Time Delay Feedback Control based Chaos Stabilization in Current Mode Controlled DC Drive System

This paper focuses on delay feedback control scheme to eliminate chaos in a current mode controlled DC drive system. The delay feedback method is applied for the current mode DC drive system which exhibits chaotic behavior for some parameter variations to control the chaos in DC drive system. Firstly, the change of system behavior from normal to chaotic operation is shown by changing some parameters. To control the chaos in current mode DC drive system, the controller designed based on time delay feedback control method is applied to DC drive system which works in chaotic regime. It is showed that the behavior of system changes from chaotic regimes to normal operation by applying the time delay feedback control

Analysis of Enterococcus faecalis in samples from Turkish patients with primary endodontic infections and failed endodontic treatment by real-time PCR SYBR green method

OBJECTIVE: The aims of this study were to investigate the presence of Enterococcus faecalis in primary endodontic infections and failed endodontic treatments using real-time PCR and to determine the statistical importance of the presence of E. faecalis in a Turkish population with endodontic infections. MATERIAL AND METHODS: E. faecalis was investigated from 79 microbial samples collected from patients who were treated at the Endodontic Clinic of the Dental School of Atatürk University (Erzurum, Turkey). Microbial samples were taken from 43 patients (Group 1) with failed endodontic treatments and 36 patients (Group 2) with chronic apical periodontitis (primary endodontic infections). DNA was extracted from the samples by using a QIAamp® DNA mini-kit and analyzed with real-time PCR SYBR Green. RESULTS: E. faecalis was detected in 41 out of 79 patients, suggesting that it exists in not less than 61% of all endodontic infections when the proportion test (z= -1.645

The densities of fiber follicles in the Karakas, Norduz, and Zom sheep and a comparative analysis

This study aimed to determine the densities of fiber follicles in the skin of the Karakas, Norduz, and Zom sheep breeds and to carry out a comparative analysis between them. The study included a total of 36 animals aged 1-2 years and 3-4 years. Skin samples were obtained through biopsies taken from the right sides of the animals to determine the densities and ratios of the fleece follicles. Examination of these samples revealed that the primary follicle densities of the three sheep breeds (Karakas, Norduz and Zom) were 3.11 ± 0.42, 3.14 ± 0.49 and 3.34 ± 0.59, while the secondary follicle densities were 8.42 ± 1.48, 8.51 ± 1.54 and 6.36 ± 1.44. The secondary to primary (S/P) follicle ratios of the sheep were 2.71 ± 0.70, 2.79 ± 0.69 and 1.85 ± 0.36, respectively. The primary follicle densities of the Karakas, Norduz and Zom sheep were statistically similar for both age groups. The density of secondary follicles and S/P ratio decreased with age in both age groups. The similarity of the S/P ratios to those from other local sheep breeds suggest that Karakas, Norduz, Zom sheep can be included in the sheep group that has coarse fleece

A transportation type aggregate production model with bounds on inventory and backordering

We consider a certain T period aggregate production planning model, where the two sources of production are regular and overtime. The model allows for time varying production, holding and backordering costs and includes bounds on inventory and backorders. We show that the problem has a rather interesting network structure and exploit this structure to develop a greedy algorithm to solve the problem. The procedure is easy to implement and has a computational complexity of O(T2). We report computational experience with the greedy procedure and demonstrate its superiority to a well known network simplex code, Gnet, implemented on the classical network formulation of the problem. © 1988