Artistic Path Space Editing of Physically Based Light Transport

Die Erzeugung realistischer Bilder ist ein wichtiges Ziel der Computergrafik, mit Anwendungen u.a. in der Spielfilmindustrie, Architektur und Medizin. Die physikalisch basierte Bildsynthese, welche in letzter Zeit anwendungsübergreifend weiten Anklang findet, bedient sich der numerischen Simulation des Lichttransports entlang durch die geometrische Optik vorgegebener Ausbreitungspfade; ein Modell, welches für übliche Szenen ausreicht, Photorealismus zu erzielen. Insgesamt gesehen ist heute das computergestützte Verfassen von Bildern und Animationen mit wohlgestalteter und theoretisch fundierter Schattierung stark vereinfacht. Allerdings ist bei der praktischen Umsetzung auch die Rücksichtnahme auf Details wie die Struktur des Ausgabegeräts wichtig und z.B. das Teilproblem der effizienten physikalisch basierten Bildsynthese in partizipierenden Medien ist noch weit davon entfernt, als gelöst zu gelten. Weiterhin ist die Bildsynthese als Teil eines weiteren Kontextes zu sehen: der effektiven Kommunikation von Ideen und Informationen. Seien es nun Form und Funktion eines Gebäudes, die medizinische Visualisierung einer Computertomografie oder aber die Stimmung einer Filmsequenz -- Botschaften in Form digitaler Bilder sind heutzutage omnipräsent. Leider hat die Verbreitung der -- auf Simulation ausgelegten -- Methodik der physikalisch basierten Bildsynthese generell zu einem Verlust intuitiver, feingestalteter und lokaler künstlerischer Kontrolle des finalen Bildinhalts geführt, welche in vorherigen, weniger strikten Paradigmen vorhanden war. Die Beiträge dieser Dissertation decken unterschiedliche Aspekte der Bildsynthese ab. Dies sind zunächst einmal die grundlegende Subpixel-Bildsynthese sowie effiziente Bildsyntheseverfahren für partizipierende Medien. Im Mittelpunkt der Arbeit stehen jedoch Ansätze zum effektiven visuellen Verständnis der Lichtausbreitung, die eine lokale künstlerische Einflussnahme ermöglichen und gleichzeitig auf globaler Ebene konsistente und glaubwürdige Ergebnisse erzielen. Hierbei ist die Kernidee, Visualisierung und Bearbeitung des Lichts direkt im alle möglichen Lichtpfade einschließenden "Pfadraum" durchzuführen. Dies steht im Gegensatz zu Verfahren nach Stand der Forschung, die entweder im Bildraum arbeiten oder auf bestimmte, isolierte Beleuchtungseffekte wie perfekte Spiegelungen, Schatten oder Kaustiken zugeschnitten sind. Die Erprobung der vorgestellten Verfahren hat gezeigt, dass mit ihnen real existierende Probleme der Bilderzeugung für Filmproduktionen gelöst werden können

Ray-tracing based Inference Attacks on Physical Layer Security

In wireless network security, physical layer security provides a viable alternative to classical cryptography, which deliver high security guarantees with minimal energy expenditure. Nevertheless, these cryptograhpic primitives are based on assumptions about physical conditions which in practice may not be fulfilled.In this work we present a ray-tracing based attack, which challenges the basic assumption of uncorrelated channel properties for eavesdroppers. We realize this attack and evaluate it with real world measurement, and thereby show that such attacks can predict channel properties better than previous attacks and are also more generally applicable

A luminescence line-narrowing spectroscopic study of the uranium(VI) interaction with cementitious materials and titanium dioxide

Non-selective luminescence spectroscopy and luminescence line-narrowing spectroscopy were used to study the retention of UO22+ on titanium dioxide (TiO2), synthetic calcium silicate hydrate (C-S-H) phases and hardened cement paste (HCP). Non-selective luminescence spectra showed strong inhomogeneous line broadening resulting from a strongly disordered UO22+ bonding environment. This problem was largely overcome by using luminescence line-narrowing spectroscopy. This technique allowed unambiguous identification of three different types of UO22+ sorbed species on C-S-H phases and HCP. Comparison with spectra of UO22+ sorbed onto TiO2 further allowed these species to be assigned to a surface complex, an incorporated species and an uranate-like surface precipitate. This information provides the basis for mechanistic models describing the UO22+ sorption onto C-S-H phases and HCP and the assessment of the mobility of this radionuclide in a deep geological repository for low and intermediate level radioactive waste (L/ILW) as this kind of waste is often solidified with cement prior to storage.Swiss National Cooperative for the Disposal of Radioactive Wast

Efficient communication protection of many-core systems against active attackers

Many-core system-on-chips, together with their established communication infrastructures, Networks-on-Chip (NoC), are growing in complexity, which encourages the integration of third-party components to simplify and accelerate production processes. However, this also adversely exposes the surface for attacks through the injection of hardware Trojans. This work addresses active attacks on NoCs and focuses on the integrity and availability of transmitted data. In particular, we consider the modification and/or dropping of data during transmission as active attacks that might be performed by malicious routers. To mitigate the impact of such active attacks, we propose two lightweight solutions that respect the performance constraints of NoCs. Assuming the presence of symmetric keys, these approaches combine lightweight authentication codes for integrity protection with network coding for increased efficiency and robustness. The proposed solutions prevent undetected modifications and significantly increase availability through a reliable detection of attacks. The efficiency of these solutions is investigated in different scenarios using cycle-accurate simulations and the area overhead is analyzed relative to state-of-the-art many-core system. The results demonstrate that one authentication scheme with network coding protects the integrity of data to a low residual error of 1.36% at 0.2 attack probability with an area overhead of 2.68%. For faster and more flexible evaluation, an analytical approach is developed which is validated against the cycle-accurate simulations. The analytical approach is more than 1000× faster while having a maximum estimation error of 5%. Moreover, the analytical model provides a deeper insight into the system’s behavior. For example, it reveals which factors influence the performance parameters

Transapical aortic valve implantation with a self-expanding anatomically oriented valve

Aims The Medtronic Engager™ aortic valve bioprosthesis is a self-expanding valve with support arms facilitating anatomically correct positioning and axial fixation. Valve leaflets, made of bovine pericardium, are mounted on a Nitinol frame. Here, we report the first in man study with this new implant (Trial Identifier NCT00677638). Methods and results Thirty patients (mean age 83.4 ± 3.8 years; 83% female) with tricuspid aortic valve stenosis were included in the study. Mean logistic EuroSCORE was 23.4 ± 11.9. Mean aortic annulus diameter was 21.8 ± 1.4 mm. For this study, the Engager was available in only one size (23 mm), to fit aortic annuli of 19-23 mm. Standard transapical valve implantation was performed using predilation of the aortic valve and rapid ventricular pacing during ballon valvuloplasty and most valve deployments. Accurate valve placement was achieved in 29/30 cases (97%). Post-implant peak-to-peak gradient was 13.3 ± 9.3 mmHg. In 80% of the patients, no more than grade I paravalvular leakage was observed, in 13% grades I-II and in 3% grade II. Three patients (10%) required permanent pacemaker implantation for higher-degree or complete atrioventricular block. Four dissections (13%) occurred during positioning of the valve and were treated surgically in three cases. Thirty-day and in-hospital mortality were 20% and 23%, respectively, and 6-month survival was 56.7%. No structural failure occurred for up to 1 year. Conclusion This series established the feasibility of implanting a novel self-expanding transapical aortic valve prosthesis predictably into an anatomically correct position. Observed complications led to complete redesign of the delivery system for upcoming clinical studies with the goal of establishing safety and performanc

Cytidine-5-diphosphocholine reduces microvascular permeability during experimental endotoxemia

Background: Microvascular permeability and leukocyte adhesion are pivotal mechanisms in sepsis pathophysiology contributing to the development of shock and mortality. No effective pharmacological therapy is currently available to restore microvascular barrier function in sepsis. Cholinergic mediators have been demonstrated to exert anti-inflammatory effects during inflammation. Cytidine-5-diphosphocholine (CDP-choline) is an extensively studied cholinergic drug due to its brain protective characteristics in cerebrovascular diseases. This study evaluated the effect of CDP-choline on microvascular permeability and leukocyte adhesion during endotoxemia. Methods: Macromolecular leakage, leukocyte adhesion, and venular wall shear rate were examined in mesenteric postcapillary venules of rats by using intravital microscopy (IVM). Lipopolysaccharide (LPS) (4 mg/kg/h) or equivalent volumes of saline were continuously infused following baseline IVM at 0 min. IVM was repeated after 60 and 120 min in endotoxemic and nonendotoxemic animals. CDP-choline (100 mg/kg) was applied as an i.v. bolus. Animals received either saline alone, CDP-choline alone, CDP-choline 10 min before or 30 min after LPS administration, or LPS alone. Due to nonparametric data distribution, Wilcoxon test and Dunn's multiple comparisons test were used for data analysis. Data were considered statistically significant at p < 0.05. Results: Treatment with LPS alone significantly increased microvascular permeability and leukocyte adhesion and decreased venular wall shear rate. CDP-choline significantly reduced microvascular permeability in animals treated with LPS. Leukocyte adhesion and venular wall shear rate were not affected by CDP-choline during endotoxemia. Conclusion: CDP-choline has a protective effect on microvascular barrier function during endotoxemia. Considering the excellent pharmacologic safety profile of CDP-choline, its use could be an approach for the treatment of capillary leakage in sepsis

Trägerbefragung zur Verbreitung der betrieblichen Altersversorgung (BAV 2017): Endbericht

Im Auftrag des Bundesministeriums für Arbeit und Soziales hat Kantar Public (ehemals TNS Infratest Sozialforschung) im Jahr 2018 zum achten Mal nach 2003, 2004, 2006, 2008, 2011, 2013 und 2015 eine empirische Untersuchung zur Situation und Entwicklung der betrieblichen Altersversorgung durchgeführt. Einbezogen in die "Trägerbefragung zur betrieblichen Altersversorgung 2017" (BAV 2017) wurden Pensionskassen, Pensionsfonds, Lebensversicherungen, die betriebliche Direktversicherungen anbieten, und öffentliche Zusatzversorgungsträger. Die Daten zu Direktzusagen und Unterstützungskassen basieren dagegen auf Geschäftsstatistiken des "Pensions-Sicherungs-Vereins auf Gegenseitigkeit" (PSVaG). Damit wird nunmehr die Entwicklung der betrieblichen Altersversorgung seit Inkrafttreten des Altersvermögensgesetzes (AVmG) und des Altersvermögensergänzungsgesetzes (AVmEG) am 1. Januar 2002 aufgezeigt. Mit BAV 2017 wird die bestehende Zeitreihe um die Referenzpunkte Dezember 2016 und Dezember 2017 ergänzt und damit bis unmittelbar vor Inkrafttreten des Betriebsrentenstärkungsgesetzes (BRSG) im Januar 2018. Neben der Entwicklung der Zahl von Versicherten und Anwartschaften werden in BAV 2017 auch die Beitragshöhe sowie die Inanspruchnahme von Förderwegen analysiert.On behalf of the Federal Ministry of Labour and Social Affairs, Kantar Public (formerly TNS Infratest Social Research) conducted a survey on the situation and development of occupational pension provision in 2018 for the eighth time after 2003, 2004, 2006, 2008, 2011, 2013 and 2015. Included in the "Trägerbefragung zur betrieblichen Altersversorgung 2017" (BAV 2017) were pension pools, pension funds, life insurance companies offering direct insurances and public supplementary pension funds. The data on direct pension promises and benevolent funds are based on statistics from the "Pensions-Sicherungs-Verein auf Gegenseitigkeit" (PSVaG), the German pension protection system. BAV 2017 covers the situation in December 2016 and December 2017. Thus, the latest reference period of the survey is immediately before the Betriebsrentenstärkungsgesetz (BRSG) came into force in January 2018. Together with its predecessor surveys, it shows the development of the occupational pensions since the Altersvermögensgesetz (AVmG) and the Altersvermögensergänzungsgesetz (AVmEG) came into force in January 2002, giving employees the right to have part of their earnings paid into to a company pension plan (known as a deferred compensation). In addition to the development of the number of insured persons and entitlements, BAV 2017 also analyses the level of contributions as well as the use of subsidy schemes

Trägerbefragung zur Verbreitung der betrieblichen Altersversorgung (BAV 2017): Methodenbericht

Im Auftrag des Bundesministeriums für Arbeit und Soziales hat Kantar Public (ehemals TNS Infratest Sozialforschung) im Jahr 2018 zum achten Mal nach 2003, 2004, 2006, 2008, 2011, 2013 und 2015 eine empirische Untersuchung zur Situation und Entwicklung der betrieblichen Altersversorgung durchgeführt. Einbezogen in die "Trägerbefragung zur betrieblichen Altersversorgung 2017" (BAV 2017) wurden Pensionskassen, Pensionsfonds, Lebensversicherungen, die betriebliche Direktversicherungen anbieten, und öffentliche Zusatzversorgungsträger. Die Daten zu Direktzusagen und Unterstützungskassen basieren dagegen auf Geschäftsstatistiken des "Pensions-Sicherungs-Vereins auf Gegenseitigkeit" (PSVaG). Damit wird nunmehr die Entwicklung der betrieblichen Altersversorgung seit Inkrafttreten des Altersvermögensgesetzes (AVmG) und des Altersvermögensergänzungsgesetzes (AVmEG) am 1. Januar 2002 aufgezeigt. Mit BAV 2017 wird die bestehende Zeitreihe um die Referenzpunkte Dezember 2016 und Dezember 2017 ergänzt und damit bis unmittelbar vor Inkrafttreten des Betriebsrentenstärkungsgesetzes (BRSG) im Januar 2018. Neben der Entwicklung der Zahl von Versicherten und Anwartschaften werden in BAV 2017 auch die Beitragshöhe sowie die Inanspruchnahme von Förderwegen analysiert.On behalf of the Federal Ministry of Labour and Social Affairs, Kantar Public (formerly TNS Infratest Social Research) conducted a survey on the situation and development of occupational pension provision in 2018 for the eighth time after 2003, 2004, 2006, 2008, 2011, 2013 and 2015. Included in the "Trägerbefragung zur betrieblichen Altersversorgung 2017" (BAV 2017) were pension pools, pension funds, life insurance companies offering direct insurances and public supplementary pension funds. The data on direct pension promises and benevolent funds are based on statistics from the "Pensions-Sicherungs-Verein auf Gegenseitigkeit" (PSVaG), the German pension protection system. BAV 2017 covers the situation in December 2016 and December 2017. Thus, the latest reference period of the survey is immediately before the Betriebsrentenstärkungsgesetz (BRSG) came into force in January 2018. Together with its predecessor surveys, it shows the development of the occupational pensions since the Altersvermögensgesetz (AVmG) and the Altersvermögensergänzungsgesetz (AVmEG) came into force in January 2002, giving employees the right to have part of their earnings paid into to a company pension plan (known as a deferred compensation). In addition to the development of the number of insured persons and entitlements, BAV 2017 also analyses the level of contributions as well as the use of subsidy schemes

Subgroup-specific gene expression profiles and mixed epistasis in chronic lymphocytic leukemia

Understanding the molecular and phenotypic heterogeneity of cancer is a prerequisite for effective treatment. For chronic lymphocytic leukemia (CLL), recurrent genetic driver events have been extensively cataloged, but this does not suffice to explain the disease's diverse course. Here, we performed RNA sequencing on 184 CLL patient samples. Unsupervised analysis revealed two major, orthogonal axes of gene expression variation: the first one represented the mutational status of the immunoglobulin heavy variable (IGHV) genes, and concomitantly, the three-group stratification of CLL by global DNA methylation. The second axis aligned with trisomy 12 status and affected chemokine, MAPK and mTOR signaling. We discovered non-additive effects (epistasis) of IGHV mutation status and trisomy 12 on multiple phenotypes, including the expression of 893 genes. Multiple types of epistasis were observed, including synergy, buffering, suppression and inversion, suggesting that molecular understanding of disease heterogeneity requires studying such genetic events not only individually but in combination. We detected strong differentially expressed gene signatures associated with major gene mutations and copy number aberrations including SF3B1, BRAF and TP53, as well as del(17)(p13), del(13)(q14) and del(11)(q22.3) beyond dosage effect. Our study reveals previously underappreciated gene expression signatures for the major molecular subtypes in CLL and the presence of epistasis between them