AcMus: an Open, Integrated Platform for Room Acoustics Research

This article describes the design, implementation, and experiences with AcMus, an open and integrated software platform for room acoustics research, which comprises tools for measurement, analysis, and simulation of rooms for music listening and production. Through use of affordable hardware, such as laptops, consumer audio interfaces and microphones, the software allows evaluation of relevant acoustical parameters with stable and consistent results, thus providing valuable information in the diagnosis of acoustical problems, as well as the possibility of simulating modifications in the room through analytical models. The system is open-source and based on a flexible and extensible Java plug-in framework, allowing for cross-platform portability, accessibility and experimentation, thus fostering collaboration of users, developers and researchers in the field of room acoustics.

PD controller synthesis from open-loop response measurements of rotating system

In this work, a method of computing PD stabilising gains for rotating systems is presented based on the D-decomposition technique, which requires the sole knowledge of frequency response functions. By applying this method to a rotating system with electromagnetic actuators, it is demonstrated that the stability boundary locus in the plane of feedback gains can be easily plotted, and the most suitable gains can be found to minimise the resonant peak of the system. Experimental results for a Laval rotor show the feasibility of not only controlling lateral shaft vibration and assuring stability, but also helps in predicting the final vibration level achieved by the closed-loop system. These results are obtained based solely on the input-output response information of the system as a whole.

Comparison between endoscopic and open surgery in 37 patients with nasopharyngeal angiofibroma

Juvenile nasopharyngeal angiofibroma is a rare benign vascular tumor of the nasopharynx. Although the treatment of choice is surgery, there is no consensus on what is the best approach. Aim: To compare surgical time and intraoperative transfusion requirements in patients undergoing endoscopic surgery versus open / combined and relate the need for transfusion during surgery with the time between embolization and surgery. Material and Methods: Study descriptive, analytical, retrospective study with a quantitative approach developed in the Otorhinolaryngology department of a teaching hospital. Analyzed 37 patients with angiofibroma undergoing surgical treatment. Data obtained from medical records. Analyzed with tests of the Fisher-Freeman-Halton and Games-Howell. Was considered significant if p <0.05. Study design: Historical cohort study with cross-sectional. Results: The endoscopic approach had a shorter operative time (p <0.0001). There is less need for transfusion during surgery when the embolization was performed on the fourth day. Conclusion: This suggests that the period ahead would be ideal to perform the process of embolization and endoscopic surgery by demanding less time would be associated with a lower morbidity. This study, however, failed to show which group of patients according to tumor stage would benefit from specific technical.

RAND-like Appropriateness Methodology Consensus for Primary Open-Angle Glaucoma in Latin America

PURPOSE: To report the results of a Latin American consensus panel regarding the diagnosis and management of primary open-angle glaucoma and to compare these results with those from a similar panel in the United States. DESIGN: A RAND-like (Research and Development) appropriateness methodology was used to assess glaucoma practice in Latin America. METHODS: The 148 polling statements created for the RAND-like analysis in the United States and 10 additional statements specific to glaucoma care in Latin America were presented to a panel of Latin American glaucoma experts. Panelists were polled in private using the RAND-like methodology before and after the panel meeting. RESULTS: Consensus agreement or disagreement among Latin American experts was reached for 51.3% of statements before the meeting and increased to 66.5% in the private, anonymous meeting after polling (79.0% agreement, 21.0% disagreement). Although there was a high degree of concordance (111 of 148 statements; 75%) between the results of this Latin American panel and the United States panel, there were some notable exceptions relating to diagnostic and therapeutic decision making. CONCLUSIONS: This RAND-like consensus methodology provides a perspective of how Latin American glaucoma practitioners view many aspects of glaucoma and compares these results with those obtained using a similar methodology from practitioners in the United States. These findings may be helpful to ophthalmologists providing glaucoma care in Latin America and in other regions of the world. (Am J Ophthalmol 2012;154: 460-465. (C) 2012 by Elsevier Inc. All rights reserved.)