Verification of the Schorr-Waite Algorithm - From Trees to Graphs

16 pagesInternational audienceThis article proposes a method for proving the correctness of graph algorithms by manipulating their spanning trees enriched with additional references. We illustrate this concept with a proof of the correctness of a (pseudo-)imperative version of the Schorr-Waite algorithm by re finement of a functional one working on trees. It is composed of two orthogonal steps of re finement -- functional to imperative and tree to graph -- fi nally merged to obtain the result. Our imperative speci fications use monadic constructs and syntax sugar, making them close to common imperative languages. This work has been realized within the Isabelle/HOL proof assistant

Dynamic contrast enhancement of paragangliomas of the head and neck: evaluation with time-resolved 2D MR projection angiography

Abstract.: Our objective was to evaluate tumor hemodynamics of paragangliomas of the head and neck. A 2D magnetic resonance projection angiography (MRPA) protocol was developed. Six patients with histologically proven paragangliomas were included in the study. The sequence protocol and data post-processing procedure were optimized in view of a high temporal resolution and maximum contrast-to-noise ratio. Image-time series of two freely orientated slabs could be obtained. Correlation analysis was performed to generate selective arterial and venous weighted angiographic images. Glomus tumors showed a rapid and intense homogeneous enhancement following the intravenous administration of contrast material. The smallest tumors investigated measured 10mm and could be visualized clearly. Time-resolved analysis of the tumor enhancement revealed an early bolus arrival within the vascular bed of the tumor and prolonged incomplete washout indicating blood pooling. The dynamic contrast enhancement of glomus tumors can be evaluated non-invasively with MRPA providing a high temporal resolution and high image quality. The characteristic contrast enhancement of glomus tumors can be helpful in the diagnostic workup of lesions that may mimic glomus tumor

Non-Invasive Follow-up Evaluation of Post-Embolized AVM with Time-Resolved MRA: A Case Report

We report the hemodynamic assessment in a patient with cerebral arteriovenous malformation using time-resolved magnetic resonance angiography (TR-MRA), a non-invasive modality, and catheter-based digital subtraction angiography (DSA), before and after embolization. Comparison of the results showed that TR-MRA produced very fast dynamic images and the findings closely matched those obtained at DSA. For initial work-up and follow-up studies in patients with vascular lesions, TR-MRA and DSA are therefore comparable

Молодежь и современные информационные технологии: сборник трудов XVI Международной научно-практической конференции студентов, аспирантов и молодых учёных, 3-7 декабря 2018 г., г. Томск

Сборник содержит доклады, представленные на XVI Международной научно-практической конференции студентов, аспирантов и молодых ученых «Молодежь и современные информационные технологии», прошедшей в Томском политехническом университете на базе Инженерной школы информационных технологий и робототехники. Материалы сборника отражают доклады студентов, аспирантов и молодых ученых, принятые к обсуждению на секциях: «Компьютерное моделирование и интеллектуальный анализ данных», «Автоматизация и управление в технических системах», «Робототехнические и мехатронные системы», «Цифровизация, IT и цифровая экономика», «Компьютерная графика и дизайн». Сборник предназначен для специалистов в области информационных технологий, студентов и аспирантов соответствующих специальностей