01617nas a2200253   4500008004100000022001400041245006100055210006000116300001000176490000600186520088300192653001801075653001501093653002401108653001501132100002001147700003001167700002301197700002601220700002201246700002701268700002901295856003901324       2020                        eng d  a2167-835900aEcosystem antifragility: beyond integrity and resilience0 aEcosystem antifragility beyond integrity and resilience  ae85330 v83 aWe review the concept of ecosystem resilience in its relation to ecosystem integrity from an information theory approach. We summarize the literature on the subject identifying three main narratives: ecosystem properties that enable them to be more resilient; ecosystem response to perturbations; and complexity. We also include original ideas with theoretical and quantitative developments with application examples. The main contribution is a new way to rethink resilience, that is mathematically formal and easy to evaluate heuristically in real-world applications: ecosystem antifragility. An ecosystem is antifragile if it benefits from environmental variability. Antifragility therefore goes beyond robustness or resilience because while resilient/robust systems are merely perturbation-resistant, antifragile structures not only withstand stress but also benefit from it.10aAntifragility10aComplexity10aEcosystem integrity10aResilience1 aEquihua, Miguel1 aAldama, Mariana, Espinosa1 aGershenson, Carlos1 aLópez-Corona, Oliver1 aMunguía, Mariana1 aPérez-Maqueo, Octavio1 aRamírez-Carrillo, Elvia  uhttps://doi.org/10.7717/peerj.853300539nas a2200157   4500008004100000245004000041210003900081100002300120700002200143700001900165700001900184700001900203700001700222700002000239856012200259       2019                        eng d00aEvasión en IVA: Análisis de redes0 aEvasión en IVA Análisis de redes1 aGershenson, Carlos1 aIñiguez, Gerardo1 aPineda, Carlos1 aGuerrero, Rita1 aIslas, Eduardo1 aPineda, Omar1 aZumaya, Martín  uhttp://omawww.sat.gob.mx/gobmxtransparencia/Paginas/documentos/estudio_opiniones/Evasion_en_IVA_Analisis_de_Redes.pdf01329nas a2200145   4500008004100000245010300041210006900144300000700213490000900220520085300229100001601082700002101098700002301119856004101142       2019                        eng d00aA Multilayer Structure Facilitates the Production of Antifragile Systems in Boolean Network Models0 aMultilayer Structure Facilitates the Production of Antifragile S  a110 v20193 aAntifragility is a property from which systems are able to resist stress and furthermore benefit from it. Even though antifragile dynamics is found in various real-world complex systems where multiple subsystems interact with each other, the attribute has not been quantitatively explored yet in those complex systems which can be regarded as multilayer networks. Here we study how the multilayer structure affects the antifragility of the whole system. By comparing single-layer and multilayer Boolean networks based on our recently proposed antifragility measure, we found that the multilayer structure facilitated the production of antifragile systems. Our measure and findings will be useful for various applications such as exploring properties of biological systems with multilayer structures and creating more antifragile engineered systems.1 aKim, Hyobin1 aPineda, Omar, K.1 aGershenson, Carlos  uhttps://doi.org/10.1155/2019/278321701320nas a2200145   4500008004100000245011800041210006900159300000700228490000900235520082900244100002101073700001601094700002301110856004101133       2019                        eng d00aA Novel Antifragility Measure Based on Satisfaction and Its Application to Random and Biological Boolean Networks0 aNovel Antifragility Measure Based on Satisfaction and Its Applic  a100 v20193 aAntifragility is a property that enhances the capability of a system in response to external perturbations. Although the concept has been applied in many areas, a practical measure of antifragility has not been developed yet. Here we propose a simply calculable measure of antifragility, based on the change of ``satisfaction'' before and after adding perturbations, and apply it to random Boolean networks (RBNs). Using the measure, we found that ordered RBNs are the most antifragile. Also, we demonstrated that seven biological systems are antifragile. Our measure and results can be used in various applications of Boolean networks (BNs) including creating antifragile engineering systems, identifying the genetic mechanism of antifragile biological systems, and developing new treatment strategies for various diseases.1 aPineda, Omar, K.1 aKim, Hyobin1 aGershenson, Carlos  uhttps://doi.org/10.1155/2019/372862101720nas a2200241   4500008004100000022001400041245009300055210006900148300001100217490000800228520098300236653002901219653001401248653002001262653001801282100002001300700002901320700002101349700001801370700001901388700002301407856004801430       2019                        eng d  a0378-437100aRank-frequency distribution of natural languages: A difference of probabilities approach0 aRankfrequency distribution of natural languages A difference of   a1217950 v5323 aIn 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.10aFokker–Planck equation10aLanguages10aMaster equation10aRank dynamics1 aCocho, Germinal1 aRodríguez, Rosalío, F.1 aSánchez, Sergio1 aFlores, Jorge1 aPineda, Carlos1 aGershenson, Carlos  uhttps://doi.org/10.1016/j.physa.2019.12179502151nas a2200193   4500008004100000020001400041245007300055210006900128300001400197490000600211520154100217100002601758700002901784700002301813700002201836700002301858700003001881856004601911       2018                        eng d  a2432-272500aFrom neuroscience to computer science: a topical approach on Twitter0 aFrom neuroscience to computer science a topical approach on Twit  a187–2080 v13 aTwitter is perhaps the most influential microblogging service, with 271 million regular users producing approximately 500 million tweets per day. Previous studies of tweets discussing scientific topics are limited to local surveys or may not be representative geographically. This indicates a need to harvest and analyse tweets with the aim of understanding the level of dissemination of science related topics worldwide. In this study, we use Twitter as case of study and explore the hypothesis of science popularization via the social stream. We present and discuss tweets related to popular science around the world using eleven keywords. We analyze a sample of 306,163 tweets posted by 91,557 users with the aim of identifying tweets and those categories formed around temporally similar topics. We systematically examined the data to track and analyze the online activity around users tweeting about popular science. In addition, we identify locations of high Twitter activity that occur in several places around the world. We also examine which sources (mobile devices, apps, and other social networks) are used to share popular science related links. Furthermore, this study provides insights into the geographic density of popular science tweets worldwide. We show that emergent topics related to popular science are important because they could help to explore how science becomes of public interest. The study also offers some important insights for studying the type of scientific content that users are more likely to tweet.1 aPiña-García, C., A.1 aSiqueiros-García, Mario1 aRobles-Belmont, E.1 aCarreón, Gustavo1 aGershenson, Carlos1 aLópez, Julio, Amador Dí  uhttps://doi.org/10.1007/s42001-017-0002-901973nas a2200229   4500008004100000022001400041245005100055210005100106300000700157490000600164520131800170100002301488700001701511700002101528700002801549700001901577700002201596700002001618700001801638700002301656856006401679       2018                        eng d  a2296-424X00aRank Dynamics of Word Usage at Multiple Scales0 aRank Dynamics of Word Usage at Multiple Scales  a450 v63 aThe 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.1 aMorales, José, A.1 aColman, Ewan1 aSánchez, Sergio1 aSánchez-Puig, Fernanda1 aPineda, Carlos1 aIñiguez, Gerardo1 aCocho, Germinal1 aFlores, Jorge1 aGershenson, Carlos  uhttps://www.frontiersin.org/article/10.3389/fphy.2018.0004500950nas a2200181   4500008004100000245005900041210005900100300001200159490000900171520042400180100002100604700002000625700001800645700002300663700002200686700001900708856004100727       2018                        eng d00aTrajectory Stability in the Traveling Salesman Problem0 aTrajectory Stability in the Traveling Salesman Problem  a28260820 v20183 aTwo generalizations of the traveling salesman problem in which sites change their position in time are presented. The way the rank of different trajectory lengths changes in time is studied using the rank diversity. We analyze the statistical properties of rank distributions and rank dynamics and give evidence that the shortest and longest trajectories are more predictable and robust to change, that is, more stable.1 aSánchez, Sergio1 aCocho, Germinal1 aFlores, Jorge1 aGershenson, Carlos1 aIñiguez, Gerardo1 aPineda, Carlos  uhttps://doi.org/10.1155/2018/282608203133nas a2200253   4500008004100000020001400041245005000055210005000105260000600155300001100161490000700172520244900179653001602628653001802644653001402662653001602676653002302692653002202715100002302737700001902760700002602779700002302805856005102828       2017                        eng d  a1476-945X00aComplexity of lakes in a latitudinal gradient0 aComplexity of lakes in a latitudinal gradient  c9  a1–200 v313 aMeasuring complexity is fast becoming a key instrument to compare different ecosystems at various scales in ecology. To date there has been little agreement on how to properly describe complexity in terms of ecology. In this regard, this manuscript assesses the significance of using a set of proposed measures based on information theory. These measures are as follows: emergence, self-organization, complexity, homeostasis and autopoiesis. A combination of quantitative and qualitative approaches was used in the data analysis with the aim to apply these proposed measures. This study systematically reviews the data previously collected and generated by a model carried out on four aquatic ecosystems located between the Arctic region and the tropical zone. Thus, this research discusses the case of exploring a high level of self-organization in terms of movement, distribution, and quality of water between the northern temperate zone and the tropics. Moreover, it was assessed the significance of the presence of a complex variable (pH) in the middle of the latitudinal transect. Similarly, this study explores the relationship between self-organization and limiting nutrients (nitrogen, phosphorus and silicates). Furthermore, the importance of how a biomass subsystem is affected by seasonal variations is highlighted in this manuscript. This case study seeks to examine the changing nature of how seasonality affects the complexity dynamics of photosynthetic taxa (lakes located in northern temperate zone) at high latitudes, and it also investigates how a high level of self-organization at the tropical zone can lead to increase the amount of planktonic and benthic fish which determines the dynamics of complexity. This research also compares the emerging role of how a biomass subsystem has a highest temporal dynamics compared to he limiting nutrients' subsystem. In the same way, the results associated to autopoiesis reflect a moderate degree of autonomy of photosynthetic biomass. It is also discussed the case of how complexity values change in the middle of the latitudinal gradient for all components. Finally, a comparison with Tsallis information was carried out in order to determine that these proposed measures are more suitable due to they are independent of any other parameter. Thus, this approach considers some elements closely related to information theory which determine and better describe ecological dynamics.10aAutopoiesis10aBiocomplexity10aEmergence10aHomeostasis10aInformation theory10aSelf-organization1 aFernández, Nelson1 aAguilar, José1 aPiña-García, C., A.1 aGershenson, Carlos  uhttp://dx.doi.org/10.1016/j.ecocom.2017.02.00202214nas a2200157   4500008004100000245014100041210006900182260003400251300000900285490000700294520164000301100002201941700002301963700002101986856004902007       2017                        eng d00aImproving public transportation systems with self-organization: A headway-based model and regulation of passenger alighting and boarding0 aImproving public transportation systems with selforganization A   bPublic Library of Sciencec12  a1-200 v123 aThe equal headway instability—the fact that a configuration with regular time intervals between vehicles tends to be volatile—is a common regulation problem in public transportation systems. An unsatisfactory regulation results in low efficiency and possible collapses of the service. Computational simulations have shown that self-organizing methods can regulate the headway adaptively beyond the theoretical optimum. In this work, we develop a computer simulation for metro systems fed with real data from the Mexico City Metro to test the current regulatory method with a novel self-organizing approach. The current model considers overall system’s data such as minimum and maximum waiting times at stations, while the self-organizing method regulates the headway in a decentralized manner using local information such as the passenger’s inflow and the positions of neighboring trains. The simulation shows that the self-organizing method improves the performance over the current one as it adapts to environmental changes at the timescale they occur. The correlation between the simulation of the current model and empirical observations carried out in the Mexico City Metro provides a base to calculate the expected performance of the self-organizing method in case it is implemented in the real system. We also performed a pilot study at the Balderas station to regulate the alighting and boarding of passengers through guide signs on platforms. The analysis of empirical data shows a delay reduction of the waiting time of trains at stations. Finally, we provide recommendations to improve public transportation systems.1 aCarreón, Gustavo1 aGershenson, Carlos1 aPineda, Luis, A.  uhttps://doi.org/10.1371/journal.pone.019010000593nas a2200157   4500008004100000245007000041210006900111300001200180490000800192100002600200700001700226700002300243700002900266700002300295856011700318       2016                        eng d00aExploring Dynamic Environments Using Stochastic Search Strategies0 aExploring Dynamic Environments Using Stochastic Search Strategie  a43–570 v1211 aPiña-García, C., A.1 aGu, Dongbing1 aGershenson, Carlos1 aSiqueiros-García, Mario1 aRobles-Belmont, E.  uhttp://rcs.cic.ipn.mx/2016_121/Exploring%20Dynamic%20Environments%20Using%20Stochastic%20Search%20Strategies.pdf02428nas a2200229   4500008004100000022001400041245007400055210006900129300000700198490000600205520173500211100002301946700002101969700001801990700001902008700002302027700002002050700002302070700002902093700002202122856005402144       2016                        eng d  a2193-112700aGeneric temporal features of performance rankings in sports and games0 aGeneric temporal features of performance rankings in sports and   a330 v53 aMany complex phenomena, from trait selection in biological systems to hierarchy formation in social and economic entities, show signs of competition and heterogeneous performance in the temporal evolution of their components, which may eventually lead to stratified structures such as the worldwide wealth distribution. However, it is still unclear whether the road to hierarchical complexity is determined by the particularities of each phenomena, or if there are generic mechanisms of stratification common to many systems. Human sports and games, with their (varied but simple) rules of competition and measures of performance, serve as an ideal test-bed to look for universal features of hierarchy formation. With this goal in mind, we analyse here the behaviour of performance rankings over time of players and teams for several sports and games, and find statistical regularities in the dynamics of ranks. Specifically the rank diversity, a measure of the number of elements occupying a given rank over a length of time, has the same functional form in sports and games as in languages, another system where competition is determined by the use or disuse of grammatical structures. We use a Gaussian random walk model to reproduce the rank diversity of the studied sports and games. We also discuss the relation between rank diversity and the cumulative rank distribution. Our results support the notion that hierarchical phenomena may be driven by the same underlying mechanisms of rank formation, regardless of the nature of their components. Moreover, such regularities can in principle be used to predict lifetimes of rank occupancy, thus increasing our ability to forecast stratification in the presence of competition.1 aMorales, José, A.1 aSánchez, Sergio1 aFlores, Jorge1 aPineda, Carlos1 aGershenson, Carlos1 aCocho, Germinal1 aZizumbo, Jerónimo1 aRodríguez, Rosalío, F.1 aIñiguez, Gerardo  uhttp://dx.doi.org/10.1140/epjds/s13688-016-0096-y00489nas a2200133   4500008004100000245010700041210006900148300000600217490000600223100002600229700002300255700002900278856004800307       2016                        eng d00aTowards a Standard Sampling Methodology on Online Social Networks: Collecting Global Trends on Twitter0 aTowards a Standard Sampling Methodology on Online Social Network  a30 v11 aPiña-García, C., A.1 aGershenson, Carlos1 aSiqueiros-García, Mario  uhttp://dx.doi.org/10.1007/s41109-016-0004-101729nas a2200181   4500008004100000245007900041210006900120260003400189300001300223490000700236520115000243100002001393700001801413700002301431700001901454700002101473856005301494       2015                        eng d00aRank Diversity of Languages: Generic Behavior in Computational Linguistics0 aRank Diversity of Languages Generic Behavior in Computational Li  bPublic Library of Sciencec04  ae01218980 v103 a<p>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.</p>
1 aCocho, Germinal1 aFlores, Jorge1 aGershenson, Carlos1 aPineda, Carlos1 aSánchez, Sergio  uhttp://dx.doi.org/10.1371%2Fjournal.pone.012189801277nas a2200157   4500008004100000245009900041210006900140260001300209300001000222520076000232100002300992700002201015700002301037700002401060856003501084       2014                        eng d00aInformation Measures of Complexity, Emergence, Self-organization, Homeostasis, and Autopoiesis0 aInformation Measures of Complexity Emergence Selforganization Ho  bSpringer  a19-513 a<p>This chapter reviews measures of emergence, self-organization, complexity, homeostasis, and autopoiesis based on information theory. These measures are derived from proposed axioms and tested in two case studies: random Boolean networks and an Arctic lake ecosystem. Emergence is defined as the information produced by a system or process. Self-organization is defined as the opposite of emergence, while complexity is defined as the balance between emergence and self-organization. Homeostasis reflects the stability of a system. Autopoiesis is defined as the ratio between the complexity of a system and the complexity of its environment. The proposed measures can be applied at different scales, which can be studied with multi-scale profiles.</p>
1 aFernández, Nelson1 aMaldonado, Carlos1 aGershenson, Carlos1 aProkopenko, Mikhail  uhttp://arxiv.org/abs/1304.184201387nas a2200205   4500008004100000245004900041210004900090260001300139300001000152490000800162520081200170100002300982700002301005700002301028700002201051700001901073700002101092700003301113856003501146       2014                        eng d00aMeasuring Complexity in an Aquatic Ecosystem0 aMeasuring Complexity in an Aquatic Ecosystem  bSpringer  a83-890 v2323 aWe apply formal measures of emergence, self-organization, homeostasis, autopoiesis and complexity to an aquatic ecosystem; in particular to the physiochemical component of an Arctic lake. These measures are based on information theory. Variables with an homogeneous distribution have higher values of emergence, while variables with a more heterogeneous distribution have a higher self-organization. Variables with a high complexity reflect a balance between change (emergence) and regularity/order (self-organization). In addition, homeostasis values coincide with the variation of the winter and summer seasons. Autopoiesis values show a higher degree of independence of biological components over their environment. Our approach shows how the ecological dynamics can be described in terms of information.1 aFernández, Nelson1 aGershenson, Carlos1 aCastillo, Luis, F.1 aCristancho, Marco1 aIsaza, Gustavo1 aPinzón, Andrés1 aRodríguez, Juan, Manuel Cor  uhttp://arxiv.org/abs/1305.541301555nas a2200169   4500008004100000245004900041210004800090260003200138300001200170520107700182100002301259700002101282700001501303700001801318700001401336856003501350       2012                        eng d00aSelf-organizing urban transportation systems0 aSelforganizing urban transportation systems  aBerlin HeidelbergbSpringer  a269-2793 aUrban transportation is a complex phenomenon. Since many agents are constantly interacting in parallel, it is difficult to predict the future state of a transportation system. Because of this, optimization techniques tend to give obsolete solutions, as the problem changes before it can be optimized. An alternative lies in seeking adaptive solutions. This adaptation can be achieved with self-organization. In a self-organizing transportation system, the elements of the system follow local rules to achieve a global solution. Like this, when the problem changes the system can adapt by itself to the new configuration. In this chapter, I will review recent, current, and future work on self-organizing transportation systems. Self-organizing traffic lights have proven to improve traffic flow considerably over traditional methods. In public transportation systems, simple rules are being explored to prevent the "equal headway instability" phenomenon. The methods we have used can be also applied to other urban transportation systems and their generality is discussed.1 aGershenson, Carlos1 aPortugali, Juval1 aMeyer, Han1 aStolk, Egbert1 aTan, Ekim  uhttp://arxiv.org/abs/0912.158800436nas a2200145   4500008004100000245002100041210002100062260002000083300001400103490000700117520008400124100002300208700002400231856003500255       2011                        eng d00aComplex Networks0 aComplex Networks  bMIT PresscFall  a259–2610 v173 aIntroduction to the Special Issue on Complex Networks, Artificial Life journal.1 aGershenson, Carlos1 aProkopenko, Mikhail  uhttp://arxiv.org/abs/1104.553800958nas a2200145   4500008004100000245003800041210003600079260001400115300001400129490000700143520057300150100003100723700002300754856003500777       2011                        eng d00aModular Random {Boolean} Networks0 aModular Random Boolean Networks  bMIT Press  a331–3510 v173 aRandom Boolean networks (RBNs) have been a popular model of genetic regulatory networks for more than four decades. However, most RBN studies have been made with random topologies, while real regulatory networks have been found to be modular. In this work, we extend classical RBNs to define modular RBNs. Statistical experiments and analytical results show that modularity has a strong effect on the properties of RBNs. In particular, modular RBNs have more attractors and are closer to criticality when chaotic dynamics would be expected, compared to classical RBNs.1 aPoblanno-Balp}, Rodrigo, {1 aGershenson, Carlos  uhttp://arxiv.org/abs/1101.189300483nas a2200145   4500008004100000245006800041210005900109300001200168490000700180100002300187700002000210700002100230700002100251856006500272       2010                        eng d00aMechanical Love. Phie Ambo. (2009, Icarus Films.) $390, 52 min.0 aMechanical Love Phie Ambo 2009 Icarus Films 390 52 min  a269-2700 v161 aGershenson, Carlos1 aMeza, Iván, V.1 aAvilés, Héctor1 aPineda, Luis, A.  uhttp://www.mitpressjournals.org/doi/abs/10.1162/artl_r_0000400702nas a2200229   4500008004100000245003800041210003600079260003100115300001200146100003100158700002300189700002300212700001600235700002400251700002900275700001800304700001900322700002600341700002000367700002100387856006400408       2010                        eng d00aModular Random {Boolean} Networks0 aModular Random Boolean Networks  aOdense, DenmarkbMIT Press  a303-3041 aPoblanno-Balp}, Rodrigo, {1 aGershenson, Carlos1 aFellermann, Harold1 aDörr, Mark1 aHanczyc, Martin, M.1 aLaursen, Lone, Ladegaard1 aMaurer, Sarah1 aMerkle, Daniel1 aMonnard, Pierre-Alain1 aSt$ø$y, Kasper1 aRasmussen, Steen  uhttp://mitpress.mit.edu/books/chapters/0262290758chap56.pdf01719nas a2200133   4500008004100000245009700041210006900138300001000207490000600217520126700223100002301490700002101513856005101534       2009                        eng d00aWhy does public transport not arrive on time? The pervasiveness of equal headway instability0 aWhy does public transport not arrive on time The pervasiveness o  ae72920 v43 aBackground The equal headway instability phenomenon is pervasive in public transport systems. This instability is characterized by an aggregation of vehicles that causes inefficient service. While equal headway instability is common, it has not been studied independently of a particular scenario. However, the phenomenon is apparent in many transport systems and can be modeled and rectified in abstraction. Methodology We present a multi-agent simulation where a default method with no restrictions always leads to unstable headways. We discuss two methods that attempt to achieve equal headways, called minimum and maximum. Since one parameter of the methods depends on the passenger density, adaptive versions–-where the relevant parameter is adjusted automatically–-are also put forward. Our results show that the adaptive maximum method improves significantly over the default method. The model and simulation give insights of the interplay between transport design and passenger behavior. Finally, we provide technological and social suggestions for engineers and passengers to help achieve equal headways and thus reduce delays. Conclusions The equal headway instability phenomenon can be avoided with the suggested technological and social measures.1 aGershenson, Carlos1 aPineda, Luis, A.  uhttp://dx.doi.org/10.1371/journal.pone.000729200941nas a2200157   4500008004100000245005900041210005700100260001300157300001200170520046800182100002200650700002300672700002300695700002400718856004100742       2007                        eng d00aSelf-organizing traffic lights: A realistic simulation0 aSelforganizing traffic lights A realistic simulation  bSpringer  a41–493 aWe have previously shown in an abstract simulation (Gershenson, 2005) that self-organizing traffic lights can improve greatly traffic flow for any density. In this paper, we extend these results to a realistic setting, implementing self-organizing traffic lights in an advanced traffic simulator using real data from a Brussels avenue. On average, for different traffic densities, travel waiting times are reduced by 50% compared to the current green wave method.1 aCools, Seung, Bae1 aGershenson, Carlos1 aD'Hooghe}, Bart, {1 aProkopenko, Mikhail  uhttp://arxiv.org/abs/nlin.AO/061004001111nas a2200181   4500008004100000245007400041210006900115260001400184300001400198520057100212100002300783700001600806700001400822700001700836700001600853700001900869856004100888       2004                        eng d00aUpdating Schemes in Random {Boolean} Networks: Do They Really Matter?0 aUpdating Schemes in Random Boolean Networks Do They Really Matte  bMIT Press  a238–2433 aIn this paper we try to end the debate concerning the suitability of different updating schemes in random Boolean networks (RBNs). We quantify for the first time loose attractors in asyncrhonous RBNs, which allows us to analyze the complexity reduction related to different updating schemes. We also report that all updating schemes yield very similar critical stability values, meaning that the "edge of chaos" does not depend much on the updating scheme. After discussion, we conclude that synchonous RBNs are justifiable theoretical models of biological networks.1 aGershenson, Carlos1 aPollack, J.1 aBedau, M.1 aHusbands, P.1 aIkegami, T.1 aWatson, R., A.  uhttp://arxiv.org/abs/nlin.AO/040200601233nas a2200193   4500008004100000245008600041210006900127260005900196300001200255490000700267520056100274100002300835700002800858700002100886700001700907700001900924700002500943856007100968       2002                        eng d00aBehaviour-Based Knowledge Systems: An Epigenetic Path from Behaviour to Knowledge0 aBehaviourBased Knowledge Systems An Epigenetic Path from Behavio  aEdinburgh, ScotlandbLund University Cognitive Studies  a35–410 v943 aIn this paper we expose the theoretical background underlying our current research. This consists in the development of behaviour-based knowledge systems, for closing the gaps between behaviour-based and knowledge-based systems, and also between the understandings of the phenomena they model. We expose the requirements and stages for developing behaviour-based knowledge systems and discuss their limits. We believe that these are necessary conditions for the development of higher order cognitive capacities, in artificial and natural cognitive systems.1 aGershenson, Carlos1 aPrince, Christopher, G.1 aDemiris, Yiannis1 aMarom, Yuval1 aKozima, Hideki1 aBalkenius, Christian  uhttp://www.lucs.lu.se/ftp/pub/LUCS%5FStudies/LUCS94/Gershenson.pdf01997nas a2200145   4500008004100000245005000041210005000091520158700141100001401728700001401742700001501756700001901771700001901790856004201809       2002                        eng d00aNeural Net Model for Featured Word Extraction0 aNeural Net Model for Featured Word Extraction3 aSearch engines perform the task of retrieving information related to the user-supplied query words. This task has two parts; one is finding 'featured words' which describe an article best and the other is finding a match among these words to user-defined search terms. There are two main independent approaches to achieve this task. The first one, using the concepts of semantics, has been implemented partially. For more details see another paper of Marko et al., 2002. The second approach is reported in this paper. It is a theoretical model based on using Neural Network (NN). Instead of using keywords or reading from the first few lines from papers/articles, the present model gives emphasis on extracting 'featured words' from an article. Obviously we propose to exclude prepositions, articles and so on, that is , English words like "of, the, are, so, therefore, " etc. from such a list. A neural model is taken with its nodes pre-assigned energies. Whenever a match is found with featured words and user-defined search words, the node is fired and jumps to a higher energy. This firing continues until the model attains a steady energy level and total energy is now calculated. Clearly, higher match will generate higher energy; so on the basis of total energy, a ranking is done to the article indicating degree of relevance to the user's interest. Another important feature of the proposed model is incorporating a semantic module to refine the search words; like finding association among search words, etc. In this manner, information retrieval can be improved markedly.1 aDas, Atin1 aMarko, M.1 aProbst, A.1 aPorter, M., A.1 aGershenson, C.  uhttp://uk.arxiv.org/abs/cs.NE/020600100445nas a2200133   4500008004100000245007700041210006900118100001700187700001900204700001500223700001900238700001200257856004200269       2002                        eng d00aTransforming the World Wide Web Into a Complexity-Based Semantic Network0 aTransforming the World Wide Web Into a ComplexityBased Semantic 1 aMarko, Matus1 aPorter, M., A.1 aProbst, A.1 aGershenson, C.1 aDas, A.  uhttp://uk.arxiv.org/abs/cs.NI/020508001236nas a2200169   4500008004100000245008500041210006900126260001500195520069200210100002200902700001800924700001900942700001600961700002100977700002600998856004201024       2001                        eng d00aIntegration of Computational Techniques for the Modelling of Signal Transduction0 aIntegration of Computational Techniques for the Modelling of Sig  bWSES Press3 aA cell can be seen as an adaptive autonomous agent or as a society of adaptive autonomous agents, where each can exhibit a particular behaviour depending on its cognitive capabilities. We present an intracellular signalling model obtained by integrating several computational techniques into an agent-based paradigm. Cellulat, the model, takes into account two essential aspects of the intracellular signalling networks: cognitive capacities and a spatial organization. Exemplifying the functionality of the system by modelling the EGFR signalling pathway, we discuss the methodology as well as the purposes of an intracellular signalling virtual laboratory, presently under development.1 aGonzález, P., P.1 aCárdenas, M.1 aGershenson, C.1 aLagunez, J.1 aMastorakis, N.E.1 aPecorelli-Peres, L.A.  uhttp://uk.arxiv.org/abs/cs.MA/0211030