Roborobo! a Fast Robot Simulator for Swarm and Collective Robotics

Roborobo! is a multi-platform, highly portable, robot simulator for large-scale collective robotics experiments. Roborobo! is coded in C++, and follows the KISS guideline ("Keep it simple"). Therefore, its external dependency is solely limited to the widely available SDL library for fast 2D Graphics. Roborobo! is based on a Khepera/ePuck model. It is targeted for fast single and multi-robots simulation, and has already been used in more than a dozen published research mainly concerned with evolutionary swarm robotics, including environment-driven self-adaptation and distributed evolutionary optimization, as well as online onboard embodied evolution and embodied morphogenesis.Comment: 2 pages, 1 figur

Simulation of a micro jet cooling array

The new generation of electronic devices are more powerful, and they produce more heat. Hence, there is a need for micro cooling systems for removing the heat from these micro chips. This research focused on one micro cooling system-the micro jet cooling array. Some test simulations were made on a single jet cooling system. In addition, the inlet Reynolds number was varied in order to obtain the variation of the heat transfer coefficient. These simulations gave a basic idea of how the impingement cooling method works on the micro jet cooling array. Numerical simulations were made on the actual micro jet cooling array. Simulations consisted of variation of parameters (geometry, Reynolds number, heat flux). When the micro jet cooling array from MEZZO systems was simulated with no wall separating the outlet region from the impingement area, performance was enhanced. In fact, this system presents the lowest pressure drop through the device and has the same heat transfer rate on the cooling surface. The relationship between the heat transfer rate and the inlet Reynolds number was established for the micro jet cooling array system (for instance an inlet Reynolds number of 1033, the heat transfer coefficient average on the cooling surface is 9.9W/(cm2.K))

Embedded Evolutionary Robotics: The (1+1)-Restart-Online Adaptation Algorithm

International audienceThis paper deals with online onboard behavior optimization for an autonomous mobile robot in the scope of the European FP7 Symbrion Project. The work presented here extends the (1+1)-online algorithm introduced in earlier publication. This algorithm is a variation of a famous Evolution Strategies adapted to autonomous robots. In this paper, we address a limitation of this algorithm regarding the ability to perform global search whenever a local optimum is reached. A new implementation of the algorithm, termed (1+1)-restart-online algorithm, is described and implemented within the Symbrion robotic Cortex M3 microcontroller. Results from the experiments show that the new algorithm is able to escape local optima and, as a consequence, converge faster and provides a richer set of relevant controllers

Behavioral Specialization in Embodied Evolutionary Robotics: Why So Difficult?

Embodied evolutionary robotics is an on-line distributed learning method used in collective robotics where robots are facing open environments. This paper focuses on learning behavioral specialization, as defined by robots being able to demonstrate different kind of behaviors at the same time (e.g., division of labor). Using a foraging task with two resources available in limited quantities, we show that behavioral specialization is unlikely to evolve in the general case, unless very specific conditions are met regarding interactions between robots (a very sparse communication network is required) and the expected outcome of specialization (specialization into groups of similar sizes is easier to achieve). We also show that the population size (the larger the better) as well as the selection scheme used (favoring exploration over exploitation) both play important – though not always mandatory – roles. This research sheds light on why existing embodied evolution algorithms are limited with respect to learning efficient division of labor in the general case, i.e., where it is not possible to guess before deployment if behavioral specialization is required or not, and gives directions to overcome current limitations.This work is supported by the European Unions Horizon 2020 research and innovation programme under grant agreement No 640891, and the ERC Advanced Grant EPNet (340828). Part of the experiments presented in this paper were carried out using the Grid’5000 experimental testbed, being developed under the INRIA ALADDIN development action with support from CNRS, RENATER, and several Universities as well as other funding bodies (see https://www.grid5000.fr). The other parts of the simulations have been done in the supercomputer MareNostrum at Barcelona Supercomputing Center – Centro Nacional de Supercomputacion (The Spanish National Supercomputing Center).Peer ReviewedPostprint (published version

Modelling the co-evolution of trade and culture

We presents a new framework to study the co-evolution of cultural change and trade. The design aims for a trade-off between the flexibility necessary for the implementation of multiple models and the structure necessary for the comparison between the models implemented. To create this framework we propose an Agent-Based Model relying on agents producing, exchanging and associating values to a list of goods. We present the key concepts of the framework and two examples of its implementation which allow us to show the flexibility of our framework. Moreover, we compare the results obtained by the two models, thus validating the structure of the framework. Finally, we validate the implementation of a trading model by studying the price structure it produces

Modelling the co-evolution of trade and culture in past societies

This paper presents a new framework to study the co-evolution of cultural change and trade. The design aims for a trade-off between the flexibility necessary for the implementation of multiple models and the structure necessary for the comparison between the models implemented. To create this framework we propose an Agent-Based Model relying on agents producing, exchanging and associating values to a list of goods. We present the key concepts of the framework and two examples of its implementation which allow us to show the flexibility of our framework. Moreover, we compare the results obtained by the two models, thus validating the structure of the framework. Finally, we validate the implementation of a trading model by studying the price structure it produces.Funding for this work was provided by the ERC Advanced Grant EPNet (340828) and the SimulPast Consolider Ingenio project (CSD2010-00034) of the former Ministry for Science and Innovation of the Spanish Government. The model was created using Pandora (Rubio-Campillo 2014). R was used for figures and statistical analysis (R Development Team 2012). The estimation of the a parameters have been computed with the R package poweRlaw (Gillespie 2015). The simulations have been done in the supercomputer MareNostrum at Barcelona Supercomputing Center - Centro Nacional de Supercomputación (The Spanish National Supercomputing Center). The source code of the model is licensed under a GNU General Public License.Peer ReviewedPostprint (author's final draft

Embodied Evolution in Collective Robotics: A Review

This paper provides an overview of evolutionary robotics techniques applied to on-line distributed evolution for robot collectives -- namely, embodied evolution. It provides a definition of embodied evolution as well as a thorough description of the underlying concepts and mechanisms. The paper also presents a comprehensive summary of research published in the field since its inception (1999-2017), providing various perspectives to identify the major trends. In particular, we identify a shift from considering embodied evolution as a parallel search method within small robot collectives (fewer than 10 robots) to embodied evolution as an on-line distributed learning method for designing collective behaviours in swarm-like collectives. The paper concludes with a discussion of applications and open questions, providing a milestone for past and an inspiration for future research.Comment: 23 pages, 1 figure, 1 tabl

The ecology of Roman trade. Reconstructing provincial connectivity with similarity measures

The creation of the Roman Empire promoted the connectivity of a vast area around the Mediterranean sea. Mobility and trade flourished over the Roman provinces as massive amounts of goods were shipped over thousands of kilometres through sea, rivers and road networks. Several works have explored these dynamics of interaction in specific case studies but there is still no consensus on the intensity of this connectivity beyond local trade. We argue here that the debate on the degree of large-scale connectivity across the empire is caused by a lack of appropriate methods and proxies of economic activity. The last years have seen an improvement on the availability of evidence as a growing amount of datasets is collected and published. However, data does not equal knowledge and the methods used to analyse this evidence have not advanced at the same pace. A new framework of connectivity analysis has been applied here to reveal the existence of distinctive trade routes through the provinces of the Western region of Rome. The amphora stamps collected over more than a thousand sites have been analysed using quantitative measures of similarity. The patterns that emerge from the analysis highlight the intense connectivity derived from factors such as the spatial closeness, presence of military units and the relevance of the Atlantic sea as a main shipping route

Hybrid Societies : Challenges and Perspectives in the Design of Collective Behavior in Self-organizing Systems

Hybrid societies are self-organizing, collective systems, which are composed of different components, for example, natural and artificial parts (bio-hybrid) or human beings interacting with and through technical systems (socio-technical). Many different disciplines investigate methods and systems closely related to the design of hybrid societies. A stronger collaboration between these disciplines could allow for re-use of methods and create significant synergies. We identify three main areas of challenges in the design of self-organizing hybrid societies. First, we identify the formalization challenge. There is an urgent need for a generic model that allows a description and comparison of collective hybrid societies. Second, we identify the system design challenge. Starting from the formal specification of the system, we need to develop an integrated design process. Third, we identify the challenge of interdisciplinarity. Current research on self-organizing hybrid societies stretches over many different fields and hence requires the re-use and synthesis of methods at intersections between disciplines. We then conclude by presenting our perspective for future approaches with high potential in this area

The contribution of non-catalytic carbohydrate binding modules to the activity of lytic polysaccharide monooxygenases

Lignocellulosic biomass is a sustainable industrial substrate. Copper-dependent lytic polysaccharidemonooxygenases (LPMOs) contribute to the degradation of lignocellulose and increase the efficiency of biofuel production. LPMOs can contain non-catalytic carbohydrate binding modules (CBMs), but their role in the activity of these enzymes is poorly understood. Here we explored the importance of CBMs in LPMO function. The family 2a CBMs of two monooxygenases, CfLPMO10 and TbLPMO10 from Cellulomonas fimi and Thermobispora bispora, respectively, were deleted and/or replaced with CBMs from other proteins. The data showed that the CBMs could potentiate and, surprisingly, inhibit LPMO activity, and that these effects were both enzyme-specific and substrate-specific. Removing the natural CBM or introducing CtCBM3a, from the Clostridium thermocellum cellulosome scaffoldin CipA, almost abolished the catalytic activity of the LPMOs against the cellulosic substrates. The deleterious effect of CBM removal likely reflects the importance of prolonged presentation of the enzyme on the surface of the substrate for efficient catalytic activity, as only LPMOs appended to CBMs bound tightly to cellulose. The negative impact of CtCBM3a is in sharp contrast with the capacity of this binding module to potentiate the activity of a range of glycoside hydrolases including cellulases. The deletion of the endogenous CBM from CfLPMO10 or the introduction of a family 10 CBM from Cellvibrio japonicus LPMO10B into TbLPMO10 influenced the quantity of non-oxidized products generated, demonstrating that CBMs can modulate the mode of action of LPMOs. This study demonstrates that engineered LPMO-CBM hybrids can display enhanced industrially relevant oxygenations