(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

The growths of internet, Global Positioning System (GPS) and wireless telecommunication technologies have opened new avenues in potential area of mobile computing called Location Based Services (LBS). Recommendation of personalized information / services in location based services has become an attractive trend for success of businesses. A Recommender System attempts to solve the problem of information overload and provides product and service recommendation based on user profile and preferences. The location of the user is an important information item that can be associated to the existing user profile in order to provide efficient recommendations. Also, easy availability of GPS enabled devices brings a large amount of GPS trajectories representing user's mobile logs. These GPS trajectories can be used to mine interesting patterns about users. We have studied the utility and application of information extracted from user's GPS trajectory data in recommender systems. We conceive that recommendation has an intrinsic social component and therefore this work takes a perspective towards the social aspect in location based recommender systems. In this paper, we are presenting the stateof- the-art research trends, challenges and applications in the area of Location-Based Recommender Systems (LBRS).

World University root node

Computer Science and Engineering

IET Conference Publications

Location based recommender systems: Architecture, trends and research areas

The increasing trend of embedding positioning capabilities (e.g., GPS) in mobile devices facilitates the widespread use of Location Based Services. For such applications to succeed, privacy and confidentiality are key issues. Over all privacy will have to be managed through a combination of technology, legislation, corporate policy, and social norms. There are many data privacy schemes including Zero Knowledge Proof (ZKP) those can be used for location privacy. ZKP is also useful for removing the bottleneck problem introduced by use of trusted third party. In the earlier work, authors proposed the concept of middleware architecture in which, request and response are not routed through middleware for every transaction. This has reduced the dependency on middleware. This paper presents correspondence between the authentication techniques used in above said architecture and zero knowledge proof technique. Use of the concept of zero knowledge proof for authentication and authorization in the domain of location based services is also explored. © 2012 IEEE.

Proceedings - 2012 IEEE 13th International Conference on Mobile Data Management, MDM 2012

Defending location privacy using zero knowledge proof concept in location based services

The middleware is the most commonly used solution to address the location privacy. But it becomes a bottleneck in terms of system performance and availability as the entire client's service transactions are routed through the middleware to the actual Location Based Service Providers (LSP). The proposed architecture mainly targets a variety of applications where the availability of the services is probably more important than the location security. In the new flexible middleware based architecture the client and the LSPs can communicate directly. Autonomy on the client-server communication increases the possibility of communication even in the scenarios where the middleware is not available. But it also introduces authentication and security challenges to be addressed. The trusted middleware is used to generate the authentication certificates containing the Proxy Identity (also called Pseudonyms) to fulfill the authentication requirements at the LSP servers. The rest of transactions among the clients and the LSPs are accomplished independently. Further, the level of anonymity can be tuned by altering pseudonyms generation techniques i.e. "One-to-One", "One-to-Many" and "Many-to-One" depending on the type of the service and security requirements. It also attempts to maintain almost the same level of security for the targeted services. © 2012 ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering.

Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering

Reducing dependency on middleware for pull based active services in LBS systems

In this abstract, the impact of the gate and substrate biasing on the 3D current crowding behavior in the drain extended devices has been correlated with the shape of the NWell. Role of am-bipolar current flow in an optimized device structure for designing an efficient ESD protection device has been discussed by utilizing the self ballasting mechanisms under high current injection. © 2012 IEEE.

Electrical Engineering

International Conference on Simulation of Semiconductor Processes and Devices, SISPAD

Physics of optimized high current ESD performance of drain extended NMOS (De-NMOS)

Erosion in industrial appliances causes huge loss of valuable resources especially when solid particles are present in the working medium. A number of erosion models that are available in the literature claimed to predict the erosion response. In this work, five erosion models have been evaluated using computational fluid dynamics (CFD) methodology. Three most commonly used experimental test rigs (solid particle and unsubmerged slurry jet type and pot type) have been simulated and comparisons with the experimental results have been performed. The study helps in understanding the effect of fluid medium and flow pattern on the erosion process. The knowledge acquired shows that phenomenological based erosion models give better results considering the wide range of operating parameters. The in-depth study of the flow field shows the possibility that erosion mechanism, being parameter dependent, could change with location on the same specimen. © 2012 The Minerals, Metals, & Materials Society. All rights reserved.

Mechanical Engineering

CFD Modeling and Simulation in Materials Processing

Numerical Simulation of Erosion Using Computational Fluid Dynamics

Two series of polycatenar molecules consisting of a π-conjugated rigid core derived from 3-hexen-1,5-diyne coupled to different types of benzoic acid derivatives have been prepared and their potential as multifunctional materials has been investigated. The size ratio between the rigid core and the benzoate-derived groups, which vary in bulk, is crucial to address self-organization, thus indicating the delicate balance of forces involved in liquid crystalline (LC) behaviour. LC nematic, crystalline or LC columnar behaviour is observed depending on the structure of the benzoate moiety. Hexagonal two-dimensional columnar organization is attained for mesogens with benzoate-derived groups bearing six and nine alkoxylic tails. The stacking unit of the columnar organizations is different depending on the total number of tails, twelve or eighteen, with two molecules and half a molecule per columnar stratum, respectively. Macroscopic properties related to molecular structure, such as luminescence, chirality and electroactivity, have also been studied. Luminescent behaviour is observed for all mesogenic materials, which show higher Stokes shifts than in solution. In addition, supramolecular chirality in the mesophase has been observed for a chiral mesogen. Finally, the photoconducting behaviour of two of the columnar materials has been evaluated. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2012.

Fulltext

New Journal of Chemistry

A linear conjugated core for functional columnar liquid crystals

An objective comparison of three different thermal non-destructive evaluation (NDE) techniques - pulsed thermography (PT), lock-in (LI) thermography, and frequency modulated thermal wave imaging (FMTWI), has been carried out on a CFRP sample. The matched energy comparison shows that on the basis of computed SNR, the shallow defects are better detected by PT, while deeper defects are detected equally by all techniques. © 2012 American Institute of Physics.

AIP Conference Proceedings

An objective comparison of pulsed, lock-in, and frequency modulated thermal wave imaging

In this paper, the development of large volume double ring Penning plasma discharge source for efficient light emissions is reported. The developed Penning discharge source consists of two cylindrical end cathodes of stainless steel having radius 6 cm and a gap 5.5 cm between them, which are fitted in the top and bottom flanges of the vacuum chamber. Two stainless steel anode rings with thickness 0.4 cm and inner diameters 6.45 cm having separation 2 cm are kept at the discharge centre. Neodymium (Nd2Fe14B) permanent magnets are physically inserted behind the cathodes for producing nearly uniform magnetic field of ∼0.1 T at the center. Experiments and simulations have been performed for single and double anode ring configurations using helium gas discharge, which infer that double ring configuration gives better light emissions in the large volume Penning plasma discharge arrangement. The optical emission spectroscopy measurements are used to complement the observations. The spectral line-ratio technique is utilized to determine the electron plasma density. The estimated electron plasma density in double ring plasma configuration is ∼2 × 1011 cm-3, which is around one order of magnitude larger than that of single ring arrangement. © 2012 American Institute of Physics.

Review of Scientific Instruments

Development of large volume double ring penning plasma discharge source for efficient light emissions

The paper presents a novel feature based indexing scheme for image collections. The scheme presents the extension of distance based hashing to kernel space for generating the indexing structure based on similarity in kernel space. The objective of the scheme is to incorporate multiple features for defining the image indexing space using the concept of multiple kernel learning. However, the indexing problems are defined with unique learning objective; therefore, a novel application of genetic algorithm is presented for the optimization task. The extensive evaluation of the proposed concept is performed for developing word based document indexing application of Devanagari, Bengali, and English scripts. In addition, the efficacy of the proposed concept is shown by experimental evaluations on handwritten digits and natural image collection. © 2012 IEEE.

IEEE Transactions on Multimedia

Feature combination in kernel space for distance based image hashing

Micro. -reaction/reactor technology has been used to intensify several chemical processes involving gas-liquid and liquid-liquid reactions. However, potential of intensifying gas-liquid-liquid reactions still remains unexplored. In the present work, we report experimental investigations of gas-liquid-liquid three-phase flows in microchannels. High-speed imaging experiments were performed to identify and to map flow regimes; to understand the effect of flow rates of continuous (kerosene) and dispersed phases (air and water) on the flow regimes, formation mechanisms of air bubbles/slugs and water drops/slugs and also to measure the slug lengths. In particular, the effects of different gas and liquid distributors and addition of surfactant were investigated to understand controlled generation of bubbles and drops and formation of different flow regimes in microchannels. The results presented in this manuscript will be important to device microreactor systems for catalytic reactions involving gas-liquid-liquid flows. © 2012 Elsevier B.V.