24 research outputs found

    Transposition Rearrangement: Linear Algorithm for Length-Cost Model

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    The contemporary computational biology gives motivation to study dependencies between finite sequences. Primary structures of DNA or proteins are represented by such sequences (also called words or strings). In the paper a linear algorithm, computing the distance between two words, is presented. The model operates with transpositions of single letters. The cost of a single transposition is equal to the distance which transposed letter has to cover. Other papers concerning the model give, as the best known, algorithms of time complexity O(n log n). The complexity of our algorithm is O(nk), where k is the size of the alphabet, and O(n) when the size is fixed

    Analysing Multi-Agent Systems using 1-safe Petri Nets

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    In the modelling and analysis of large, real systems, the main problem in their efficient processing is the size of the global model. One of the popular approaches that address this issue is the decomposition of such global model into much smaller submodels and interaction between them. In this paper we discuss the translation of multi-agent systems with the common-action-based synchronization to 1-safe Petri nets. We prove that the composition in terms of transition systems is equivalent to the transition-based fusion of nets modelling different agents. We also address the issue of permanent disabling of some parts of the system by constraints implied by the synchronization and discuss the methods of solving it without the computation of the entire global model.Comment: https://ceur-ws.org/Vol-3170/paper8.pd

    STV+AGR: Towards Practical Verification of Strategic Ability Using Assume-Guarantee Reasoning

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    We present a substantially expanded version of our tool STV for strategy synthesis and verification of strategic abilities. The new version provides a web interface and support for assume-guarantee verification of multi-agent systems

    Assume-Guarantee Verification of Strategic Ability

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    Model checking of strategic abilities is a notoriously hard problem, even more so in the realistic case of agents with imperfect information. Assume-guarantee reasoning can be of great help here, providing a way to decompose the complex problem into a small set of exponentially easier subproblems. In this paper, we propose two schemes for assume-guarantee verification of alternating-time temporal logic with imperfect information. We prove the soundness of both schemes, and discuss their completeness. We illustrate the method by examples based on known benchmarks, and show experimental results that demonstrate the practical benefits of the approach

    Towards Assume-Guarantee Verification of Strategic Ability

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    Formal verification of strategic abilities is a hard problem. We propose to use the methodology of assume-guarantee reasoning in order to facilitate model checking of alternating-time temporal logic with imperfect information and imperfect recall

    Contests Hosting Service as a tool to teach programming

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    Computer science would not exist without the concept of algorithm. Therefore design of algorithms plays an important role in education while implementation is usually considered to be straightforward. Increasing variety of programming languages, wealth of possible constructions, programming environments and tools makes programming difficult for the beginners.Apart from the idea of problem solution, it is important to teach programming skills. Size of classes of 10-20 pupils and a limited number of lessons and their short time are the major problem. The teacher has to check solution of every pupil, compile it and run tests. This is definitely a time-consuming process which makes teaching difficult. In this paper the authors present the use of problem solutions validation systems during classes. With the help of such a system called Zawody WEB, the authors teach algorithms and programming for the secondary school students

    Verification of Multi-Agent Properties in Electronic Voting: A Case Study

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    Formal verification of multi-agent systems is hard, both theoretically and in practice. In particular, studies that use a single verification technique typically show limited efficiency, and allow to verify only toy examples. Here, we propose some new techniques and combine them with several recently developed ones to see what progress can be achieved for a real-life scenario. Namely, we use fixpoint approximation, domination-based strategy search, partial order reduction, and parallelization to verify heterogeneous scalable models of the Selene e-voting protocol. The experimental results show that the combination allows to verify requirements for much more sophisticated models than previously

    Emissions from a medium-duty crdi engine fuelled with diesel : biodiesel blends

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    In the present work, biofuels produced from different raw fatty materials have been proposed as a dominant fuel component in biodiesel–diesel fuel blends. Biofuels were produced from pork lard and rapeseed oil by alkali transesterification using methyl alcohol. Blends of biofuels in volumetric proportions of 60 and 80% of the biocomponent and the remaining part of the conventional fuel were used in a compression ignition engine designed for medium-duty vehicles. The experiments were conducted at two engine rotational speeds (1500 and 3000 rpm, respectively) and a set of load conditions (50, 100, and 200 Nm, respectively). The tests focused on engine efficiency parameters (brake-specific fuel consumption and brake fuel conversion efficiency) as well as exhaust gas emissions (hydrocarbons, carbon monoxide, and carbon dioxide were determined). The obtained results indicate that blends containing biocomponents produced from pork lard were characterized by superior fuel consumption and efficiency results, compared to blends containing biocomponents produced from rapeseed oil. In terms of exhaust emissions, biocomponents produced from pork lard were also characterized by lower emission of all of the examined components compared to rapeseed methyl ester–diesel blends. This study proposes that fuel components obtained from custom (animal) raw-fatty material can be an effective substitute for commonly used rapeseed oil methyl esters.© The Authors. Published by Exeley Inc. with Creative Commons licence (CC BY 4.0).fi=vertaisarvioitu|en=peerReviewed

    Transposition Rearrangement: Linear Algorithm for Length-Cost Model

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