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This paper reports the results of a study that examined Arabic-speaking children’s interaction with the International Children’s Digital Library (ICDL). Assessment of the ICDL to Arabic-speaking children as a culturally diverse group was grounded in “representations” and “meaning” rather than in internationalization and localization. The utility of the ICDL navigation controls was judged based on the extent it supported children’s navigation. Most of the ICDL representations and their meanings were found to be highly appropriate for older children but inappropriate for younger ones. The design of the ICDL navigation controls was supportive of children’s navigation. Recommendations for assessing the cross-cultural usability of the ICDL are made and suggestions for system design improvements are provided. 相似文献
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Disturbance rejection in nonlinear uncertain systems is a challenging issue especially when the sensor noise cannot be eliminated by low pass filtering. Fuzzy relational models (FRM) can effectively represent the sensor noise in the fuzzy control signal. Due to the large amount of sensor noise there will be huge actuator movement. In most of the cases the actuator movement is in response to the noise and not due to the set-point change. Conditional defuzzification is employed to reduce the control activity. The amount of control activity depends on the threshold level of the conditional defuzzification scheme. A novel scheme has been presented in this paper which can significantly reduce the actuator movement due to noise by adapting the conditional defuzzification threshold. Effective disturbance rejection can be achieved if the controller is modeled as an exact inverse of the plant model. The controller is a fuzzy relational model which develops the inverse plant model by incorporating feedback error learning. Sensitivity analyses have been carried out which demonstrate the efficiency of the proposed methodology. 相似文献
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Servin Yeşil Günal Bilal Üstündağ Ali İhsan Günal 《Indian journal of clinical biochemistry : IJCB》2013,28(4):390-395
The aim of this study is to evaluate the oxidative stress in predialysis, hemodialysis (HD) and peritoneal dialysis patients and to test the effects of antihypertensive drugs and volume control on oxidative stress parameters. The study was composed of five groups as follows: control group (n = 30), predialysis group (n = 30), peritoneal dialysis group (n = 30), hemodialysis group, (normotensive with strict volume control, n = 30), hemodialysis group (normotensive with medication, n = 30). Plasma malondialdehyde (MDA), erythrocyte superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) and routine biochemical parameters were studied in all patients. Hemodialysis patients with strict volume control (HDvc) had lower levels of MDA than other patient groups (p < 0.001), and CAT, SOD values had highest level other patient groups (p < 0.001). The treatment of hypertension with strict volume control in chronic renal failure patients causes less damage to the antioxidant capacity. 相似文献