Synthesis of Parametric Programs using Genetic Programming and Model Checking

Formal methods apply algorithms based on mathematical principles to enhance the reliability of systems. It would only be natural to try to progress from verification, model checking or testing a system against its formal specification into constructing it automatically. Classical algorithmic synthesis theory provides interesting algorithms but also alarming high complexity and undecidability results. The use of genetic programming, in combination with model checking and testing, provides a powerful heuristic to synthesize programs. The method is not completely automatic, as it is fine tuned by a user that sets up the specification and parameters. It also does not guarantee to always succeed and converge towards a solution that satisfies all the required properties. However, we applied it successfully on quite nontrivial examples and managed to find solutions to hard programming challenges, as well as to improve and to correct code. We describe here several versions of our method for synthesizing sequential and concurrent systems.Comment: In Proceedings INFINITY 2013, arXiv:1402.661

Peer review for the evaluation of the academic research: the Italian experience

Peer review, that is the evaluation process based on judgments formulated by independent experts, is generally used for different goals: the allocation of research funding, the review of the research results submitted for publication in scientific journals, and the assessment of the quality of research conducted by Universities and university-related Institutes. The paper deals with the latter type of peer review. The aim is to understand how the characteristics of the Italian experience provide useful lessons for improving peer review effectiveness for evaluating the academic research. More specifically, the paper investigates the peer review process developed within the Three-Year Research Assessment Exercise (VTR) in Italy. Our analysis covers four disciplinary sectors: chemistry, biology, humanities and economics. Thus, the choice includes two “hard science” sectors, which have similar type of research output submitted for the three-year evaluation process, and two sectors with different types of output. The results provide evidences, which highlight the important role played by peer review for judging the quality of the academic research in different fields of science, and for comparing different institutions’ performance. Moreover, some basic features of the evaluation process are discussed, in order to understand their usefulness for reinforcing the effectiveness of the peers’ final outcome.Scientific research, Evaluation, Peer review, University, Academic institutions

Thrombolysis in very elderly people: controlled comparison of SITS international stroke thrombolysis registry and virtual international stroke trials archive

<p>Objective To assess effect of age on response to alteplase in acute ischaemic stroke.</p> <p>Design Adjusted controlled comparison of outcomes between non-randomised patients who did or did not undergo thrombolysis. Analysis used Cochran-Mantel-Haenszel test and proportional odds logistic regression analysis.</p> <p>Setting Collaboration between International Stroke Thrombolysis Registry (SITS-ISTR) and Virtual International Stroke Trials Archive (VISTA).</p> <p>Participants 23 334 patients from SITS-ISTR (December 2002 to November 2009) who underwent thrombolysis and 6166 from VISTA neuroprotection trials (1998-2007) who did not undergo thrombolysis (as controls). Of the 29 500 patients (3472 aged >80 (“elderly,” mean 84.6), data on 272 patients were missing for baseline National Institutes of Health stroke severity score, leaving 29 228 patients for analysis adjusted for age and baseline severity.</p> <p>Main outcome measures Functional outcomes at 90 days measured by score on modified Rankin scale.</p> <p>Results Median severity at baseline was the same for patients who underwent thrombolysis and controls (median baseline stroke scale score: 12 for each group, P=0.14; n=29 228). The distribution of scores on the modified Rankin scale was better among all thrombolysis patients than controls (odds ratio 1.6, 95% confidence interval 1.5 to 1.7; Cochran-Mantel-Haenszel P<0.001). The association occurred independently among patients aged ≤80 (1.6, 1.5 to 1.7; P<0.001; n=25 789) and in those aged >80 (1.4, 1.3 to 1.6; P0.001; n=3439). Odds ratios were consistent across all 10 year age ranges above 30, and benefit was significant from age 41 to 90; dichotomised outcomes (score on modified Rankin scale 0-1 v 2-6; 0-2 v 3-6; and 6 (death) v rest) were consistent with the results of the ordinal analysis.</p> <p>Conclusions Outcome in patients with acute ischaemic stroke is significantly better in those who undergo thrombolysis compared with those who do not. Increasing age is associated with poorer outcome but the association between thrombolysis treatment and improved outcome is maintained in very elderly people. Age alone should not be a barrier to treatment.</p&gt

Alcohol, intraocular pressure and open-angle glaucoma: A systematic review and meta-analysis

TOPIC: This systematic review and meta-analysis summarizes the existing evidence for the association of alcohol use with intraocular pressure (IOP) and open-angle glaucoma (OAG). CLINICAL RELEVANCE: Understanding and quantifying these associations may aid clinical guidelines or treatment strategies and shed light on disease pathogenesis. The role of alcohol, a modifiable factor, in determining IOP and OAG risk may also be of interest from an individual or public health perspective. METHODS: The study protocol was pre-registered in the Open Science Framework Registries (https://osf.io/z7yeg). Eligible articles (as of 14 May 2021) from three databases (PubMed, Embase, Scopus) were independently screened and quality assessed by two reviewers. All case-control, cross-sectional and cohort studies reporting a quantitative effect estimate and 95% confidence interval (CI) for the association between alcohol use and either IOP or OAG were included. The evidence for the associations with both IOP and OAG were qualitatively summarized. Effect estimates for the association with OAG were pooled using random effects meta-analysis. Studies not meeting formal inclusion criteria for systematic review, but with pertinent results, were also appraised and discussed. Certainty of evidence was assessed using the GRADE framework. RESULTS: Thirty four studies were included in the systematic review. Evidence from 10 studies reporting an association with IOP suggest that habitual alcohol use is associated with higher IOP and prevalence of ocular hypertension (IOP >21mmHg), although absolute effect sizes were small. Eleven of 26 studies, comprising 173 058 participants, that tested for an association with OAG met inclusion criteria for meta-analysis. Pooled effect estimates indicated a positive association between any use of alcohol and OAG (1.18; 95% CI, 1.02-1.36; p=0.03; I2=40.5%), with similar estimates for both prevalent and incident OAG. The overall GRADE certainty of evidence was very low. CONCLUSION: While this meta-analysis suggests a harmful association between alcohol use and OAG, our results should be interpreted cautiously given the weakness and heterogeneity of the underlying evidence base, the small absolute effect size and the borderline statistical significance. Nonetheless, these findings may be clinically relevant and future research should focus on improving the quality of evidence

Logic Programming approaches for routing fault-free and maximally-parallel Wavelength Routed Optical Networks on Chip (Application paper)

One promising trend in digital system integration consists of boosting on-chip communication performance by means of silicon photonics, thus materializing the so-called Optical Networks-on-Chip (ONoCs). Among them, wavelength routing can be used to route a signal to destination by univocally associating a routing path to the wavelength of the optical carrier. Such wavelengths should be chosen so to minimize interferences among optical channels and to avoid routing faults. As a result, physical parameter selection of such networks requires the solution of complex constrained optimization problems. In previous work, published in the proceedings of the International Conference on Computer-Aided Design, we proposed and solved the problem of computing the maximum parallelism obtainable in the communication between any two endpoints while avoiding misrouting of optical signals. The underlying technology, only quickly mentioned in that paper, is Answer Set Programming (ASP). In this work, we detail the ASP approach we used to solve such problem. Another important design issue is to select the wavelengths of optical carriers such that they are spread across the available spectrum, in order to reduce the likelihood that, due to imperfections in the manufacturing process, unintended routing faults arise. We show how to address such problem in Constraint Logic Programming on Finite Domains (CLP(FD)). This paper is under consideration for possible publication on Theory and Practice of Logic Programming.Comment: Paper presented at the 33nd International Conference on Logic Programming (ICLP 2017), Melbourne, Australia, August 28 to September 1, 2017. 16 pages, LaTeX, 5 figure

Design and real-time control of shipboard power system testbed

The objective of this thesis is to design and test a small scale testbed for the all-electric shipboard power distribution system. Shipboard power system is increasingly becoming more reconfigurable, and multi-agent systems are developed to automate routine operation and emergency reconfiguration. Underlying algorithms of these systems have been verified using software simulation tools. However, these simulators run in soft realtime by using simple mathematical models to represent the physical system. These models do not incorporate every aspect of the physical system. A testbed provides a cost effective physical environment to verify these algorithms and control techniques in the real world. This testbed, based on the Navy\u27s notional all electric ship, keeps characteristic features of the Office of Naval Research\u27s Integrated Power System. It provides a platform for testing local and distributed controls. Local embedded controllers on the testbed run in hard real-time, and a CAN bus builds the communication networking among them. Performance of the controllers has been verified successfully, and the platform provides an environment that allows prototyping and testing agent-based higher-level controls and decision making entities

The cultural, ethnic and linguistic classification of populations and neighbourhoods using personal names

There are growing needs to understand the nature and detailed composition of ethnicgroups in today?s increasingly multicultural societies. Ethnicity classifications areoften hotly contested, but still greater problems arise from the quality and availabilityof classifications, with knock on consequences for our ability meaningfully tosubdivide populations. Name analysis and classification has been proposed as oneefficient method of achieving such subdivisions in the absence of ethnicity data, andmay be especially pertinent to public health and demographic applications. However,previous approaches to name analysis have been designed to identify one or a smallnumber of ethnic minorities, and not complete populations.This working paper presents a new methodology to classify the UK population andneighbourhoods into groups of common origin using surnames and forenames. Itproposes a new ontology of ethnicity that combines some of its multidimensionalfacets; language, religion, geographical region, and culture. It uses data collected atvery fine temporal and spatial scales, and made available, subject to safeguards, at thelevel of the individual. Such individuals are classified into 185 independentlyassigned categories of Cultural Ethnic and Linguistic (CEL) groups, based on theprobable origins of names. We include a justification for the need of classifyingethnicity, a proposed CEL taxonomy, a description of how the CEL classification wasbuilt and applied, a preliminary external validation, and some examples of current andpotential applications