Your comments matter: incorporating viewers’ comments for ranking online video content using bibliometrics

ABSTRACT

The quality of user-generated content over World Wide Web media is a matter of serious concern for both creators and users. To measure the quality of content, webometric techniques are commonly used. In recent times, bibliometric techniques have been introduced to good effect for evaluation of the quality of user-generated content, which were originally used for scholarly data. However, the application of bibliometric techniques to evaluate the quality of YouTube content is limited to h-index and g-index considering only views. This paper advocates for and demonstrates the adaptation of existing Bibliometric indices including h-index, g-index and M-index exploiting both views and comments and proposes three indices h_vc, g_vc and m_vc for YouTube video channel ranking. The empirical results prove that the proposed indices using views along with the comments outperform the existing approaches on a real-world dataset of YouTube.     

Topological evolution of laminar juncture flows under different critical parameters

Horseshoe vortex topological structure has been studied extensively in the past, traditional “saddle of separation” and new “attachment saddle point” topologies found in literature both have theoretical basis and experimental and computational evidences for support. The laminar incompressible juncture flows at low Reynolds numbers especially are observed to have new topology. Studies concerning the existence of the new topology though found in literature, the topological evolution and its dependency on various critical flow parameters require further investigation. A Particle Image Velocimetry based analysis is carried out to observe the effect of aspect ratio, δ*/D and shape of the obstacle on laminar horseshoe vortex topology for small obstacles. Rise in aspect ratio evolves the topology from the traditional to new for all the cases observed. The circular cross section obstacles are found more apt to having the new topology compared to square cross sections. It is noted that the sweeping effect of the fluid above the vortex system in which horseshoe vortex is immersed plays a critical role in this evolution. Topological evolution is observed not only in the most upstream singular point region of horseshoe vortex system but also in the corner region. The corner vortex topology evolves from the traditional type to new one before the topological evolution of the most upstream singular point, resulting in a new topological pattern of the laminar juncture flows “separation-attachment combination”. The study may help extend the understanding of the three-dimensional boundary layer separation phenomenon.     

Microstructural and thermal stability of a Ti-43AI alloy containing dispersoids of titanium di-boride

Ti-43Al (atomic percent) alloy containing a dispersion of 7 vol pct TiB₂ particles was exposed to various thermal treatments to determine the stability of TiB₂ in an ⇌₂ + β-phase matrix. No new phases were detected at the particle/matrix interfaces even after thermal exposure at 1473 K for 7 days. The absence of an Al peak in the energy dispersive X-ray analysis system (EDS) spectra from TiB₂ particles chemically extracted from the specimens aged at 1473 K for 7 days indicated no diffusion of Al from the matrix to the particles. These results indicate that TiB₂ is stable in an α₂+ β matrix at 1473 K. E. Clevenger, formerly Undergraduate Student, Department of Mechanical and Materials Engineering, Wright State University     

Improved oxidation resistance of group VB refractory metals by Al+ ion implantation

Aluminum ion implantation of vanadium, niobium, and tantalum improved the metals’ oxidation resistances at 500 °C and 735 °C. Implanted vanadium oxidized only to one-third the extent of unimplanted vanadium when exposed at 500 °C to air. The oxidative weight gains of implanted niobium and tantalum proved negligible when measured at 500 °C and for times sufficient to fully convert the untreated metals to their pentoxides. At 735 °C, implantation of vanadium only slightly retarded its oxidation, while oxidative weight gains of niobium and tantalum were reduced by factors of 3 or more. Implanted niobium exhibited weight gain in direct proportion to oxidation time squared at 735 °C. Microstructural examination of the metals implanted with selected fluences of the 180 kV aluminum ions showed the following. The solubility limit of aluminum is extended by implantation, the body centered cubic (bcc) phases being retained to ～60 at. pct Al in all three metals. The highest fluence investigated, 2.4 × 10²² ions/m², produced an ～400-nm layer of VAl₃ beneath the surface of vanadium, and ～300-nm layers of an amorphous phase containing ～70 at. pct Al beneath the niobium and tantalum surfaces. All three metals, implanted to this fluence and annealed at 600 °C, contained tri-aluminides, intermetallic compounds known for their oxidation resistances. Specimens implanted to this fluence were thus selected for the oxidation measurements.     

Synthesis,characterization and use of iron oxide nano particles for antibacterial activity

In this decade, the use of nano particles (NPs) against bacterial growth is increasing day by day due to remarkable alternative properties compared to molecular antibiotics. Thus, the use of iron oxide nanoparticles (IONPs) has proven one of the most important transition metals oxide‐based remedy in nanotechnological advances and biological applications due to enriched biocompatibility of iron. In this study synthesis of IONPs was carried out via co‐precipitation method. The crystallographic morphology of the synthesized particles was studied via X‐ray diffraction which revealed cubic structure of the particles, whereas, the spinal shaped morphology of the prepared NPs was confirmed from scanning electron microscopy. Likewise, the presence of the major elements in the sample was determined through energy dispersive X‐ray analysis characterization. Bactericidal effect of the NPs was assessed at pre‐defined concentrations (50 and 100 μg/ml) against Gram +ve bacteria Staphylococcus aureus, Gram ?ve bacteria Shigella dysentry and Escherichia coli . Bacterial strains, which demonstrate the potential of NPs. The purpose of this study was assessing the structure of the synthesized NPs for protective effect against harmful bacterial activity.     

Laser beam machining of zirconia ceramic: An investigation of micro-machining geometry and surface roughness

Journal of Mechanical Science and Technology - Micro-machining of dental ceramics namely as zirconium oxide is carried out through laser beam machining. Micro-channels of different sizes are...