Abstract

In the perfectly secure message transmission (PSMT) problem, two synchronized non-faulty players (or processors), the Sender S and the Receiver R are connected by n wires (each of which facilitates 2-way communication); S has a message, represented by a sequence oft elements from a finite field, that he wishes to send to R; after exchanging messages in phases R should correctly obtain S 's message, while an adversary listening on and actively controlling any set of t (or less) wires should have no information about S 's message. Similarly, in the problem of perfect reliable message transmission (PRMT), the receiver R should correctly obtain S's message, in spite of the adversary actively controlling any set oft (or less) wires.

Abstract

This work deals with the problem of fault-tolerant communication over networks, some of whose nodes are corrupted by a centralized byzantine adversary. The extant literature’s perspective of the problem of reliable communication, especially in networks whose topology is known, is that of a simple problem to which even some naive solutions (like message-flooding etc.) turn out to be reasonably efficient. In this paper, we give an example of a directed graph and a non threshold adversary structure, which will require every protocol for perfect reliable unicast to transmit exponential number of bits in order to reliably transmit a single bit.

Abstract

The growth of Internet has opened up new avenues for business and corporate model. Information sharing over Internet can help business houses in better cooperative strategic planning and growth. However despite such an impact, business houses are quite reluctant to share information because of the fear of information leakage. In this paper we study and propose an elegant, simple and practical solution for the problem of how can one party avail the data clustering service of another party without affecting each other's privacy. In our solution, we introduce the following two problems: (a) Secure multiparty computation of a depth of a query point, (b) Secure multiparty computation of whether a query point is a hull vertex. To the best of our knowledge this is the first time in literature that the aforementioned problems have been considered in privacy preserving framework.

Abstract

Automatic identification of a script in a given document image facilitates many important applications such as automatic archiving of multilingual documents, searching online archives of document images and for the selection of script specific OCR in a multilingual environment. In this paper, we model script identification as a texture classification problem and examine a global approach inspired by human visual perception. A generalised, hierarchical framework is proposed for script identification. A set of energy and intensity space features for this task is also presented. The framework serves to establish the utility of a global approach to the classification of scripts. The framework has been tested on two datasets: 10 Indian and 13 world scripts. The obtained accuracy of identification across the two datasets is above 94%. The results demonstrate that the framework can be used to develop solutions for script identification from document images across a large set of script classes.

Abstract

Unsupervised methods for automatic vessel segmentation from retinal images are attractive when only small datasets, with associated ground truth markings, are available. We present an unsupervised, curvature-based method for segmenting the complete vessel tree from colour retinal images. The vessels are modeled as trenches and the medial lines of the trenches are extracted using the curvature information derived from a novel curvature estimate. The complete vessel structure is then extracted using a modified region growing method. Testresults of the algorithm using the DRIVE dataset are superior to previously reported unsupervised methods and comparable to those obtained with the supervised methods.

Abstract

This paper presents a multi-component; distributed system (MuDiS) based solution for building a virtual learning environment which combines a wide range of technology, tools and digital gaming concepts to create an interactive tool for science education. MuDiS has been designed to be an extensible and easy-to-use system. The proposed environment is intended for designing and monitoring of educational content as well as creating a platform for exploring ideas. The system allows exchange of educational content and integrate different pedagogical approaches to learning and teaching under the same environment. We have developed a virtual physics lab that serves as an exemplar for the proposed virtual environment. We present the design details of the physics lab and discuss its performance.

Abstract

A distribution-based classification approach and a set of recently developed texture measures are applied to rotation-invariant texture classification. The performance is compared to that obtained with the well-known circular-symmetric autoregressive random field (CSAR) model approach. A difficult classification problem of 15 different Brodatz textures and seven rotation angles is used in experiments. The results show much better performance for our approach than for the CSAR features. A detailed analysis of the confusion matrices and the rotation angles of misclassified samples produces several interesting observations about the classification problem and the features used in this study

Abstract

In this paper, we focus on the information in speech data and discuss the research issues involved in collecting, organizing,indexing, retrieving and summarization of speech data. We share our experience about the problems and prospects in collection of spoken language data. We highlight some of the procedures,standards that need to be adapted in collecting the speech data, and discuss our plan to collect the speech data for all the languages in Indian sub-continent and from the neighboring countries

Abstract

Abstract The trans Watson-Crick/Watson-Crick family of base pairs represent a geometric class which play important structural and possible functional roles in the ribosome, tRNA and other functional RNA molecules. They nucleate base triplets and quartets, participate as loop closing terminal base pairs in hair pin motifs and are also responsible for several tertiary interactions which enable sequentially distant regions to interact with each other in. Eleven representative examples spanning nine systems belonging to this geometric family of RNA base pairs, having widely different occurrence statistics in the PDB database, were studied at the HF/6-31G (d, p) level using Morokuma decomposition, Atoms in Molecule as well as Natural Bond Orbital methods in the optimized gas phase geometries and in their crystal structure geometries respectively. The BSSE and deformation energy corrected interaction energy values for the optimized geometries for non protonated base pairs ranged from -8.19 kcal/mol to -21.84 kcal/mol and compared favorably with those of canonical base pairs. The interaction energies of these base pairs, in their respective crystal geometries, were however lesser to varying extents and in one case, that of A:A W:W trans, it was actually found to be positive. The variation in RMSD between the two geometries was also large and ranged from 0.32 2.19 . Our analysis shows that the hydrogen bonding characteristics and interaction energies obtained, correlated with the nature and type of hydrogen bonds between base pairs; but the occurrence frequencies, interaction energies and geometric variabilities were conspicuous by the absence of any apparent correlation. Instead, the functional geometry of base pairs and the nature of their local interaction energy hyperspace, in conjunction with tertiary and neighboring group interaction potentials in the global context, could be correlated with the identities of free and bound hydrogen bond donor/acceptor groups present in interacting bases. It also suggests that the concept of isostericity alone may not always determine covariation potentials for base pairs, particularly those which may be participating in functional dynamics. These considerations are more important than the absolute values of the interaction energies in their respective optimized geometries in rationalizing their occurrences in functional RNAs. They highlight the importance of revising some of the existing DNA based structure analysis approaches and may have significant implications for RNA structure and dynamics, especially in the context of structure prediction algorithms.

Abstract

Abstract. The base pairing patterns in RNA structures are more versatile and completely different as compared to DNA. We present here results of ab-initio studies of structures and interaction energies of eight selected RNA base pairs reported in literature. Interaction energies, including BSSE correction, of hydrogen added crystal geometries of base pairs have been calculated at the HF/6-31G** level. The structures and interaction energies of the base pairs in the crystal geometry are compared with those obtained after optimization of the base pairs. We find that the base pairs become more planar on full optimization. No change in the hydrogen bonding pattern is seen. The dipole moments of the bases are reduced on full optimization. It is expected that the inclusion of appropriate considerations of many of these aspects of RNA base pairing would significantly improve the accuracy of RNA secondary structure prediction.