A novel approach for measuring hyperspectral similarity

Hyperspectral measures are used to capture the degree of similarity between two spectra. Spectral angle mapper (SAM) is an example of such measures. SAM similarity values range from 0 to 1. These values do not indicate whether the two spectra are similar or not. A static similarity threshold is imposed to recognize similar and dissimilar spectra. Adjusting such threshold is a troublesome process. To overcome this problem, the proposed approach aims to develop learnable hyperspectral measures. This is done through using hyperspectral measures values as similarity patterns and employing a classifier. The classifier acts as an adaptive similarity threshold. The derived similarity patterns are flexible, as they are able to capture the specific notion of similarity that is appropriate for each spectral region. Two similarity patterns are proposed. The first pattern is the cosine similarity vector for the second spectral derivative pair. The second pattern is a composite vector of different similarity measures values. The proposed approach is applied on full hyperspectral space and subspaces. Experiments were conducted on a challenging benchmark dataset. Experimental results showed that, classifications based on second patterns were far better than first patterns. This is because first patterns were concerned only with the geometrical features of the spectral signatures, while second patterns combined various discriminatory features such as: orthogonal projections information, correlation coefficients, and probability distributions produced by the spectral signatures. The proposed approach results are statistically significant. This implies that using simple learnable measures outperforms complex and manually tuned techniques used in classification.     

Handling Mobility Management and QoS Aspects in All-IP Networks

It is well-known that all-IP networks will be more dynamic and should be more flexible than current networks. Deploying these networks requires, however, overcoming many challenges. One of the main challenges is how to provide Quality of Service (QoS) guarantees in such highly dynamic mobile environments. Addressing this challenge is the main focus of this paper, which provides an insight into how mobility management and QoS solutions can be coupled with each other. Moreover, the paper describes in detail the QoS-aware Mobile IP Fast Authentication Protocol (QoMIFA), which is capable of handling mobility management and simultaneously reserving resources, thus, satisfying the requirements of all-IP mobile communication networks. The paper evaluates also the performance of QoMIFA compared to the well-known Simple QoS signaling protocol (Simple QoS) by means of simulation studies modeled in the network simulator 2 (ns2). The evaluation comprises the investigation of the impact of the network load on both protocols. Our simulation results show that QoMIFA is capable of achieving fast and smooth handoffs in addition to its capability of reserving resources very quickly. With respect to the time required to reserve resources for uplink traffic, QoMIFA is up to 80% faster than Simple QoS. If the resources are reserved for downlink traffic, QoMIFA performs up to 93% better. Considering the number of dropped packets per handoff, QoMIFA reduces the packets lost per handoff by 22% up to 76% on uplink and by 55% up to 93% on downlink as compared to Simple QoS. A main advantage of QoMIFA is that it minimizes the packets sent as best-effort (without QoS guarantees) after handoffs. QoMIFA reduces the best-effort packets transmitted on downlink by approximately 94% compared to Simple QoS and eliminates these packets on uplink.     

Attachment strength and biofilm forming ability of Bacillus cereus on green-leafy vegetables: cabbage and lettuce

The present study was designed to investigate the ability of six Bacillus cereus strains to attach and form biofilm on cabbage and lettuce surfaces. These six strains were; a reference strain DSMZ 345 and five biofilm-producing strains (aquatic strains; TUB8, TUB30, TUB31, TUB32 and TUB33) isolated from drinking-water distribution network. Hydrophobicity, biofilm formation ability, attachment strength (S_R) of spores and vegetative cells of the six B. cereus strains were also determined. Due to their high hydrophobicity, spores of all strains had high ability to attach polystyrene and did not affect by dilution of tryptone soy broth (TSB, 1:20 v/v) in the in vitro experiment. Significant (p < 0.05) enhancement in vitro biofilm formation by vegetative cells of B. cereus was recorded in the diluted TSB. The highest biofilm formation on cabbage and lettuce surfaces was obtained by spores and vegetative cells of all tested strains on the 4^th hour of the incubation period. These populations were significantly (p < 0.05) increased by elongating incubation time from 4 h to 24 h except DSMZ 345 and TUB8. Biofilm formation behavior obtained by B. cereus spores and vegetative cells on the polystyrene surface was different compared with that recorded on produce surface. The S_R of both spores and vegetative cells of the studied strains to the lettuce surface was higher than that of the cabbage surface. The hydrophobicity, biofilm formation and S_R of spores and vegetative cells of the biofilm-producing strains were higher than that of the reference strain DSMZ 345. Scanning electron microscopy (SEM) exposed random distribution of cells either on the surface or cut edge, without clear obvious affinity for the surface structures. Increasing in the presence of large clusters of cells on leaf surfaces was demonstrated after 4 and 24 h.In conclusion, use of aquatic environmental isolates is more useful for studying biofilm formation than the reference strain. Lettuce surface supported the attachment of B. cereus spores and vegetative cells compared with the cabbage surface. Further investigations are required to improve our knowledge of biofilm formation mechanisms by the human pathogenic microorganisms, especially by using the environmental and clinical isolates. To ensure safety level of green-leafy vegetables, biofilm formation after harvest should be considered as critical control point during handling of these vegetables.     

Effect of Li-Substitution on the Resistivity and Magnetoresistance of LaMnO y

The temperature dependence of the resistivity (??) and magneto-resistance (MR) effect of La_1?x Li _x MnO _y (x=0.05, 0.1, 0.15, 0.2 & 0.25 at.%) fixed valence doped compounds were studied between 80 and 320 K. X-ray powder diffraction (XRD) at room temperature shows that the samples are single phase. The resistivity of all samples with and without magnetic field shows a metal?Csemiconductor (M?CS) transition for all compositions. In addition, the replacement of the Li-substitution results in a reduction of the transition temperature T _ms and increases ??. In the magnetic field of 0.5 Tesla a large negative magnetoresistance (MR=50%) was observed, which is encouraging for potential application of colossal magnetoresistance (CMR) material at low fields. We determine the activation energy (E _?? ) in the semiconductor region.     

Quality and safety of halawa modified with mushroom

Halawa supplemented with 10–120 g mushroom, was evaluated for its acceptability (color, taste, texture, separate oil and overall acceptability by a ten‐member panel), protein content (as amino acid content), microbiological safety and quality. Halawa supplemented with both 10 and 20 g mushroom was equally as acceptable as the unsupplemented halawa in most sensory attributes. Results indicated that the low percentage of mushroom in halawa and control samples gave a higher panel score of all organoleptic characteristics than the high percentage of mushroom in halawa samples after 6 months storage at room temperature (25 °C). This result indicated that mushroom addition could prevent defects like oil separation and non‐coherence in halawa. It would be logical to expect a strong correlation between the sensory measure (color) of halawa and color parameters obtained by instrumental determination as well as non‐enzymatic browning (A_420nm). Techniques of regression analysis were used to predict the coefficient of correlation between the visual color score and each of the seven color parameters. The estimated values of RSQ was found to range between 0.97 (in the case of H*) to 0.98 (in the case of a*). The results showed that the aerobic plate counts increased during first the 2 months, and then decreased during the storage period for halawa fortified by different percentages of mushroom. Lipolytic microorganisms did not change during storage and remained in low numbers for halawa fortified by mushroom. Results revealed that all samples of halawa fortified by mushroom were free from clostridia, total Enterobacteriaceae count and pathogenic bacteria (Salmonella spp. and Staphylococcus aureus). It was concluded that halawa in the presence of mushroom was useful for minimizing the extent of Maillard browning reaction, maintaining color characteristics and parameters, maintaining quality and reducing water activity, and in increasing shelf‐life through inhibiting the bathogenic and reducing the spoilage bacteria. Copyright © 2006 Society of Chemical Industry     

Optical and physical behaviours of newly developed germanium-tellurium (GeTe) glasses: a comprehensive experimental and in-silico study with commercial glasses and ordinary shields

Journal of Materials Science: Materials in Electronics - In this study, synthesis and determination of physical, optical, and radiation shielding properties of glasses based on TeO2 and GeO2 were...     

Time-to-Pinch Investigation of 5 kJ Mather-Type Plasma Focus Device

The Egyptian Atomic Energy Authority-Plasma focus (EAEA-PF2) has been upgraded to a 5 kJ plasma focus device. Its characteristics have been investigated at various pressures and different voltages in a 5 kJ Mather-type plasma focus device for Ar gas. Its time-to-pinch has been measured, simulated and analyzed at different operating conditions. It is observed from the results that, the time-to-pinch decreased when either the charging voltage increased or the gas pressure decreased. In addition, the time-to-pinch is estimated theoretically using Lee model RADPF5.15. A comparison between the experimental and theoretical time-to-pinch is discussed. Also, the drive factor of plasma focus is analyzed at different pressures and charging voltages. It is noticed that, the mass and current factors are affected by changing the pressure and voltage. Finally, it is observed that, the drive factor is proportional inversely to the pressure and directly to the charging voltage.     

Manganese in apatites,chemical, ligand-field and electron paramagnetic resonance spectroscopy studies

Hydroxapatites precipitated with different amounts of carbonate and Mn²⁺ were studied. Infrared spectra, X-ray diffraction lattice parameters and thermal behaviour indicate that the presence of Mn²⁺ does not have any effect on the formation and properties of the carbonate apatites obtained. Interaction of apatite with a Mn²⁺-containing aqueous solution reveals that the molar uptake of Mn²⁺ by the apatite is higher than the Ca²⁺ released by it. Ligand-field and electron paramagnetic resonance spectroscopy results show that in Mn²⁺-doped Cd₅(PO₄)₃Cl, Mn²⁺ replaces Ca²⁺ in the apatite lattice, but in precipitated carbonate apatite it is in an MnO phase. The conclusion that Mn²⁺ in precipitated carbonate apatites is not incorporated in the apatite crystal is discussed in the light of the size differences between Mn²⁺ and Ca²⁺.