An Improved Interface for Interactive Proofs in Separation Logic

Seit Software entwickelt wird, stellt sich die Frage, ob diese korrekt ist, d.h. ob sie das tut, was sie tun soll. Gegeben eine formale Spezifikation der Anforderungen, ist eine Aufgabe der Softwareverifikation also zu beweisen, ob eine Implementierung diese Spezifikation erfüllt. Diese Aufgabe kann schwierig zu lösen sein, wenn die verwendete Programmiersprache Befehle mit globalem Effekt erlaubt, sodass diese andere Befehle in unabhängigen Teilen des Programms beeinflussen können, zum Beispiel durch einen gemeinsam genutzten Heap-Speicher. Separation-Logic löst dieses Problem, indem es Aussagen um einen separierenden Operator erweitert, wodurch es möglich ist, Teile eines Programms als unabhängig vom Rest des Programms anzusehen. Ein Werkzeug, das Beweise zur Softwareverifikation unterstützt, sind interaktive Theorembeweiser. Allerdings benötigen Separation-Logic-Beweise in interaktiven Theorembeweisern, besonders mit nicht-linearem Typsystem, viel manuellen Aufwand zur Verwaltung der benötigten Datenstrukturen. Dies kann vermieden werden, indem dem Nutzer eine Schnittstelle zur Verfügung gestellt wird, die Beweise auf der typischen, höheren Abstraktionsebene ermöglicht. Diese Arbeit beschreibt eine neue Schnittstelle für Separation-Logic-Beweise in dem interaktiven Theorembeweiser Lean 4, basierend auf dem Iris-Projekt, und die Verbesserungen an dieser Schnittstelle

Investitionen in Collateralized Debt Obligations

The paper deals with the evaluation of Collateralized Debt Obligations for investment purposes. CDOs are classified in the asset backed environment. Its specific risks (market, timing, recovery, agency) are discussed. To understand the portfolio aspect, the concept of the diversity score is carefully explained. On this basis the investment process in different tranches is described. Especially for the equity piece it can be shown, that a less diversified portfolio is more valuable. --Ausfallrisiko , Ausfallkorrelation , Binomial Expansion Technique , Credit Enhancement , Diversity Score , Excess Spread , Expected Loss , Rating Arbitrage , Target Rating , Waterfall , Weighted Average Rating

EfficientAD: Accurate Visual Anomaly Detection at Millisecond-Level Latencies

Detecting anomalies in images is an important task, especially in real-time computer vision applications. In this work, we focus on computational efficiency and propose a lightweight feature extractor that processes an image in less than a millisecond on a modern GPU. We then use a student-teacher approach to detect anomalous features. We train a student network to predict the extracted features of normal, i.e., anomaly-free training images. The detection of anomalies at test time is enabled by the student failing to predict their features. We propose a training loss that hinders the student from imitating the teacher feature extractor beyond the normal images. It allows us to drastically reduce the computational cost of the student-teacher model, while improving the detection of anomalous features. We furthermore address the detection of challenging logical anomalies that involve invalid combinations of normal local features, for example, a wrong ordering of objects. We detect these anomalies by efficiently incorporating an autoencoder that analyzes images globally. We evaluate our method, called EfficientAD, on 32 datasets from three industrial anomaly detection dataset collections. EfficientAD sets new standards for both the detection and the localization of anomalies. At a latency of two milliseconds and a throughput of six hundred images per second, it enables a fast handling of anomalies. Together with its low error rate, this makes it an economical solution for real-world applications and a fruitful basis for future research

Teachers in training: Their opinions about the digitization of the educational system and the potential teaching subjects programming and entrepreneurship

In aktuellen Bildungsdebatten wird häufig über die Digitalisierung im Bildungssystem und die potenziellen Unterrichtsfächer Programmieren und Unternehmertum diskutiert. Wenngleich diverse Positionen in den Debatten vertreten werden, ist wenig über die Meinung von derzeitigen Lehramtsstudierenden zu diesen Themenkomplexen bekannt. Die vorliegende Arbeit präsentiert die Ergebnisse einer explorativen Befragung von Lehramtsstudierenden zu den Themen Digitalisierung im Bildungssystem sowie den Unterrichtsfächern Programmieren und Unternehmertum. Die Ergebnisse zeigen, dass die Mehrheit der befragten Lehramtsstudierenden den Unterrichtfächern Unternehmertum und Programmieren negativ gegenübersteht: Das Erlernen unternehmerischer Fertigkeiten als auch das Erlernen einer Programmiersprache sollten laut der Mehrheit keine Kernaufgaben schulischer Bildung sein. Zudem sollten beide Fächer weder den Charakter eines Hauptfaches haben noch Pflichtfächer in der Primarstufe, Sekundarstufe 1 und Sekundarstufe 2 sein. Zur Digitalisierung gibt die Mehrheit an, dass sie die Qualität des Bildungssystems zwar verbessern, jedoch nicht für mehr Chancengleichheit sorgen wird. Die Mehrheit gibt an, sich weder im Studium noch in der Freizeit ausreichend mit den Auswirkungen der Digitalisierung auf das Bildungssystem zu beschäftigen. Zudem wird mehrheitlich angegeben, dass man weder ausreichend informiert noch vorbereitet auf die Auswirkungen der Digitalisierung auf das Bildungssystem sei.The digitization of the educational system as well as the potential teaching subjects programming and entrepreneurship are in focus in current educational debates. Whilst different positions towards this manner are represented, there has not been paid a lot of attention towards the opinions of future teachers who are still in training. This paper outlines the results of an explorative survey in which teachers in training gave their opinion. One of the main results is that teachers in training seem to have a rather skeptical view on the potential teaching subjects programming and entrepreneurship: The majority beliefs that the acquisition of entrepreneurial skills as well as the learning of a programming language should not be predominant tasks of the educational system. Furthermore, the majority beliefs that both subjects should not be equal to major subjects (mathematics, languages, etc.) and should not be obligatory in neither primary schools nor high schools nor collegiate. Although the majority of teachers in training beliefs that the digitization is going to improve the quality of the educational system, they also state that it will not equalize chances within the educational system. Moreover, the majority declares to neither deal sufficiently with the impacts of the digitization on the educational system at university nor in their private leisure time. Furthermore, the majority acknowledges that they are neither adequately informed about nor prepared for the impacts of the digitization on the educational system

Conditional Bisimilarity for Reactive Systems

Reactive systems \`a la Leifer and Milner, an abstract categorical framework for rewriting, provide a suitable framework for deriving bisimulation congruences. This is done by synthesizing interactions with the environment in order to obtain a compositional semantics. We enrich the notion of reactive systems by conditions on two levels: first, as in earlier work, we consider rules enriched with application conditions and second, we investigate the notion of conditional bisimilarity. Conditional bisimilarity allows us to say that two system states are bisimilar provided that the environment satisfies a given condition. We present several equivalent definitions of conditional bisimilarity, including one that is useful for concrete proofs and that employs an up-to-context technique, and we compare with related behavioural equivalences. We instantiate reactive systems in order to obtain DPO graph rewriting and consider a case study in this setting

CMOS-Based Peptide Arrays

CMOS - Based Peptide Arrays Peptide arrays are an important tool in proteomics and peptidomics, allowing a large number of peptides to be synthesized on a common support and exposed to a solution of target molecules in parallel. In particle-based synthesis, the amino acids for in situ synthesis of peptides are transported to synthesis loci in solid particles and released upon melting, allowing an increase in density over liquid-based systems. This thesis focuses on the development of application-specific high voltage integrated circuits for electrostatic deposition of charged amino acid particles and their integration into a combinatorial peptide synthesis system. Transfer of amino acid particles from the aerosol to synthesis loci on the chip surface was investigated for a pixel pitch between 45 µm and 100 µm, and compatibility between the chips, particle transfer and the poly(ethylene glycol)methacrylate - based surface modifi¬cations was established. The first combinatorial syntheses on CMOS chips were performed with over 16,000 distinct synthesis sites per chip, at a density of 10,000 spots per cm2, which is a 25-fold increase over the 400 spots per cm2 currently available on laser-printed glass slides. For FLAG and HA peptide epitopes, immonostaining showed regular spots of comparable signal intensity over the whole chip area

Formalizing a Procedure for Generating Uncertain Resource Availability Assumptions Based on Real Time Logistic Data Capturing with Auto-ID Systems for Reactive Scheduling

As one result of the project "Reactive Construction Project Scheduling using Real Time Construction Logistic Data and Simulation", a procedure for using data about uncertain resource availability assumptions in reactive scheduling processes has been developed. Prediction data about resource availability is generated in a formalized way using real-time monitoring data e.g. from auto-ID systems on the construction site and in the supply chains. The paper focuses on the formalization of the procedure for monitoring construction logistic processes, for the detection of disturbance and for generating of new and uncertain scheduling assumptions for the reactive resource constrained simulation procedure that is and will be further described in other papers