Caching and D2D sharing for content delivery in software-defined UAV networks

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In cases of catastrophic events such as natural disasters or physical calamities, current network infrastructure can become inoperative. Furthermore, there are transient events leading to excessive demand surges where it is needed to deploy additional network capacity on-demand. In such cases, rapid network deployments become vital to establish communications and enable networked services. Unmanned Aerial Vehicle (UAV) networks are good candidates for this kind of operation. Software-defined networking and content-centric operation are promising technologies to enable agile control, network visibility and efficient content delivery via centralized optimization in these challenged systems. In this work, we consider an edge network which is composed of UAVs and serves in a content-centric mode with in-network caching and device-to-device (D2D) transmissions. We develop a cache placement and selection scheme for energy efficient operation. We also investigate how such a system performs under different operating conditions

Using neuroimaging genomics to investigate the evolution of human brain structure

Alterations in brain size and organization represent some of the most distinctive changes in the emergence of our species. Yet, there is limited understanding of how genetic factors contributed to altered neuroanatomy during human evolution. Here, we analyze neuroimaging and genetic data from up to 30,000 people in the UK Biobank and integrate with genomic annotations for different aspects of human evolution, including those based on ancient DNA and comparative genomics. We show that previously reported signals of recent polygenic selection for cortical anatomy are not replicable in a more ancestrally homogeneous sample. We then investigate relationships between evolutionary annotations and common genetic variants shaping cortical surface area and white-matter connectivity for each hemisphere. Our analyses identify single-nucleotide polymorphism heritability enrichment in human-gained regulatory elements that are active in early brain development, affecting surface areas of several parts of the cortex, including left-hemispheric speech-associated regions. We also detect heritability depletion in genomic regions with Neanderthal ancestry for connectivity of the uncinate fasciculus; this is a white-matter tract involved in memory, language, and socioemotional processing with relevance to neuropsychiatric disorders. Finally, we show that common genetic loci associated with left-hemispheric pars triangularis surface area overlap with a human-gained enhancer and affect regulation of ZIC4, a gene implicated in neurogenesis. This work demonstrates how genomic investigations of present-day neuroanatomical variation can help shed light on the complexities of our evolutionary past

Photocatalytic selective oxidation of 5-(hydroxymethyl)-2-furaldehyde to 2,5-furandicarbaldehyde in water by using anatase, rutile and brookite TiO2 nanoparticles

5-(Hydroxymethyl)-2-furaldehyde (HMF) was selectively oxidized to 2,5-furandicarbaldehyde (FDC) in aqueous medium by using home-prepared (HP) anatase, rutile, and brookite TiO2 nanoparticles. HP samples were prepared via a sol−gel method by using TiCl4 as the TiO2 precursor. Commercial TiO2 catalysts were also used for comparison. All samples were characterized by BET specific surface area, XRD, TGA, and SEM, and the reactivity results showed that HP catalysts are predominantly amorphous and give rise to selectivities toward FDC more than twice that of commercial and well-crystallized catalysts

A Markovian model for satellite integrated cognitive and D2D HetNets

Next-generation wireless systems are expected to provide bandwidth-hungry services in a cost-efficient and ubiquitous manner. D2D communications, spectrum sharing and heterogeneous network architectures (HetNets) are touted as crucial enablers to attain these goals. Moreover, the shifting characteristics of network traffic towards content consumption necessitate content-centric architectures and protocols. In this work, we propose a comprehensive analytical model for a content-oriented heterogeneous wireless network with cognitive capability. We model our HetNet architecture with a Continuous Time Markov Chain (CTMC) and characterize the trade-off between energy efficiency and system goodput. We elaborate on novel elements in our model, namely the integration of universal source concept (modeling the content retrieval operation from external networks), caching and overlaying in D2D mode. Besides, our investigation on network mode selection provides further insight on how resource allocation and performance are intertwined

Cooperative caching and video characteristics in D2D edge networks

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Device-to-device (D2D) transmissions in wireless edge networks are promising for optimizing system-wide energy consumption and improving system service capacity. Cooperative content caching similarly serves efficiency goals for data-intensive applications in edge networks. In this work, we propose two cooperative cache replacement algorithms in D2D networks to support these techniques: i) distance-based ii) priority-class based. Video content dissemination in an edge network is our main use-case. In such content traffic, video characteristics have a significant impact on the system behavior. Therefore, we also investigate the effect of content scene change dynamics in our system. Distance based cooperation outperforms LRU, MIN-ACC and SXO in terms of goodput while priority-class based approach consumes less energy than MIN-ACC with almost the same consumption as LRU, especially under fast changing scene regime. Besides, it is energy-wise slightly more rewarding than SXO for the fastest-changing scene case

Multidimensional content modeling and caching in D2D edge networks

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Future Internet is going to be shaped by networked multimedia services with exploding video traffic becoming the dominant payload. That evolution requires a remedial shift from the connection-oriented architecture to a content-centric one. Another technique to address this capacity crunch is to improve spectral utilization through new networking paradigms at the wireless network edge. To this end, Device-to-Device (D2D) communications has the potential for boosting the capacity and energy efficiency for content-centric networking. To design and implement efficient content-centric D2D networks, rigorous content modeling and in-network caching mechanisms based on such models are crucial. In this work, we develop a multidimensional content model based on popularity, chunking and layering, and devise caching schemes through this model. Our main motivation is to improve the system performance via our caching strategies. The numerical analysis shows the interplay among different system parameters and performance metrics: while our schemes perform slightly poorer in terms of system goodput, they also decrease the system energy expenditure. Overall, this improvement dominates the loss in the goodput, leading to greater energy efficiency compared to the commonly-used caching technique Least Recently Used (LRU)

Polynomials over quaternions and coquaternions: a unified approach

This paper aims to present, in a unified manner, results which are valid on both the algebras of quaternions and coquaternions and, simultaneously, call the attention to the main differences between these two algebras. The rings of one-sided polynomials over each of these algebras are studied and some important differences in what concerns the structure of the set of their zeros are remarked. Examples illustrating this different behavior of the zero-sets of quaternionic and coquaternionic polynomials are also presented.(undefined)info:eu-repo/semantics/publishedVersio

SETBP1 variants outside the degron disrupt DNA-binding and transcription independent of protein abundance to cause a heterogeneous neurodevelopmental disorder

Germline de novo SETBP1 variants cause clinically distinct and heterogeneous neurodevelopmental disorders. Heterozygous missense variants at a hotspot encoding a canonical degron lead to SETBP1 accumulation and Schinzel-Giedion syndrome (SGS), a rare severe developmental disorder involving multisystem malformations. Heterozygous loss-of-function variants result in SETBP1 haploinsufficiency disorder which is phenotypically much milder than SGS. Following an initial description of four individuals with atypical SGS carrying heterozygous missense variants adjacent to the degron, a few individual cases of variants outside the degron were reported. Due to the lack of systematic investigation of genotype-phenotype associations of different types of SETBP1 variants, and limited understanding of the roles of the gene in brain development, the extent of clinical heterogeneity and how this relates to underlying pathophysiological mechanisms remain elusive, imposing challenges for diagnosis and patient care. Here, we present a comprehensive investigation of the largest cohort to-date of individuals carrying SETBP1 missense variants outside the degron (n=18, including one in-frame deletion). We performed thorough clinical and speech phenotyping with functional follow-up using cellular assays and transcriptomics. Our findings suggest that such variants cause a clinically and functionally variable developmental syndrome, showing only partial overlaps with classical SGS and SETBP1 haploinsufficiency disorder, and primarily characterised by intellectual disability, epilepsy, speech and motor impairment. We provide evidence of loss-of-function pathophysiological mechanisms impairing ubiquitination, DNA-binding and transcription. In contrast to SGS and SETBP1 haploinsufficiency, these effects are independent of protein abundance. Overall, our study provides important novel insights into diagnosis, patient care and aetiology of SETBP1-related disorders