TY - JOUR T1 - Rank-frequency distribution of natural languages: A difference of probabilities approach JF - Physica A: Statistical Mechanics and its Applications Y1 - 2019 A1 - Germinal Cocho A1 - Rosalío F. Rodríguez A1 - Sergio Sánchez A1 - Jorge Flores A1 - Carlos Pineda A1 - Carlos Gershenson KW - Fokker–Planck equation KW - Languages KW - Master equation KW - Rank dynamics AB - In this paper we investigate the time variation of the rank k of words for six Indo-European languages using the Google Books N-gram Dataset. Based on numerical evidence, we regard k as a random variable whose dynamics may be described by a Fokker–Planck equation which we solve analytically. For low ranks the distinct languages behave differently, maybe due to the syntax rules, whereas for k>50 the law of large numbers predominates. We analyze the frequency distribution of words using the data and their adjustment in terms of time-dependent probability density distributions. We find small differences between the data and the fits due to conflicting dynamic mechanisms, but the data show a consistent behavior with our general approach. For the lower ranks the behavior of the data changes among languages presumably, again, due to distinct dynamic mechanisms. We discuss a possible origin of these differences and assess the novel features and limitations of our work. VL - 532 UR - https://doi.org/10.1016/j.physa.2019.121795 ER - TY - JOUR T1 - A robustness approach to the distributed management of traffic intersections JF - Journal of Ambient Intelligence and Humanized Computing Y1 - 2019 A1 - González, Cesar L. A1 - Zapotecatl, Jorge L. A1 - Gershenson, Carlos A1 - Alberola, Juan M. A1 - Julian, Vicente AB - Nowadays, the development of autonomous vehicles has emerged as an approach to considerably improve the traffic management in urban zones. Thanks to automation in vehicles as well as in other sectors, the probability of errors, typically due to repetitive tasks, has been drastically reduced. Therefore, technological aids in current driving systems are aimed to avoid or reduce human errors like imprudences or distractions. According to this, it is possible to tackle complex scenarios such as the automation of the vehicles traffic at intersections, as this is one of the points with the highest probability of accidents. In this sense, the coordination of autonomous vehicles at intersections is a trending topic. In the last few years, several approaches have been proposed using centralized solutions. However, centralized systems for traffic coordination have a limited fault-tolerance. This paper proposes a distributed coordination management system for intersections of autonomous vehicles through the employment of some well-defined rules to be followed by vehicles. To validate our proposal, we have developed different experiments in order to compare our proposal with other centralized approaches. Furthermore, we have incorporated the management of communication faults during the execution in our proposal. This improvement has also been tested in front of centralized or semi-centralized solutions. The introduction of failures in the communication process demonstrates the sensitivity of the system to possible disturbances, providing a satisfactory coordination of vehicles during the intersection. As final result, our proposal is kept with a suitable flow of autonomous vehicles still with a high communication fails rate. SN - 1868-5145 UR - https://doi.org/10.1007/s12652-019-01424-w ER - TY - JOUR T1 - Rank Dynamics of Word Usage at Multiple Scales JF - Frontiers in Physics Y1 - 2018 A1 - Morales, José A. A1 - Colman, Ewan A1 - Sánchez, Sergio A1 - Sánchez-Puig, Fernanda A1 - Pineda, Carlos A1 - Iñiguez, Gerardo A1 - Cocho, Germinal A1 - Flores, Jorge A1 - Gershenson, Carlos AB - The recent dramatic increase in online data availability has allowed researchers to explore human culture with unprecedented detail, such as the growth and diversification of language. In particular, it provides statistical tools to explore whether word use is similar across languages, and if so, whether these generic features appear at different scales of language structure. Here we use the Google Books $N$-grams dataset to analyze the temporal evolution of word usage in several languages. We apply measures proposed recently to study rank dynamics, such as the diversity of $N$-grams in a given rank, the probability that an $N$-gram changes rank between successive time intervals, the rank entropy, and the rank complexity. Using different methods, results show that there are generic properties for different languages at different scales, such as a core of words necessary to minimally understand a language. We also propose a null model to explore the relevance of linguistic structure across multiple scales, concluding that $N$-gram statistics cannot be reduced to word statistics. We expect our results to be useful in improving text prediction algorithms, as well as in shedding light on the large-scale features of language use, beyond linguistic and cultural differences across human populations. VL - 6 UR - https://www.frontiersin.org/article/10.3389/fphy.2018.00045 ER - TY - JOUR T1 - Rank Diversity of Languages: Generic Behavior in Computational Linguistics JF - PLoS ONE Y1 - 2015 A1 - Cocho, Germinal A1 - Flores, Jorge A1 - Gershenson, Carlos A1 - Pineda, Carlos A1 - Sánchez, Sergio AB -

Statistical studies of languages have focused on the rank-frequency distribution of words. Instead, we introduce here a measure of how word ranks change in time and call this distribution rank diversity. We calculate this diversity for books published in six European languages since 1800, and find that it follows a universal lognormal distribution. Based on the mean and standard deviation associated with the lognormal distribution, we define three different word regimes of languages: “heads” consist of words which almost do not change their rank in time, “bodies” are words of general use, while “tails” are comprised by context-specific words and vary their rank considerably in time. The heads and bodies reflect the size of language cores identified by linguists for basic communication. We propose a Gaussian random walk model which reproduces the rank variation of words in time and thus the diversity. Rank diversity of words can be understood as the result of random variations in rank, where the size of the variation depends on the rank itself. We find that the core size is similar for all languages studied.

PB - Public Library of Science VL - 10 UR - http://dx.doi.org/10.1371%2Fjournal.pone.0121898 ER - TY - JOUR T1 - Requisite Variety, Autopoiesis, and Self-organization JF - Kybernetes Y1 - 2015 A1 - Carlos Gershenson VL - 44 ER - TY - JOUR T1 - Reviving the Living: Meaning Making in Living Systems. Yair Neuman. (2008, Elsevier, Studies in Multidisciplinarity, Vol. 6). $197 (hardbound), 320 pages. JF - Artificial Life Y1 - 2011 A1 - Gershenson, Carlos VL - 17 UR - http://www.mitpressjournals.org/doi/abs/10.1162/artl_a_00026 ER - TY - JOUR T1 - Reinventing the Sacred: A New View of Science, Reason, and Religion. Stuart A. Kauffman. (2008, Basic Books.) $27. JF - Artificial Life Y1 - 2009 A1 - Gershenson, Carlos VL - 15 UR - http://www.mitpressjournals.org/doi/abs/10.1162/artl.2009.Gershenson.B6 ER - TY - CONF T1 - The Role of Redundancy in the Robustness of Random {Boolean} Networks T2 - {Artificial Life X}, Proceedings of the Tenth International Conference on the Simulation and Synthesis of Living Systems. Y1 - 2006 A1 - Carlos Gershenson A1 - Stuart A. Kauffman A1 - Ilya Shmulevich ED - Rocha, L. M. ED - L. S. Yaeger ED - M. A. Bedau ED - D. Floreano ED - R. L. Goldstone ED - A. Vespignani AB - Evolution depends on the possibility of successfully exploring fitness landscapes via mutation and recombination. With these search procedures, exploration is difficult in "rugged" fitness landscapes, where small mutations can drastically change functionalities in an organism. Random Boolean networks (RBNs), being general models, can be used to explore theories of how evolution can take place in rugged landscapes; or even change the landscapes. In this paper, we study the effect that redundant nodes have on the robustness of RBNs. Using computer simulations, we have found that the addition of redundant nodes to RBNs increases their robustness. We conjecture that redundancy is a way of "smoothening" fitness landscapes. Therefore, redundancy can facilitate evolutionary searches. However, too much redundancy could reduce the rate of adaptation of an evolutionary process. Our results also provide supporting evidence in favour of Kauffman's conjecture (Kauffman, 2000, p.195). JF - {Artificial Life X}, Proceedings of the Tenth International Conference on the Simulation and Synthesis of Living Systems. PB - MIT Press UR - http://uk.arxiv.org/abs/nlin.AO/0511018 ER -