Designing a collector overlay architecture for fault diagnosis in video networks

To prevent subscriber churn, network service providers of VoD, SDV and IPTV have a pressing need to pro-actively detect, isolate and fix outages within an access network. Network induced degradations prove to be detrimental for streaming applications. This typically leads to a poor quality of experience (QoE) for subscribers. By monitoring key functional points of the access network for traces of degradation, service providers can devise mechanisms to mitigate the problem.In this work we propose a hierarchy of exporters, collectors and ANCON (ANalysis and CONtrol) nodes that can semi-autonomously monitor, detect and isolate impairments within an access network. Exporters on the data plane gather and disseminate statistics for individual subnets, which are streamed onto “collector” nodes on an orthogonal plane. Collector nodes aggregate traffic from various exporters, and stream them onto the root of the tree (ANCON). With an even placement of exporters, root cause analysis can now take the granularity of loss rates or delay rates in individual segments or subnets of an access network. As an extension to our architecture, we show that the overlay can support instrumentations of quality evaluation for streaming video. As an example, we use a simple MOS plugin that is in part an extension of the ITU-T Erlang model to predict the quality of a video stream much before it reaches the end user. We show that our overlay can support a wide variety of quality evaluation metrics. Through extensive simulations and an implementation, we discuss issues of engineering such an overlay, isolating impairments in access networks, instrumenting MOS plugins and predicting video quality of multimedia streams in transit.     

Analysis of uniform structured RF MEMS switch with different uniform and non-uniform meandering techniques

Microsystem Technologies - This paper mainly focuses on the investigation of different meandering techniques for the MEMS RF shunt capacitive switch. It involves three meandering techniques for the...     

Highly Efficient n-Doping via Proton Abstraction of an Acceptor1-Acceptor2 Alternating Copolymer toward Thermoelectric Applications

Electron transporting (n-type) polymers are the coveted complementary counterpart to more thoroughly studied hole transporting (p-type) semiconducting polymers. Besides intrinsic stability issues of the doped form of n-type polymer toward ubiquitous oxidizing agents (H₂O and O₂), the choice of suitable n-dopants and underlying mechanism of doping is an open research field. Using a low LUMO, n-type unipolar acceptor₁-acceptor₂ copolymer poly(DPP-TPD) in conjunction with bulk n-doping using Cs₂CO₃ these issues can be addressed. A solid-state acid-base interaction between polymer and basic carbonate increases the backbone electron density by deprotonation of the thiophene comonomer while forming bicarbonate, as revealed by NMR and optical spectroscopy. Comparable to N-DMBI hydride/electron transfer, Cs₂CO₃ proton abstraction doping shifts the poly(DPP-TPD) work function toward the LUMO. Thereby, the anionic doped state is resilient against O₂ but is susceptible toward H₂O. Based on GIWAXS, Cs₂CO₃ is mostly incorporated into the amorphous regions of poly(DPP-TPD) with the help of hydrophilic side chains and has minor impact on the short-range order of the polymer. Cs₂CO₃ proton abstraction doping and the acceptor₁-acceptor₂ copolymer architecture creates a synergistic n-doped system with promising properties for thermoelectric energy conversion, as evidenced by a remarkable power factor of (5.59 ± 0.39) × µW m⁻¹ K⁻².     

Primary drug resistance to Mycobacterium tuberculosis in renal transplant recipients

The author describes artificial retention of the testicle caused by a technical mistake of the surgeon during surgery of an inguinal hernia or hydrocele. The author emphasizes the experience of the surgeon needed during "minor" operations in children.     

Optical and Material Characteristics of MoS2/Cu2O Sensor for Detection of Lung Cancer Cell Types in Hydroplegia

In this study, n-type MoS₂ monolayer flakes are grown through chemical vapor deposition (CVD), and a p-type Cu₂O thin film is grown via electrochemical deposition. The crystal structure of the grown MoS₂ flakes is analyzed through transmission electron microscopy. The monolayer structure of the MoS₂ flakes is verified with Raman spectroscopy, multiphoton excitation microscopy, atomic force microscopy, and photoluminescence (PL) measurements. After the preliminary processing of the grown MoS₂ flakes, the sample is then transferred onto a Cu₂O thin film to complete a p-n heterogeneous structure. Data are confirmed via scanning electron microscopy, SHG, and Raman mapping measurements. The luminous energy gap between the two materials is examined through PL measurements. Results reveal that the thickness of the single-layer MoS₂ film is 0.7 nm. PL mapping shows a micro signal generated at the 627 nm wavelength, which belongs to the B2 excitons of MoS₂ and tends to increase gradually when it approaches 670 nm. Finally, the biosensor is used to detect lung cancer cell types in hydroplegia significantly reducing the current busy procedures and longer waiting time for detection. The results suggest that the fabricated sensor is highly sensitive to the change in the photocurrent with the number of each cell, the linear regression of the three cell types is as high as 99%. By measuring the slope of the photocurrent, we can identify the type of cells and the number of cells.     

Efficient and stable, structurally inverted poly(3-hexylthiopen): [6,6]-phenyl-C61-butyric acid methyl ester heterojunction solar cells with fibrous like poly(3-hexylthiopen)

We investigated an inverted organic photovoltaic device structure in which a densely packed ~ 100 nm thin TiO₂ layer on fluorine doped conducting glass serves as anode and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)/Au layer on top of the active layer serves as cathode. The active layer is comprised of a blend of poly(3-hexylthiopene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The rectification behavior of such a device is improved significantly and injection losses are minimized compared to devices without any compact TiO₂ layer. Moreover, nanostructured P3HT active layer was achieved in-situ by spin coating concentrated pure P3HT and P3HT:PCBM blend and solar cell performances on thickness of the active layer were also investigated. For the inverted solar cells constructed with different concentrations of P3HT and PCBM keeping the P3HT:PCBM ratio 1:0.8 (wt.%), the highest short circuit current and efficiency was observed when the P3HT and PCBM concentration was equal to 1.5 (wt.%) and 1.2 (wt.%) respectively. This leads to highly stable and reproducible power conversion efficiency above 3.7% at 100 mW/cm² light intensity under AM 1.5 conditions.     

Viscoelastic and acoustic characterization of polyurethane-based acoustic absorber panels for underwater applications

Acoustic absorbers that can have applications in a desired frequency band are a challenge often encountered in underwater acoustic absorber panel design. Polyurethane-based sound absorbing composite panels were designed with the help of finite element method (FEM) modeling using COMSOL for material formulations that can give optimum performance of echo reduction (ER) with minimum thickness. Polyurethanes of different compositions were evaluated for their acoustic performance using FEM modeling and experimental validation of the modeling results was done. The frequency-dependent modulus and damping properties were generated using dynamic mechanical analyzer and time–temperature superposition were performed to generate the material properties in the high frequency range (up to 25 kHz), which are significant for underwater acoustic detection applications and these data were used as inputs for modeling studies. Acoustic properties of the samples were experimentally evaluated using a water-filled pulse tube in 2–15 kHz frequency range as well as in an acoustic tank test facility for bigger dimension panels. These are nonresonant type absorbers capable to overcome limitations arising from environmental factors such as high hydrostatic pressures and also they are effective over a broad range of frequency (500 Hz–15 kHz) with ER > 15 dB. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47165.     

Performance analysis of series: shunt configuration based RF MEMS switch for satellite communication applications

Microsystem Technologies - In this paper the RF-MEMS switch with series–shunt configuration on a single quartz substrate is presented to achieve high isolation than the individual series or...