TY - THES A1 - Sailer, Rudolf T1 - Stability and Stabilization of Large-Scale Digital Networks T1 - Stabilität und Stabilisierung großskaliger digitaler Netze N2 - Several aspects of the control of large-scale systems communicating over digital channels are considered. In particular, the issue of delay, quantization, and packet loss is addressed with the help of dynamic quantization. New small-gain results suitable for networked control systems are introduced and it is shown that many of the known small-gain conditions are equivalent. The issue of bandwidth limitations is addressed with the help of event-triggered control. A novel approach termed parsimonious triggering is introduced, which helps to rule out the occurrence of an infinite number of triggering events within finite time. Moreover, the feasibility of the presented approaches is demonstrated by numerical examples. N2 - Es werden großskalige Netzwerke betrachtet, bei denen die Zustandsrückführung über digitale Kommunikationskanäle erfolgt. Typische Effekte digitaler Kommunikation wie Totzeiten, Quantisierung und Paketverlust werden mithilfe der sogenannten dynamischen Quantisierung bearbeitet. Im Kontext der Netzwerkkontrollsysteme werden neue small-gain Ergebnisse eingeführt, die auf den Bedarf der digitalen Kommunikation eingehen. Des Weiteren wird gezeigt, dass viele der aus der Literatur bekannten small-gain Ergebnisse äquivalent sind. Eventbasierte Kontrollstrategien werden vorgestellt, um das Problem der Bandbreitenbeschränkung zu umgehen. Ein neuer Ansatz, parsimonious triggering genannt, wird vorgestellt, um das Problem des unendlich oft Schaltens in endlicher Zeit zu umgehen. Abschließend wird anhand von numerischen Beispielen die Anwendbarkeit der vorgestellten Methoden demonstriert. KW - networked control systems KW - ISS KW - small-gain KW - nonlinear control KW - Rechnernetz KW - Kommunikationssystem KW - Stabilisierung KW - digitale Netze Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-101509 ER - TY - JOUR A1 - von Rüden, Christian A1 - Woltmann, Alexander A1 - Röse, Marc A1 - Wurm, Simone A1 - Rüger, Matthias A1 - Hierholzer, Christian A1 - Bühren, Volker T1 - Outcome after severe multiple trauma: a retrospective analysis JF - Journal of Trauma Management & Outcomes N2 - Background Aim of this study was to evaluate prognosis of severely injured patients. Methods All severely injured patients with an Injury Severity Score (ISS) ≥ 50 were identified in a 6-year-period between 2000 and 2005 in German Level 1 Trauma Center Murnau. Data was evaluated from German Trauma Registry and Polytrauma Outcome Chart of the German Society for Trauma Surgery and a personal interview to assess working ability and disability and are presented as average. Results 88 out of 1435 evaluated patients after severe polytrauma demonstrated an ISS ≥ 50 (6.5%), among them 23% women and 77% men. 66 patients (75%) had an ISS of 50-60, 14 (16%) 61-70, and 8 (9%) ≥ 70. In 27% of patients trauma was caused by motor bike accidents. 3.6 body regions were involved. Patients had to be operated 5.3 times and were treated 23 days in the ICU and stayed 73 days in hospital. Mortality rate was 36% and rate of multi-organ failure 28%. 15% of patients demonstrated severe senso-motoric dysfunction as well as residues of severe head injury. 25% recovered well or at least moderately. 29 out of 56 survivors answered the POLO-chart. A personal interview was performed with 13 patients. The state of health was at least moderate in 72% of patients. In 48% interpersonal problems and in 41% severe pain was observed. In 57% of patients problems with working ability regarding duration, as well as quantitative and qualitative performance were observed. Symptoms of post-traumatic stress disorder were found in 41%. The more distal the lesions were located (foot/ankle) the more functional disability affected daily life. In only 15%, working ability was not impaired. 8 out of 13 interviewed patients demonstrated complete work disability. Conclusions Even severely injured patients after multiple trauma have a good prognosis. The ISS is an established tool to assess severity and prognosis of trauma, whereas prediction of clinical outcome cannot be deducted from this score. KW - post-traumatic stress disorder KW - severe multiple trauma KW - ISS KW - POLO-chart Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132249 VL - 7 IS - 4 ER -