764 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

    The comparison of satisfaction of prosthesis in below amputation men using a mechanical and Myoelectric prosthesis by using of TAPES questionnaire

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    Design and manufacturing of the Myoelecterical prosthesis (in compared to Mechanical prosthesis) is time consuming and expensive. Therefore, considering the high cost of these prostheses should be increase the satisfaction of prosthesis. This study was conducted on assessing the quality of life between two groups. The two groups compared from the aspect of quality of life. The participants were categorized in two groups of 20 below elbow amputation veterans that use from Mechanical or Myoelectrical prosthesis that refer to central technical orthopedic Kosar. For gathering the data we use TPEAS questionnaire. This questionnaire evaluates participants from 3 items: psychosocial adaptation, functional limitation and satisfaction of life. For data analysis use to t independent and ANOVA test. The obtained results revealed that there are significant differentiations in prosthesis satisfaction. This identified that the Myoelecterical groups have upper prosthesis satisfaction in compare to Mechanical group. Therefore the hypothesis of this research in terms of higher satisfaction in the Myoelecterical group was accepted. Keivani Hafshejani mA, Sattari Naeini M, Langari A. The comparison of satisfaction of prosthesis in below amputation men using a mechanical and Myoelectric prosthesis by using of TAPES questionnaire. Life Sci J 2012;9(4):5588-5592] (ISSN: 1097-8135). http://www.lifesciencesite.com. 83

    Inhibitory effect of plant essential oils on Malassezia strains from Iranian dermatitis patients

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    Introduction: The genus Malassezia is an important skin resident of human. The present study aimed to analyze in vitro activity of the essential oils of Lavandula stoechas, Cuminum cyminum and Artemisia sieberi against clinical strains of Malassezia species. Methods: A total of 47 Malassezia strains, including Malassezia furfur, Malassezia globosa and Malassezia obtuse, were used in this study. A disk diffusion technique was selected for testing the susceptibility of Malassezia strains to the essential oils. Results: All the essential oils showed in vitro activity against Malassezia strains, with M. furfur and M. obtusa being the highest and lowest susceptible of the strains, respectively. The highest antifungal activity was associated with the essential oil of C. cyminum (mean ± SD: 50.0 ± 0.0 mm), followed by L. stoechas (mean ± SD: 46.8 ± 3.1 mm) and A. sieberi (mean ± SD: 36.9 ± 5.7 mm). The inhibition zone ranges were 12.5 to 15.6 mm (mean ± SD: 14.4 ± 1.6 mm) for ketoconazole and 11.6 to 13.3 mm (mean ± SD: 12.4 ± 0.9 mm) for fluconazole. Although all the antifungal drugs were found to possess good antifungal activities against Malassezia strains, their effects were lower than the activities shown by the essential oils tested (P < 0.05). Conclusion: These results indicated that the essential oils tested, especially the one from C. cyminum, inhibited the growth of clinical strains of Malassezia, implying its potential use in the treatment of Malassezia infections. This indicates that this plant may be useful in preparation of new drugs

    On the functional limitation in below elbow amputation men using Mechanical and Myoelectric prosthesis via TAPES questionnaire

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    It is well established that the Myoelecterical prosthesis must also be effective, smart, light, strong and high permanence, compared to those of Mechanical prosthesis. It is time consuming and expensive that has ultimately led to significant increases in the price of Myoelecterical prosthesis. Therefore, considering the high cost of these prostheses should be decrease the functional limitation, hence assessment the functional limitations between two groups must be clear and explicit. Therefore this study was conducted in this regard. In this descriptive cross-sectional analytical study, to groups compared to each other from quality of life, participants was two groups of 20 below elbow amputation veterans that use from Mechanical or Myoelectrical prosthesis that refer to central technical orthopedic Kosar. For gathering the data we use TPEAS questionnaire. This questionnaire evaluates participants from 3 items: psychosocial adaptation, functional limitation and satisfaction of life. For data analysis use to t independent and ANOVA test. This research showed that there are significant differences between two groups from functional limitation. The findings identified that the Myoelecterical groups have lower functional limitation in compare to Mechanical group. So that the hypothesis of this research in terms of lower functional limitation in the Myoelecterical group was accepted. Keivani Hafshejani mA, Sattari Naeini M, Langari A. On the functional limitation in below elbow amputation men using Mechanical and Myoelectric prosthesis via TAPES questionnaire. Life Sci J 2012;9(4):5579-5582] (ISSN: 1097-8135). http://www.lifesciencesite.com. 82

    Detection and Molecular Characterization of Cryptosporidium species in Recreational Waters of Chaharmahal va Bakhtiyari Province of Iran using nested-PCR-RFLP

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    Background: The aim of this study was to detect and characterize Cryptosporidium spp. in water sam­ples collected from recreational ponds of Chaharmahal va Bakhtiyari Province of Iran .Meth­ods: Thirty water samples were collected from November 2009 to May 2010. Each sample con­tained 10 liters of water. We used the SSU rRNA-based PCR-RFLP technique.Results: Out of thirty samples examined, 6 (20%) were positive for different Cryptosporidium spp. Restriction pattern analysis showed that C. parvum has been the most prevalent genotype, fol­lowed by C. hominis and C. canis , respectively. In this area, the higher prevalence of C. par­vum compared with other genotypes is consistent with the distribution of cattle.Conclusion: Farm animals, particularly cattle are the main source of cryptosporidial contamina­tion for recreational waters in this area

    Cascading Failures in Interdependent Infrastructures: An Interdependent Markov-Chain Approach

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    Many critical infrastructures are interdependent networks in which the behavior of one network impacts those of the others. Despite the fact that interdependencies are essential for the operation of critical infrastructures, such interdependencies can negatively affect the reliability and fuel the cascade of failures within and across the networks. In this paper, a novel interdependent Markov-chain framework is proposed that enables capturing interdependencies between two critical infrastructures with the ultimate goal of predicting their resilience to cascading failures and characterizing the effects of interdependencies on system reliability. The framework is sufficiently general to model cascading failures in any interdependent networks; however, this paper focuses on the electric-cyber infrastructure as an example. Using this framework it is shown that interdependencies among reliable systems, i.e., systems with exponentially distributed failure sizes, can make the individually reliable systems behave unreliably as a whole with power-law failure-size distributions

    Use of artificial neural network for medical risk assessment analysis

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    For new medical products and new drugs, unanticipated side effects that rise after consuming the new product is a dominant factor in decision making. In this project, an artificial neural network (NN) engine is designed and developed by the authors to the aim of a medical risk assessment. Firstly, an appropriate NN system is designed and trained. We mostly concerned with the procedure of how the developed NN construction and training. The designed NN for this case has three layers of neuron. These three layers include an input layer, a hidden layer and finally an output layer, with 25 neurons in the hidden layer. The results from NN models can match the data used for training. Hafshejani M K, Sattari Naeini M, Mohammadsharifi A, Langari A. Use of Artificial Neural Network for Medical Risk Assessment Analysis. Life Sci J 2012;9(4):923-925] (ISSN:1097-8135). http://www.lifesciencesite.com. 14
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