5G-V2X: standardization,architecture, use cases,network-slicing,and edge-computing

Wireless Networks - Vehicular communication is one of the critical technologies in intelligent transportation system to provide connectivity between vehicles, road side units, and pedestrians....     

Variational learning from implicit bandit feedback

Machine Learning - Recommendations are prevalent in Web applications (e.g., search ranking, item recommendation, advertisement placement). Learning from bandit feedback is challenging due to the...     

A Reconfigurable TDMP Decoder for Raptor Codes

A Raptor code is a concatenation of a fixed rate precode and a Luby-Transform (LT) code that can be used as a rateless error-correcting code over communication channels. By definition, Raptor codes are characterized by irregularity features such as dynamic rate, check-degree variability, and joint coding, which make the design of hardware-efficient decoders a challenging task. In this paper, serial turbo decoding of architecture-aware Raptor codes is mapped into sequential row processing of a regular matrix by using a combination of code enhancements and architectural optimizations. The proposed mapping approach is based on three basic steps: (1) applying systematic permutations on the source matrix of the Raptor code, (2) confining LT random encoding to pseudo-random permutation of messages and periodic selection of row-splitting scenarios, and (3) developing a reconfigurable parallel check-node processor that attains a constant throughput while processing LT- and LDPC-nodes of varying degrees and count. The decoder scheduling is, thus, made simple and uniform across both LDPC and LT decoding. A serial decoder implementing the proposed approach was synthesized in 65 nm, 1.2 V CMOS technology. Hardware simulations show that the decoder, decoding a rate-0.4 code instance, achieves a throughput of 36 Mb/s at SNR of 1.5 dB, dissipates an average power of 27 mW and occupies an area of 0.55 mm².     

Platform level support for high throughput edge applications: the Twin Cities prototype

Even in the face of increasing network bandwidth, there is a desire among service providers to improve network security, availability, and performance. These improvements require increasingly complex computations on network packets. Current networking platforms cannot keep up, leading to less than desired throughput or functionality. Network processors deliver high networking throughput, but not the complex processing capabilities required. High-performance general-purpose processors deliver the complex processing needed, but not the network throughput. Combination platforms that include high-performance general-purpose CPUs and network processors hold the promise of greatly increasing platform performance, enabling desired edge application improvements. This article presents Twin Cities, a heterogeneous multiprocessor research platform we have constructed from a standard IXP1240 platform, a high-volume Intel/spl reg/ Pentium/spl reg/ III processor platform, and custom hardware. This platform provides a high-performance path (high throughput, low latency) between the two processors and presents a shared memory model to the programmer. We motivate and describe the Twin Cities platform, discuss the applications it targets, and present performance measurements.     

Optimization of Novel Human Acellular Dermal Dressing Sterilization for Routine Use in Clinical Practice

Gamma rays and electrons with kinetic energy up to 10 MeV are routinely used to sterilize biomaterials. To date, the effects of irradiation upon human acellular dermal matrices (hADMs) remain to be fully elucidated. The optimal irradiation dosage remains a critical parameter affecting the final product structure and, by extension, its therapeutic potential. ADM slides were prepared by various digestion methods. The influence of various doses of radiation sterilization using a high-energy electron beam on the structure of collagen, the formation of free radicals and immune responses to non-irradiated (native) and irradiated hADM was investigated. The study of the structure changes was carried out using the following methods: immunohistology, immunoblotting, and electron paramagnetic resonance (EPR) spectroscopy. It was shown that radiation sterilization did not change the architecture and three-dimensional structure of hADM; however, it significantly influenced the degradation of collagen fibers and induced the production of free radicals in a dose-dependent manner. More importantly, the observed effects did not disrupt the therapeutic potential of the new transplants. Therefore, radiation sterilization at a dose of 35kGy can ensure high sterility of the dressing while maintaining its therapeutic potential.     

Volume Changes of Iron Oxide Compacts under Isothermal Reduction Conditions

Compacts made from chemically grade Fe₂O₃ were fired at 1473K for 6 hrs. The fired compacts were isothermally reduced either by hydrogen or carbon monoxide at 1073–1373K. The O₂ weight‐loss resulting from the reduction process was continuously recorded as a function of time using TGA technique, whereas the volume change at different reduction conditions was measured by displacement method. Porosity measurements, microscopic examination and X‐ray diffraction analysis were used to characterize the fired and reduced products. The rate of reduction at both the initial and final stages was increased with temperature. The reduction mechanism deduced from the correlations between apparent activation energy values, structure of partially reduced compacts and application of gas‐solid reaction models revealed the reduction rate (dr/dt) at both the initial and final stages. At early stages, the reduction was controlled by a combined effect of gaseous diffusion and interfacial chemical reaction mechanism, while at the final stages the interfacial chemical reaction was the rate determining step. In H₂ reduction, maximum swelling (80%) was obtained at 1373K, which was attributed to the formation of metallic iron plates. In CO reduction, catastrophic swelling (255%) was obtained at 1198K due to the formation of metallic iron plates and whiskers.     

Duty Cycling Centralized Hierarchical Routing Protocol With Content Analysis Duty Cycling Mechanism for Wireless Sensor Networks

In this paper, a Duty Cycling Centralized Hierarchical Protocol (DCCHP) has been proposed for wireless sensor networks. DCCHP is an energy efficient protocol that prolongs the lifetime of the network by applying a duty cycling mechanism named DCM that chooses the nodes that send unimportant data in a certain epoch to be candidates to be put to sleep. But if the proposed equations for choosing the cluster head nodes put any of them in a high priority it works in the active mode. When comparing DCCHP to the previously proposed LEACH-CS, LEACH-C protocols, using a simulation study, DCCHP in average extends the network lifetime 50% more than LEACH-CS and about 60% more than LEACH-C across a different number of nodes in the network scaled up to 1000 nodes. That is because DCCHP chooses the definite number of nodes of unimportant data to be switched to sleeping mode unlike LEACH-CS and unlike LEACH- C which keeps all nodes in active mode. Also an analytical study of energy consumption proves that DCCHP preserves energy consumption more than LEACH-CS and DCCHP. DCCHP has been proposed for applications with scarce resources.     

MHD free convection flow along a vertical wavy surface with heat generation or absorption effect

We formulate the problem of free convection from a vertical wavy surface embedded in a uniform porous medium in the presence of an external magnetic field and internal heat generation or absorption effects. Using the appropriate transformations, the boundary layer equations are reduced to non-linear partial differential equations. The transformed boundary layer equations are solved numerically using Runge–Kutta integration scheme with the shooting technique. We have focused our attention on the evaluation of the local Nusselt number Nu_x, dimensionless velocity, f′, and temperature, θ. The governing parameters are the amplitude of the waviness of the surface, a, ranging from 0.0 (flat plate) to 0.3, and the heat generation absorption parameter Q ranging from − 0.25 to 0.25, and magnetic parameter Mn, ranging from 0.0 to 2.0. The effect of all these parameters are discussed and plotted.     

Uncertainty drives deviations in normative foraging decision strategies

Nearly all animals forage to acquire energy for survival through efficient search and resource harvesting. Patch exploitation is a canonical foraging behaviour, but there is a need for more tractable and understandable mathematical models describing how foragers deal with uncertainty. To provide such a treatment, we develop a normative theory of patch foraging decisions, proposing mechanisms by which foraging behaviours emerge in the face of uncertainty. Our model foragers statistically and sequentially infer patch resource yields using Bayesian updating based on their resource encounter history. A decision to leave a patch is triggered when the certainty of the patch type or the estimated yield of the patch falls below a threshold. The time scale over which uncertainty in resource availability persists strongly impacts behavioural variables like patch residence times and decision rules determining patch departures. When patch depletion is slow, as in habitat selection, departures are characterized by a reduction of uncertainty, suggesting that the forager resides in a low-yielding patch. Uncertainty leads patch-exploiting foragers to overharvest (underharvest) patches with initially low (high) resource yields in comparison with predictions of the marginal value theorem. These results extend optimal foraging theory and motivate a variety of behavioural experiments investigating patch foraging behaviour.