4,516 research outputs found
A modern vision of simulation modelling in mining and near mining activity
The paper represents the creation of the software simulation
system, which reproduce the basic processes of mining and near
production. It presents the consideration of such systems for both
traditional and non-traditional mineral extraction systems. The principles
of using computer recognition of processes are also presented in other
processes of carbon-containing raw materials transition, as well as power
production and waste utilization of mining production. These systems
considerably expand the manageability of a rather complicated mining
enterprise. The main purpose of such research is the simulation
reproduction of all technological processors associated with the activity of
mining enterprises on the display of the dispatch center. For this purpose,
is used so-called UML-diagrams, which allows to simulate mining and
near mining processes. Results of this investigation were included to the
Roman Dychkovskyi thesis of the scientific degree of the Doctor of the
Technique Sciences βScientific Principles of Technologies Combination
for Coal Mining in Weakly Metamorphoses Rockmassβ
A multi-paradigm language for reactive synthesis
This paper proposes a language for describing reactive synthesis problems
that integrates imperative and declarative elements. The semantics is defined
in terms of two-player turn-based infinite games with full information.
Currently, synthesis tools accept linear temporal logic (LTL) as input, but
this description is less structured and does not facilitate the expression of
sequential constraints. This motivates the use of a structured programming
language to specify synthesis problems. Transition systems and guarded commands
serve as imperative constructs, expressed in a syntax based on that of the
modeling language Promela. The syntax allows defining which player controls
data and control flow, and separating a program into assumptions and
guarantees. These notions are necessary for input to game solvers. The
integration of imperative and declarative paradigms allows using the paradigm
that is most appropriate for expressing each requirement. The declarative part
is expressed in the LTL fragment of generalized reactivity(1), which admits
efficient synthesis algorithms, extended with past LTL. The implementation
translates Promela to input for the Slugs synthesizer and is written in Python.
The AMBA AHB bus case study is revisited and synthesized efficiently,
identifying the need to reorder binary decision diagrams during strategy
construction, in order to prevent the exponential blowup observed in previous
work.Comment: In Proceedings SYNT 2015, arXiv:1602.0078
Uncovering Bugs in Distributed Storage Systems during Testing (not in Production!)
Testing distributed systems is challenging due to multiple sources of nondeterminism. Conventional testing techniques, such as unit, integration and stress testing, are ineffective in preventing serious but subtle bugs from reaching production. Formal techniques, such as TLA+, can only verify high-level specifications of systems at the level of logic-based models, and fall short of checking the actual executable code. In this paper, we present a new methodology for testing distributed systems. Our approach applies advanced systematic testing techniques to thoroughly check that the executable code adheres to its high-level specifications, which significantly improves coverage of important system behaviors. Our methodology has been applied to three distributed storage systems in the Microsoft Azure cloud computing platform. In the process, numerous bugs were identified, reproduced, confirmed and fixed. These bugs required a subtle combination of concurrency and failures, making them extremely difficult to find with conventional testing techniques. An important advantage of our approach is that a bug is uncovered in a small setting and witnessed by a full system trace, which dramatically increases the productivity of debugging
Architecture Description for Mobile Distributed Systems
In this paper we motivate an Architecture Description Language (ADL) for mobile distributed systems based on the Ο-calculus. Different from other approaches, the non-functional properties, which are essential when mobile architectures are described, are treated in a flexible manner by inserting logical formulae for expressing and checking non-functional properties into Ο-calculus processes. A formal example is
given to illustrate the approach before the constituents of the ADL are sketched
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