ViComp: composition of user-generated videos

We propose ViComp, an automatic audio-visual camera selection framework for composing uninterrupted recordings from multiple user-generated videos (UGVs) of the same event. We design an automatic audio-based cut-point selection method to segment the UGV. ViComp combines segments of UGVs using a rank-based camera selection strategy by considering audio-visual quality and camera selection history. We analyze the audio to maintain audio continuity. To filter video segments which contain visual degradations, we perform spatial and spatio-temporal quality assessment. We validate the proposed framework with subjective tests and compare it with state-of-the-art methods.     

Employing transport layer multi-railing in cluster networks

Building clusters from commodity off-the-shelf parts is a well-established technique for building inexpensive medium- to large-size computing clusters. Many commodity mid-range motherboards come with multiple Gigabit Ethernet interfaces, and the low cost per port for Gigabit Ethernet makes switches inexpensive as well. Our objective in this work is to take advantage of multiple inexpensive Gigabit network cards and Ethernet switches to enhance the communication and reliability performance of a cluster. Unlike previous approaches that take advantage of multiple network connections for multi-railing, we consider CMT (Concurrent Multipath Transfer) that extends SCTP (Stream Control Transmission Protocol), a transport protocol developed by the IETF, to make use of the multiple paths that exist between two hosts. In this work, we explore the applicability of CMT in the transport layer of the network stack to high-performance computing environments. We develop SCTP-based MPI (Message Passing Interface) middleware for MPICH2 and Open MPI, and evaluate the reliability and communication performance of the system. Using Open MPI with support for message striping over multiple paths at the middleware level, we compare the differences in supporting multi-railing in the middleware versus at the transport layer.     

Generalized Maxwell-Wagner response in dispersive silver borophosphate glasses

The dielectric response of a glass-forming system (Ag₂OB₂O₃P₂O₅) has been measured in the frequency range from 10^–3–10⁵ Hz and over temperatures in the range 150–400 K for three different compositions. The dynamic behaviour of the conductance and capacitance in these glasses has been observed to follow fractional power-law dependencies on frequency which obey the generalized Maxwell-Wagner relationships. The power-law dispersions for the bulk and the surface layer of the non-ideal solid electrolyte 0.6Ag₂OxB₂O₃(0.4–x) P₂O₅ have been modelled mathematically using frequency-dependent resistive and capacitive elements in a conventional equivalent network. It is shown that controlled substitution of B₂O₃ in the glassy network influences the response and introduces an imperfect charge transport, the quasi-d.c. process of limited charge transport in place of bulk conduction, at higher frequencies, and affects the diffusion barrier at the electrodes to make them, weakly, more conductive at the lowest frequencies. The magnitudes of the activation energies of conduction indicate thermally activated localized hopping of silver ions between neighbouring sites in a structure that is modified by the addition of boron oxide.     

Electrical studies of leaves over wide frequency range

Dielectric properties of fresh leaves samples from different plant species were studied over the frequency range 10^-3 to 10⁴ Hz. The dynamic behaviour of the conductance and capacitance in leaf samples has been observed to follow fractional power law. The observed power-law dispersions have been modelled using frequency dependent resistive and capacitive elements of a conventional equivalent circuit     

Comparative analysis of different bioactivities of Curcuma longa,Nigella sativa seeds,and Camellia sinensis extracted by four different methods: A green way to reduce oxidative stress

Food Science and Biotechnology - Medicinal use of plants is as old as human history. Curcuma longa, Nigella sativa seeds, and Camellia sinensis have been widely used in various remedies since ages....     

Synthesis and characterization of some aromatic polyimides

The diamine 2‐methyl‐1,3‐bis(4‐aminophenyloxy)benzene was prepared via a nucleophilic substitution reaction and was characterized with Fourier transform infrared, elemental analysis, and ¹H‐ and ¹³C‐NMR spectroscopy. The prepared diamine was also characterized with single‐crystal analysis. The geometric parameters of C₁₉H₁₈N₂O₂ were in the usual ranges. The dihedral angles between the central phenyl ring and the two terminal aromatic rings were 88.9 and 91.6°. The crystal structure was stabilized by N? H···N hydrogen bonds. The diamine was then polymerized with 3,3′,4,4′‐benzophenone tetracarboxylic acid dianhydride, 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride, 3,4,9,10‐perylenetetracarboxylic acid dianhydride, and pyromellitic dianhydride by either a one‐step solution polymerization reaction or a two‐step procedure. These polymers had inherent viscosities ranging from 0.61 to 0.85 dL/gm. Some of the polymers were soluble in most common organic solvents even at room temperature, and some were soluble on heating. The degradation temperatures of the resultant polymers fell in the range of 260–500°C in nitrogen (with only 10% weight loss). The specific heat capacity at 200°C ranged from 1.0 to 2.21 J g^?1 K^?1. The temperatures at which the maximum degradation of the polymer occurred ranged from 510 to 610°C. The glass‐transition temperatures of the polyimides ranged from 182 to 191°C. The activation energy and enthalpy of the polyimides ranged from 44.44 to 73.91 kJ/mol and from 42.58 to 72.08 kJ/mol K, respectively. The moisture absorption was found in the range of 0.23–0.71%. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Fluorescent,electroactive, thermally stable triphenylamine‐ and naphthalene‐based polyimides for optoelectronic applications

To tune the photophysical properties of polyimides (PIs), a diamine containing naphthalene and triphenylamine units, N¹‐(4‐aminophenyl)‐N¹‐[(4‐naphthalene‐2‐yloxy)phenyl]benzene‐1,4‐diamine (DA), was synthesized. A series of fluorescent electroactive new PIs from synthesized DA were prepared with conventional thermal imidization with dianhydride. The selected dianhydride were used to study and compare the effects of rigid planar phenyl, flexible phenoxy, and nonplanar flexible hexafluoroisopropyidene and carbonyl groups in the main polymer backbone on the optoelectronic properties and processability of materials. The structures of the synthesized diamine and its PIs were evaluated by spectral and CHNS elemental analysis. The optoelectronic and thermal properties of PIs revealed intense blue‐light emission (428–477 nm), a low oxidation potential (0.3–1.3 V), and a lower highest occupied molecular orbital–lowest unoccupied molecular orbital gap (2.92–3.21 eV). The observed behavior and properties of our synthesized PIs suggest their potential as future hole‐transport materials in optoelectronic applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44526.     

Evolution of electrooptical properties of epoxy–amine thermoset/liquid crystal blends during polymerization after the gel point of the polymer matrix

Polymer dispersed liquid crystals (PDLC) were obtained by polymerization‐induced phase separation of the nematic E7 liquid crystal in a reactive diepoxide–diamine thermosetting matrix prepared by polycondensation (in two thermal steps). The evolution of some important electrooptical characteristics (transmittance in the off‐state, threshold voltage, maximum transmittance of the on‐state, transmittance at maximum applied voltage) were studied at three different reaction conversions of the polymer matrix beyond the gel point. The electrooptical curves greatly depended on the reaction conversion, especially beyond the gel point of the polymer matrix. It was found that the transmission in both the off‐state and the on‐state decreased with the extent of cure. In addition, threshold and saturation voltages increased with the reaction conversion. The electrooptical curve showed unusual behavior at approximately 60% of reaction conversion (i.e., near the gel conversion). At higher conversions, the expected normal mode was recovered. We discussed these electrooptical characteristics in the light of the very significant evolution of some properties of the crosslinked polymer matrix (glass‐transition temperatures, concentration of crosslink points, molar mass, and weight fraction of the residual uncrosslinked oligomers), whereas the droplet morphology did not exhibit dramatic changes. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2621–2628, 2004