University of Erlangen-Nuremberg

About: University of Erlangen-Nuremberg is a education organization based out in Erlangen, Bayern, Germany. It is known for research contribution in the topics: Population & Immune system. The organization has 42405 authors who have published 85600 publications receiving 2663922 citations.

The benefits of event: driven energy accounting in power-sensitive systems

Abstract: A prerequisite of energy-aware scheduling is precise knowledge of any activity inside the computer system. Embedded hardware monitors (e.g., processor performance counters) have proved to offer valuable information in the field of performance analysis. The same approach can be applied to investigate the energy usage patterns of individual threads. We use information about active hardware units (e.g., integer/floating-point unit, cache/memory interface) gathered by event counters to establish a thread-specific energy accounting. The evaluation shows that the correlation of events and energy values provides the necessary information for energy-aware scheduling policies.Our approach to OS-directed power management adds the energy usage pattern to the runtime context of a thread. Depending on the field of application we present two scenarios that benefit from applying energy usage patterns: Workstations with passive cooling on the one hand and battery-powered mobile systems on the other hand.Energy-aware scheduling evaluates the energy usage of each thread and throttles the system activity so that the scheduling goal is achieved. In workstations we throttle the system if the average energy use exceeds a predefined power-dissipation capacity. This makes a compact, noiseless and affordable system design possible that meets sporadic yet high demands in computing power. Nowadays, more and more mobile systems offer the features of reducible clock speed and dynamic voltage scaling. Energy-aware scheduling can employ these features to yield a longer battery life by slowing down low-priority threads while preserving a certain quality of service.

Reduction in Adhesive Small-Bowel Obstruction by Seprafilm® Adhesion Barrier After Intestinal Resection

Abstract: Although Seprafilm® has been demonstrated to reduce adhesion formation, it is not known whether its usage would translate into a reduction in adhesive small-bowel obstruction. This was a prospective, randomized, multicenter, multinational, single-blind, controlled study. This report focuses on those patients who underwent intestinal resection (n = 1,701). Before closure of the abdomen, patients were randomized to receive Seprafilm® or no treatment. Seprafilm® was applied to adhesiogenic tissues throughout the abdomen. The incidence and type of bowel obstruction was compared between the two groups. Time to first adhesive small-bowel obstruction was compared during the course of the study by using survival analysis methods. The mean follow-up time for the occurrence of adhesive small-bowel obstruction was 3.5 years. There was no difference between the treatment and control group in overall rate of bowel obstruction. The incidence of adhesive small-bowel obstruction requiring reoperation was significantly lower for Seprafilm® patients compared with no-treatment patients: 1.8 vs. 3.4 percent (P < 0.05). This finding represents an absolute reduction in adhesive small-bowel obstruction requiring reoperation of 1.6 percent and a relative reduction of 47 percent. In addition, a stepwise multivariate analysis indicated that the use of Seprafilm® was the only predictive factor for reducing adhesive small-bowel obstruction requiring reoperation. In both groups, 50 percent of first adhesive small-bowel obstruction episodes occurred within 6 months after the initial surgery with nearly 30 percent occurring within the first 30 days. Additionally no first adhesive small-bowel obstruction events were reported in Years 4 and 5 of follow-up. The overall bowel obstruction rate was unchanged; however, adhesive small-bowel obstruction requiring reoperation was significantly reduced by the use of Seprafilm®, which was the only factor that predicted this outcome.