Moving object detection using spatio-temporal multilayer compound Markov Random Field and histogram thresholding based change detection

Multimedia Tools and Applications - In this article, we propose a Multi Layer Compound Markov Random Field (MLCMRF) Model to spatially segment different image frames of a given video sequence. The...     

Battery-aware rate adaptation for extending video streaming playback time

Multimedia streaming applications are computation and network intensive that put a high demand on battery usage of mobile devices. Battery usage forms an important metric in user satisfaction, as increased battery consumption results in faster battery depletion and eventually leads to battery outage. In this paper, we propose an adaptation technique, referred as Battery-Aware Rate Adaptation (BARA) scheme, which adapts to the appropriate bit rate to prolong the battery lifetime. BARA considers both the wireless channel conditions, as well as the device’s battery level, to determine the best transmission rate for optimizing the mobile battery consumption. Actual experiment and simulation results corroborate that compared to the conventional techniques, BARA can save more than 40% of battery power, while extending the video playback time by 20%.

     

Design and characterization of cellular automata based associative memory for pattern recognition.

This paper reports a cellular automata (CA) based model of associative memory. The model has been evolved around a special class of CA referred to as generalized multiple attractor cellular automata (GMACA). The GMACA based associative memory is designed to address the problem of pattern recognition. Its storage capacity is found to be better than that of Hopfield network. The GMACA are configured with nonlinear CA rules that are evolved through genetic algorithm (GA). Successive generations of GA select the rules at the edge of chaos. The study confirms the potential of GMACA to perform complex computations like pattern recognition at the edge of chaos.     

A simple approach of fabricating thermoelectric γ-NaxCoO2 and superconductive Nax(H2O)yCoO2-δ films using the sol–gel spin-coating method

We report a simple approach of fabricating thermoelectric γ-Na_xCoO₂ film with the c-axis orientation using the sol–gel spin-coating method. The inferred sodium content is x = 0.65 according to the correlation between the c-axis lattice constant and x. Temperature dependence of both the resistivity and thermopower resembles that of the γ-Na_0.68CoO₂ film grown by the reactive solid-phase epitaxy. The fitted thermopower data show that the bandwidth of γ-Na_xCoO₂ is found to be ~ 101 meV, being close to the quasi-particle band (70–100 meV) derived from an angle-resolved photoemission study of γ-Na_0.7CoO₂. These results enable the possibility of low-cost fabrication of γ-Na_xCoO₂-based thermoelectric film devices. Furthermore, we have also topotactically transformed the of γ-Na_xCoO₂ film to a superconducting Na_x(H₂O)_yCoO_2-δ film with T_{c, onset} = 4.12 K.     

Earthquake hazards for cross-country pipelines

A review of the current state-of-knowledge in risk-based earthquake-resistant design of pipeline systems is presented. Damage to pipelines during past earthquakes is studied, and the necessity of evaluating the risk to such systems from earthquakes for their economic design is illustrated. The various aspects of seismic risk analysis of pipeline systems are briefly studied and a conclusion reached that given a tectonic and seismic data for the region in which pipelines lie, in addition to proper definition of various levels of pipeline unserviceability, it is possible to estimate the earthquake hazards to such pipelines with a reasonable degree of accuracy. Since this subject is of topical interest to this country, with increasing number of pipeline systems laid in earthquake-prone areas, specific areas are identified where more information is required before meaningful seismic risk analysis of pipelines can be done in India.     

Partial acetylation of lysine residues improves intraprotein cross-linking

Intramolecular cross-linking coupled with mass spectrometric identification of cross-linked amino acids is a rapid method for elucidating low-resolution protein tertiary structures or fold families. However, previous cross-linking studies on model proteins, such as cytochrome c and ribonuclease A, identified a limited number of peptide cross-links that are biased toward only a few of the potentially reactive lysine residues. Here, we report an approach to improve the diversity of intramolecular protein cross-linking starting with a systematic quantitation of the reactivity of lysine residues of a model protein, bovine cytochrome c. Relative lysine reactivities among the 18 lysine residues of cytochrome c were determined by the ratio of d0 and acetyl-d3 groups at each lysine after partial acetylation with sulfosuccinimidyl acetate followed by denaturation and quantitative acetylation of remaining unmodified lysines with acetic-d6 anhydride. These lysine reactivities were then compared with theoretically derived pKa and relative solvent accessibility surface values. To ascertain if partial N-acetylation of the most reactive lysine residues prior to cross-linking can redirect and increase the observable Lys-Lys cross-links, partially acetylated bovine cytochrome c was cross-linked with the amine-specific, bis-functional reagent, bis(sulfosuccinimidyl)suberate. After proteolysis and mass spectrometry analysis, partial acetylation was shown to significantly increase the number of observable peptides containing Lys-Lys cross-links, shifting the pattern from the most reactive lysine residues to less reactive ones. More importantly, these additional cross-linked peptides contained novel Lys-Lys cross-link information not seen in the non-acetylated protein and provided additional distance constraints that were consistent with the crystal structure and facilitated the identification of the proper protein fold.     

A parallel LEGION algorithm and cell-based architecture for real time split and merge video segmentation

Split and merge segmentation is a popular region-based segmentation scheme for its robustness and computational efficiency. But it is hard to realize for larger size images or video frames in real time due to its iterative sequential data flow pattern. A quad-tree data structure is quite popular for software implementation of the algorithm, where a local parallelism is difficult to establish due to inherent data dependency between processes. In this paper, we have proposed a parallel algorithm of splitting and merging which depends only on local operations. The algorithm is mapped onto a hierarchical cell network, which is a parallel version of Locally Excitory Globally Inhibitory Oscillatory Network (LEGION). Simulation results show that the proposed design is faster than any of the standard split and merge algorithmic implementations, without compromising segmentation quality. The timing performance enhancement is manifested in its Finite State Machine based VLSI implementation in VIRTEX series FPGA platforms. We have also shown that, though segmentation qualitywise split-and-merge algorithm is little bit behind the state-of-the-art algorithms, computational speedwise it over performs those sophisticated and complex algorithms. Good segmentation performance with minimal computational cost enables the proposed design to tackle real time segmentation problem in live video streams. In this paper, we have demonstrated live PAL video segmentation using VIRTEX 5 series FPGA. Moreover, we have extended our design to HD resolution for which the time taken is less than 5 ms rendering a processing throughput of 200 frames per second.     

Nearly optimal bounds for distributed wireless scheduling in the SINR model

We study the wireless scheduling problem in the SINR model. More specifically, given a set of \(n\) links, each a sender–receiver pair, we wish to partition (or schedule) the links into the minimum number of slots, each satisfying interference constraints allowing simultaneous transmission. In the basic problem, all senders transmit with the same uniform power. We analyze a randomized distributed scheduling algorithm proposed by Kesselheim and Vöcking, and show that it achieves \(O(\log n)\)-approximation, an improvement of a logarithmic factor. This matches the best ratio known for centralized algorithms and holds in arbitrary metric space and for every length-monotone and sublinear power assignment. We also show that every distributed algorithm uses \(\varOmega (\log n)\) slots to schedule certain instances that require only two slots, which implies that the best possible absolute performance guarantee is logarithmic.     

Evaporation-induced natural convection of a liquid slug of binary mixture inside a microchannel: effect of confinement

Both experimental and simulation studies have been carried out on internal convection of an evaporating liquid slug of aqueous NaCl solution inside a microcapillary. Effect of confinement due to the extended channel length beyond the interface of the liquid slug has been investigated by placing the liquid slug inside the microcapillary of different lengths. Micro-PIV technique has been used for measurement of velocity field inside the liquid slug. Simulation studies have been carried out using COMSOL Multiphysics software for reporting the evaporative flux distribution on the meniscus and the concentration field distribution inside the liquid slug. The combined experimental and simulation studies successfully explain the underlying flow physics. Evaporation from the liquid–air interface of the slug induces buoyancy-driven Rayleigh convection. Evaporative flux of the interface depends on the extended length of the microcapillary beyond the liquid slug. The presence of extended channel region beyond the meniscus suppresses the evaporation from the meniscus due to the absence of evaporation flux normal to the channel wall. Evaporation occurs primarily from only one meniscus when the slug is located at one end of a long channel. Evaporation occurs from both the menisci when both the menisci are directly exposed to the atmosphere. Evaporation from only one meniscus of a slug leads to one recirculation bubble inside the liquid slug, whereas evaporation from both the menisci leads to two recirculation bubbles inside the liquid slug. Liquid slug with asymmetric extended channel length beyond the liquid slug interface leads to asymmetric evaporative flux, concentration field distribution and recirculation bubble size. The extended channel length beyond an evaporating liquid slug can influence/control the performance of a digital microfluidic system/device.