1,192 research outputs found

    2D Face Recognition System Based on Selected Gabor Filters and Linear Discriminant Analysis LDA

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    We present a new approach for face recognition system. The method is based on 2D face image features using subset of non-correlated and Orthogonal Gabor Filters instead of using the whole Gabor Filter Bank, then compressing the output feature vector using Linear Discriminant Analysis (LDA). The face image has been enhanced using multi stage image processing technique to normalize it and compensate for illumination variation. Experimental results show that the proposed system is effective for both dimension reduction and good recognition performance when compared to the complete Gabor filter bank. The system has been tested using CASIA, ORL and Cropped YaleB 2D face images Databases and achieved average recognition rate of 98.9 %

    Classical Analogue of the Ionic Hubbard Model

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    In our earlier work [M. Hafez, {\em et al.}, Phys. Lett. A {\bf 373} (2009) 4479] we employed the flow equation method to obtain a classic effective model from a quantum mechanical parent Hamiltonian called, the ionic Hubbard model (IHM). The classical ionic Hubbard model (CIHM) obtained in this way contains solely Fermionic occupation numbers of two species corresponding to particles with \up and \down spin, respectively. In this paper, we employ the transfer matrix method to analytically solve the CIHM at finite temperature in one dimension. In the limit of zero temperature, we find two insulating phases at large and small Coulomb interaction strength, UU, mediated with a gap-less metallic phase, resulting in two continuous metal-insulator transitions. Our results are further supported with Monte Carlo simulations.Comment: 12 figure

    Electrohydrodynamic Instability of Two Superposed Viscous Dielectric Fluids Flowing down an Inclined Plane with Thermal Conductivity Variation

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    The linear electrohydrodynamic instability of two superposed viscous dielectric fluids flowing down an inclined plane in the presence of thermal conductivity variation and applied electric fields is investigated. Using long-wavelength approximation, a new instability is presented. It is shown that when there is a variation in thermal conductivity in the fluid even in absence of electric fields or when applied electric fields are present even in absence of thermal conductivity variation, instability can occur under a longitudinal gravitational field. The effects of various parameters as Prandtl number, Reynolds number, electric field, inclination angle, and thermal conductivity variation on the stability of the system are discussed analytically and numerically in detail. The presence of electric field is important to prevent the drop out of the analysis when there is no stratification in thermal conductivity. Key words: Hydrodynamic stability; Viscous fluids; Flows down an inclined plane; Thermal conductivity; Electro-hydrodynamic

    Isolation of avian influenza H5N1 virus from vaccinated commercial layer flock in Egypt

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    Uninterrupted transmission of highly pathogenic avian influenza virus (HPAIV) H5N1 of clade 2.2.1 in Egypt since 2006 resulted in establishment of two main genetic clusters. The 2.2.1/C group where all recent human and majority of backyard origin viruses clustered together, meanwhile the majority of viruses derived from vaccinated poultry in commercial farms grouped in 2.2.1.1 clade. In the present investigation, an HPAIV H5N1 was isolated from twenty weeks old layers chickens that were vaccinated with a homologous H5N1 vaccine at 1, 7 and 16 weeks old. At twenty weeks of age, birds showed cyanosis of comb and wattle, decrease in egg production and up to 27% mortality. Examined serum samples showed low antibody titer in HI test (Log2 3.2 ± 4.2). The hemagglutinin (HA) and neuraminidase (NA) genes of the isolated virus were closely related to viruses in 2.2.1/C group isolated from poultry in live bird market (LBM) and backyards or from infected people. Conspicuous mutations in the HA and NA genes including a deletion within the receptor binding domain in the HA globular head region were observed. Despite repeated vaccination of layer chickens using a homologous H5N1 vaccine, infection with HPAIV H5N1 resulted in significant morbidity and mortality. In endemic countries like Egypt, rigorous control measures including enforcement of biosecurity, culling of infected birds and constant update of vaccine virus strains are highly required to prevent circulation of HPAIV H5N1 between backyard birds, commercial poultry, LBM and humans

    Poultry Production and Sustainability in Developing Countries under the COVID-19 Crisis: Lessons Learned

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    Poultry farming is a significant source of revenue generation for small farmers in developing countries. It plays a vital role in fulfilling the daily protein requirements of humans through meat and eggs consumption. The recently emerged pandemic Coronavirus Disease-19 (COVID-19) impacts the poultry production sector. Although the whole world is affected, these impacts may be more severe in developing countries due to their dependency on exporting necessary supplies such as feed, vaccines, drugs, and utensils. In this review, we have discussed poultry production in developing countries under the COVID-19 crisis and measures to regain the loss in the poultry industries. Generally, due to the lockdown, trade limitations have negatively impacted poultry industries, which might exacerbate global poverty. Coordinated activities have to be taken at the private and government levels to arrange soft loans so that these farms can restore their production and marketing to normal levels. In addition, here, we have focused on the supply of farm input, feed, other raw materials, management system, improved breeding efficiency, veterinary services, and marketing of egg and meat, which have to be ensured to secure a sustainable poultry production chain

    From Gapped Excitons to Gapless Triplons in One Dimension

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    Often, exotic phases appear in the phase diagrams between conventional phases. Their elementary excitations are of particular interest. Here, we consider the example of the ionic Hubbard model in one dimension. This model is a band insulator (BI) for weak interaction and a Mott insulator (MI) for strong interaction. Inbetween, a spontaneously dimerized insulator (SDI) occurs which is governed by energetically low-lying charge and spin degrees of freedom. Applying a systematically controlled version of the continuous unitary transformations (CUTs) we are able to determine the dispersions of the elementary charge and spin excitations and of their most relevant bound states on equal footing. The key idea is to start from an externally dimerized system using the relative weak interdimer coupling as small expansion parameter which finally is set to unity to recover the original model.Comment: 18 pages, 10 figure

    Interpretation of multispectral and infrared thermal surveys of the Suez Canal Zone, Egypt

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    Remote sensing airborne surveys were conducted, as part of the plan of rehabilitation, of the Suez Canal Zone using I2S multispectral camera and Bendix LN-3 infrared passive scanner. The multispectral camera gives four separate photographs for the same scene in the blue, green, red, and near infrared bands. The scanner was operated in the microwave bands of 8 to 14 microns and the thermal surveying was carried out both at night and in the day time. The surveys, coupled with intensive ground investigations, were utilized in the construction of new geological, structural lineation and drainage maps for the Suez Canal Zone on a scale of approximately 1:20,000, which are superior to the maps made by normal aerial photography. A considerable number of anomalies belonging to various types were revealed through the interpretation of the executed multispectral and infrared thermal surveys
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