Machine Learning for Wireless Communication Channel Modeling: An Overview

Wireless Personal Communications - In real time communication system, packets of lower prioritized flows suffer a longer queuing delay than the packets having higher priority. As a result, they...     

The Influence of Peritectic Reaction/Transformation on Crack Susceptibility in the Continuous Casting of Steels

The work presented here examines the surface cracks that can form during the continuous casting of near peritectic steels due to the volume changes during the peritectic reaction/transformation. The investigated samples were collected during plant trials from two different steel grades. The role and mode of the peritectic reaction/transformation are found to depend on the composition of the alloy, resulting in different types of surface cracks. The effect of the local variation in the cooling rate on the formation of the different types of cracks present in each steel grade, which can be due, for example, to the formation of oscillation marks, is demonstrated. The enhanced severity of the surface and internal oxidation, both of which depend on the alloy composition and consequent peritectic reaction, is highlighted. Experimental and theoretical studies show that different types of surface cracks can occur in peritectic steels depending upon the alloy composition and cooling rate, both of which define the fraction of the remaining liquid upon completion of the peritectic reaction/transformation.     

Microfluidic multi-target sorting by magnetic repulsion

In magnetophoresis-based microfluidic systems, the free-flow sorting is achieved by incrementally navigating the magnetic target toward a designated outlet. This is typically enabled using high-gradient magnetic concentrators (HGMCs), axially aligned or slightly slanted with the streaming sample flow. Such axial and incremental magnetic manipulation critically constraints the throughput and the number of targets that can be sorted simultaneously. To overcome these constraints, we present an alternative repulsion-based sorting method. The repulsion force is due that induced, over a limited angular expanse, around a single ferromagnetic wire. The wire is positioned transversally against the focused sample flow. Differentially repelled by the repulsive force, each target deflects from its focused path to follow a ribbon-like trajectory that leads to a spatially addressable outlet. The mediated sorting takes place more rapidly and is confined to the region facing the transversal wire. More importantly, the introduced concept design allows for a throughput that is geometrically scalable with the length of the wire. The functionality of the systems is demonstrated experimentally and numerically to yield the simultaneous and complete multi-target sorting of two and more magnetic beads.     

CFD simulation for biomagnetic separation involving dilute suspensions

Full‐Eulerian simulation of the separation of magnetic particles carried by a Newtonian fluid through a planar channel under the influence of a magnetic field is presented. The simulation is based on the application of the Navier–Stokes and concentration equations. The scheme for the magnetic separation of particles is achieved by applying an external magnetic dipole field. The hydrodynamic and magnetophoretic interactions between the particles and the carrier fluid are analysed. Analysis of the competing tendencies of mass transfer indicates that the magnetophoresis migration of magnetic particles is dominant over the molecular diffusion. This dominance becomes more evident at lower diffusivities leading to a drastic magnetic separation confined within a small region in the proximity of the magnetic field source. © 2012 Canadian Society for Chemical Engineering     

Pulse oximetry: an added criterion for discharge from the post-operative care unit

BACKGROUND: In previous studies, transcutaneous electrical nerve stimulation (TENS), tactile stimulation, and a combination of the two resulted in cognitive and affective improvements in patients with Alzheimer's disease (AD). As in those studies the therapist was present during the treatment of the experimental and control group (sham stimulation), a positive effect of the combination of TENS with interpersonal communication could not be excluded. Therefore, the effects of "isolated" TENS, i.e., in the absence of the therapist, on memory and affective disturbances in AD patients were examined. METHODS: Eighteen subjects (78-92 years old) met the NINCDS-ADRDA criteria for the clinical diagnosis of probable AD. To evaluate treatment effects, the experimental group (9) and the control group (9) underwent a number of neuropsychological tests and two observation scales. RESULTS: Treatment effects were observed for nonverbal short-term (Visual Memory) and long-term (Face Recognition) memory, word fluency (Verbal Fluency), and need of help, whereas patients' affective behavior did not improve. CONCLUSIONS: The results of the present study show that isolated TENS has a positive effect on patients' cognitive and independent functioning; however, isolated TENS appeared not to have a therapeutic effect on patients' affective behavior.     

Harris Hawks Optimizer with Graph Convolutional Network Based Weed Detection in Precision Agriculture

Precision agriculture includes the optimum and adequate use of resources depending on several variables that govern crop yield. Precision agriculture offers a novel solution utilizing a systematic technique for current agricultural problems like balancing production and environmental concerns. Weed control has become one of the significant problems in the agricultural sector. In traditional weed control, the entire field is treated uniformly by spraying the soil, a single herbicide dose, weed, and crops in the same way. For more precise farming, robots could accomplish targeted weed treatment if they could specifically find the location of the dispensable plant and identify the weed type. This may lessen by large margin utilization of agrochemicals on agricultural fields and favour sustainable agriculture. This study presents a Harris Hawks Optimizer with Graph Convolutional Network based Weed Detection (HHOGCN-WD) technique for Precision Agriculture. The HHOGCN-WD technique mainly focuses on identifying and classifying weeds for precision agriculture. For image pre-processing, the HHOGCN-WD model utilizes a bilateral normal filter (BNF) for noise removal. In addition, coupled convolutional neural network (CCNet) model is utilized to derive a set of feature vectors. To detect and classify weed, the GCN model is utilized with the HHO algorithm as a hyperparameter optimizer to improve the detection performance. The experimental results of the HHOGCN-WD technique are investigated under the benchmark dataset. The results indicate the promising performance of the presented HHOGCN-WD model over other recent approaches, with increased accuracy of 99.13%.     

Accelerated weathering effects on the mechanical and surface properties of CFRP composites

This study provides data regarding the characteristics of three carbon fiber reinforced polymer (FRP) systems with three types of resins exposed to accelerated natural weathering conditions according to ASTM G-154-00a for 1000 h. The FRP system consists of three-layered CFRP sheets bonded together with an adhesive. Degussa, Sika and Fosroc were the providers of the three FRP systems. Three-point bend testing according to ASTM D790 showed that ultra-violet (UV) light exposure decreased the flexural modulus of the three-layered FRP samples by 10%, 36% and 2% for Deagussa, Fosroc and Sika samples, respectively. While the reduction for the resin samples was 11.8%, 8.3% and 14.3% for Deagussa, Fosroc and Sika samples, respectively. SEM analysis showed cracking and deterioration in the resin and FRP systems as a result of the exposure to natural weathering.     

Synthesis and Characterization of Hybrid Materials Consisting of n-octadecyltriethoxysilane by Using n-Hexadecylamine as Surfactant and Q(0) and T(0) Cross-Linkers

Novel hybrid xerogel materials were synthesized by a sol-gel procedure. n-octadecyltriethoxysilane was co-condensed with and without different cross-linkers using Q(0) and T(0) mono-functionalized organosilanes in the presence of n-hexadecylamine with different hydroxyl silica functional groups at the surface. These polymer networks have shown new properties, for example, a high degree of cross-linking and hydrolysis. Two different synthesis steps were carried out: simple self-assembly followed by sol-gel transition and precipitation of homogenous sols. Due to the lack of solubility of these materials, the compositions of the new materials were determined by infrared spectroscopy, (13)C and (29)Si CP/MAS NMR spectroscopy and scanning electron microscopy.