Abstract

This paper proposes a hash-based indexing method to speed up fingerprint identification in large databases. For each minutia, its local neighborhood information is com-puted with features defined based on the geometric arrangements of its neighboring minutiae points. The features used are provably invariant to translation, rotation, scale and shear. These features are used to create an affine invariant local descriptor, called an arrangement vector, for each minutia. To account for missing and spurious minutiae, we consider subsets of the neighboring minutiae and hashes of these structures are used in the indexing process. The primary goal of the work is to explore the effectiveness of affine invariant features for representing local minutiae structures. Experiments on FVC 2002 databases show that representation is quite effective even though the technique performs slightly below the state-of-the-art methods. One could use the representation in combination with other techniques to improve the overall performance.

Abstract

This paper addresses the issue of moving object tracking from video. Two steps of processing are PCA reconstruction for classification the area and Optical flow-based tracking of feature points. Optimal flow-based tracking algorithm predicts and restores the feature of area in the real time object tracking. The proposed system is computationally more efficient for learning of dynamic object and object tracking to shape information. PCA based method compare to other methods is powerful algorithm in object detection and the Optical flowbased tracking algorithm could be used for decreasing the false point tracking and remove the error of the motion tracking in real time system tracking. The proposed algorithm tracks a set of feature points; during the tracking, feature is restored inside the predicted region. One important contribution of this work is to provide a restoration process for missing feature points, which occurs at almost every frame under realistic, noisy environment.

Abstract

Algorithms for detection of repeating patterns in images of-ten assume that the repetition is regular and highly similar across the instances. Approximate repetitions are also of interest in many domains such as hand carved sculptures, wall decorations, groups of natural objects, etc. Detection of such repetitive structures can help in applications such as image retrieval, image in painting, 3D reconstruction, etc. In this work, we look at a specific class of approximate repetitions:those in images of hand carved relief structures. We present a robust hierarchical method for detecting such repetitions.Given a single image with reliefs, our algorithm finds dense matches of local features across the image at various scales.The matching features are then grouped based on their ge-ometric configuration to find repeating elements. We also propose a method to group the repeating elements to segment the repetitive patterns in an image. In relief images,foreground and background have nearly the same texture,and matching of a single feature would not provide reliable evidence of repetition. Our grouping algorithm integrates evidences of repetition to reliably find repeating patterns.Input image is processed on a scale-space pyramid to effectively detect all possible repetitions at different scales. Our method has been tested on images with large varieties of complex repetitive patterns and the qualitative results show the robustness of our approach.

Abstract

Texture mapping algorithms use mesh parameterization methods to find an optimal map for the vertices of a 3D model in texture space. These techniques vary in the properties they try to optimize such as stretch and skewness of the texture when mapped onto the surface. While most of them do well in terms of quality, they tend to be computationally intensive for large mesh models, which limits their use in interactive applications. We propose a greedy alternative that is significantly faster than current algorithms and achieves comparable quality. We use a priority queue to store polygons and use tangential vectors to guide the texture over the surface. Our algorithm is simple to implement and can texture over a million polygons per second on a typical desktop.The algorithm does not impose any constraints on the meshtopology and we do not require the model to be cut into patches before texturing. Stretch and distortion measures are stable across models and are comparable to current algorithms. We also propose a method to generate self tileable textures for use in conjunction with our texture mapping algorithm. We present qualitative and quantitative results in comparison with several other texture mapping algorithms.The efficiency and robustness of our algorithm makes it use-ful in interactive modeling applications and texture mapping large mesh models such as heritage monuments.

Abstract

Rapid urbanization is resulting in the irreversible land use and land cover (LULC) changes, which is the prime driver of global warming and consequent climate changes. This communication investigates landscape dynamics assessed through spatio-temporal pattern analysis using free and open source softwares [FOSS, http://ces. iisc. ernet. in/foss]. Bangalore has been experiencing urbanization tide since globalisation era and is one of the fastest growing cities in India. Migration and policy decision of setting up major facilities and industries seem to be the reason for rapid urbanisation with impacts on the local ecology and natural resources. As the city centre has reached the threshold of urbanisation, intense sprawl has been noticed at outskirts. In order to understand the urbanisation and sprawl dynamics, spatio-temporal analysis has been done in the city administrative region with 10 km buffer. To understand the dynamics at local level with drivers, spatial metrics is computed for the study region, which is divided into eight zones (radial), 13 circles of 2 km incrementing radius. The results show that extensive land conversion to urban utility has occurred since 1992 within the city and from 2000 conversion started at periphery, especially by industrialisation activities. The land scape metrics exhibited remarkable spatial and temporal variations and urban sprawl. Overall changes in the land use from 1973 to 2012 shows the increase in the built-up (paved surface) area from 1.87% to 29.33% and decrease in vegetation cover from 62.38% to 33.68%. The landscape metrics depicts the city is more concentrated at center and fragmented towards its …

Abstract

Tropical islands are special and sensitive ecosystems which are subjected to various disturbances imposed by human activities and natural disasters. A detailed study about the changing landscape scenarios of these fragile island systems induced by various driving factors could be used for setting up measurements in support of conservation and sustainable development projects. The current research is a meta-analysis of the studies carried out in Andaman and Nicobar islands which analyzed the impact of tsunami of 2004 using geospatial tools. Based on the analysis, it was observed that the Nicobar islands were more affected compared to the Andaman islands. The majority of the researchers used pre- and post-tsunami satellite imagery and adopted visual interpretation method to delineate the changed classes. The study infers uplift of land in Andaman (exposing) and subsidence in Nicobar islands …

Abstract

One of the challenges in risk analysis has been that the determinants which are identified are based on a causality-driven approach drawn largely from the correlation studies of underlying factors. These approaches not only require numerous thematic information layers-spatial and non-spatial, that may potentially represent the factors of interest, but also tend to ignore the spatial and temporal variability of the outcome itself (say, disease incidence). On the other hand, owing to the advances in surveillance and monitoring systems resulting in enhanced availability of spatially explicit data over the last 25 years, there is a need to use these effectively at understanding or explaining the phenomenon itself. In this paper, we propose a method to leverage the observed event data-both spatial and temporal characterizations of disease occurrences, to generate a risk map that will provide valuable insights into its

Abstract

In this paper, we study the usefulness of the best path and the complete trellis in dynamic programming based template matching approach for detecting pronunciation mismatch. We show that there exists cues in trellis (a matrix representing all paths), which could be exploited for detecting pronunciation mismatch. Such an approach could be used to build a template based approach for detecting pronunciation mismatch independent of the language

Abstract

Riboswitches constitute an important class of non coding RNAs, present in the UTR of mRNAs. The ligand discriminating aptamer domain of a riboswitch can undergo conformational changes in absence or presence of its binding cognate metabolite affecting the downstream expression platform, through the activation or attenuation of either transcription or translation. The preQ1 responsive family of riboswitches, which show high affinity towards the guanine derived metabolites such as 7-cyano-7-deazaguanine (PreQ0) and 7-aminomethyl-7-deazaguanine (PreQ1), consist of the smallest riboswitches known. There are two subclasses of preQ1 riboswitches categorised based on sequence and structural differences: Class I and Class II. Class I is further subdivided into Type I and Type II, based on the mechanism of gene regulation. Class I Type I riboswitches regulate gene expression at translational level, and Class I Type II riboswitches regulate gene expression at transcriptional level. X-ray crystal structures of aptamer domains of Class I Types I and II riboswitches bound with cognate ligands preQ0 and preQ1 have been reported. However, the ligand free structure of only Class I Type I is available. We have modelled both ligand bound and ligand free structures of Class I Type I riboswitches belonging to Thermoanaerobacter tengcongensis. Crystal structures show that the presence or absence of ligand results in changes in molecular interactions within the binding pocket, eventually resulting in either sequestration or opening of ribosomal binding site leading to translational regulation. In order to study the stability of base pairs in the aptamer region, we have modelled the interactions observed in binding pocket, both pairing and stacking, and carried out gas phase quantum chemical studies. The ideal geometries and interaction energies of the complexes, evaluated at B3LYP/6-31G(d,p)//RIMP2/aug-cc-pVDZ respectively. The effect of stacking interactions in the complex is evaluated with DFT-D calculations at PBE/6-31G(d,p) level of theory. Morokuma energy decomposition is performed to investigate the contributions of various non covalent interactions to the total energy of the complex. We have identified the contributions of different interactions towards the stability of binding pocket and recognition of the ligands. Our studies also provide insights into the differential ligand affinities of the aptamer domain towards two similar ligands: preQ0 and preQ1.

Abstract

Protonation and deprotonation of RNA bases, although energetically unfavorable, are known to play a key role in stabilization of the global structure of the RNA molecules and in regulating their functionalities.1 It is expected that protonation/deprotonation induced geometric changes and charge redistribution, in the concerned bases, govern their consequent stabilization through base pairing and other noncovalent interactions. We have used QM methods to look at these aspects, along with their gas phase and solvent phase energies, for individual, protonated and deprotonated bases. Geometry optimization and energy calculations were carried out at different levels of theory (B3LYP/6-31G+ +(2d,2p) and MP2/aug-ccpvdz) and solvent phase calculations were performed using CPCM polarizable conductor calculation model. Protonation/deprotonation processes have been modeled as isodesmic reactions considering water as proton acceptor/donor. It has been observed that protonation and deprotonation at all possible sites are disfavored processes characterized by a positive free energy change. It is however important to note that protonation at any exocyclic site or at ring imino nitrogen sites, and deprotonation from any site lead to planar and stable geometry with a decrease in entropy of the corresponding conjugate acids and bases respectively. Comparison of the geometrical parameters and Mulliken charge distribution in the neutral bases, with those of the corresponding charged species, showed interesting variations depending on the identity of the bases as well as on their respective protonation/deprotonation sites. The HOMOLUMO band gap has been found to increase on protonation and decrease on deprotonation. In solvent phase, a decrease in the pka values has been observed indicating the increased stabilization of the charged species in polar environment. This study can be useful in understanding the structure and dynamics of RNA under pH strain.