94 research outputs found

    Demosaicing of Color Images by Accurate Estimation of Luminance

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    Digital cameras acquire color images using a single sensor with Color filter Arrays. A single color component per pixel is acquired using color filter arrays and the remaining two components are obtained using demosaicing techniques. The conventional demosaicing techniques existent induce artifacts in resultant images effecting reconstruction quality. To overcome this drawback a frequency based demosaicing technique is proposed. The luminance and chrominance components extracted from the frequency domain of the image are interpolated to produce intermediate demosaiced images. A novel Neural Network Based Image Reconstruction Algorithm is applied to the intermediate demosaiced image to obtain resultant demosaiced images. The results presented in the paper prove the proposed demosaicing technique exhibits the best performance and is applicable to a wide variety of images

    A Multi-layer Routing Protocol for Mobility Management in Wireless Mesh Networks

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    AbstractIn the recent trends, Wireless Mesh networks are proven to be one of the emerging fields in the wireless networks. WMNs comprises of Gateways (GWs), Mesh Clients (MCs) and Mesh Routers (MRs). However, it is challenging job to provide seamless connectivity when MC moves around the network. The recent advances in the field of wireless technology created a chance to overwhelmed the disadvantages of wired and wireless networks. The mobility management in the WMNs motivated the researchers to concentrate. In this paper, we are proposing a model called as multi-layer routing protocol for WMNs. This protocol works with the data link layer and network layer for data frame transmission. The proposed algorithm is implemented with intra domain for experimental evaluation. The experimental results show the effectiveness of the routing protocol

    CPW-Fed Microstrip Patch Antenna for Millimeter Wave Applications

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    The antenna elements have been consuming more power and inoperative area with high operational frequency. Therefore, an advanced antenna element design is necessary to cross over the above faults. In this research work, the CPW-Fed microstrip patch antenna is designed using EHF range for millimeter-wave applications. CPW-fed and combinations of DGS-CPW-fed microstrip patch antennas are novel methods, these designs are enhancing many characteristics of microwave circuits, such as narrow bandwidth, cross-polarization, low gain, etc. The researchers are facing many issues in this research area, therefore Fed-CPW design has been taken as a challenging issue. Investigators are working on wideband antennas, as well as patch antennas that can be used for both single- and dual-band applications. In addition to multiband applications, DGS, CPW-Fed Slot antennas are loaded with filters, these enhancements are providing waveguides and amplification tuning. The proposed research deals with a CPW-Fed Microstrip Patch satellite antenna, which is specially modeled to operate at various high-frequency values as well as Extremely High Frequency (EHF) range. A T-Shaped Microstrip patch antenna, which is dimensioned at 11.4x2.5x1.6 mm3 has been placed on Rogers R04003 substrate. The proposed antenna has CPW-Fed with ground dimensions which are considered as 5.9mm*8mm & feed dimensions as 3.8mm*9mm. Due to CPW-feed, the proposed antenna has achieved huge bandwidth i.e 13GHz. Hence the proposed antenna design is compact and suitable at higher frequencies. Simulation results approve that it is a good antenna model. The performance measures like return loss, gain, and VSWR has been improved compared to earlier models. Moreover, this CPW-fed microstrip patch antenna approach is most useful for 5G applications and simulation results are outperforms with designed frameworks. The proposed antenna resonates from 24GHz to 37.6GHz, with good impedance matching at |S11|<=-10dB. The obtained VSWR is in the range of 1 and 2. The gain at resonant frequencies is ranged from 4 to 6 dB. The proposed antenna is useful to deploy in 5G applications as it is resonating in millimeter-wave frequencies. The following model is very useful for 5G applications and provides resonant frequencies 4 to 6 dB. The impedance matching is also improved by 15% compared to earlier models. The following experiment is designed on the HFSS software tool and CPW-Fed functionality is verified

    CPW-Fed Microstrip Patch Antenna for Millimeter Wave Applications

    Get PDF
    The antenna elements have been consuming more power and inoperative area with high operational frequency. Therefore, an advanced antenna element design is necessary to cross over the above faults. In this research work, the CPW-Fed microstrip patch antenna is designed using EHF range for millimeter-wave applications. CPW-fed and combinations of DGS-CPW-fed microstrip patch antennas are novel methods, these designs are enhancing many characteristics of microwave circuits, such as narrow bandwidth, cross-polarization, low gain, etc. The researchers are facing many issues in this research area, therefore Fed-CPW design has been taken as a challenging issue. Investigators are working on wideband antennas, as well as patch antennas that can be used for both single- and dual-band applications. In addition to multiband applications, DGS, CPW-Fed Slot antennas are loaded with filters, these enhancements are providing waveguides and amplification tuning. The proposed research deals with a CPW-Fed Microstrip Patch satellite antenna, which is specially modeled to operate at various high-frequency values as well as Extremely High Frequency (EHF) range. A T-Shaped Microstrip patch antenna, which is dimensioned at 11.4x2.5x1.6 mm3 has been placed on Rogers R04003 substrate. The proposed antenna has CPW-Fed with ground dimensions which are considered as 5.9mm*8mm & feed dimensions as 3.8mm*9mm. Due to CPW-feed, the proposed antenna has achieved huge bandwidth i.e 13GHz. Hence the proposed antenna design is compact and suitable at higher frequencies. Simulation results approve that it is a good antenna model. The performance measures like return loss, gain, and VSWR has been improved compared to earlier models. Moreover, this CPW-fed microstrip patch antenna approach is most useful for 5G applications and simulation results are outperforms with designed frameworks. The proposed antenna resonates from 24GHz to 37.6GHz, with good impedance matching at |S11|<=-10dB. The obtained VSWR is in the range of 1 and 2. The gain at resonant frequencies is ranged from 4 to 6 dB. The proposed antenna is useful to deploy in 5G applications as it is resonating in millimeter-wave frequencies. The following model is very useful for 5G applications and provides resonant frequencies 4 to 6 dB. The impedance matching is also improved by 15% compared to earlier models. The following experiment is designed on the HFSS software tool and CPW-Fed functionality is verified

    Evan’s syndrome secondary to COVID-19 infection

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    Wide range of autoimmune diseases are known to occur following SARS-CoV-2 infection. There are very few case reports of Evan’s syndrome secondary to COVID-19. We hereby report a case of Evan’s syndrome secondary to COVID-19 infection and discuss its management

    HIV Exploits Antiviral Host Innate GCN2-ATF4 Signaling for Establishing Viral Replication Early in Infection.

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    Antiviral innate host defenses against acute viral infections include suppression of host protein synthesis to restrict viral protein production. Less is known about mechanisms by which viral pathogens subvert host antiviral innate responses for establishing their replication and dissemination. We investigated early innate defense against human immunodeficiency virus (HIV) infection and viral evasion by utilizing human CD4+ T cell cultures in vitro and a simian immunodeficiency virus (SIV) model of AIDS in vivo Our data showed that early host innate defense against the viral infection involves GCN2-ATF4 signaling-mediated suppression of global protein synthesis, which is exploited by the virus for supporting its own replication during early viral infection and dissemination in the gut mucosa. Suppression of protein synthesis and induction of protein kinase GCN2-ATF4 signaling were detected in the gut during acute SIV infection. These changes diminished during chronic viral infection. HIV replication induced by serum deprivation in CD4+ T cells was linked to the induction of ATF4 that was recruited to the HIV long terminal repeat (LTR) to promote viral transcription. Experimental inhibition of GCN2-ATF4 signaling either by a specific inhibitor or by amino acid supplementation suppressed the induction of HIV expression. Enhancing ATF4 expression through selenium administration resulted in reactivation of latent HIV in vitro as well as ex vivo in the primary CD4+ T cells isolated from patients receiving suppressive antiretroviral therapy (ART). In summary, HIV/SIV exploits the early host antiviral response through GCN2-ATF4 signaling by utilizing ATF4 for activating the viral LTR transcription to establish initial viral replication and is a potential target for HIV prevention and therapy.IMPORTANCE Understanding how HIV overcomes host antiviral innate defense response in order to establish infection and dissemination is critical for developing prevention and treatment strategies. Most investigations focused on the viral pathogenic mechanisms leading to immune dysfunction following robust viral infection and dissemination. Less is known about mechanisms that enable HIV to establish its presence despite rapid onset of host antiviral innate response. Our novel findings provide insights into the viral strategy that hijacks the host innate response of the suppression of protein biosynthesis to restrict the virus production. The virus leverages transcription factor ATF4 expression during the GCN2-ATF4 signaling response and utilizes it to activate viral transcription through the LTR to support viral transcription and production in both HIV and SIV infections. This unique viral strategy is exploiting the innate response and is distinct from the mechanisms of immune dysfunction after the critical mass of viral loads is generated

    A Comparative Rugoscopic Study of the Dentate and Edentulous Individuals in the South Indian Population

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    This study analyzes the rugae pattern in dentulous and edentulous patients and also evaluates the association of rugae pattern between males and females. Aims and Objectives. This study aims to investigate rugae patterns in dentulous and edentulous patients of both sexes in South Indian population and to find whether palatoscopy is a useful tool in human identification. Materials and Methods. Four hundred outpatients from Sree Balaji Dental College and Hospital, Chennai, were included in the study. The study group was equally divided between the sexes, which was further categorized into 100 dentulous and edentulous patients, respectively. Results. The edentulous male showed the highest mean of wavy pattern and total absence of circular pattern while the edentulous female group showed the highest mean of curved pattern and total absence of nonspecific pattern, while dentate population showed similar value as that of the overall population such as straight, wavy, and curved patterns. Conclusion. The present study concludes that there is similar rugae pattern of distribution between male and female dentate population while there is varied pattern between the sexes of edentulous population. However, the most predominant patterns were straight, wavy, and circular patterns
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