Case-Analysis for Rippling and Inductive Proof

Rippling is a heuristic used to guide rewriting and is typically used for inductive theorem proving. We introduce a method to support case-analysis within rippling. Like earlier work, this allows goals containing if-statements to be proved automatically. The new contribution is that our method also supports case-analysis on datatypes. By locating the case-analysis as a step within rippling we also maintain the termination. The work has been implemented in IsaPlanner and used to extend the existing inductive proof method. We evaluate this extended prover on a large set of examples from Isabelle’s theory library and from the inductive theorem proving literature. We find that this leads to a significant improvement in the coverage of inductive theorem proving. The main limitations of the extended prover are identified, highlight the need for advances in the treatment of assumptions during rippling and when conjecturing lemmas

Assessment of regression methods for inference of regulatory networks involved in circadian regulation

We assess the accuracy of three established regression methods for reconstructing gene and protein regulatory networks in the context of circadian regulation. Data are simulated from a recently published regulatory network of the circadian clock in Arabidopsis thaliana, in which protein and gene interactions are described by a Markov jump process based on Michaelis-Menten kinetics. We closely follow recent experimental protocols, including the entrainment of seedlings to different light-dark cycles and the knock-out of various key regulatory genes. Our study provides relative assessment scores for the comparison of state-of-the art regression methods, investigates the influence of systematically missing values related to unknown protein concentrations and mRNA transcription rates, and quantifies the dependence of the performance on the degree of recurrency

Evaluation von Risikofaktoren zur Fehleinschätzung der TNM Klassifikation im Rahmen des prätherapeutischen Stagings

Die Einteilung maligner Tumore im HNO Bereich anhand der TNM Klassifikation im Rahmen des prätherapeutischen Stagings ist der erste kritische Schritt, dessen Qualität richtungweisenden Einfluss auf die spätere Therapieentscheidung hat. Mittels klinischer Untersuchung, spezieller Untersuchungsverfahren und Biopsie kann eine Diagnose-Zuverlässigkeit erreicht werden, die einem "certainty-factor" von maximal 3 entspricht. Erst die histopathologische Aufarbeitung eines kompletten Tumor-Präparats im posttherapeutischen Rahmen erlaubt eine genauere Klassifikation, die unter Umständen erheblich von der ersten, rein klinischen Klassifikation abweichen kann. In dieser monozentrischen, retrospektiven Studie werden die prätherapeutischen cTNM Klassifikationen mit den posttherapeutischen pTNM Klassifikationen von Kopf-Hals-Tumorpatienten verglichen, die seit 2012 in unserer Tumorkonferenz vorgestellt wurden und in der Folge eine primär chirurgische Therapie erhalten haben. Die Daten werden nach Lokalisation, klinischer sowie technischer Untersuchungsmethode und Untersucher aufgearbeitet und miteinander verglichen.Das Ziel der Studie ist es Risikofaktoren zu identifizieren, die eine prätherapeutische Fehleinschätzung des TNM Status wahrscheinlich machen und Strategien zu diskutieren, die dieses Risiko minimieren können.Der Erstautor gibt keinen Interessenkonflikt an

Co-optimisation of send and receive coils

Magnetic particle imaging exploits the nonlinear magnetization behaviour of iron oxide nanoparticles, by modulating the magnetic flux density of those particles. This modulation is achieved by creating time-varying magnetic fields using a drive coil. The generated signal is picked up with a receive coil. In order to minimize mutual influence, those coils need to be optimized. The decision process for an optimal combination of drive and focus field coil and the receive coil is described with respect to the signal chain and power consumption of the scanner. It is shown that the advantages of longer coils result in a linear increase of the power loss in the scanner, while the obtained sensitivity no longer increases relevantly. Based on this analysis a coil with favourable cost-benefit ratio can be chosen.   Int. J. Mag. Part. Imag. 6(2), Suppl. 1, 2020, Article ID: 2009037, DOI: 10.18416/IJMPI.2020.200903

Context dependent procedures and computed types in veriFun

AbstractWe present two enhancements of the functional language L which is used in the ✓eriFun system to write programs and formulate statements about them. Context dependent procedures allow to stipulate the context under which procedures are sensibly executed, thus avoiding runtime tests in program code as well as verification of absence of exceptions by proving stuck-freeness of procedure calls. Computed types lead to more compact code, increase the readability of programs, and make the well-known benefits of type systems available to non-freely generated data types as well. Since satisfaction of context requirements as well as type checking becomes undecidable, proof obligations are synthesized to be proved by the verifier at hand, thus supporting static code analysis. Information about the type hierarchy is utilized for increasing the performance and efficiency of the verifier