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This paper presents the tool COMICS 1.0, which performs model checking and generates counterexamples for DTMCs. For an input DTMC, COMICS computes an abstract system that carries the model checking information and uses this result to compute a critical subsystem, which induces a counterexample. This abstract subsystem can be refined and concretized(More)
—Model checkers for concurrent probabilistic systems have become very popular within the last decade. The study of long-run average behavior has however received only scant attention in this area, at least from the implementation perspective. This paper studies the problem of how to efficiently realize an algorithm for computing optimal long-run average(More)
BACKGROUND/PURPOSE OF THE STUDY Vitamin D3-deficiency is common in patients with chronic liver-disease and may promote disease progression. Vitamin D3-administration has thus been proposed as a therapeutic approach. Vitamin D3 has immunomodulatory effects and may modulate autoimmune liver-disease such as primary sclerosing cholangitis. Although various(More)
We present a graphical toolset for verifying AADL models, which are gaining widespread acceptance in aerospace, automobile and avionics industries for comprehensively specifying safety-critical systems by capturing functional, probabilistic and hybrid aspects. Analyses are implemented on top of mature model checking tools and range from requirements(More)
—Discrete-Time Markov Chains (DTMCs) are a widely-used formalism to model probabilistic systems. On the one hand, available tools like PRISM or MRMC offer efficient model checking algorithms and thus support the verification of DTMCs. However, these algorithms do not provide any diagnostic information in the form of counterexamples, which are highly(More)
This paper is an introductory survey of available methods for the computation and representation of probabilistic counterexamples for discrete-time Markov chains and probabilistic automata. In contrast to traditional model checking, probabilistic counterexamples are sets of finite paths with a critical probability mass. Such counterexamples are not obtained(More)
Counterexamples for property violations have a number of important applications like supporting the debugging of erroneous systems and verifying large systems via counterexample-guided abstraction refinement. In this paper, we propose the usage of minimal critical subsystems of discrete-time Markov chains and Markov decision processes as counterexamples for(More)
BACKGROUND & AIMS Glycochenodeoxycholate (GCDC) and taurolithocholate (TLC) are hepatotoxic and cholestatic bile salts, whereas tauroursodeoxycholate (TUDC) is cytoprotective and anticholestatic. Yet they all act, in part, through phosphatidylinositol-3-kinase(PI3K)-dependent mechanisms ("PI3K-paradox"). Hepatocytes express three catalytic PI3K Class I(More)
Taurolithocholic acid (TLCA) is a potent cholestatic agent. Our recent work suggested that TLCA impairs hepatobiliary exocytosis, insertion of transport proteins into apical hepatocyte membranes, and bile flow by protein kinase Cepsilon (PKCepsilon)-dependent mechanisms. Products of phosphatidylinositol 3-kinases (PI3K) stimulate PKCepsilon. We studied the(More)
AIM Hepatic apoptosis is involved in the pathogenesis of immune-mediated liver diseases such as autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC). The aim of our study was to quantify distinct markers of apoptosis in sera of patients with AIH, PBC and PSC, and to evaluate correlation with markers of disease(More)