Nowadays, our daily live concerns the usage of Information Technology, increasingly. As a result, a huge amount of data has to be processed which is outsourced from local devices to data centers. Due to fluctuating demands these are not fully utilized all the time and consume a significant amount of energy while idling. A common approach to avoid unnecessary idle times is to consolidate running services on a subset of machines and switch off the remaining ones. Unfortunately, the services on a single machine interfere with each other due to the competition for shared resources such as caches after the consolidation, which leads to a degradation of performance. Hence, data centers have to trade off between reducing the energy consumption and certain performance criteria defined in the Service Level Agreement. In order to make the trade off in advance, it is necessary to characterize services and quantify the impact to each other after a potential consolidation. Our approach is to use random variables for characterization, which includes the fluctuations of the resource consumptions. Furthermore, we would like to model the interference of services to provide a probability of exceeding a certain performance criterion.

Based on an application in the field of server consolidation, we consider the one-dimensional cutting stock problem with nondeterministic item lengths. After a short introduction to the general topic we investigate the case of normally distributed item lengths in more detail. Within this framework, we present two lower bounds as well as two heuristics to obtain upper bounds, where the latter are either based on a related (ordinary) cutting stock problem or an adaptation of the first fit decreasing heuristic to the given stochastical context. For these approximation techniques, dominance relations are discussed, and theoretical performance results are stated. As a main contribution, we develop a characterization of feasible patterns by means of one linear and one quadratic inequality. Based on this, we derive two exact modeling approaches for the nondeterministic cutting stock problem, and provide results of numerical simulations.

I mitten av 1800-talet inleddes i Frankrike en renässans för den tidiga kyrkomusiken i allmänhet och den gregorianska sången i synnerhet. Charles-Marie Widor var en av dem som tog intryck av denna rörelse och genom den utvecklade och delvis omvärderade sin syn på musik i kyrkan. Han baserade sina sista två orgelsymfonier, Symphonie Gothique och Symphonie Romane på kyrkans mest centrala teman – Kristi födelse och uppståndelse. Mitt syfte med denna uppsats och att studera dessa orgelsymfonier har varit att fördjupa mig i hur gregorianiken påverkade Widors kompositionsstil och hur konsertant musik utanför gudstjänstens liturgi kan bära ett kyrkligt budskap baserat i dess valda teman. Jag har velat dokumentera min process att som organist och kyrkomusiker studera in och komma fram till en medveten konstnärlig gestaltning av symfonierna. Widor blev med åren övertygad om att kyrkomusik måste vara baserad på kyrkans egna teman för att kunna bli sakral konst. Han använde sig också av en palett av former och kompositionstekniska grepp för att variera musiken i symfoniska dimensioner. Dessa två orgelsymfonier är Widors bidrag till den rörelse som inte bara återupprättade utan gav den gregorianska sången högsta status i den romersk-katolska kyrkan vid sekelskiftet 1900.

Communications receivers that rely on 1-bit analogto-digital conversion are advantageous in terms of hardware complexity and power dissipation. Performance limitations due to the 1-bit quantization can be tackled with oversampling. This paper considers the oversampling gain from an information-theoretic perspective by analyzing the channel capacity with 1-bit quantization and oversampling at the receiver for the particular case of AWGN channels. This includes a numerical computation of the capacity and optimal transmit symbol constellations, as well as the derivation of closed-form expressions for large oversampling ratios and for high signal-to-noise ratios of the channel.

Newsletter des Sonderforschungsbereichs 912 "Highly Adaptive Energy-Efficient Computing" (HAEC)

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No description available.

Einführung - Periphere Blutmonozyten spielen eine Rolle in der Pathogenese der Arteriosklerose. Bei spontan hypertensiven Ratten wurden im Vergleich zu normotonen Wistar-Kyoto-Ratten signifikant erhöhte Zahlen aktivierter Monozyten beobachtet [Liu 1996]. Wir untersuchten Monozyten von Patienten mit essentieller Hypertonie und von gesunden Probanden hinsichtlich möglicher Unterschiede in der Aktivierung anhand ihrer Adhäsion an von uns kultivierte (HAEC) und isolierte (HSVEC, HUVEC, HUAEC) humane Endothelzellen. Wir bestimmten die Adhäsionsmoleküle ICAM-1, VCAM-1 sowie E-Selektin und analysierten die Superoxidfreisetzung von humanem Endothel und Monozyten. Methoden - Humane periphere Blutmonozyten wurden mittels Dichtegradienten-zentrifugation und Plastikadhärenz isoliert und mit LPS, Angiotensin II (Ang II), und Ang II nach Vorinkubation mit dem AT1-Antagonisten Eprosartan stimuliert. Die Monozyten wurden auf einschichtigem Endothel ausgesät und die Adhäsion als Prozentsatz der initial gesäten Zellen erfasst. Die durch PMA induzierte Superoxidfreisetzung des Endothels oder der Monozyten wurde mittels Chemilumineszenz bestimmt. Ergebnisse - Monozyten von Patienten mit essentieller Hypertonie hefteten sich im Vergleich zu gesunden Probanden spontan und nach Stimulation mit Ang II signifikant verstärkt an HAEC und HUVEC-Monolayer an. Die Spiegel von ICAM-1 und VCAM-1 waren bei Patienten mit arterieller Hypertonie im Vergleich zu den gesunden Kontrollpersonen signifikant erhöht. Die Chemilumineszenzaktivität postkonfluenter Endothelzellen erhöhte sich nach Stimulation mit Ang II im Vergleich zur Messung ohne vorherige Stimulierung. Nach Stimulation mit PMA oder mit Ang II wurden bei Hypertonikern signifikant höhere Werte für die Chemilumineszenzaktivität der Monozyten gemessen als bei gesunden Kontrollpersonen. Schluss - Mit diesen Versuchen an humanen Monozyten und Endothelzellen wurde ein weiterer Beweis für die Aktivierung der Monozyten von Patienten mit essentieller Hypertonie erbracht. Meine Ergebnisse unterstützen die Sicht einer Monozytenbeteiligung an der Pathogenese atherosklerotischer Läsionen, die mit arterieller Hypertonie in Zusammenhang stehen. / Introduction - Peripheral blood monocytes are involved in the pathogenesis of atherosclerosis. Significantly elevated numbers of activated monocytes were observed in spontaneously hypertensive rats compared to those in normotensive Wistar-Kyoto rats [Liu 1996]. We isolated and cultivated human endothelial cells and examined monocytes from patients with arterial hypertension and healthy volunteers to identify possible differences in their adhesion behavior to human endothelial cells (HAEC, HSVEC, HUVEC, HUAEC). We determined the levels of ICAM-1, VCAM-1 and E-selectin, and we analyzed superoxide release by human endothelium and human monocytes. Methods - Peripheral blood monocytes were isolated by density gradient centrifugation and plastic adherence. Subsets of the samples were stimulated with LPS, Angiotensin II, Angiotensin II following preincubation with the AT1-antagonist eprosartan or left without a stimulant. After incubation, monocytes were seeded onto confluent monolayers of human aortic endothelial cells and the adhesion was determined as the percentage of the initially seeded cells. Oxygen species release induced by PMA was analyzed for endothelium and monocytes in suspension by chemiluminescence. Results - Peripheral blood monocytes of patients with essential hypertension performed a significantly increased spontaneous adhesion and adhesion following stimulation with Angiotensin II to HAEC- and HUVEC-monolayers. Levels of human soluble adhesion molecules ICAM-1 and VCAM-1 were significantly raised in hypertensive patients. Chemiluminescence activity of post confluent endothelial cells was increased after stimulation with Angiotensin II compared to the measurement before stimulation. Following stimulation with PMA or Angiotensin II, significantly higher chem-iluminescence levels were measured in hypertensive patients compared to healthy volunteers. Conclusion - These data indicate that monocytes of patients with essential hypertension may be preactivated. My results support the view of a monocyte involvement in the pathogenesis of atherosclerotic lesions that are related to arterial hypertension.

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No description available.