detection in composite materials for its low heating excitation. The experimental data is processed with Fourier transformation to produce phase and amplitude images. Phase images, though immune to surface emissivity variation, suffer from blind frequency effect, where a defect becomes invisible at a certain excitation frequency. There exists no analytical model to predict this 3-dimensional heat flow phenomenon. This paper presents a study of blind frequency using electro-thermal model based numerical simulation on a piece of thermally anisotropic carbon fibre composite. The performance of the simulator is optimized for spatial mesh size. Further the effect of paint layer, which is often applied to the sample surface for better thermal imaging, has been incorporated in the simulation. Finally, both experimental and simulation results are presented side-by-side for easy comparison. © 2013 AIP Publishing LLC.

World University root node

Electrical Engineering

Fulltext

Journal of Applied Physics

Prediction of blind frequency in lock-in thermography using electro-thermal model based numerical simulation

Abstract Electron transport studies in Tris(8-hydroxyquinolinato) aluminum (Alq3) is hindered due to lack of efficient electron injecting electrode. We demonstrate that an electron injection layer of Cs 2CO3 forms ohmic contact with Alq3, which enables the observation of SCLC. This allows us to directly determine the electron mobility in Alq3, which was found to be 1 × 10 -9 m2/V s at room temperature. Doping of Cs 2CO3 leads to increase in conductivity as well as mobility. Mobility has increased to 1 × 10-7 m2/V s for 33% doping of Cs2CO3.© 2013 Elsevier B.V. All rights reserved.

Organic Electronics

Effect of doping of cesium carbonate on electron transport in Tris(8-hydroxyquinolinato) aluminum

A finite element based numerical method is employed to analyze the wave radiation by multiple or a group of cylinders in the time domain. The nonlinear free surface and body surface boundary conditions are satisfied based on the perturbation method up to the second order. The first- and second-order velocity potential problems at each time step are solved through a Finite Element Method (FEM). The matrix equation of the FEM is solved through iteration and the initial solution is obtained from the result at the previous time step. The three-dimensional (3-D) mesh required is generated based on a two-dimensional (2-D) hybrid mesh on a horizontal plane and its extension in the vertical direction. The hybrid mesh is generated by combining an unstructured grid away from cylinders and two structured grids near the cylinder and the artificial boundary. The fluid velocity on the free surface and the cylinder surface are calculated by using a differential method. Results for various configurations including the cases of two cylinders and four cylinders and a group of eighteen cylinders are obtained to show the joint influences of cylinders on the first- and second-order waves and forces, including the effects of spacing ratios and wave frequency on the second order waves and the mean force, in particular. © 2013 Publishing House for Journal of Hydrodynamics.

Mechanical Engineering

Journal of Hydrodynamics

Finite element analysis of second order wave radiation by a group of cylinders in the time domain

Huge information is intrinsically associated with certain places in the globe such as historical, geographical, cultural and architectural specialties. The next generation systems require access of the site specific information where the user is roaming at the moment. The on-the-spot learning (OTSL) is a system that allows the users to learn about the location, landmarks, regions where he/she is walking through. In this paper, we have proposed an OTSL model that includes the storage, retrieval and the landmark weighting heuristic. Apart from learning about the individual landmarks, we have proposed two ways of storing the spatial learning objects. First, use the administrative hierarchy of the region to fetch the information. This can be easily done by the reverse-geocoding operation without actually storing the physical hierarchy. Second, spatial chunking, creates the region based on the groups of landmarks in order to define a learning region. A hybrid solution has also been considered to achieve the advantages of both the region based methods. We use a weighting model to select the correct landmarks in the basic model. We extend the core model to include other factors such as speed, direction, side of the road etc. A prototype has been implemented to show the feasibility of the proposed model. © Springer International Publishing Switzerland 2013.

Computer Science and Engineering

Studies in Computational Intelligence

Modeling on-the-spot learning: Storage, landmarks weighting heuristic and annotation algorithm

We consider a distributed MAC setting with block-wise flat fading links and full receiver CSI (channel state information). Of the L transmitters, a subset is assumed to have knowledge of the global CSI vector in each block, whereas the remaining users have access only to their respective link qualities, i.e. each one in the latter set is unaware of the quality of other links. Outage is not allowed in any communication block. We propose efficient power-allocation and rate-adaptation strategies which are sum-rate optimal when users in each subset observe identical fading distributions chosen from a class, which includes the popular Rayleigh, Ricean etc. {\textcopyright} 2013 IEEE.

IEEE International Symposium on Information Theory - Proceedings

On fading MAC channels with asymmetric CSI

A new modelling method of image jacobian estimation is presented for uncalibrated visual servoing of robots, in which a kernel recursive least squares (KRLS) technique is used for non-linear mapping between target image features and robot joint angles, and an image jacobian expression is derived from the KRLS algorithm with gaussian kernel. The simulations of robot visual servoing with eye-in-hand camera configuration are conducted using the KRLS jacobian estimator and the same are compared with SVR and LS-SVM jacobian estimators. The simulation results have shown that the robot visual servoing converges at the desired goal and KRLS is proved to be a better choice. © 2013 IEEE.

IEEE International Symposium on Intelligent Control - Proceedings

Kernel machines for uncalibrated visual servoing of robots

The paper proposes a novel multi-modal document image retrieval framework by exploiting the information of text and graphics regions. The framework applies multiple kernel learning based hashing formulation for generation of composite document indexes using different modalities. The existing multimedia management methods for imaged text documents have not addressed the requirement of old and degraded documents. In the subsequent contribution, we propose novel multi-modal document indexing framework for retrieval of old and degraded text documents by combining OCR'ed text and image based representation using learning. The evaluation of proposed concepts is demonstrated on sampled magazine cover pages, and documents of Devanagari script. © 2013 IEEE.

Proceedings of the International Conference on Document Analysis and Recognition, ICDAR

Multi-modal information integration for document retrieval

In this study, we investigated and assessed the dependence of dummy head injury mitigation on the side curtain airbag and occupant distance under a side impact of a Dodge Neon. Full-scale finite element vehicle simulations of a Dodge Neon with a side curtain airbag were performed to simulate the side impact. Owing to the wide range of parameters, an optimal matrix of finite element calculations was generated using the design method of experiments (DOE); the DOE method was performed to independently screen the finite element results and yield the desired parametric influences as outputs. Also, analysis of variance (ANOVA) techniques were used to analyze the finite element results data. The results clearly show that the influence of moving deformable barrier (MDB) strike velocity was the strongest influence parameter on both cases for the head injury criteria (HIC36) and the peak head acceleration, followed by the initial airbag inlet temperature. Interestingly, the initial airbag inlet temperature was only a ~30% smaller influence than the MDB velocity; also, the trigger time was a ~54% smaller influence than the MDB velocity when considering the peak head accelerations. Considering the wide range in MDB velocities used in this study, results of the study present an opportunity for design optimization using the different parameters to help mitigate occupant injury. As such, the initial airbag inlet temperature, the trigger time, and the airbag pressure should be incorporated into vehicular design process when optimizing for the head injury criteria. © 2013 Elsevier Ltd. All rights reserved.

Accident Analysis and Prevention

Finite element analysis of occupant head injuries: Parametric effects of the side curtain airbag deployment interaction with a dummy head in a side impact crash

The effect of microfabric on the mechanical behaviour of clays has been explored previously based on the response of dispersed and flocculated microfabrics only. However, the natural clays often have the geometric arrangement of particles between these two extreme cases which can be termed as intermediate microfabric. This paper explores the formation of intermediate microfabric of kaolin clay and its impact on soil's consolidation behaviour by performing self-weight consolidation, slurry consolidation and 1-D consolidation tests. The effect of calgon content (dispersing agent) on geometric arrangement of the particles has been evaluated through cluster size distribution by performing double hydrometer tests. Then these clay slurries have been used to perform the AFM (Atomic Force Microscopy) test to obtain the variation in average angle of particle orientation with respect to the calgon content present in the slurry. AFM technique provides 3D image of the clay sample and 2D image with Z-information with the potential of measuring intermediate microfabric of clayey soil quantitatively including dispersed and flocculated microfabrics. Other traditional techniques such as SEM, TEM & XRD are limited to only qualitative analysis of soil's microfabric, thus, having no capability to measure intermediate microfabric of clay. A methodology of preparing bulk specimens of clay with intermediate microfabric has been developed using slurry consolidation technique; and then these specimens have been consolidated under 1-D loading to evaluate the effect of intermediate microfabric on compressibility and permeability of clay. In this study, all the experiments reports that the dispersed type geometric arrangement increases with the increase in calgon content in soil up to 2 % and then the reverse behaviour is observed at 3 %; which may depend on the required amount of sodium cations to neutralize the negatively charged faces of the clay platelets present in the slurry. © 2012 Springer Science+Business Media Dordrecht.

Civil Engineering

Geotechnical and Geological Engineering

Development of Intermediate Microfabric in Kaolin Clay and Its Consolidation Behaviour

During the last two decades, active research has gone into the theoretical and the practical aspects of the electro-mechanical impedance (EMI) technique for structural health monitoring (SHM). This paper reviews the theoretical developments in modelling the force transfer mechanism between the piezoelectric-ceramic (PZT) patch and the host structure pertinent to the EMI technique. The review covers the modelling efforts spanning about last one and a half decades. The models reviewed include the shear lag based model, simplified shear lag model, the refined shear lag model and the continuum shear lag model. The first three listed models ignored the inertia term. The last model, that is the continuum based model, takes care of all the piezo, structural and adhesive effects rigorously and simultaneously. Typical comparisons between the outcomes resulting from the models are discussed. © (2013) Trans Tech Publications.