A distributed self-reconfiguration algorithm for cylindrical lattice-based modular robots

International audienceModular self-reconfigurable robots are composed of independent connected modules which can self-rearrange their connectivity using processing, communication and motion capabilities, in order to change the overall robot structure. In this paper, we consider rolling cylindrical modules arranged in a two-dimensional vertical hexagonal lattice. We propose a parallel, asynchronous and fully decentralized distributed algorithm to self-reconfigure robots from an initial configuration to a goal one. We evaluate our algorithm on the millimeter-scale cylindrical robots, developed in the Claytronics project, through simulation of large ensembles composed of up to ten thousand modules. We show the effectiveness of our algorithm and study its performance in terms of communications, movements and execution time. Our observations indicate that the number of communications, the number of movements and the execution time of our algorithm is highly predictable. Furthermore, we observe execution times that are linear in the size of the goal shape

The Management of Manufacturing-Oriented Informatics Systems Using Efficient and Flexible Architectures

Industry and in particular the manufacturing-oriented sector has always been researched and innovated as a result of technological progress, diversification and differentiation among consumers' demands. A company that provides to its customers products matching perfectly their demands at competitive prices has a great advantage over its competitors. Manufacturing-oriented information systems are becoming more flexible and configurable and they require integration with the entire organization. This can be done using efficient software architectures that will allow the coexistence between commercial solutions and open source components while sharing computing resources organized in grid infrastructures and under the governance of powerful management tools.Manufacturing-Oriented Informatics Systems, Open Source, Software Architectures, Grid Computing, Web-Based Management Systems

Compiler-Driven Reconfiguration of Multiprocessors

Hussmann M, Thies M, Kastens U, Purnaprajna M, Porrmann M, Rückert U. Compiler-Driven Reconfiguration of Multiprocessors. In: Proceedings of the Workshop on Application Specific Processors (WASP) 2007. 2007.Multiprocessors enable parallel execution of a single large application to achieve a performance improvement. An application is split at instruction, data or task level (based on the granularity), such that the overhead of partitioning is minimal. Parallelization for multiprocessors is mostly restricted to a fixed granularity. Reconfiguration enables architectural variations to allow multiple granularities of operation within a multiprocessor. This adaptability optimizes resource utilization over a fixed organization. Here, a unified hardware-software approach to design a reconfigurable multiprocessor system called QuadroCore is presented. In our holistic methodology, compiler-driven reconfiguration selects from a fixed set of modes. Each mode relies on matching program analysis to exploit the architecture efficiently. For instance, a multiprocessor may adapt to different parallelization paradigms. The compiler can determine the best execution mode for each piece of code by analyzing the parallelism in a program. A fast, singlecycle, run-time reconfiguration between these predetermined modes is enabled by executing special instructions which switch coarse-grained components like instruction decoders, ALUs and register banks. Performance is evaluated in terms of execution cycles and achieved clock frequency. First results indicate suitability especially in audio and video processing applications

CATS: linearizability and partition tolerance in scalable and self-organizing key-value stores

Distributed key-value stores provide scalable, fault-tolerant, and self-organizing storage services, but fall short of guaranteeing linearizable consistency in partially synchronous, lossy, partitionable, and dynamic networks, when data is distributed and replicated automatically by the principle of consistent hashing. This paper introduces consistent quorums as a solution for achieving atomic consistency. We present the design and implementation of CATS, a distributed key-value store which uses consistent quorums to guarantee linearizability and partition tolerance in such adverse and dynamic network conditions. CATS is scalable, elastic, and self-organizing; key properties for modern cloud storage middleware. Our system shows that consistency can be achieved with practical performance and modest throughput overhead (5%) for read-intensive workloads

Model Checking Paxos in Spin

We present a formal model of a distributed consensus algorithm in the executable specification language Promela extended with a new type of guards, called counting guards, needed to implement transitions that depend on majority voting. Our formalization exploits abstractions that follow from reduction theorems applied to the specific case-study. We apply the model checker Spin to automatically validate finite instances of the model and to extract preconditions on the size of quorums used in the election phases of the protocol.Comment: In Proceedings GandALF 2014, arXiv:1408.556

Proceedings of the 5th International Workshop on Reconfigurable Communication-centric Systems on Chip 2010 - ReCoSoC\u2710 - May 17-19, 2010 Karlsruhe, Germany. (KIT Scientific Reports ; 7551)

ReCoSoC is intended to be a periodic annual meeting to expose and discuss gathered expertise as well as state of the art research around SoC related topics through plenary invited papers and posters. The workshop aims to provide a prospective view of tomorrow\u27s challenges in the multibillion transistor era, taking into account the emerging techniques and architectures exploring the synergy between flexible on-chip communication and system reconfigurability

Extending Rebeca with synchronous messages and reusable components

In this paper, we propose extended Rebeca as a tool-supported actor-based language for modeling and verifying of concurrent and distributed systems. We enrich Rebeca with a formal concept of components which integrates the message-driven computational model of actor-based languages with synchronous message passing. Components are used to encapsulate a set of internal active objects which react asynchronously to messages by means of methods and which additionally interact via a synchronous message passing mechanism. Components themselves interact only via asynchronous and anonymous messages. We present our compositional verification approach and abstraction techniques, and the theory corresponding to it, based on formal semantics of Rebeca. These techniques are exploited to overcome state explosion problem in model checkin