Utility Optimal Scheduling and Admission Control for Adaptive Video Streaming in Small Cell Networks

We consider the jointly optimal design of a transmission scheduling and admission control policy for adaptive video streaming over small cell networks. We formulate the problem as a dynamic network utility maximization and observe that it naturally decomposes into two subproblems: admission control and transmission scheduling. The resulting algorithms are simple and suitable for distributed implementation. The admission control decisions involve each user choosing the quality of the video chunk asked for download, based on the network congestion in its neighborhood. This form of admission control is compatible with the current video streaming technology based on the DASH protocol over TCP connections. Through simulations, we evaluate the performance of the proposed algorithm under realistic assumptions for a small-cell network.Comment: 5 pages, 4 figures. Accepted and will be presented at IEEE International Symposium on Information Theory (ISIT) 201

Using Jet Substructure at the LHC to Search for the Light Higgs Bosons of the CP-Violating MSSM

The CP-violating version of the Minimal Supersymmetric Standard Model (MSSM) is an example of a model where experimental data do not preclude the presence of light Higgs bosons in the range around 10 -- 110 GeV. Such light Higgs bosons, decaying almost wholly to b-bbar pairs, may be copiously produced at the LHC, but would remain inaccessible to conventional Higgs searches because of intractable QCD backgrounds. We demonstrate that a significant number of these light Higgs bosons would be boosted strongly enough for the pair of daughter $b$-jet pairs to appear as a single `fat' jet with substructure. Tagging such jets could extend the discovery potential at the LHC into the hitherto-inaccessible region for light Higgs bosons.Comment: LaTeX, 33 pages, 5 eps figures and 5 tables embedded. minor changes, to appear in Physical Review

Dependence of temperature variation of the Jahn-Teller potential well splitting and phase transition temperature in CuxZn1-xTiF6.6H2O crystals on Cu2+ ion concentration, x

The energy Eo by which one of the three Jahn-Teller potential wells becomes lower than the other two in Cu2+:ZnTiF6.6H2O single crystal at phase transition temperature, Tcl are determined at temperatures below Tcl for different Cu2+ concentrations from the electron paramagnetic resonance (EPR) spectra. As the sample is cooled, it is found that for high Cu2+ concentration, Eo increases below Tcl at a rate much slower than that for low concentration and over a much broader temperature range. With the increase of Cu2+ concentration, Tcl is found to decrease significantly. These findings appear to have a bearing on the monoclinic distortion that proceeds in this system below Tcl. Qualitative explanation of the decrease of Tcl with Cu2+ impurity concentration is presented. Eo is negligibly small for Cu2+ concentrations above certain limits means that the barrier height is also vanishing for such Cu2+ concentrations that is, phase transition of host lattice ceases. This is likely the reason for nonexistence of phase transition in some compounds like CuTiF6.6H2O and ZnSiF6.6H2O belonging to the same class with ZnTiF6.6H2O

Role of Internal Motions and Molecular Geometry on the NMR Relaxation of Hydrocarbons

The role of internal motions and molecular geometry on $^1$H NMR relaxation times $T_{1,2}$ in hydrocarbons is investigated using MD (molecular dynamics) simulations of the autocorrelation functions for in{\it tra}molecular $G_R(t)$ and in{\it ter}molecular $G_T(t)$ $^1$H-$^1$H dipole-dipole interactions arising from rotational ($R$) and translational ($T$) diffusion, respectively. We show that molecules with increased molecular symmetry such as neopentane, benzene, and isooctane show better agreement with traditional hard-sphere models than their corresponding straight-chain $n$-alkane, and furthermore that spherically-symmetric neopentane agrees well with the Stokes-Einstein theory. The influence of internal motions on the dynamics and $T_{1,2}$ relaxation of $n$-alkanes are investigated by simulating rigid $n$-alkanes and comparing with flexible (i.e. non-rigid) $n$-alkanes. Internal motions cause the rotational and translational correlation-times $\tau_{R,T}$ to get significantly shorter and the relaxation times $T_{1,2}$ to get significantly longer, especially for longer-chain $n$-alkanes. Site-by-site simulations of $^1$H's along the chains indicate significant variations in $\tau_{R,T}$ and $T_{1,2}$ across the chain, especially for longer-chain $n$-alkanes. The extent of the stretched (i.e. multi-exponential) decay in the autocorrelation functions $G_{R,T}(t)$ are quantified using inverse Laplace transforms, for both rigid and flexible molecules, and on a site-by-site bases. Comparison of $T_{1,2}$ measurements with the site-by-site simulations indicate that cross-relaxation (partially) averages-out the variations in $\tau_{R,T}$ and $T_{1,2}$ across the chain of long-chain $n$-alkanes. This work also has implications on the role of nano-pore confinement on the NMR relaxation of fluids in the organic-matter pores of kerogen and bitumen

FORMULATION AND EVALUATION OF ACARBOSE PELLETS BY EXTRUSION SPHERONIZATION TECHNIQUE

Objective: The objective of our work is to formulate and evaluate acarbose pellets for sustain drug delivery. The present study was aimed to develop sustain drug delivery system of acarbose pellets by extrusion spheronization technique using different polymers like Hydroxypropyl methyl cellulose, chitosan, ethylcellulose, microcrystalline cellulose. Pelletization of acarbose was done to achieve sustain drug release profile suitable for oral administration. Methods: The acarbose pellets were prepared by extrusion spheronization technique. The Fourier transform-infrared spectrum (FT-IR) and Differential scanning calorimetry thermogram of pure drug and drug-polymer blend showed the stable character of acarbose in the pellets. The prepared pellets were evaluated for different quality control parameters like particle size analysis, drug content, and Drug release characteristics. Results: The results obtained from different quality control parameters are within acceptable range and In vitro dissolution studies indicated that drug release from pellets follows zero-order kinetics with sustain release drug release up to 12 h with the use of ethyl cellulose as a sustain release polymer and mechanism of drug release is non-fickian. The formulated pellets were stable with respect to their physicochemical characters and drug content over a period of 60 d at accelerated stability condition. Conclusion: From present study, it was concluded that formulation of acarbose pellets by this will be a promising technique for the preparation of pellets to sustain drug release for the treatment of diabetes with better patient compliance

Adaptive Video Streaming for Wireless Networks with Multiple Users and Helpers

We consider the optimal design of a scheduling policy for adaptive video streaming in a wireless network formed by several users and helpers. A feature of such networks is that any user is typically in the range of multiple helpers. Hence, in order to cope with user-helper association, load balancing and inter-cell interference, an efficient streaming policy should allow the users to dynamically select the helper node to download from, and determine adaptively the video quality level of the download. In order to obtain a tractable formulation, we follow a "divide and conquer" approach: i) Assuming that each video packet (chunk) is delivered within its playback delay ("smooth streaming regime"), the problem is formulated as a network utility maximization (NUM), subject to queue stability, where the network utility function is a concave and componentwise non-decreasing function of the users' video quality measure. ii) We solve the NUM problem by using a Lyapunov Drift Plus Penalty approach, obtaining a scheme that naturally decomposes into two sub-policies referred to as "congestion control" (adaptive video quality and helper station selection) and "transmission scheduling" (dynamic allocation of the helper-user physical layer transmission rates).Our solution is provably optimal with respect to the proposed NUM problem, in a strong per-sample path sense. iii) Finally, we propose a method to adaptively estimate the maximum queuing delays, such that each user can calculate its pre-buffering and re-buffering time in order to cope with the fluctuations of the queuing delays. Through simulations, we evaluate the performance of the proposed algorithm under realistic assumptions of a network with densely deployed helper nodes, and demonstrate the per-sample path optimality of the proposed solution by considering a non-stationary non-ergodic scenario with user mobility, VBR video coding.Comment: final version to appear in IEEE Transactions on Communication