20 research outputs found
Formal Modelling, Testing and Verification of HSA Memory Models using Event-B
The HSA Foundation has produced the HSA Platform System Architecture
Specification that goes a long way towards addressing the need for a clear and
consistent method for specifying weakly consistent memory. HSA is specified in
a natural language which makes it open to multiple ambiguous interpretations
and could render bugs in implementations of it in hardware and software. In
this paper we present a formal model of HSA which can be used in the
development and verification of both concurrent software applications as well
as in the development and verification of the HSA-compliant platform itself. We
use the Event-B language to build a provably correct hierarchy of models from
the most abstract to a detailed refinement of HSA close to implementation
level. Our memory models are general in that they represent an arbitrary number
of masters, programs and instruction interleavings. We reason about such
general models using refinements. Using Rodin tool we are able to model and
verify an entire hierarchy of models using proofs to establish that each
refinement is correct. We define an automated validation method that allows us
to test baseline compliance of the model against a suite of published HSA
litmus tests. Once we complete model validation we develop a coverage driven
method to extract a richer set of tests from the Event-B model and a user
specified coverage model. These tests are used for extensive regression testing
of hardware and software systems. Our method of refinement based formal
modelling, baseline compliance testing of the model and coverage driven test
extraction using the single language of Event-B is a new way to address a key
challenge facing the design and verification of multi-core systems.Comment: 9 pages, 10 figure
ESPGHAN and NASPGHAN 2023 protocol for paediatric FAPD treatment guidelines (standard operating procedure)
Introduction To date, no international guidelines have been published for the treatment of paediatric functional abdominal pain disorders (FAPDs), subcategorised into functional abdominal painânot otherwise specified (FAP-NOS), irritable bowel syndrome (IBS), functional dyspepsia and abdominal migraine (AM). We aim for a treatment guideline, focusing on FAP-NOS, IBS and AM, that appreciates the extensive array of available therapies in this field. We present the prospective operating procedure and technical summary protocol in this manuscript.
Methods Grading of Recommendations, Assessment, Development and Evaluation (GRADE) will be followed in the development of the guideline, following the approach as laid out in the GRADE handbook, supported by the WHO. The Guideline Development Group (GDG) is formed by paediatric gastroenterologists from both the European Society for Pediatric Gastroenterology, Hepatology and Nutrition, as well as the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition. Also, one clinical psychologist with expertise in FAPDs is a voting member in the GDG. A final consensus list of treatment options is translated into âpatient, intervention, comparison, outcomeâ format options. Prospective agreement on the magnitude of health benefits or harms categories was reached through a Delphi process among the GDG to support grading of the literature.
There will be a detailed technical evidence review with randomised controlled trial data that will be judged for risk of bias with the Cochrane tool. Recommendations are preferably based on GRADE but could also be best practice statements following the available evidence. A full Delphi process will be used to make recommendations using online response systems. This set of procedures has been approved by all members of the GDG
Symmetry Reduction for STE Model Checking Using Structured Models
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