CoordMaude Simplifying Formal Coordination Specifications of Cooperation Environments

AbstractDeveloping concurrent applications in cooperative environments is an arduous task. This is mainly due to the fact that it is very difficult to specify the synchronized interaction between the entities composing the system. Using coordination models makes this task easier. The latest trends in this area suggest that to manage the successful implementation of complex systems, coordination models must support some key features regarding the coordination constraints: their separated specification, their unanticipated evolution and their dynamic change. However, supporting these features is not only a technical challenge: it must be also guaranteed that the application of a separately specified coordination pattern to a set of encapsulated entities, or the change of the coordination constraints in an already running software system will not produce semantic errors. This is just the problem focused in this paper. In particular, a method for generating formal interpretable specifications reproducing coordinated environments is presented. The method is based on the Coordinated Roles coordination model and makes use of Maude as a formal language. The benefits obtained are: (i) easy specification using the coordination model syntax, (ii) automatic generation of the corresponding formal specification and (iii) simulation of system behaviour

Modelling and simulation framework for reactive transport of organic contaminants in bed-sediments using a pure java object - oriented paradigm

Numerical modelling and simulation of organic contaminant reactive transport in the environment is being increasingly relied upon for a wide range of tasks associated with risk-based decision-making, such as prediction of contaminant profiles, optimisation of remediation methods, and monitoring of changes resulting from an implemented remediation scheme. The lack of integration of multiple mechanistic models to a single modelling framework, however, has prevented the field of reactive transport modelling in bed-sediments from developing a cohesive understanding of contaminant fate and behaviour in the aquatic sediment environment. This paper will investigate the problems involved in the model integration process, discuss modelling and software development approaches, and present preliminary results from use of CORETRANS, a predictive modelling framework that simulates 1-dimensional organic contaminant reaction and transport in bed-sediments

A Rewriting Logic Semantics for ATL

As the complexity of model transformation (MT) grows, the need to rely on formal semantics of MT languages becomes a critical issue. Formal semantics provide precise speci cations of the expected behavior of transformations, allowing users to understand them and to use them properly, and MT tool builders to develop correct MT engines, compilers, etc. In addition, formal semantics allow modelers to reason about the MTs and to prove their correctness, something specially important in case of large and complex MTs (with, e.g., hundreds or thousands of rules) for which manual debugging is no longer possible. In this paper we give a formal semantics of the ATL 3.0 model transformation language using rewriting logic and Maude, which allows addressing these issues. Such formalization provides additional bene ts, such as enabling the simulation of the speci cations or giving access to the Maude toolkit to reason about them

Hierarchical design rewriting with Maude

Architectural Design Rewriting (ADR) is a rule-based approach for the design of dynamic software architectures. The key features that make ADR a suitable and expressive framework are the algebraic presentation and the use of conditional rewrite rules. These features enable, e.g. hierarchical (top-down, bottom-up or composition-based) design and inductively-defined reconfigurations. The contribution of this paper is twofold: we define Hierarchical Design Rewriting (HDR) and present our prototypical tool support. HDR is a flavour of ADR that exploits the concept of hierarchical graph to deal with system specifications combining both symbolic and interpreted parts. Our prototypical implementation is based on Maude and its presentation serves several purposes. First, we show that HDR is not only a well-founded formal approach but also a tool-supported framework for the design and analysis of software architectures. Second, our illustration tailored to a particular algebra of designs and a particular scenario traces a general methodology for the reuse and exploitation of ADR concepts in other scenarios

A new P-Lingua toolkit for agile development in membrane computing

Membrane computing is a massively parallel and non-deterministic bioinspired computing paradigm whose models are called P systems. Validating and testing such models is a challenge which is being overcome by developing simulators. Regardless of their heterogeneity, such simulators require to read and interpret the models to be simulated. To this end, P-Lingua is a high-level P system definition language which has been widely used in the last decade. The P-Lingua ecosystem includes not only the language, but also libraries and software tools for parsing and simulating membrane computing models. Each version of P-Lingua supported new types or variants of P systems. This leads to a shortcoming: Only a predefined list of variants can be used, thus making it difficult for researchers to study custom ones. Moreover, derivation modes cannot be user-defined, i.e, the way in which P system computations should be generated is determined by the simulation algorithm in the source code. The main contribution of this paper is a completely new design of the P-Lingua language, called P-Lingua 5, in which the user can define custom variants and derivation modes, among other improvements such as including procedural programming and simulation directives. It is worth mentioning that it has backward-compatibility with previous versions of the language. A completely new set of command-line tools is provided for parsing and simulating P-Lingua 5 files. Finally, several examples are included in this paper covering the most common P system types.Agencia Estatal de Investigación TIN2017-89842-

An executable Theory of Multi-Agent Systems Refinement

Complex applications such as incident management, social simulations, manufacturing applications, electronic auctions, e-institutions, and business to business applications are pervasive and important nowadays. Agent-oriented methodology is an advance in abstractionwhich can be used by software developers to naturally model and develop systems for suchapplications. In general, with respect to design methodologies, what it may be important tostress is that control structures should be added at later stages of design, in a natural top-downmanner going from specifications to implementations, by refinement. Too much detail (be itfor the sake of efficiency) in specifications often turns out to be harmful. To paraphrase D.E.Knuth, “Premature optimization is the root of all evil” (quoted in ‘The Unix ProgrammingEnvironment’ by Kernighan and Pine, p. 91).The aim of this thesis is to adapt formal techniques to the agent-oriented methodologyinto an executable theory of refinement. The justification for doing so is to provide correctagent-based software by design. The underlying logical framework of the theory we proposeis based on rewriting logic, thus the theory is executable in the same sense as rewriting logicis. The storyline is as follows. We first motivate and explain constituting elements of agentlanguages chosen to represent both abstract and concrete levels of design. We then proposea definition of refinement between agents written in such languages. This notion of refinement ensures that concrete agents are correct with respect to the abstract ones. The advantageof the definition is that it easily leads to formulating a proof technique for refinement viathe classical notion of simulation. This makes it possible to effectively verify refinement bymodel-checking. Additionally, we propose a weakest precondition calculus as a deductivemethod based on assertions which allow to prove correctness of infinite state agents. Wegeneralise the refinement relation from single agents to multi-agent systems in order to ensure that concrete multi-agent systems refine their abstractions. We see multi-agent systemsas collections of coordinated agents, and we consider coordination artefacts as being basedeither on actions or on normative rules. We integrate these two orthogonal coordinationmechanisms within the same refinement theory extended to a timed framework. Finally, wediscuss implementation aspects.LEI Universiteit LeidenFoundations of Software Technolog

A Knowledge-Based Approach for Business Process Reengineering, SHAMASH

In this paper we present an initial overview of shamash, a process modeling tool for Business Process Reengineering. The main features that differentiate it from most current related tools are its ability to define and use organisation standards, and functional structure, and make automatic model simulation and optimisation of them. shamash is a knowledge based system, and we include a discussion on how knowledge acquisition did take place. Furthemore, we introduce a high level description of the architecture, the conceptual model, and other important modules of the system.Publicad

Computationally generating and simulating plant-life using parametric L-systems : a thesis presented in partial fulfilment of the requirements for the degree of Master of Information Science in Computer Science at Massey University, Albany, New Zealand

Producing and simulating realistic-looking plant-life assets for 3D applications is a challenging task. An important contributing factor in the realism of plant models in modern graphics applications is its motion, but creating plant assets that both look and move realistically is a tedious and time-consuming process. Lindenmayer systems are a useful tool for producing a set of instructions that represent the structures of organic life, such as algae, flora, and trees. These instructions can be interpreted using turtle graphics to render realistic models. A class of L-system known as parametric L-systems can provide extra information through the rewriting process using parameters. The use of parametric L-systems is investigated to provide both the physical and geometric properties of a plant, such that a model can be rendered and physically simulate the effects of gravity and wind. The relationship between the L-systems’ rewriting mechanism and the interpreter system is investigated and discussed. The parametric class of L-system is a grammar similar to that of a recursive programming language. A compiler-like software solution is developed, that is capable of taking L-system language as input and producing instructions and information to the interpreter system. A three-stage 3D graphics software system is implemented to interpret the L-system instructions and information in order to display complex plant models. A separate physics system is also developed to simulate the motion of the resulting plant models under gravity or wind. There is a trade-off between the complexity of the rewriting system and the interpreting system. Consideration as to the advantages and disadvantages of these trade-offs is discussed. It is shown that parametric L-systems can create plant structures that have variations in their branching structure and physical features, which can provide the physical properties of branches necessary to simulate forces like gravity and wind. There is considerable benefit to having a software system produce both the geometry of a plant model and the information necessary for simulation, as it allows a plant to be defined in a single definition in the form of an L-system

Autonomous vehicle control using a kinematic Lyapunov-based technique with LQR-LMI tuning

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/This paper presents the control of an autonomous vehicle using a Lyapunov-based technique with a LQR-LMI tuning. Using the kinematic model of the vehicle, a non-linear control strategy based on Lyapunov theory is proposed for solving the control problem of autonomous guidance. To optimally adjust the parameters of the Lyapunov controller, the closed loop system is reformulated in a linear parameter varying (LPV) form. Then, an optimization algorithm that solves the LQR-LMI problem is used to determine the controller parameters. Furthermore, the tuning process is complemented by adding a pole placement constraint that guarantees that the maximum achievable performance of the kinematic loop could be achieved by the dynamic loop. The obtained controller jointly with a trajectory generation module are in charge of the autonomous vehicle guidance. Finally, the paper illustrates the performance of the autonomous guidance system in a virtual reality environment (SYNTHIA) and in a real scenario achieving the proposed goal: to move autonomously from a starting point to a final point in a comfortable way.Peer ReviewedPostprint (author's final draft