Modelling the Dynamics of an Aedes albopictus Population

We present a methodology for modelling population dynamics with formal means of computer science. This allows unambiguous description of systems and application of analysis tools such as simulators and model checkers. In particular, the dynamics of a population of Aedes albopictus (a species of mosquito) and its modelling with the Stochastic Calculus of Looping Sequences (Stochastic CLS) are considered. The use of Stochastic CLS to model population dynamics requires an extension which allows environmental events (such as changes in the temperature and rainfalls) to be taken into account. A simulator for the constructed model is developed via translation into the specification language Maude, and used to compare the dynamics obtained from the model with real data.Comment: In Proceedings AMCA-POP 2010, arXiv:1008.314

Combustion characteristics of biodiesel saturated with pyrolysis oil for power generation in gas turbines

There is a perceived need for multi-fuel burner geometries capable of operating with variable composition fuels from diverse sources to achieve fuel flexibility in gas turbines. The objective of the research covered herein is a comparison study between two liquid fuels, a biodiesel (in a pure form) and the biodiesel as a saturated mixture with a pyrolysis by-product; these two fuels were compared against a standard kerosene as a baseline. The research methodology involved two stages: firstly atomization patterns and injection regimes were obtained using a high speed imaging method, secondly a combustion test campaign was undertaken using a swirl burner to quantify the operational behaviour, species production and exhaust gas compositions of the fuels. Emissions, flame stability trends and power outputs were measured at gas turbine relevant equivalence ratios. Excess oxygen and atomization trends in the biodiesel seem to be playing a major role in the production of emissions and flame stability when compared to kerosene. Also, heavy organics seem to be acting as catalytic substances for OH production close to the burner mouth. In terms of stability and combustion, it is proposed that the saturated blend would be a viable candidate for power generation

Formal Methods. FM 2019 International Workshops Porto, Portugal, October 7–11, 2019, Revised Selected Papers, Part I

This book constitutes the refereed proceedings of the workshops which complemented the 23rd Symposium on Formal Methods, FM 2019, held in Porto, Portugal, in October 2019. This volume presents the papers that have been accepted for the following workshops: Third Workshop on Practical Formal Verification for Software Dependability, AFFORD 2019; 8th International Symposium From Data to Models and Back, DataMod 2019; First Formal Methods for Autonomous Systems Workshop, FMAS 2019; First Workshop on Formal Methods for Blockchains, FMBC 2019; 8th International Workshop on Formal Methods for Interactive Systems, FMIS 2019; First History of Formal Methods Workshop, HFM 2019; 8th International Workshop on Numerical and Symbolic Abstract Domains, NSAD 2019; 9th International Workshop on Open Community Approaches to Education, Research and Technology, OpenCERT 2019; 17th Overture Workshop, Overture 2019; 19th Refinement Workshop, Refine 2019; First International Workshop on Reversibility in Programming, Languages, and Automata, RPLA 2019; 10th International Workshop on Static Analysis and Systems Biology, SASB 2019; and the 10th Workshop on Tools for Automatic Program Analysis, TAPAS 2019

A distributed blockchain model of selfish mining

Bitcoin, still the most widely used cryptocurrency maintains a distributed ledger for transactions known as the blockchain. Miners should expect a reward proportional to the computational power they provide to the network. Eyal and Sirer introduced seflish mining, a strategy gives a significant edge in profits. This paper models the behaviour of honest and selfish mining pools in Uppaal. Unlike earlier models in literature, it does not assume a single view of the blockchain but does include the presence of network delay. Results for our model show the effects of selfish mining on the share of profits, but more importantly the outwards observable effect on the number of orphaned blocks. This paper compares the analysis results to known results from literature and real-world data

Comparing correctness-by-construction with post-hoc verification—a qualitative user study

Correctness-by-construction (CbC) is a refinement-based methodology to incrementally create formally correct programs. Programs are constructed using refinement rules which guarantee that the resulting implementation is correct with respect to a pre-/postcondition specification. In contrast, with post-hoc verification (PhV) a specification and a program are created, and afterwards verified that the program satisfies the specification. In the literature, both methods are discussed with specific advantages and disadvantages. By letting participants construct and verify programs using CbC and PhV in a controlled experiment, we analyzed the claims in the literature. We evaluated defects in intermediate code snapshots and discovered a trial-and-error construction process to alter code and specification. The participants appreciated the good feedback of CbC and state that CbC is better than PhV in helping to find defects. Nevertheless, some defects in the constructed programs with CbC indicate that the participants need more time to adapt the CbC process

CM-Path Molecular Diagnostics Forum—consensus statement on the development and implementation of molecular diagnostic tests in the United Kingdom

Background: Pathology has evolved from a purely morphological description of cellular alterations in disease to our current ability to interrogate tissues with multiple ‘omics’ technologies. By utilising these techniques and others, ‘molecular diagnostics’ acts as the cornerstone of precision/personalised medicine by attempting to match the underlying disease mechanisms to the most appropriate targeted therapy. Methods: Despite the promises of molecular diagnostics, significant barriers have impeded its widespread clinical adoption. Thus, the National Cancer Research Institute (NCRI) Cellular Molecular Pathology (CM-Path) initiative convened a national Molecular Diagnostics Forum to facilitate closer collaboration between clinicians, academia, industry, regulators and other key stakeholders in an attempt to overcome these. Results: We agreed on a consensus ‘roadmap’ that should be followed during development and implementation of new molecular diagnostic tests. We identified key barriers to efficient implementation and propose possible solutions to these. In addition, we discussed the recent reconfiguration of molecular diagnostic services in NHS England and its likely impacts. Conclusions: We anticipate that this consensus statement will provide practical advice to those involved in the development of novel molecular diagnostic tests. Although primarily focusing on test adoption within the United Kingdom, we also refer to international guidelines to maximise the applicability of our recommendations