Multiprocessor task scheduling in multistage hyrid flowshops: a genetic algorithm approach

This paper considers multiprocessor task scheduling in a multistage hybrid flow-shop environment. The objective is to minimize the make-span, that is, the completion time of all the tasks in the last stage. This problem is of practical interest in the textile and process industries. A genetic algorithm (GA) is developed to solve the problem. The GA is tested against a lower bound from the literature as well as against heuristic rules on a test bed comprising 400 problems with up to 100 jobs, 10 stages, and with up to five processors on each stage. For small problems, solutions found by the GA are compared to optimal solutions, which are obtained by total enumeration. For larger problems, optimum solutions are estimated by a statistical prediction technique. Computational results show that the GA is both effective and efficient for the current problem. Test problems are provided in a web site at www.benchmark.ibu.edu.tr/mpt-h; fsp

Comparing the Effects of Atorvastatin with Sodium Valproate (Divalproex) on Frequency and Intensity of Frequent Migraine Headaches: A Double-blind Randomized Controlled Study

Objectives To evaluate the prophylactic effects of atorvastatin on frequency, intensity, and duration of migraine attacks compared with sodium valproate. Methods In this randomized, double-blind, single-center controlled trial, patients with 6 to 15 migraine attacks per month, which were candidates of preventive treatment, were recruited. The patients were randomly allocated into 2 groups. The first group (A) received atorvastatin 40 mg daily, and the second group (B) received sodium valproate 500 mg daily. All patients were visited each month and followed up for 3 months. The characteristics of migraine headaches including frequency, intensity, and duration of attacks were recorded, as well as the number of analgesics taken per each attack and probable adverse effects. Results From 100 patients enrolled in the study, 18 cases were excluded owing to adverse effects (2 cases) or lost to follow-up (16 cases). From 82 patients who completed the trial, 46 and 36 were in group A (atorvastatin) and group B (sodium valproate), respectively. Mean age of the patients was not significantly different in the 2 arms of the study (33.56 ± 8.51 in group A and 33.25 ± 9.91 years in group B, P = 0.877). Number, duration, and intensity of attacks and number of analgesics taken during attacks decreased significantly in both groups in monthly follow-ups. However, there was no statistically significant difference between 2 arms of the study in terms of attenuation in the characteristics of migraine attacks. On the other hand, patients in group A suffered fewer adverse effects compared with group B. Conclusions This study indicates that atorvastatin could be an alternative for sodium valproate in migraine prophylaxis with comparable efficacy and fewer adverse effects. Multicenter studies with larger sample size are recommended. © Wolters Kluwer Health, Inc. All rights reserved

Comparing the Effects of Atorvastatin with Sodium Valproate (Divalproex) on Frequency and Intensity of Frequent Migraine Headaches: A Double-blind Randomized Controlled Study

Objectives To evaluate the prophylactic effects of atorvastatin on frequency, intensity, and duration of migraine attacks compared with sodium valproate. Methods In this randomized, double-blind, single-center controlled trial, patients with 6 to 15 migraine attacks per month, which were candidates of preventive treatment, were recruited. The patients were randomly allocated into 2 groups. The first group (A) received atorvastatin 40 mg daily, and the second group (B) received sodium valproate 500 mg daily. All patients were visited each month and followed up for 3 months. The characteristics of migraine headaches including frequency, intensity, and duration of attacks were recorded, as well as the number of analgesics taken per each attack and probable adverse effects. Results From 100 patients enrolled in the study, 18 cases were excluded owing to adverse effects (2 cases) or lost to follow-up (16 cases). From 82 patients who completed the trial, 46 and 36 were in group A (atorvastatin) and group B (sodium valproate), respectively. Mean age of the patients was not significantly different in the 2 arms of the study (33.56 ± 8.51 in group A and 33.25 ± 9.91 years in group B, P = 0.877). Number, duration, and intensity of attacks and number of analgesics taken during attacks decreased significantly in both groups in monthly follow-ups. However, there was no statistically significant difference between 2 arms of the study in terms of attenuation in the characteristics of migraine attacks. On the other hand, patients in group A suffered fewer adverse effects compared with group B. Conclusions This study indicates that atorvastatin could be an alternative for sodium valproate in migraine prophylaxis with comparable efficacy and fewer adverse effects. Multicenter studies with larger sample size are recommended. © Wolters Kluwer Health, Inc. All rights reserved