The Challenge of Believability in Video Games: Definitions, Agents Models and Imitation Learning

In this paper, we address the problem of creating believable agents (virtual characters) in video games. We consider only one meaning of believability, ``giving the feeling of being controlled by a player'', and outline the problem of its evaluation. We present several models for agents in games which can produce believable behaviours, both from industry and research. For high level of believability, learning and especially imitation learning seems to be the way to go. We make a quick overview of different approaches to make video games' agents learn from players. To conclude we propose a two-step method to develop new models for believable agents. First we must find the criteria for believability for our application and define an evaluation method. Then the model and the learning algorithm can be designed

Pluriculturalidad e interculturalidad en el Ecuador: el reconocimiento constitucional de la justicia indígena

En la matriz del Estado Nacional se fueron cuajando una gama de procesos de integración, mestizaje, aculturación y resistencias que han permitido construir esta inacabada nación, donde el indigenado ha colaborado de múltiples formas y a donde se potencian la diversidad y, por ende, la interculturalidad. Hoy, el Estado unitario, devenido centralista está en una profunda crisis, que lo torna ineficiente, antieconómico y poco funcional

Explaining computer predictions with augmented appraisal degrees

An augmented appraisal degree (AAD) has been conceived as a mathematical representation of the connotative meaning in an experience-based evaluation, which depends on a particular experience or knowledge. Aiming to improve the interpretability of computer predictions, we explore the use of AADs to represent evaluations that are per- formed by a machine to predict the class of a particular object. Hence, we propose a novel method whereby predictions made using a support vector machine classification process are augmented through AADs. An illustra- tive example, in which the classes of handwritten digits are predicted, shows how the augmentation of such predictions can favor their interpretability

Urinary chitinase 3-like protein 1 for early diagnosis of acute kidney injury : a prospective cohort study in adult critically ill patients

Background: Acute kidney injury (AKI) occurs frequently and adversely affects patient and kidney outcomes, especially when its severity increases from stage 1 to stages 2 or 3. Early interventions may counteract such deterioration, but this requires early detection. Our aim was to evaluate whether the novel renal damage biomarker urinary chitinase 3-like protein 1 (UCHI3L1) can detect AKI stage >= 2 more early than serum creatinine and urine output, using the respective Kidney Disease vertical bar Improving Global Outcomes (KDIGO) criteria for definition and classification of AKI, and compare this to urinary neutrophil gelatinase-associated lipocalin (UNGAL). Methods: This was a translational single-center, prospective cohort study at the 22-bed surgical and 14-bed medical intensive care units (ICU) of Ghent University Hospital. We enrolled 181 severely ill adult patients who did not yet have AKI stage >= 2 based on the KDIGO criteria at time of enrollment. The concentration of creatinine (serum, urine) and CHI3L1 (serum, urine) was measured at least daily, and urine output hourly, in the period from enrollment till ICU discharge with a maximum of 7 ICU-days. The concentration of UNGAL was measured at enrollment. The primary endpoint was the development of AKI stage >= 2 within 12 h after enrollment. Results: After enrollment, 21 (12 %) patients developed AKI stage >= 2 within the next 7 days, with 6 (3 %) of them reaching this condition within the first 12 h. The enrollment concentration of UCHI3L1 predicted the occurrence of AKI stage >= 2 within the next 12 h with a good AUC-ROC of 0.792 (95 % CI: 0.726-0.849). This performance was similar to that of UNGAL (AUC-ROC of 0.748 (95 % CI: 0.678-0.810)). Also, the samples collected in the 24-h time frame preceding diagnosis of the 1st episode of AKI stage >= 2 had a 2.0 times higher (95 % CI: 1.3-3.1) estimated marginal mean of UCHI3L1 than controls. We further found that increasing UCHI3L1 concentrations were associated with increasing AKI severity. Conclusions: In this pilot study we found that UCHI3L1 was a good biomarker for prediction of AKI stage >= 2 in adult ICU patients

Enaction-Based Artificial Intelligence: Toward Coevolution with Humans in the Loop

This article deals with the links between the enaction paradigm and artificial intelligence. Enaction is considered a metaphor for artificial intelligence, as a number of the notions which it deals with are deemed incompatible with the phenomenal field of the virtual. After explaining this stance, we shall review previous works regarding this issue in terms of artifical life and robotics. We shall focus on the lack of recognition of co-evolution at the heart of these approaches. We propose to explicitly integrate the evolution of the environment into our approach in order to refine the ontogenesis of the artificial system, and to compare it with the enaction paradigm. The growing complexity of the ontogenetic mechanisms to be activated can therefore be compensated by an interactive guidance system emanating from the environment. This proposition does not however resolve that of the relevance of the meaning created by the machine (sense-making). Such reflections lead us to integrate human interaction into this environment in order to construct relevant meaning in terms of participative artificial intelligence. This raises a number of questions with regards to setting up an enactive interaction. The article concludes by exploring a number of issues, thereby enabling us to associate current approaches with the principles of morphogenesis, guidance, the phenomenology of interactions and the use of minimal enactive interfaces in setting up experiments which will deal with the problem of artificial intelligence in a variety of enaction-based ways

Learning a Representation of a Believable Virtual Character's Environment with an Imitation Algorithm

In video games, virtual characters' decision systems often use a simplified representation of the world. To increase both their autonomy and believability we want those characters to be able to learn this representation from human players. We propose to use a model called growing neural gas to learn by imitation the topology of the environment. The implementation of the model, the modifications and the parameters we used are detailed. Then, the quality of the learned representations and their evolution during the learning are studied using different measures. Improvements for the growing neural gas to give more information to the character's model are given in the conclusion

Guiding for Associative Learning : How to Shape Artificial Dynamic Cognition ?

Je n'ai pas de nouvelles de la date de parution de ces actes. La conférence est passée, les organisateurs ont confirmés que les papiers sortiront dans deux numéros de LNAI, en attendant, je souhaitais mettre notre travail en ligne pour qu'il soit diffusé ...International audienceThis paper describes an evolutionary robotics experiment, which aims at showing the possibility of learning by guidance in a dynamic cognition perspective. Our model relies on Continuous Time Recurrent Neural Networks and Hebbian plasticity. The agents have the ability to be guided by stimuli and we study the influence of a guidance on their external behavior and internal dynamic when faced with other stimuli. The article develops the experiment and presents some results on the dynamic of the systems

Réalité Virtuelle et énaction

Cet article argumente sur la capacité du paradigme de l'énaction, à offrir un cadre épistémologique pour le domaine de la réalité virtuelle

Potencial hidráulico del Ecuador

Cabe mencionar que el presente trabajo que versa sobre el Potencial Hidráulico del Ecuador, constituye por su propio nombre algo muy ambicioso ya que al mencionar el agua sabemos que éste elemento líquido vital es de gran importancia en el convivir de la humanidad. El aire, el agua, y la tierra son elementos indispensables para la existencia de los seres vivos en nuestro continente. Al hacer referencia de los elementos constitutivos de la tierra, y en mi caso específico sobre lo que tiene relación al agua, vale la pena clasificar a esta bajo parámetros tanto por su origen, calidad, usos, etc. Al hacer referencia de los elementos constitutivos de Ia tierra, y en mi caso específico sobre lo que tiene relación al agua, vale la pena clasificar a ésta bajo parámetros tanto por su origen, calidad, usos, etc. En el País existen muchos recursos hidráulicos, los mismos que por falta de un buen uso así como un adecuado aprovechamiento técnico han sido factor negativo en su mayor parte. Con el aprovechamiento técnico racional ésta fuente inagotable de recursos hidráulicos constituyen Verdaderos potenciales de riqueza o sea, factor predominante de desarrollo tanto para la agricultura como para la energía eléctrica. Al mismo tiempo puedo decir que algunas cuencas y ríos han sido optimas de uso múltiple como para represar agua para riego y para generar fuerza eléctrica; estos proyectos son los que en realidad interesan al país y en este caso específico al trabajo de investigación individual

Restoration of Taxol Sensitivity of Multidrug-Resistant Cells by the Cyclosporine SDZ PSC 833 and the Cyclopeptolide SDZ 280-446

Background: Taxol, a promising agent for the treatment of cancer, has entered phase II clinical trials. Nevertheless, it belongs to the class of compounds that show impaired retention in multidrug-resistant cells expressing P-glycoprotein (Pgp), a drug efflux pump. Chemosensitizers like verapamil modulate multidrug resistance by interfering with the efflux action of Pgp and thus can decrease drug resistance or can restore drug sensitivity by restoring normal drug accumulation and distribution within the multidrug-resistant tumor cell. The two strongest, nearly equipotent chemosensitizers identified to date are the cyclosporine derivative SDZ PSC 833 and the semisynthetic cyclopeptolide SDZ 280-446. Purpose: This study was designed to investigate the capacities of verapamil, SDZ PSC 833, and SDZ 280-446 to decrease resistance of two multidrug-resistant cell lines to taxol. Methods: We studied in vitro the growth of two multidrug-resistant tumor cell lines displaying high resistance to taxol: multidrug-resistant Chinese hamster ovary cells and murine monocytic leukemia P388 cells. We determined the taxol concentration that produced 50% inhibition of cell growth (IC50) in the two multidrug-resistant cell lines and in the parent cell lines, in the presence of a range of chemosensitizer concentrations (0-30 μM). IC50 values were determined in the presence and in the absence of verapamil, SDZ PSC 833, or SDZ 280-446. Results: At nontoxic concentrations (0.3-1 μM), SDZ PSC 833 and SDZ 280-446 produced an almost complete reversal of the high taxol resistance of the multidrug-resistant tumor cells, whereas only partial restoration of sensitivity to taxol was achieved with verapamil. Conclusion: SDZ PSC 833 and SDZ 280-446 can restore the normal taxol sensitivity of highly resistant multidrug-resistant tumor cells. Implications: The combination of taxol with SDZ PSC 833 or SDZ 280-446 may be recommended for treatment of multidrug-resistant cancers. [J Natl Cancer Inst 85: 478-483, 1993