Stepwise refinement of sequence diagrams with soft real-time constraints

UML sequence diagrams and similar notations are much used to specify and analyze computer systems and their requirements. Probabilities are often essential, in particular for capturing soft real-time constraints. It is also important to be able to specify systems at different levels of abstraction. Refinement is a means to relate abstract specifications to more concrete specifications in such a way that constraints and analysis results are preserved through the transition. In order to allow soft real-time constraints to be included as an integral part of sequence diagram specifications, this paper presents an approach to extend UML 2.x sequence diagrams to capture probabilistic choice in general and soft real-time constraints in particular. The approach is supported by formal semantics and pragmatic refinement relations with mathematical properties that allow stepwise and modular development of specifications. An example focusing on communication is provided to demonstrate the language and refinement relations.acceptedVersio

Quantitative Assurance and Synthesis of Controllers from Activity Diagrams

Probabilistic model checking is a widely used formal verification technique to automatically verify qualitative and quantitative properties for probabilistic models. However, capturing such systems, writing corresponding properties, and verifying them require domain knowledge. This makes it not accessible for researchers and engineers who may not have the required knowledge. Previous studies have extended UML activity diagrams (ADs), developed transformations, and implemented accompanying tools for automation. The research, however, is incomprehensive and not fully open, which makes it hard to be evaluated, extended, adapted, and accessed. In this paper, we propose a comprehensive verification framework for ADs, including a new profile for probability, time, and quality annotations, a semantics interpretation of ADs in three Markov models, and a set of transformation rules from activity diagrams to the PRISM language, supported by PRISM and Storm. Most importantly, we developed algorithms for transformation and implemented them in a tool, called QASCAD, using model-based techniques, for fully automated verification. We evaluated one case study where multiple robots are used for delivery in a hospital and further evaluated six other examples from the literature. With all these together, this work makes noteworthy contributions to the verification of ADs by improving evaluation, extensibility, adaptability, and accessibility.Comment: 43 pages, 29 figures, 5 tables, submitted to Journal of Systems and Software (JSS

Система для розвитку навичок швидкісного та сліпого набору тексту. Серверна частина

Проєкт містить 135 с. тексту, 39 рисунків, 88 таблиць, посилання на 17 літературних джерел, додатки та 6 конструкторських документів. Об’єкт розробки: система для розвитку навичок швидкісного та сліпого набору тексту. Мета дипломного проєкту: ефективне вдосконалення навичок швидкісного та сліпого набору тексту за рахунок створення особистого навчального плану. У дипломному проєкті було визначено архітектуру серверної частини системи «Smart Typer» та надалі її реалізовано. Побудована функціональна модель, на основі дослідження переваг та недоліків аналогів даної системи. Також проведено аналіз методів багатокритеріальної оптимізації для побудови оптимального навчально плану, в результаті чого запропоновано модифікацію на основі алгоритму AHP(Analytic Hierarchy Process). Отримані результати можуть бути використані для розвитку навичок друку, що забезпечує ефективність виконання як завдань професійної діяльності, так і повсякденних справ.In diploma project, the architecture of server part of Smart Typer system was defined and subsequently implemented. A functional model was built based on a study of the advantages and disadvantages of analogs of system. Also, the analysis of multicriteria optimization methods for building an optimal curriculum was carried out, as a result of which a modification based on the AHP (Analytic Hierarchy Process) algorithm was proposed. The obtained results can be used to develop typing skills, which ensures the efficiency of performing both professional tasks and everyday activities