Towards a method for rigorous development of generic requirements patterns

We present work in progress on a method for the engineering, validation and verification of generic requirements using domain engineering and formal methods. The need to develop a generic requirement set for subsequent system instantiation is complicated by the addition of the high levels of verification demanded by safety-critical domains such as avionics. Our chosen application domain is the failure detection and management function for engine control systems: here generic requirements drive a software product line of target systems. A pilot formal specification and design exercise is undertaken on a small (twosensor) system element. This exercise has a number of aims: to support the domain analysis, to gain a view of appropriate design abstractions, for a B novice to gain experience in the B method and tools, and to evaluate the usability and utility of that method.We also present a prototype method for the production and verification of a generic requirement set in our UML-based formal notation, UML-B, and tooling developed in support. The formal verification both of the structural generic requirement set, and of a particular application, is achieved via translation to the formal specification language, B, using our U2B and ProB tools

The State of Democracy in Sub-Saharan Africa

Africa experienced a wave of democratization over the past 20 years and this increase in democracy, we find, positively and significantly affects income per capita. Our dynamic panel data results suggest that countries only slowly converge to their long-run income values as predicted by current democracy levels, however. African countries may therefore be currently too democratic relative to their income levels. In keeping with this possibility, a significant number of countries are experiencing political ‘back sliding’: elections are won by the use of illicit tactics, term limits on political leaders have been overturned and there have been unconstitutional seizures of power.Governmen

Second-Order Belief Hidden Markov Models

Hidden Markov Models (HMMs) are learning methods for pattern recognition. The probabilistic HMMs have been one of the most used techniques based on the Bayesian model. First-order probabilistic HMMs were adapted to the theory of belief functions such that Bayesian probabilities were replaced with mass functions. In this paper, we present a second-order Hidden Markov Model using belief functions. Previous works in belief HMMs have been focused on the first-order HMMs. We extend them to the second-order model

Double exponential stability of quasi-periodic motion in Hamiltonian systems

We prove that generically, both in a topological and measure-theoretical sense, an invariant Lagrangian Diophantine torus of a Hamiltonian system is doubly exponentially stable in the sense that nearby solutions remain close to the torus for an interval of time which is doubly exponentially large with respect to the inverse of the distance to the torus. We also prove that for an arbitrary small perturbation of a generic integrable Hamiltonian system, there is a set of almost full positive Lebesgue measure of KAM tori which are doubly exponentially stable. Our results hold true for real-analytic but more generally for Gevrey smooth systems

From imaging to simulation: a framework applied to simulate the blood flow in the carotids

In this work we present a methodology to extract information from medical imaging and use it for hemodynamical simulation in arteries. Based on in-vivo magnetic resonance images (MRI), the velocity of the blood flow has been measured at different positions and times. Also, the anatomy of the vessel has been converted into a volume mesh suitable for numerical modeling. This data has been used to solve computationally the dynamics of the fluid inside the artery in healthy and pathologic cases. As an application, we have developed a computational model within the carotids. The next step in the pipeline will be to extend the simulation to fluidstructure interaction (FSI) to find the parameters in an atherosclerotic plaque that could lead to rupture.Peer Reviewe

Infinite ergodic theory and Non-extensive entropies

We bring into account a series of result in the infinite ergodic theory that we believe that they are relevant to the theory of non-extensive entropie

Ophiorrhiza mungos var. angustifolia – Estimation of camptothecin and pharmacological screening

Ophiorrhiza mungose var. angustifolia (Thwaites) Hook. f (Family- Rubiaceae) is a recently identified plant from Ophiorrhiza species in Western Ghats of Kerala. The plant is a promising candidate for the production of camptothecin (CPT) - a high value anticancer compound. Preliminary screening of hexane and methanol extract revealed the presence of phenolics, flavonoids, caumarins, steroids, terpeanoids, saponins, carbohydrates and alkaloids. Camptothecin was estimated from methanol extract using high performance liquid chromatography and the level of CPT was 297.94 ± 2.27 µg/g dry weight. The in vitro antioxidant assay revealed both extract showed moderate level of total phenolic content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, ferric chloride reducing power assay, phospho-molybdate assay of total anti-oxidant capacity and nitric oxide scavenging activity assay. Antimicrobial study reveals that only hexane extract inhibits pathogenic bacteria and fungus. Overall these findings will lead to isolation of active compounds other than camptothecin, elucidate them against wider range of bioactivity studies to find new therapeutic principles