Feedback-Based Iterative Learning Control for MIMO LTI Systems Feedback-Based Iterative Learning Control for MIMO LTI Systems

Abstract: This paper proposes a necessary and sufficient condition of convergence in the 2 Lnorm sense for a feedback-based iterative learning control (ILC) system including a multi-input multi-output (MIMO) linear time-invariant (LTI) plant. It is shown that the convergence conditions for a nominal plant and an uncertain plant are equal to the nominal performance condition and the robust performance condition in the feedback control theory, respectively. Moreover, no additional effort is required to design an iterative learning controller because the performance weighting matrix is used as an iterative learning controller. By proving that the least upper bound of the 2 L -norm of the remaining tracking error is less than that of the initial tracking error, this paper shows that the iterative learning controller combined with the feedback controller is more effective to reduce the tracking error than only the feedback controller. The validity of the proposed method is verified through computer simulations

Design for Layer Jump in Optical Disc Drives Using Internal State Manipulation

Layer jump operation is a vertical seek operation of an actuator between adjacent data layers in an optical disc. As a number of the data layers are raised for high capacity data, the layer jump gradually gains importance for fast playing and recording. Therefore, a systematic design methodology for the layer jump is required to guarantee layer pull-in stability and robustness of model uncertainty. In this paper, a layer jump strategy is proposed for minimizing transient motion and overcoming the effect of model uncertainty by estimating the current velocity of the actuator. The proposed algorithm has been implemented in a system-on-chip for a multi-layered Blu-ray disc drive. The experimental results show the notable performance of the proposed algorithm(1).X11sciescopu

Actinomyces meyeri Empyema: A Case Report and Review of the Literature

Actinomyces meyeri is an uncommon cause of human actinomycosis. Here, we report a rare case of empyema caused by A. meyeri. A 49-year-old male presented with a history of 10 days of dyspnea and chest pain. A large amount of loculated pleural effusion was present on the right side and multiple lung nodules were documented on radiological studies. A chest tube was inserted and purulent pleural fluid was drained. A. meyeri was isolated in anaerobic cultures of the pleural fluid. The infection was alleviated in response to treatment with intravenous penicillin G (20 million IU daily) and oral amoxicillin (500 mg every 8 hours) for 4 months, demonstrating that short-term antibiotic treatment was effective

A Case of Gastro-Gastric Intussusception Secondary to Primary Gastric Lymphoma

In adults, most intussusceptions develop from a lesion, usually a benign or malignant neoplasm, and can occur at any site in the gastrointestinal tract. Intussusception in the proximal gastrointestinal tract is uncommon, and gastro-gastric intussusception is extremely rare. We present a case of gastro-gastric intussusception secondary to a primary gastric lymphoma. An 82-year-old female patient presented with acute onset chest pain and vomiting. Abdominal CT revealed a gastro-gastric intussusception. We performed upper gastrointestinal endoscopy, revealing a large gastric mass invaginated into the gastric lumen and distorting the distal stomach. Uncomplicated gastric reposition was achieved with endoscopy of the distal stomach. Histological evaluation of the gastric mass revealed a diffuse large B cell lymphoma that was treated with chemotherapy. (Korean J Gastroenterol 2016;68:40-44