54 research outputs found

    Teaching Coloured Petri Nets - a Gentle Introduction to Formal Methods in a Distributed Systems Course

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    This paper is about the two compulsory project assignments set to the students in an undergraduate course on distributed systems. In the first assignment the students design and validate a non-trivial layered protocol by means of Coloured Petri Nets, and in the second they implement the designed protocol in an object-oriented language. From the two assignments the students experience that Coloured Petri Nets, as a formal method, are useful for designing and analysing distributed systems. In the course students are introduced to basic concepts and techniques for distributed systems, and it is explained that such systems are often too complex to manage without using formal methods. In this paper we also report on our experience with teaching the course and describe the didactic methods applied. Based on the obtained experience we conclude that the combination of distributed systems and Coloured Petri Nets is fruitful --- the two areas complement each other. Although our experiences origin in Coloured Petri Nets, we believe that many of our observations hold for other formal methods as well.Topics. Education issues related to nets; Coloured Petri Nets; distributed systems; experience with using nets,case studies; applications of nets to protocols

    Identitets-, Byggelinie- og Servitutattest

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    En Identitet-, Byggelinie- og Servitutattest er en attest, som anvendes til at atteste-re for et byggeris lovlige placering. Attesten knytter sig til et behov og der gives ingen retningslinjer i nogen lov, der præciserer, hvordan attesten skal udarbejdes. Attesten har i praksis opnået en grad af udbredelse, der gør, at det synes væsentligt at undersøge, hvorledes attestens anvendelse og indhold forholder sig til lan-dinspektørens professionelle ansvar. Derfor valgte en specialegruppe på Aalborg Universitet i foråret 2017 at undersøge emnet og denne artikel er blevet til i et efterfølgende samarbejde mel-lem specialegruppen og Aalborg Universitet med henblik på at formidle resultaterne. Undersøgelsen blev bygget op omkring den juridiske metode, hvilket afspejles i artiklen, der på denne ene side undersøger praksis og på den anden side reglen

    Macroscopic Hematuria and a Bladder Mass: Eosinophilic Cystitis in a 7-Year-Old Boy

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    We report a case of eosinophilic cystitis in a 7-year-old boy with a history of atopic symptoms, with focus on the radiological findings. He presented with hematuria and dysuria and ultrasonography (US) showed irregular bladder wall thickening resembling a bladder mass. CT urography did not characterize the lesion any further and showed no local or distant spread. Biopsies revealed eosinophilic cystitis, a benign inflammatory condition. We found that US characterized the lesion at least as well as CT and should be the first choice of imaging. When staging is considered before biopsy, MRI should be preferred to CT. There are no specific radiological signs of eosinophilic cystitis. On follow-up, US was a safe, cost-effective imaging modality, but findings should be interpreted in a clinical context. In a child with hematuria and a bladder mass, eosinophilic cystitis is a relevant but rare differential diagnosis, especially when there is a known atopic history

    Acute Myocarditis in a Patient with Newly Diagnosed Granulomatosis with Polyangiitis

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    A 22-year-old woman recently diagnosed with granulomatosis with polyangiitis (GPA) was admitted to the department of cardiology due to chest pain and shortness of breath. The ECG showed widespread mild PR-segment depression, upwardly convex ST-segment elevation, and T-wave inversion. The troponin T level was elevated at 550 ng/L. Transthoracic echocardiography showed basal inferoseptal thinning and hypokinesis, mild pericardial effusion, and an overall preserved left ventricular ejection fraction of 55%. Global longitudinal strain, however, was clearly reduced. Cardiac magnetic resonance imaging (MRI) showed findings consistent with myocarditis but the etiology of the apical hypokinesis could not be determined with certainty and may well have been due to a myocardial infarction, a notion supported by a coronary angiogram displaying slow flow in the territory of the left anterior descending artery. Finally, an endomyocardial biopsy confirmed the diagnosis of myocarditis. The cardiac symptoms subsided upon treatment with high-dose prednisolone and rituximab

    Hypereosinophilic Syndrome Leading to Severe Right-Sided Heart Failure in a Patient with Ebstein's Anomaly

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    A 36-year-old male with mild Ebstein's anomaly developed severe right-sided heart failure, following a 5-year-long course of hypereosinophilic syndrome. No regular followups had been done, during the years of antineoplastic therapy. A year after being cured from the hypereosinophilic syndrome, the patient developed right-sided heart failure symptoms and was found to have excessive fibrosis of the right ventricular endocardium and free tricuspid regurgitation. The findings were compatible with substantial scarring of the endocardium caused by the hypereosinophilic syndrome. Over a few years, the patient deteriorated significantly and was finally offered a heart transplant. Examination of the explanted heart revealed severe fibrosis of the right ventricle and almost complete sparing of the left
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