20 research outputs found

    Harmonic elimination in a single phase inverter output voltage with 2 and 4 bipolar notches in a half cycle by the HGA

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    2010 International Symposium on Power Electronics, Electrical Drives, Automation and Motion, SPEEDAM 2010 -- 14 June 2010 through 16 June 2010 -- Pisa -- 81684Inverters are power devices used for many industrial applications such as power conversion, the speed control of induction motors etc. When a magnetic device is energized by an inverter power supply, its magnetic core is subjected to additional core losses due to harmonic contents. One solution to this problem may be the selective harmonic elimination based on the simultaneous solution of non-linear equations that are mainly function of the switching angles. In this paper, the hybrid genetic algorithms method was used to eliminate the dominant harmonics leading to additional losses in a strip wound toroidal core used to build a low power transformer. The results indicated that the proposed method works well and it achieves to reduce the total harmonic distortion at the primary current and the induced voltage of the transformer under both ohmic and inductive loads. © 2010 IEEE

    Improved three-step input shaping control of crane system

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    Shaping command input is performed for reducing residual vibrations in motion control of dynamical structures. System inputs are changed so that the structure reaches to planned motion in minimum duration without residual oscillation. Shaping input is obtained by convolving desired input with an impulse sequence. Main goal of the input shaper design is to define impulse amplitudes and their instants from the dynamical behavior of uncontrolled response. Zero Vibration (ZV), Zero Vibration and Derivative (ZVD) and Extra Insensitive (EI) are the most common shaper types. Improving the robustness respect to modeling errors requires more impulses. These increase control duration and make difficult to solve constraint equations directly. Required parameters can be determined from the derivation of constraint equations. This paper presents Three-Step (TS) input shaping technique. A solution space for three-impulse shaping is given including both positive and negative shapers. It is shown here that ZVD and EI shapers are the special solution points in TS shaping space. The duration of the shaper less or more than ZVD's can be obtained in the defined space. Some of the new shapers give better robustness than ZVD. Experimental results from a prototype planar crane system are used to support the numerical results

    Analysis of geographical variations in the epidemiology and management of non-valvular atrial fibrillation: results from the RAMSES registry.

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    Objective: This study aimed to determine the differences in terms of demographic characteristics and preferred stroke prevention strategies for patients with non-valvular atrial fibrillation living in seven geographical regions of Turkey.Methods: In total, 6273 patients were enrolled to this prospective, observational RAMSES study. The patients were divided into seven groups based on the geographical region of residence.Results: In terms of the geographical distribution of the overall Turkish population, the highest number of patients were enrolled from Marmara (1677, 26.7%). All demographic characteristics were significantly different among regions. Preferred oral anticoagulants (OACs) also differed between geographical regions; non-vitamin K OACs were preceded by warfarin in East Anatolia, Aegean, Southeast Anatolia, and Black Sea. Nearly one-third of the patients (28%) did not receive any OAC therapy. However, the number of patients not receiving any OAC therapy was higher in Southeast Anatolia (51.1%) and East Anatolia (46.8%) compared with other geographical regions of Turkey. Inappropriate use of OACs was also more common in East and Southeast Anatolia.Conclusion: This study was the first to show that the demographic differences among the geographical regions may result in different prefer-ences of stroke prevention strategies in Turkey. OACs are still under- or inappropriately utilized, particularly in the eastern provinces of Turkey

    Deferasirox in children with transfusion-dependent thalassemia or sickle cell anemia: A large cohort real-life experience from Turkey (REACH-THEM)

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    Objectives: To evaluate the long-term efficacy and safety of deferasirox therapy in a large observational cohort of children with transfusion-dependent thalassemia (TDT) and sickle cell anemia (SCA) in Turkey. Methods: This was a multicenter, prospective cohort study including TDT and SCA patients aged 2-18 years with iron overload (≥100 mL/kg of pRBC or a serum ferritin [SF] level >1000 μg/L) receiving deferasirox. Patients were followed for up to 3 years according to standard practice. Results: A total of 439 patients were evaluated (415 [94.5%] TDT, 143 [32.6%] between 2 and 6 years). Serum ferritin levels consistently and significantly decreased across 3 years of deferasirox therapy from a median of 1775.5 to 1250.5 μg/L (P < 0.001). Serum ferritin decreases were noted in TDT (1804.9 to 1241 μg/L), SCA (1655.5 to 1260 μg/L), and across age groups of 2-6 years (1971.5 to 1499 μg/L), 7-12 years (1688.5 to 1159.8 μg/L), and 13-18 years (1496.5 to 1107 μg/L). Serum ferritin decreases were also noted for all deferasirox dose groups but only significant in patients with doses ≥30 mg/kg/d (n = 120, −579.6 median reduction, P < 0.001). Only 9 (2%) patients had adverse events suspected to be related to deferasirox. Serum creatinine slightly increased but remained within the normal range. Conclusions: Deferasirox has long-term efficacy and safety in children with TDT and SCA, although higher doses (≥30 mg/kg/d) may be required to achieve iron balance. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Lt

    Deferasirox in children with transfusion-dependent thalassemia or sickle cell anemia: A large cohort real-life experience from Turkey (REACH-THEM).

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    OBJECTIVES: To evaluate the long-term efficacy and safety of deferasirox therapy in a large observational cohort of children with transfusion-dependent thalassemia (TDT) and sickle cell anemia (SCA) in Turkey. METHODS: This was a multicenter, prospective cohort study including TDT and SCA patients aged 2-18 years with iron overload (≥100 mL/kg of pRBC or a serum ferritin [SF] level >1000 μg/L) receiving deferasirox. Patients were followed for up to 3 years according to standard practice. RESULTS: A total of 439 patients were evaluated (415 [94.5%] TDT, 143 [32.6%] between 2 and 6 years). Serum ferritin levels consistently and significantly decreased across 3 years of deferasirox therapy from a median of 1775.5 to 1250.5 μg/L (P < 0.001). Serum ferritin decreases were noted in TDT (1804.9 to 1241 μg/L), SCA (1655.5 to 1260 μg/L), and across age groups of 2-6 years (1971.5 to 1499 μg/L), 7-12 years (1688.5 to 1159.8 μg/L), and 13-18 years (1496.5 to 1107 μg/L). Serum ferritin decreases were also noted for all deferasirox dose groups but only significant in patients with doses ≥30 mg/kg/d (n = 120, -579.6 median reduction, P < 0.001). Only 9 (2%) patients had adverse events suspected to be related to deferasirox. Serum creatinine slightly increased but remained within the normal range. CONCLUSIONS: Deferasirox has long-term efficacy and safety in children with TDT and SCA, although higher doses (≥30 mg/kg/d) may be required to achieve iron balance
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