6,077 research outputs found

    Comment on "Head-on collision of electron acoustic solitary waves in a plasma with nonextensive hot electrons"

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    In a recent paper "Head-on collision of electron acoustic solitary waves in a plasma with nonextensive hot electrons" [Astrophys. Space Sci. 338, 271-278 (2012)] Eslami, Mottaghizadeh and Pakzad deal with the problem of the head-on collisions between two weakly nonlinear electron-acoustic solitary waves. Unfortunately, their treatment is deficient and leads to erroneous conclusions.Comment: Accepted for publication in "Astrophysics and Space Science

    On discrete control of nonlinear systems with applications to robotics

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    Much progress has been reported in the areas of modeling and control of nonlinear dynamic systems in a continuous-time framework. From implementation point of view, however, it is essential to study these nonlinear systems directly in a discrete setting that is amenable for interfacing with digital computers. But to develop discrete models and discrete controllers for a nonlinear system such as robot is a nontrivial task. Robot is also inherently a variable-inertia dynamic system involving additional complications. Not only the computer-oriented models of these systems must satisfy the usual requirements for such models, but these must also be compatible with the inherent capabilities of computers and must preserve the fundamental physical characteristics of continuous-time systems such as the conservation of energy and/or momentum. Preliminary issues regarding discrete systems in general and discrete models of a typical industrial robot that is developed with full consideration of the principle of conservation of energy are presented. Some research on the pertinent tactile information processing is reviewed. Finally, system control methods and how to integrate these issues in order to complete the task of discrete control of a robot manipulator are also reviewed

    The effect of 12 weeks regular physical activity and vitamin E in the treatment of non-alcoholic steatohepatitis: A pilot study

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    Background: Despite the prevalence of Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH), there was no treatment has been proven to be effective in these common diseases. Although many studies have shown that lifestyle modifications such as increasing physical activities and exercise could be effective in the treatment of these common diseases, the optimal strategy was still not determined. According to the beneficial effects of antioxidant agents in the treatment of NASH, vitamin E has been used for this purpose by some clinicians. We designed this study for assessing beneficial effects of regular physical activity on the biochemical and imaging responses in patients with NASH and comparing this with vitamin E as an accepted treatment for NASH. Materials and Methods: This study was Randomized and single-blind clinical trials were carried out in Gonbad-e Kavus through which a total of 30 consecutive patients with the ultra sonographic diagnosis of non-alcoholic steatohepatitis (NASH)were enrolled and randomized to one of the three groups: Vitamin E 800 mg/day, regular physical activity, or both. Results: In all treatment groups improvement in liver transaminases level, serum lipids and ultrasonographic grading of fatty liver occurred after three months of treatment. When these decrement was compared between the treatment groups, there was no statistically significant difference in the value of improvement between the three groups (ANOVA: p>0.5). I.e. all three interventions improved the biochemical and ultrasonographic finding of fatty liver in the same way. Both groups with regular exercise had significant mean weight loss in comparison with the vitamin E group (a mean decrease of 3.0 kg in exercise group, 5.8 kg in subjects on regular exercise plus vitamin E and 0.2 kg in vitamin E group, ANOVA: p=0.04). Conclusion: There were no significant differences between exercise and vitamin E alone or in combination regarding the reduction in the level of liver enzymes and sonographic evidences of fatty liver although both resulted in significant improvements in biochemical endpoints. This implies that physical activity could be considered as effective as vitamin E in the improvement of biochemical and ultrasonographic presentations of NASH and the addition of Vitamin E does not offer any benefits. According to the findings of this pilot study a full-powered study with a control group should be designed. © 2015, Iranian Association of Gastroenterology and Hepatology. All rights reserved

    The effect of 12 weeks regular physical activity and vitamin E in the treatment of non-alcoholic steatohepatitis: A pilot study

    Get PDF
    Background: Despite the prevalence of Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH), there was no treatment has been proven to be effective in these common diseases. Although many studies have shown that lifestyle modifications such as increasing physical activities and exercise could be effective in the treatment of these common diseases, the optimal strategy was still not determined. According to the beneficial effects of antioxidant agents in the treatment of NASH, vitamin E has been used for this purpose by some clinicians. We designed this study for assessing beneficial effects of regular physical activity on the biochemical and imaging responses in patients with NASH and comparing this with vitamin E as an accepted treatment for NASH. Materials and Methods: This study was Randomized and single-blind clinical trials were carried out in Gonbad-e Kavus through which a total of 30 consecutive patients with the ultra sonographic diagnosis of non-alcoholic steatohepatitis (NASH)were enrolled and randomized to one of the three groups: Vitamin E 800 mg/day, regular physical activity, or both. Results: In all treatment groups improvement in liver transaminases level, serum lipids and ultrasonographic grading of fatty liver occurred after three months of treatment. When these decrement was compared between the treatment groups, there was no statistically significant difference in the value of improvement between the three groups (ANOVA: p>0.5). I.e. all three interventions improved the biochemical and ultrasonographic finding of fatty liver in the same way. Both groups with regular exercise had significant mean weight loss in comparison with the vitamin E group (a mean decrease of 3.0 kg in exercise group, 5.8 kg in subjects on regular exercise plus vitamin E and 0.2 kg in vitamin E group, ANOVA: p=0.04). Conclusion: There were no significant differences between exercise and vitamin E alone or in combination regarding the reduction in the level of liver enzymes and sonographic evidences of fatty liver although both resulted in significant improvements in biochemical endpoints. This implies that physical activity could be considered as effective as vitamin E in the improvement of biochemical and ultrasonographic presentations of NASH and the addition of Vitamin E does not offer any benefits. According to the findings of this pilot study a full-powered study with a control group should be designed. © 2015, Iranian Association of Gastroenterology and Hepatology. All rights reserved

    A survey on tasks performed in eldercare

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    In the Netherlands, a vast increase of the expenses on eldercare is expected for the future. Currently, an IT system is under development that aims to assist care providers with their tasks in providing care services. Before such a system can be used in practice, insight is needed on the current work situation in eldercare. This paper presents interview surveys on tasks currently performed by professionals in two nursing houses. Both the professional population and details on how it spends its time are described. Little room is observed for automating tasks in nursing and/or caring houses
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