The fifth-generation (5G) of cellular communications is expected to be deployed in the next years to support a wide range of services with different demands of peak data rates, latency and quality of ...experience (QoE). In this work, we propose a novel approach for radio network dimensioning (RND), named as Heuristic RND (HRND), which uses real open data in the network dimensioning process. This procedure, named as NetDataDrilling , provides the dimensioning target area by means of network data selection and visualization from the existing infrastructure. Moreover, the proposed NetDimensioning heuristic considers the necessary parameters of numerology and bandwidth parts (BWP) supported by New Radio (NR) to provide a balanced network design mediating among the requirements of coverage, capacity, QoE and cost. The proposed HRND is based on the novel quality of experience (QoE) parameter Formula Omitted by probabilistically characterizing the 5G radio resource control (Formula Omitted) states to ensure the availability of peak data rates for the MNO’s required percentage of the time. The simulation results show the fulfilment of QoE and load balancing parameters with significant cost savings compared to the conventional RND methodology.
Phase noise must be carefully considered when designing an OFDM-based communication system since an accurate prediction of the tolerable phase noise can allow the system and RF engineers to relax ...specifications. This paper analyzes the performance of OFDM systems under phase noise and its dependence on the number of sub-carriers both in the presence and absence of a phase correction mechanism. Besides some practical results are provided so as to give some insight into the phase noise spectral specifications that should be required of the local oscillator.
The fifth-generation (5G) of networks is being deployed to provide a wide range of new services and to manage the accelerated traffic load of the existing networks. In the present-day networks, data ...has become more noteworthy than ever to infer about the traffic load and existing network infrastructure to minimize the cost of new 5G deployments. Identifying the region of highest traffic density in megabyte (MB) per <inline-formula> <tex-math notation="LaTeX">\text {km}^{2} </tex-math></inline-formula> has an important implication in minimizing the cost per bit for the mobile network operators (MNOs). In this study, we propose a base station (BS) clustering framework based on unsupervised learning to identify the target area known as the highest traffic cluster (HTC) for 5G deployments. We propose a novel approach assisted by real data to determine the appropriate number of clusters <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula> and to identify the HTC. The algorithm, named as NetClustering , determines the HTC and appropriate value of <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula> by fulfilling MNO's requirements on the highest traffic density <inline-formula> <tex-math notation="LaTeX">\text {MB/km}^{2} </tex-math></inline-formula> and the target deployment area in <inline-formula> <tex-math notation="LaTeX">\text {km}^{2} </tex-math></inline-formula>. To compare the appropriate value of <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula> and other performance parameters, we use the Elbow heuristic as a benchmark. The simulation results show that the proposed algorithm fulfills the MNO's requirements on the target deployment area in <inline-formula> <tex-math notation="LaTeX">\text {km}^{2} </tex-math></inline-formula> and highest traffic density <inline-formula> <tex-math notation="LaTeX">\text {MB/km}^{2} </tex-math></inline-formula> with significant cost savings and achieves higher network utilization compared to the Elbow heuristic. In brief, the proposed algorithm provides a more meaningful interpretation of the underlying data in the context of clustering performed for network planning.
Este artículo trata de demostrar que la situación de inseguridad en el golfo de Guinea constituye un problema de importancia para la seguridad de la Unión Europea, y más concretamente para la ...seguridad de España. En este sentido, se defiende que la forma en la que la Unión se ha aproximado a este problema de seguridad, no ha sido ni es el adecuado ya que, a pesar de reconocer la situación de inseguridad en esta región, no se han aplicado los mismos parámetros a la hora de evaluar la necesidad de implementar una operación militar en el Cuerno de África y en el golfo de Guinea. El resultado ha sido el mantenimiento de la operación “Atalanta” en una zona sin ataques piratas desde 2019 hasta finales del 2023, y la ausencia de una misión similar en el golfo de Guinea.
Abstract Many studies have been dedicated to the development of scaffolds for improving post-traumatic nerve regeneration. The goal of this study was to develop and test hybrid chitosan membranes to ...use in peripheral nerve reconstruction, either alone or enriched with N1E-115 neural cells. Hybrid chitosan membranes were tested in vitro , to assess their ability in supporting N1E-115 cell survival and differentiation, and in vivo to assess biocompatibility as well as to evaluate their effects on nerve fiber regeneration and functional recovery after a standardized rat sciatic nerve crush injury. Functional recovery was evaluated using the sciatic functional index (SFI), the static sciatic index (SSI), the extensor postural thrust (EPT), the withdrawal reflex latency (WRL) and ankle kinematics. Nerve fiber regeneration was assessed by quantitative stereological analysis and electron microscopy. All chitosan membranes showed good biocompatibility and proved to be a suitable substrate for plating the N1E-115 cellular system. By contrast, in vivo nerve regeneration assessment after crush injury showed that the freeze-dried chitosan type III, without N1E-115 cell addition, was the only type of membrane that significantly improved posttraumatic axonal regrowth and functional recovery. It can be thus suggested that local enwrapping with this type of chitosan membrane may represent an effective approach for the improvement of the clinical outcome in patients receiving peripheral nerve surgery.
The birth of fraternal twins is a characteristic frequently observed in callitrichids. Cytogenetic studies have demonstrated hematopoietic chimerism in marmosets with the occurrence of two cell lines ...2n=46,XX/46,XY in females and males co-twins, without phenotypic changes. Amplification by PCR have also been used to verify the presence of the SRY gene in female chimaeras. Our aim was to verify the occurrence of chimerism in Callithrix sp. individuals considered as hybrids according to their intermediate phenotypes between C. jacchus and C. penicillata. Blood samples from 37 Callithrix sp. individuals were collected. Hematopoietic chimerism 2n=46,XX/46,XY was detected by cytogenetic analysis in five individuals, three males and two females. A fragment of approximately 200bp of the SRY gene was amplified in seven females with normal external genitalia. The percentage of 32% of chimeric individuals detected in the present study is similar to that observed for pure specimens of Callithrix. These data suggests that hybridization probably does not interfere with the occurrence of twin gestation, nor of chimerism. Although cytogenetics is the main tool to identify the two cell lineages present in cases of chimerism, the amplification of the SRY gene by PCR has proved to be more efficient to identify the Y chromosome in cases of chimeric female marmoset.
Children with Down's syndrome (DS) might exhibit disrupted brain functional connectivity in the motor and prefrontal cortex. To inspect the alterations in brain activation and functional connectivity ...for children with DS, the functional near-infrared spectroscopy (fNIRS) method was applied to examine the brain activation difference in the motor and prefrontal cortex between the DS and typically developing (TD) groups during a fine motor task. In addition, small-world analysis based on graph theory was also carried out to characterize the topological organization of functional brain networks. Interestingly, behavior data demonstrated that the DS group showed significantly long reaction time and low accuracy as compared to the TD group (
<
). More importantly, significantly reduced brain activations in the frontopolar area, the pre-motor, and the supplementary motor cortex (
<
) were identified in the DS group compared with the TD group. Meanwhile, significantly high global efficiency (
) and short average path length (
) were also detected for the DS group. This pilot study illustrated that the disrupted connectivity of frontopolar area, pre-motor, and supplementary motor cortex might be one of the core mechanisms associated with motor and cognitive impairments for children with DS. Therefore, the combination of the fNIRS technique with functional network analysis may pave a new avenue for improving our understanding of the neural mechanisms of DS.
Presently, several bone graft substitutes are being developed or already available for clinical use. However, the limited number of clinical and in vivo trials for direct comparison between these ...products may complicate this choice. One of the main reasons for this scarcity it is the use of models that do not readily allow the direct comparison of multiple bone graft substitutes, due especially to the small number of implantation sites. Although sheep cancellous bone models are now well established for these purposes, the limited availability of cancellous bone makes it difficult to find multiple comparable sites within a same animal. These limitations can be overcome by the monocortical model here proposed as it consists in 5–6 holes (5 mm Ø), in the femoral diaphysis, with similar bone structure, overlying soft tissue and loading pattern for all defects. Associated to this model, it is also described a fast histomorphometric analysis method using a computer image segmentation test (
Threshold method
) to assess bone regeneration parameters. The information compiled through the experimental use of 45 sheep in several studies allowed determining that this ovine model has the potential to demonstrate differences in bone-forming performance between various scaffolds. Additionally, the described histomorphometric method is fast, accurate and reproducible.
Few reports exist regarding the association between onychomadesis and an enterovirus infection presenting clinically as hand, foot, and mouth disease (HFMD). In February 2009, an outbreak of HFMD ...occurred in a Spanish nursery school, followed by onychomadesis 36–69 days later. Twelve of 17 children with HFMD developed nail shedding; enterovirus was detected in stool samples from eight (47%) of the 17. However, in only three of the children could an enterovirus serotype coxsackievirus B1 be identified. The epidemiological results of this study confirm onychomadesis as a complication in HFMD. In future outbreaks, molecular characterization of enterovirus from appropriate clinical samples should be studied.
PDF
