The Experts below are selected from a list of 738 Experts worldwide ranked by ideXlab platform
Sébastien Liarte - One of the best experts on this subject based on the ideXlab platform.
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Citius, Altius, Fortius : Red Queen Effect dans l’industrie des appareils photographiques numériques (1994-2011)
Management international = International management = Gestión internacional, 2019Co-Authors: Manuel Cartier, Hélène Delacour, Sébastien LiarteAbstract:L’objectif de cet article est d’étudier la dynamique de Red Queen Effect (RQE) à travers un prisme particulier : la dimension concurrentielle spécifique, i.e. une caractéristique du produit sur laquelle se focalise la concurrence. Dans notre cas, il s’agit de la résolution en termes de megapixels des appareils photographiques numériques (1994-2011). Les résultats soulignent que la vitesse d’évolution de la tendance centrale de l’industrie, ainsi que la dispersion des positions concurrentielles par rapport à cette tendance centrale de l’industrie influencent la dynamique de RQE. Il apparaît qu’aller toujours plus vite, plus haut n’est paradoxalement pas bénéfique pour l’industrie.
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citius altius fortius Red Queen Effect dans l industrie des appareils photographiques numeriques 1994 2011
Management international International Management Gestiòn Internacional, 2019Co-Authors: Manuel Cartier, Hélène Delacour, Sébastien LiarteAbstract:L’objectif de cet article est d’etudier la dynamique de Red Queen Effect (RQE) a travers un prisme particulier : la dimension concurrentielle specifique, i.e. une caracteristique du produit sur laquelle se focalise la concurrence. Dans notre cas, il s’agit de la resolution en termes de megapixels des appareils photographiques numeriques (1994-2011). Les resultats soulignent que la vitesse d’evolution de la tendance centrale de l’industrie, ainsi que la dispersion des positions concurrentielles par rapport a cette tendance centrale de l’industrie influencent la dynamique de RQE. Il apparait qu’aller toujours plus vite, plus haut n’est paradoxalement pas benefique pour l’industrie.
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Stratégie d’innovation continue dans un contexte de Red Queen Effect : Une étude empirique
Management international, 2015Co-Authors: Hélène Delacour, Sébastien LiarteAbstract:The aim of this research is to complete research on the Red Queen Effect (RQE) in detailing the strategies of continuous innovation implemented by different companies in an industry. Our results of the longitudinal case study of the shaving industry for men between 1898 and 2012 show how competitors vary the type of innovation (radical vs. incremental), maintain a balance between them while increasing their rate of introduction. Contrary to the literature on the RQE, the innovation race allows firms to benefit from the positive Effects of RQE and not supporting the negative ones. (English) [ABSTRACT FROM AUTHOR]
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strategie d innovation continue dans un contexte de Red Queen Effect une etude empirique
Management international, 2015Co-Authors: Hélène Delacour, Sébastien LiarteAbstract:The aim of this research is to complete research on the Red Queen Effect (RQE) in detailing the strategies of continuous innovation implemented by different companies in an industry. Our results of the longitudinal case study of the shaving industry for men between 1898 and 2012 show how competitors vary the type of innovation (radical vs. incremental), maintain a balance between them while increasing their rate of introduction. Contrary to the literature on the RQE, the innovation race allows firms to benefit from the positive Effects of RQE and not supporting the negative ones. (English) [ABSTRACT FROM AUTHOR]
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le Red Queen Effect principe synthese et implications pour la strategie
M@n@gement, 2012Co-Authors: Hélène Delacour, Sébastien LiarteAbstract:Les entreprises en situation de concurrence cherchent a obtenir un avantage concurrentiel en ameliorant leur position par rapport a celle de leurs concurrents. Une fois cet avantage obtenu, les concurrents vont, a leur tour, chercher a obtenir leur propre avantage afin de ne pas se laisser distancer voire depasser. S’enclenche alors, au sein d’un secteur, une dynamique dans laquelle il est necessaire, pour les entreprises, d’investir toujours plus de ressources pour, au final, conserver une situation concurrentielle identique. Cette spirale concurrentielle est denommee dans la litterature, Red Queen Effect (RQE). Les objectifs de cette note de recherche sont triples. Tout d’abord, il s’agit de presenter ce processus concurrentiel ainsi que les principaux resultats contradictoires mis en evidence dans la litterature. Ensuite, il s’agit de souligner les apports du RQE en le positionnant par rapport aux principaux courants de recherche en strategie afin d’en souligner les ressemblances et divergences. Enfin, l’examen des limites permet la suggestion de travaux futurs portant sur le RQE.
Uri Wilensky - One of the best experts on this subject based on the ideXlab platform.
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a spatial model of the Red Queen Effect
Genetic and Evolutionary Computation Conference, 2007Co-Authors: Jules Ottinoloffler, William Rand, Uri WilenskyAbstract:Van Valen first discoveRed the "Red Queen Effect" (RQE), where two species can dramatically co-evolve their phenotypes over time but never gain a relative advantage [2]. In the ideal version of the RQE, regardless of the actual values that the species evolve to obtain, they have not moved in relation to each other. Though previous models of the RQE exist, we developed an agent-based model (ABM) which has a base ontology more similar to real world coevolutionary systems than equation-based models (EBMs). For instance, this model contains spatial information and an individuallevel reproduction mechanism. Yet this model recreates traditional EBM results. For instance Dieckmann et al show that there are three possible outcomes of competitive coevolution: pRedator dominance, prey dominance and evolutionary cycling (RQE) [1]. By reconceptualizing this EBM using an ABM, we make it easier for students and researchers to understand, manipulate, and modify this model [4]. The model is written in the NetLogo agent-based modeling environment [3]. The model is initialized with 150 pRedator and 150 prey agents. PRedator agents have a resistance level r and prey agents have a poison p. The agents are initially randomly distributed on a toroidal real-valued 35 by 35 grid. The initial resistance and poison values for the pRedators and prey are drawn from normal distributions with means µr and µp and a standard deviation of 1. During a model timestep, each agent moves one unit at a random heading. If at the end of its move a pRedator is within 1 unit of a prey, then it will challenge the prey. The pRedator will compare its resistance value to the prey's poison value and which ever agent has the larger value will win the challenge and the other agent will be killed. At the end of an agent's turn if the total number of agents is less than the maximum carrying capacity the agent will reproduce with a 50% probability. The new agent's initial poison / resistance will be drawn from a normal distribution with the parent's poison / resistance as the mean value and a standard deviation of 1. Our goal was to investigate whether this ABMwould replicate the results of the EBM of [1]. Our parameter of interest was µp; we held µr constant at 25 and varied µp from 0 to 50 at increments of 5. For each value we ran the model 10 times for 5000 timesteps. Figure 1 illustrates the final average values of both the resistance and the poison for the various initial values. If there are no pRedators or prey then a value of 0 is plotted for the respective final trait. In most cases, one species drives the other to extinction, and there is little change in the initial trait values. However when the value of µp is similar to µr then neither species is completely destroyed, but if there is any significant difference between µr and µp then one species will die off. The highest final trait values are found when µp = µr, in this case we see the results of the RQE since the final trait values are much higher than the initial values. These final values are more than 1.5 orders of magnitude larger than the initial values. This model reproduces classical models of the RQE, but has two different mobile species interacting on a spatial grid over time which is a closer representation of reality than traditional models. This closer representation makes ABMs excellent teaching and experimental tools because their basic assumptions can easily be manipulated and exploRed. Acknowledgments: We thank the National Science Foundation and NICO for supporting this research.
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GECCO - A spatial model of the Red Queen Effect
Proceedings of the 9th annual conference on Genetic and evolutionary computation - GECCO '07, 2007Co-Authors: Jules Ottino-loffler, William Rand, Uri WilenskyAbstract:Van Valen first discoveRed the "Red Queen Effect" (RQE), where two species can dramatically co-evolve their phenotypes over time but never gain a relative advantage [2]. In the ideal version of the RQE, regardless of the actual values that the species evolve to obtain, they have not moved in relation to each other. Though previous models of the RQE exist, we developed an agent-based model (ABM) which has a base ontology more similar to real world coevolutionary systems than equation-based models (EBMs). For instance, this model contains spatial information and an individuallevel reproduction mechanism. Yet this model recreates traditional EBM results. For instance Dieckmann et al show that there are three possible outcomes of competitive coevolution: pRedator dominance, prey dominance and evolutionary cycling (RQE) [1]. By reconceptualizing this EBM using an ABM, we make it easier for students and researchers to understand, manipulate, and modify this model [4]. The model is written in the NetLogo agent-based modeling environment [3]. The model is initialized with 150 pRedator and 150 prey agents. PRedator agents have a resistance level r and prey agents have a poison p. The agents are initially randomly distributed on a toroidal real-valued 35 by 35 grid. The initial resistance and poison values for the pRedators and prey are drawn from normal distributions with means µr and µp and a standard deviation of 1. During a model timestep, each agent moves one unit at a random heading. If at the end of its move a pRedator is within 1 unit of a prey, then it will challenge the prey. The pRedator will compare its resistance value to the prey's poison value and which ever agent has the larger value will win the challenge and the other agent will be killed. At the end of an agent's turn if the total number of agents is less than the maximum carrying capacity the agent will reproduce with a 50% probability. The new agent's initial poison / resistance will be drawn from a normal distribution with the parent's poison / resistance as the mean value and a standard deviation of 1. Our goal was to investigate whether this ABMwould replicate the results of the EBM of [1]. Our parameter of interest was µp; we held µr constant at 25 and varied µp from 0 to 50 at increments of 5. For each value we ran the model 10 times for 5000 timesteps. Figure 1 illustrates the final average values of both the resistance and the poison for the various initial values. If there are no pRedators or prey then a value of 0 is plotted for the respective final trait. In most cases, one species drives the other to extinction, and there is little change in the initial trait values. However when the value of µp is similar to µr then neither species is completely destroyed, but if there is any significant difference between µr and µp then one species will die off. The highest final trait values are found when µp = µr, in this case we see the results of the RQE since the final trait values are much higher than the initial values. These final values are more than 1.5 orders of magnitude larger than the initial values. This model reproduces classical models of the RQE, but has two different mobile species interacting on a spatial grid over time which is a closer representation of reality than traditional models. This closer representation makes ABMs excellent teaching and experimental tools because their basic assumptions can easily be manipulated and exploRed. Acknowledgments: We thank the National Science Foundation and NICO for supporting this research.
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Coevolution of PRedators and Prey in a Spatial Model An Exploration of the Red Queen Effect
2007Co-Authors: Jules Ottino-lofler, William Rand, Uri WilenskyAbstract:The term “Red Queen e! ect” is used to describe the relationship which sometimes occurs between two competing species, such as a pRedator and a prey. In a typical evolutionary pRedator-prey interaction, three outcomes are possible: (i) the prey population evolves a strong defense and the pRedator population dies o! , (ii) the pRedator population evolves a strong o! ense and the prey population dies o! , or (iii) both sides (pRedator and prey) constantly evolve the same relative levels of o! ense and devense, allowing both populations to survive (the Red Queen e! ect). A Red Queen e! ect occurs when both species maintain the same relative values of a phenotypic trait, like strength of a toxin, even though the absolute value changes dramatically. We present an agent-based model which examines mobile pRedators and prey on a landscape, interacting in competitions, and evolving o! ensive and defensive capabilites. We carry out a series of experiments where we vary the relative strength of each species. Finally, we show that this model which incorporates both space and time can reproduce similar results to those found from using non-spatial, non-temporal models, while at the same time providing a base ontology more similar to real world coevolutionary systems.
Liarte Sébastien - One of the best experts on this subject based on the ideXlab platform.
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Citius, Altius, Fortius: Red Queen Effect dans l’industrie des appareils photographiques numériques (1994-2011)
'Consortium Erudit', 2019Co-Authors: Cartier Manuel, Delacour Hélène, Liarte SébastienAbstract:L’objectif de cet article est d’étudier la dynamique de Red Queen Effect (RQE) à travers un prisme particulier : la dimension concurrentielle spécifique, i.e. une caractéristique du produit sur laquelle se focalise la concurrence. Dans notre cas, il s’agit de la résolution en termes de megapixels des appareils photographiques numériques (1994-2011). Les résultats soulignent que la vitesse d’évolution de la tendance centrale de l’industrie, ainsi que la dispersion des positions concurrentielles par rapport à cette tendance centrale de l’industrie influencent la dynamique de RQE. Il apparaît qu’aller toujours plus vite, plus haut n’est paradoxalement pas bénéfique pour l’industrie.The aim of this article is to study the Red Queen Effect (RQE) dynamics through a particular prism: the specific competitive dimension, i.e. a product characteristic on which competition focuses. In our case, this refers to the megapixel resolution of digital cameras (1994–2011). The results highlight that the evolution speed of the industry's central trend, as well as the dispersion of competitive positions relative to this central industry trend, influence the dynamics of RQE. Always go faster, higher is paradoxically not beneficial for the industry.El objetivo de este artículo es estudiar la dinámica del Efecto Reina Roja (Red Queen Effect) a través una dimensión particular: la característica competitiva específica, es decir, una característica del producto en la que se centra la competencia. En nuestro caso, esta es la resolución de las cámaras digitales en megapíxel (1994-2011). Los resultados destacan que la velocidad de cambio en la tendencia central de la industria, así como la dispersión de las posiciones competitivas en relación con esta tendencia central de la industria, influyen en la dinámica del Efecto Reina Roja. Paradójicamente, parece que ir cada vez más rápido, más alto, no es siempre beneficioso para la industria
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Stratégie d’innovation continue dans un contexte de Red Queen Effect : Une étude empirique
'Consortium Erudit', 2015Co-Authors: Delacour Hélène, Liarte SébastienAbstract:L’objectif de cette recherche est de compléter les recherches portant sur le Red Queen Effect (RQE) en détaillant les stratégies d’innovation continue mises en place par les différentes entreprises dans une industrie. Les résultats de l’étude de cas longitudinale de l’industrie du rasage pour hommes de 1898 à 2012, montrent comment les entreprises font varier le type d’innovation (radical vs. incrémental) tout en maintenant un équilibre entre les deux et en accélérant leur rythme de lancement dans le temps. Par ailleurs, contrairement à la littérature, les entreprises de cette industrie profitent des effets bénéfiques du RQE sans en subir les conséquences négatives.The aim of this research is to complete research on the Red Queen Effect (RQE) in detailing the strategies of continuous innovation implemented by different companies in an industry. Our results of the longitudinal case study of the shaving industry for men between 1898 and 2012 show how competitors vary the type of innovation (radical vs. incremental), maintain a balance between them while increasing their rate of introduction. Contrary to the literature on the RQE, the innovation race allows firms to benefit from the positive Effects of RQE and not supporting the negative ones.El objetivo de esta investigación consiste en completar el estudio del Red Queen Effect (RQE), describiendo las estrategias de innovación continua implementadas por diferentes empresas en una industria. Los resultados de un estudio de caso longitudinal sobre la industria del afeitado en húmedo para hombres realizado de 1898 à 2012 muestran cómo las empresas competidoras varían el tipo de innovación (radical o incremental), manteniendo un equilibrio entre los dos y acelerando el ritmo de introducción de innovaciones en el tiempo. Finalmente, en contra de la mayoría de los resultados sobre el RQE, las empresas de esta industria benefician de los efectos positivos del RQE sin sufrir las consecuencias negativas
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Stratégie d'innovation continue dans un contexte de Red Queen Effect : Une étude empirique. (French).
HAL CCSD, 2015Co-Authors: Delacour Hélène, Liarte SébastienAbstract:International audienceThe aim of this research is to complete research on the Red Queen Effect (RQE) in detailing the strategies of continuous innovation implemented by different companies in an industry. Our results of the longitudinal case study of the shaving industry for men between 1898 and 2012 show how competitors vary the type of innovation (radical vs. incremental), maintain a balance between them while increasing their rate of introduction. Contrary to the literature on the RQE, the innovation race allows firms to benefit from the positive Effects of RQE and not supporting the negative ones. (English) [ABSTRACT FROM AUTHOR
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The Red Queen Effect: Principle, synthesis and implications for strategy.
HAL CCSD, 2012Co-Authors: Delacour Hélène, Liarte SébastienAbstract:International audienceOrganisations competing with others seek a competitive advantage by improving their position compaRed to that of their rivals. Once they have gained this advantage, their competitors will in turn try to obtain an advantage in order not to be overtaken or left behind. This gives rise to a dynamic within the sector that makes it necessary for firms to invest ever more resources in order ultimately to remain in an identical competitive position. In the literature, this competitive spiral is called the Red Queen Effect (RQE). The aims of our research paper are threefold. First, we present this competitive process together with the main contradictory findings available in the literature. We then attempt to identify the contributions of the RQE theory by positioning it in relation to the main streams of research in strategy in order to highlight where it is similar to them and where it differs. Finally, an examination of the limitations enables us to identify future avenues for research o
Marc Ebner - One of the best experts on this subject based on the ideXlab platform.
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Coevolution and the Red Queen Effect shape virtual plants
Genetic Programming and Evolvable Machines, 2006Co-Authors: Marc EbnerAbstract:According to the Red Queen hypothesis a population of individuals may be improving some trait even though fitness remains constant. We have tested this hypothesis using a population of virtual plants. The plants have to compete with each other for virtual sunlight. Plants are modeled using Lindenmayer systems and rendeRed with OpenGL. Reproductive success of a plant depends on the amount of virtual light received as well as on the structural complexity of the plant. We experiment with two different modes of evaluation. In one experiment, plants are evaluated in isolation, while in other experiments plants are evaluated using coevolution. When using coevolution plants have to compete with each other for sunlight inside the same environment. Coevolution produces much thinner and taller plants in comparison to bush-like plants which are obtained when plants are evaluated in isolation. The presence of other individuals leads to an evolutionary arms race. Because plants are evaluated inside the same environment, the leaves of one plant may be shadowed by other plants. In an attempt to gain more sunlight, plants grow higher and higher. The Red Queen Effect was observed when individuals of a single population were coevolving.
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ECAL - Evolution and Growth of Virtual Plants
Advances in Artificial Life, 2003Co-Authors: Marc EbnerAbstract:According to the Red Queen hypothesis, an evolving population may be improving some trait, even though its fitness remains constant. We have created such a scenario with a population of coevolving plants. Plants are modeled using Lindenmayer systems and rendeRed with OpenGL. The plants consist of branches and leaves. Their reproductive success depends on their ability to catch sunlight as well as their structural complexity. All plants are evaluated inside the same environment, which means that one plant is able to cover other plants leaves. Leaves which are placed in the shadow of other plants do not catch any sunlight. The shape of the plant also determines the area where offspring can be placed. Offspring can only be placed in the vicinity of a plant. A number of experiments were performed in different environments. The Red Queen Effect was seen in all cases.
Hélène Delacour - One of the best experts on this subject based on the ideXlab platform.
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Citius, Altius, Fortius : Red Queen Effect dans l’industrie des appareils photographiques numériques (1994-2011)
Management international = International management = Gestión internacional, 2019Co-Authors: Manuel Cartier, Hélène Delacour, Sébastien LiarteAbstract:L’objectif de cet article est d’étudier la dynamique de Red Queen Effect (RQE) à travers un prisme particulier : la dimension concurrentielle spécifique, i.e. une caractéristique du produit sur laquelle se focalise la concurrence. Dans notre cas, il s’agit de la résolution en termes de megapixels des appareils photographiques numériques (1994-2011). Les résultats soulignent que la vitesse d’évolution de la tendance centrale de l’industrie, ainsi que la dispersion des positions concurrentielles par rapport à cette tendance centrale de l’industrie influencent la dynamique de RQE. Il apparaît qu’aller toujours plus vite, plus haut n’est paradoxalement pas bénéfique pour l’industrie.
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citius altius fortius Red Queen Effect dans l industrie des appareils photographiques numeriques 1994 2011
Management international International Management Gestiòn Internacional, 2019Co-Authors: Manuel Cartier, Hélène Delacour, Sébastien LiarteAbstract:L’objectif de cet article est d’etudier la dynamique de Red Queen Effect (RQE) a travers un prisme particulier : la dimension concurrentielle specifique, i.e. une caracteristique du produit sur laquelle se focalise la concurrence. Dans notre cas, il s’agit de la resolution en termes de megapixels des appareils photographiques numeriques (1994-2011). Les resultats soulignent que la vitesse d’evolution de la tendance centrale de l’industrie, ainsi que la dispersion des positions concurrentielles par rapport a cette tendance centrale de l’industrie influencent la dynamique de RQE. Il apparait qu’aller toujours plus vite, plus haut n’est paradoxalement pas benefique pour l’industrie.
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Stratégie d’innovation continue dans un contexte de Red Queen Effect : Une étude empirique
Management international, 2015Co-Authors: Hélène Delacour, Sébastien LiarteAbstract:The aim of this research is to complete research on the Red Queen Effect (RQE) in detailing the strategies of continuous innovation implemented by different companies in an industry. Our results of the longitudinal case study of the shaving industry for men between 1898 and 2012 show how competitors vary the type of innovation (radical vs. incremental), maintain a balance between them while increasing their rate of introduction. Contrary to the literature on the RQE, the innovation race allows firms to benefit from the positive Effects of RQE and not supporting the negative ones. (English) [ABSTRACT FROM AUTHOR]
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strategie d innovation continue dans un contexte de Red Queen Effect une etude empirique
Management international, 2015Co-Authors: Hélène Delacour, Sébastien LiarteAbstract:The aim of this research is to complete research on the Red Queen Effect (RQE) in detailing the strategies of continuous innovation implemented by different companies in an industry. Our results of the longitudinal case study of the shaving industry for men between 1898 and 2012 show how competitors vary the type of innovation (radical vs. incremental), maintain a balance between them while increasing their rate of introduction. Contrary to the literature on the RQE, the innovation race allows firms to benefit from the positive Effects of RQE and not supporting the negative ones. (English) [ABSTRACT FROM AUTHOR]
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le Red Queen Effect principe synthese et implications pour la strategie
M@n@gement, 2012Co-Authors: Hélène Delacour, Sébastien LiarteAbstract:Les entreprises en situation de concurrence cherchent a obtenir un avantage concurrentiel en ameliorant leur position par rapport a celle de leurs concurrents. Une fois cet avantage obtenu, les concurrents vont, a leur tour, chercher a obtenir leur propre avantage afin de ne pas se laisser distancer voire depasser. S’enclenche alors, au sein d’un secteur, une dynamique dans laquelle il est necessaire, pour les entreprises, d’investir toujours plus de ressources pour, au final, conserver une situation concurrentielle identique. Cette spirale concurrentielle est denommee dans la litterature, Red Queen Effect (RQE). Les objectifs de cette note de recherche sont triples. Tout d’abord, il s’agit de presenter ce processus concurrentiel ainsi que les principaux resultats contradictoires mis en evidence dans la litterature. Ensuite, il s’agit de souligner les apports du RQE en le positionnant par rapport aux principaux courants de recherche en strategie afin d’en souligner les ressemblances et divergences. Enfin, l’examen des limites permet la suggestion de travaux futurs portant sur le RQE.