151 research outputs found

    Dual MCDRR Scheduler for Hybrid TDM/WDM Optical Networks

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    In this paper we propose and investigate the performance of a dual multi-channel deficit round-robin (D-MCDRR) scheduler based on the existing single MCDRR scheduler. The existing scheduler is used for multiple channels with tunable transmitters and fixed receivers in hybrid time division multiplexing (TDM)/wavelength division multiplexing (WDM) optical networks. The proposed dual scheduler will also be used in the same optical networks. We extend the existing MCDRR scheduling algorithm for n channels to the case of considering two schedulers for the same n channels. Simulation results show that the proposed dual MCDRR (D-MCDRR) scheduler can provide better throughput when compared to the existing single MCDRR scheduler

    Trustee: A Trust Management System for Fog-enabled Cyber Physical Systems

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    In this paper, we propose a lightweight trust management system (TMS) for fog-enabled cyber physical systems (Fog-CPS). Trust computation is based on multi-factor and multi-dimensional parameters, and formulated as a statistical regression problem which is solved by employing random forest regression model. Additionally, as the Fog-CPS systems could be deployed in open and unprotected environments, the CPS devices and fog nodes are vulnerable to numerous attacks namely, collusion, self-promotion, badmouthing, ballot-stuffing, and opportunistic service. The compromised entities can impact the accuracy of trust computation model by increasing/decreasing the trust of other nodes. These challenges are addressed by designing a generic trust credibility model which can countermeasures the compromise of both CPS devices and fog nodes. The credibility of each newly computed trust value is evaluated and subsequently adjusted by correlating it with a standard deviation threshold. The standard deviation is quantified by computing the trust in two configurations of hostile environments and subsequently comparing it with the trust value in a legitimate/normal environment. Our results demonstrate that credibility model successfully countermeasures the malicious behaviour of all Fog-CPS entities i.e. CPS devices and fog nodes. The multi-factor trust assessment and credibility evaluation enable accurate and precise trust computation and guarantee a dependable Fog-CPS system

    Multi-Channel Deficit Round-Robin Scheduling for Hybrid TDM/WDM Optical Networks

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    In this paper we propose and investigate the performance of a multi-channel scheduling algorithm based on the well-known deficit round-robin (DRR), which we call multi-channel DRR (MCDRR). We extend the original DRR to the case of multiple channels with tunable transmitters and fixed receivers to provide efficient fair queueing in hybrid time division multiplexing (TDM)/wavelength division multiplexing (WDM) optical networks. We take into account the availability of channels and tunable transmitters in extending the DRR and allow the overlap of `rounds' in scheduling to efficiently utilize channels and tunable transmitters. Simulation results show that the proposed MCDRR can provide nearly perfect fairness with ill-behaved flows for different sets of conditions for inter-frame times and frame sizes in hybrid TDM/WDM optical networks with tunable transmitters and fixed receivers

    SYMPTOMATOLOGY OF FEMALE PATIENTS ATTENDING MOBILE MEDICAL CLINICS IN A RURAL BLOCK IN TAMILNADU

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    Objectives: The objectives of the study were to find out the prevalence of symptoms not elsewhere classified†under the International Classification of Diseases, Tenth Revision, Clinical Modification among the female patients attending mobile medical clinics.Methods: A cross-sectional study was carried out among 7,124 female patients who attended weekly mobile medical clinics in a rural block in Tamil Nadu. Sociodemographic variables, symptomatology, patient history, and clinical examination details were collected using a pre-tested structured questionnaire.Results: The five common symptoms affecting the study population were myalgia (18.3%), nasal congestion (13.6%), headache (13.1%), lumbar pain (12.5%), and knee pain (9.3%). The systems commonly affected among the female patients were in the order of general symptoms and signs (R50-R69), circulatory and respiratory systems (R00-R09), and Nervous and Musculoskeletal Systems (R25-R29). In the age group of 10–19 years and 20–39 years, the most common symptom was headache (25.2% and 18.8%, respectively). In the age group of 40–59 years and 60 years and above, it was myalgia (24.2% and 32.3%, respectively).Conclusion: As pain being most common symptoms, an appropriate strategy and guidelines have to be developed to manage the problem of pain at primary care level
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