This paper discusses a Unified Modelling Language (UML) based formal verification methodology for early error detection in the model-based software development cycle. Our approach proposes a UML-based formal verification process utilising functional and behavioural modelling artifacts of UML. It reinforces these artifacts with formal model transition and property verification. The main contribution is a UML to Labelled Transition System (LTS) Translator application that automatically converts UML Statecharts to formal models. Property specifications are derived from system requirements and corresponding Computational Tree Logic (CTL)/Linear Temporal Logic (LTL) model checking procedure verifies property entailment in LTS. With its ability to verify CTL and LTL specifications, the methodology becomes generic for verifying all types of embedded system behaviours. The steep learning curve associated with formal methods is avoided through the automatic formal model generation and thus reduces the reluctance of using formal methods in software development projects. A case study of an embedded controller used in military applications validates the methodology. It establishes how the methodology finds its use in verifying the correctness and consistency of UML models before implementation.
Smart grids provide a digital upgradation of the conventional power grids by alleviating the power outages and voltage sags that occur due to their inefficient communication technologies and systems. They mainly tend to strengthen the efficiency, performance, and reliability of the traditional grids by establishing a trusted communication link between their different components through routing protocols. The conventional methods, i.e., the computer-based simulations and net testing, for analyzing these routing network protocols are error-prone and thus cannot be relied upon while analyzing the safety-critical smart grid systems. Formal methods can cater for the above-mentioned inaccuracies and thus can be very beneficial in analyzing communication protocols used in smart grids. In order to demonstrate the utilization and effectiveness of formal methods in analyzing smart grid routing protocols, we use the UPPAAL model checker to formally model the ZigBee-based routing protocol. We also verify some of its properties, such as, liveness, collision avoidance and deadlock freeness.
Background: Liver metastases are a leading cause of cancer-associated deaths in patients affected by colorectal cancer (CRC). The multidisciplinary strategy to treat CRC is more effective when the radiological diagnosis is accurate and early. Despite the evolving technologies in radiological accuracy, the radiological diagnosis of Colorectal Cancer Liver Metastases (CRCLM) is still a key point. The aim of our study was to define a new patient representation different by Artificial Intelligence models, using Formal Methods (FMs), to help clinicians to predict the presence of liver metastasis when still undetectable using the standard protocols. Methods: We retrospectively reviewed from 2013 to 2020 the CT scan of nine patients affected by CRC who would develop liver lesions within 4 months and 8 years. Seven patients developed liver metastases after primary staging before any liver surgery, and two patients were enrolled after R0 liver resection. Twenty-one patients were enrolled as the case control group (CCG). Regions of Interest (ROIs) were identified through manual segmentation on the medical images including only liver parenchyma and eventual benign lesions, avoiding major vessels and biliary ducts. Our predictive model was built based on formally verified radiomic features. Results: The precision of our methods is 100%, scheduling patients as positive only if they will be affected by CRCLM, showing a 93.3% overall accuracy. Recall was 77.8%. Conclusion: FMs can provide an effective early detection of CRCLM before clinical diagnosis only through non-invasive radiomic features even in very heterogeneous and small clinical samples.
Trust carried within it a duty of accountability, not only to show that the trustee acted in the interests of the entrustor or beneficiary but also to account financially for moneys that an entrusted official handled. This chapter examines formal methods of accountability in an age of an expanding state and empire. The chapter highlights the ambiguities over how far officials could, legally and morally, profit from public money in their hands and hence whether ‘abuse’ of public money constituted ‘corruption’. The failures of good oversight in the corporations and both the domestic and imperial contexts are stressed. The analysis then turns to the development and (at times transformative) influence of public accounts committees and commissions, beginning in the mid-seventeenth-century revolution. Throughout, the emphasis is on how long the process of achieving formal accountability took and the slow change of mentalities behind the regulatory innovations.