3,001 research outputs found
Video Tester -- A multiple-metric framework for video quality assessment over IP networks
This paper presents an extensible and reusable framework which addresses the
problem of video quality assessment over IP networks. The proposed tool
(referred to as Video-Tester) supports raw uncompressed video encoding and
decoding. It also includes different video over IP transmission methods (i.e.:
RTP over UDP unicast and multicast, as well as RTP over TCP). In addition, it
is furnished with a rich set of offline analysis capabilities. Video-Tester
analysis includes QoS and bitstream parameters estimation (i.e.: bandwidth,
packet inter-arrival time, jitter and loss rate, as well as GOP size and
I-frame loss rate). Our design facilitates the integration of virtually any
existing video quality metric thanks to the adopted Python-based modular
approach. Video-Tester currently provides PSNR, SSIM, ITU-T G.1070 video
quality metric, DIV and PSNR-based MOS estimations. In order to promote its use
and extension, Video-Tester is open and publicly available.Comment: 5 pages, 5 figures. For the Google Code project, see
http://video-tester.googlecode.com
Optimized LTE Data Transmission Procedures for IoT: Device Side Energy Consumption Analysis
The efficient deployment of Internet of Things (IoT) over cellular networks,
such as Long Term Evolution (LTE) or the next generation 5G, entails several
challenges. For massive IoT, reducing the energy consumption on the device side
becomes essential. One of the main characteristics of massive IoT is small data
transmissions. To improve the support of them, the 3GPP has included two novel
optimizations in LTE: one of them based on the Control Plane (CP), and the
other on the User Plane (UP). In this paper, we analyze the average energy
consumption per data packet using these two optimizations compared to
conventional LTE Service Request procedure. We propose an analytical model to
calculate the energy consumption for each procedure based on a Markov chain. In
the considered scenario, for large and small Inter-Arrival Times (IATs), the
results of the three procedures are similar. While for medium IATs CP reduces
the energy consumption per packet up to 87% due to its connection release
optimization
Sharing gNB components in RAN slicing: A perspective from 3GPP/NFV standards
To implement the next Generation NodeBs (gNBs) that are present in every
Radio Access Network (RAN) slice subnet, Network Function Virtualization (NFV)
enables the deployment of some of the gNB components as Virtual Networks
Functions (VNFs). Deploying individual VNF instances for these components could
guarantee the customization of each RAN slice subnet. However, due to the
multiplicity of VNFs, the required amount of virtual resources will be greater
compared to the case where a single VNF instance carries the aggregated traffic
of all the RAN slice subnets. Sharing gNB components between RAN slice subnets
could optimize the trade-off between customization, isolation and resource
utilization. In this article, we shed light on the key aspects in the Third
Generation Partnership Project (3GPP)/NFV standards for sharing gNB components.
First, we identify four possible scenarios for sharing gNB components. Then, we
analyze the impact of sharing on the customization level of each RAN slice
subnet. Later, we determine the main factors that enable isolation between RAN
slice subnets. Finally, we propose a 3GPP/NFV-based description model to define
the lifecycle management of shared gNB componentsComment: Article accepted for publication in IEEE Conference on Standards and
Networking (CSCN) 201
Preparation of Dipteran Larvae for Scanning Electron Microscopy with Special Reference to Myiasigen Dipteran Species
Although controversy exists concerning the role of chemical fixatives in scanning electron microscopy (SEM) studies of Dipteran larvae, we have observed that filtered 10% formaldehyde solution gives excellent results as a preservative. After immersing in vivo in formaldehyde, the larvae material is preserved for prolonged periods (up to 8 months), before examination with SEM. As a fixative, formaldehyde preserves the structure of the larval cuticle and produces no visible artifacts. Moreover, postfixation is not necessary.
Due to pecularities of the way of life of Wohlfahrtia magnifica (principally the accumulations of necrotic tissue, purulent particles, and other types of substances that often adhere to the numerous spines of larvae), this species must be cleaned before examination by SEM. Manual cleaning with alternating bidistilled water and 0.9% saline solution proved to be a rapid, easy and inexpensive method that gave good results.
Both lyophilization drying and critical point drying were used before sputtering the material. While lyophilization drying proved to be the most effective method for instars II and III, critical point drying was the best technique for study of specimens belonging to instar I. The optimum time for drying and conditions for lyophilization and sputter-coating with gold were determined experimentally. Samples were mounted on SEM stubs with double-sided adhesive and silver conductive paint.
The method proposed is easy and effective for the SEM study of larvae myiasis-producing diptera
Biologie de BOVICOLA LIMBATA (Mallophaga). Utilisation de milieux artificiels pour l'Ă©levage au laboratoire. Influence du poil de l'hĂ´te sur l'oviposition et l'Ă©volution larvaire
Metal content in the liver, kidney, and feathers of Northern gannets, Morus bassanus, sampled on the Spanish coast
The Strongyloides stercoralis-hookworms association as a path to the estimation of the global burden of strongyloidiasis:Â A systematic review
Soil-transmitted helminths (STH) represent a significant public health problem. However, Strongyloides stercoralis is not yet integrated into the control strategy against STH, given limi- tations to accurately assess its burden. Considering that S. stercoralis shares biological and epidemiological characteristics with hookworms, we describe a new approach for an improved estimation of the burden of infections by S. stercoralis based on the prevalence and burden of hookworms and the relationship between these species. A systematic review of publications reporting prevalence rates for S. stercoralis and hookworms was carried out. The data was classified into two categories: 1) “Community”, with surveys including all age groups, and 2) “SAC”, with surveys limited to school-aged children. The relationship between S. stercoralis and hookworms was characterized in order to estimate the global burden of S. stercoralis infections. The study is registered in PROSPERO (CRD42019131127). Spearman correlation coefficient between S. stercoralis and hookworms was estimated and the global burden of S. stercoralis infections was estimated using a regression model. A total of 119 articles were included, and a significant positive correlation between the burden of S. stercoralis and hook- worms was identified. Spearman’s coefficient for Community surveys was 0.94 and for SAC surveys it was 0.63. Based on the linear model, the global burden of S. stercoralis infections was estimated at 386 million (95%CI 324–449 million) people, including 22 million (95%CI 20–24 million) SAC. The significant relationship between S. stercoralis and hookworms allows an estimation of the global burden of S. stercoralis infections in most epidemiologic settings using hookworm burden and justifies the search of integrated control activities
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