209 research outputs found

    Robust detection, isolation and accommodation for sensor failures

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    The objective is to extend the recent advances in robust control system design of multivariable systems to sensor failure detection, isolation, and accommodation (DIA), and estimator design. This effort provides analysis tools to quantify the trade-off between performance robustness and DIA sensitivity, which are to be used to achieve higher levels of performance robustness for given levels of DIA sensitivity. An innovations-based DIA scheme is used. Estimators, which depend upon a model of the process and process inputs and outputs, are used to generate these innovations. Thresholds used to determine failure detection are computed based on bounds on modeling errors, noise properties, and the class of failures. The applicability of the newly developed tools are demonstrated on a multivariable aircraft turbojet engine example. A new concept call the threshold selector was developed. It represents a significant and innovative tool for the analysis and synthesis of DiA algorithms. The estimators were made robust by introduction of an internal model and by frequency shaping. The internal mode provides asymptotically unbiased filter estimates.The incorporation of frequency shaping of the Linear Quadratic Gaussian cost functional modifies the estimator design to make it suitable for sensor failure DIA. The results are compared with previous studies which used thresholds that were selcted empirically. Comparison of these two techniques on a nonlinear dynamic engine simulation shows improved performance of the new method compared to previous technique

    Computation of Zeros of Linear Multivariable Systems

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    Several algorithms have been proposed in the literature for the computation of the zeros of a linear system described by a state-space model {A, B, C, D}. In this paper we discuss the numerical properties of a new algorithm and compare it with some earlier techniques of computing zeros. The method is a modified version of Silverman's structure algorithm and is shown to be backward stable in a rigorous sense. The approach is shown to handle both nonsquare and/or degenerate systems. Several numerical examples are also provided

    A Review of Systemic Biologics and Local Immunosuppressive Medications in Uveitis

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    Uveitis is one of the most common causes of vision loss and blindness worldwide. Local and/or systemic immunosuppression is often required to treat ocular inflammation in noninfectious uveitis. An understanding of safety and efficacy of these medications is required to individualize treatment to each patient to ensure compliance and achieve the best outcome. In this article, we reviewed the effectiveness of systemic biologic response modifiers and local treatments commonly used in the management of patients with noninfectious uveitis

    Medication-induced Uveitis: An Update

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    Drug-induced uveitis is an uncommon but important cause of ocular inflammation. Uveitis can be seen in association with various systemic, topical, and intraocular medications. In this article, we review common medications associated with uveitis. Most cases of drug-induced uveitis resolve with termination of the suspected medication with or without administration of topical or systemic steroids. It is important for clinicians to readily identify medications that may cause uveitis in order to provide rapid treatment, avoid consequences of longstanding inflammation, and prevent costly and excessive laboratory testing

    You, Me, and IoT: How Internet-Connected Consumer Devices Affect Interpersonal Relationships

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    Internet-connected consumer devices have rapidly increased in popularity; however, relatively little is known about how these technologies are affecting interpersonal relationships in multi-occupant households. In this study, we conduct 13 semi-structured interviews and survey 508 individuals from a variety of backgrounds to discover and categorize how consumer IoT devices are affecting interpersonal relationships in the United States. We highlight several themes, providing large-scale exploratory data about the pervasiveness of interpersonal costs and benefits of consumer IoT devices. These results also inform follow-up studies and design priorities for future IoT technologies to amplify positive and reduce negative interpersonal effects.Comment: 26 pages, 5 figures, 5 tables. Updated version with additional examples and minor revisions. Original title: "You, Me, and IoT: How Internet-Connected Home Devices Affect Interpersonal Relationships

    Brain abscess as a manifestation of spinal dermal sinus

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    Dermal sinuses have been associated with a wide spectrum of clinical manifestations ranging from asymptomatic to drainage of purulent material from the sinus tract, inclusion tumors, meningitis, and spinal abscess. To date, there has been no documented report of brain abscess as a complication of spinal dermal sinus. Here, we report an 8-month-old girl who was presented initially with a brain abscess at early infancy but lumbar dermal sinus and associated spinal abscess were discovered afterwards. The probable mechanisms of this rare association have been discussed

    The Geographical Distribution of Laryngeal Cancer in Iran from 2004 to 2014

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    Background: Laryngeal cancer accounts for about 1 to 2 % of all cancers; this incidence rate depends on the geographical region and ethnicity. Due to the lack of a comprehensive epidemiological study on laryngeal cancer in recent years, we designed this study to investigate the incidence and geographical distribution of laryngeal cancer. Aim: This study aimed to investigate the incidence and geographical distribution of laryngeal cancer in Iran from 2004 to 2014. Methods: The data collected from the Iranian National Cancer Data System registry, all the cases of laryngeal cancer (with topography code 32 and histology of laryngeal cancer) have been retrieved and analyzed from a comprehensive cancer database during the 11 years' period. Then statistical data were analyzed by SPSS, version 16. Results: During the 11-year study, 13,241 new cases of laryngeal cancer were recorded, of which 11454 were men (86%) and 1788 were women (14%). According to this assessment, North Khorasan, Sistan and Baluchestan, and East Azerbaijan provinces had the highest growth rate, and North Khorasan, Gilan, and Kerman provinces with the highest incidence rates of 4.44, 3.29, and 2.23 per 100,000 respectively, between 2004 and 2014. Conclusion: According to the results of this study, the incidence rate of laryngeal cancer, especially in women, is increasing in Iran. Further studies are needed to investigate the causes of increased incidence
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