Factorization and Criticality in Finite XXZ Systems of Arbitrary Spin

We analyze ground state (GS) factorization in general arrays of spins si with XXZ couplings immersed in nonuniform fields. It is shown that an exceptionally degenerate set of completely separable symmetry-breaking GSs can arise for a wide range of field configurations, at a quantum critical point where all GS magnetization plateaus merge. Such configurations include alternating fields as well as zero-bulk field solutions with edge fields only and intermediate solutions with zero field at specific sites, valid for d-dimensional arrays. The definite magnetization-projected GSs at factorization can be analytically determined and depend only on the exchange anisotropies, exhibiting critical entanglement properties. We also show that some factorization-compatible field configurations may result in field-induced frustration and nontrivial behavior at strong fields.Fil: Cerezo, M. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Rossignoli, Raúl Dante. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Canosa, Norma Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Ríos, E.. Universidad Tecnológica Nacional; Argentin

Fuzzy Inference System for VOLT/VAR control in distribution substations in isolated power systems

This paper presents a fuzzy inference system for voltage/reactive power control in distribution substations. The purpose is go forward to automation distribution and its implementation in isolated power systems where control capabilities are limited and it is common using the same applications as in continental power systems. This means that lot of functionalities do not apply and computational burden generates high response times. A fuzzy controller, with logic guidelines embedded based upon heuristic rules resulting from operators at dispatch control center past experience, has been designed. Working as an on-line tool, it has been tested under real conditions and it has managed the operation during a whole day in a distribution substation. Within the limits of control capabilities of the system, the controller maintained successfully an acceptable voltage profile, power factor values over 0,98 and it has ostensibly improved the performance given by an optimal power flow based automation system

Interactive Embodied Agents for Cultural Heritage and Archaeological presentations

[EN] In this paper, Maxine, a powerful engine to develop applications with embodied animated agents is presented. The engine, based on the use of open source libraries, enables multimodal real-time interaction with the user: via text, voice, images and gestures. Maxine virtual agents can establish emotional communication with the user through their facial expressions, the modulation of the voice and expressing the answers of the agents according to the information gathered by the system: noise level in the room, observer’s position, emotional state of the observer, etc. Moreover, the user’s emotions are considered and captured through images. For the moment, Maxine virtual agents have been used as virtual presenters for Cultural Heritage and Archaeological shows.This work has been partially financed by the Spanish “Dirección General de Investigación'' (General Directorate of Research), contract number Nº TIN2007-63025, and by the Regional Government of Aragon through the WALQA agreement.Seron, F.; Baldassarri, S.; Cerezo, E. (2010). Interactive Embodied Agents for Cultural Heritage and Archaeological presentations. Virtual Archaeology Review. 1(1):181-184. https://doi.org/10.4995/var.2010.5143OJS18118411BALDASSARRI, S., CEREZO, E., SERON, F. (2007): An open source engine for embodied animated agents.In Proc. Congreso Español de Informática Gráfica: CEIG'07, pp. 89-98.BERRY, D.et al, (2005). Evaluating a realistic agent in an advice-giving task. In International Journal in Human-Computer Studies, Nº 63, pp. 304-327. http://dx.doi.org/10.1016/j.ijhcs.2005.03.006BOFF, E. et al, (2005). An affective agent-based virtual character for learning environments. Proceedings of the Wokshop on Motivation and Affect in Educational Software, 12th International Conference on Artificial Intelligence in Education. Amsterdam, Holland, pp 1-8.BURLESON, W. et al, (2004). A Platform for Affective Agent Research. Proceedings of the Workshop on Empathetic Agents, International Conference on Autonomous Agents and Multiagent Systems, New York, USA.CEREZO, E., BALDASSARRI, S., SERON, F. (2007): Interactive agents for multimodal emotional user interaction. In Proc. of IADIS International Conference Interfaces and Human Computer Interaction, pp. 35-42.CASELL, J. et al (eds), (2000), in Embodied Conversational Agents. MIT Press, Cambridge, USA.El-NASR, M. S. et al, (1999). A PET with Evolving Emotional Intelligence. Proceedings of the 3rd Annual Conference on Autonomous Agents. Seattle, USA, pp. 9 - 15. http://dx.doi.org/10.1145/301136.301150GRAESSER, A. et al, (2005). AutoTutor: An Intelligent tutoring system with mixed-initiative dialogue. In IEEE Transactions on Education, Vol. 48, Nº 4, pp. 612-618. http://dx.doi.org/10.1109/TE.2005.856149KASAP, Z. and N. MAGNENAT-THALMANN (2007): "Intelligent virtual humans with autonomy and personality: State-of-the-art", in IntelligentDecision Technologies. IOS PressMARSELLA S. C et al, (2000). Interactive Pedagogical Drama. Proceedings of the 4th International Conference on Autonomous Agents. Barcelona, Spain, pp. 301-308. http://dx.doi.org/10.1145/336595.337507MIGNONNEAU, L. and SOMMERER, C. (2005). Designing emotional, methaforic, natural and intuitive interfaces for interactive art, edutainment and mobile communications, in Computer & Graphics, Vol. 29, pp. 837-851.PRENDINGER, H. and ISHIZUKA, M., (2005). The Empathic Companion: A Character-Based Interface that Addresses Users' Affective States. In Applied Artificial Intelligence, Vol.19, pp.267-285. http://dx.doi.org/10.1080/08839510590910174ROSIS, F. et al, (2003). From Greta's mind to her face: modelling the dynamics of affective status in a conversational embodied agent. In International Journal of Human-computer Studies. Special Issue on Applications of Affective Computing in HCI, Vol 59, pp 81-118. http://dx.doi.org/10.1016/s1071-5819(03)00020-xYUAN, X. and CHEE, S. (2005). Design and evaluation of Elva: an embodied tour guide in an interactive virtual art gallery. In Computer Animation and Virtual Worlds, Vol. 16, pp.109-119. http://dx.doi.org/10.1002/cav.6

Duration and cost variability of construction activities: an empirical study

The unique nature of construction projects can mean that construction activities often suffer from duration and cost variability. Because this variability is unplanned, it can present a problem when attempting to complete a project on time and on budget. Various factors causing this variability have been identified in the literature, but they predominantly refer to the nature and/or context of the whole project rather than specific activities. In this paper, the order of magnitude of and correlation between activity duration and cost variability is analyzed in 101 construction projects with over 5,000 activities. To do this, the first four moments (mean, standard deviation, skewness, and kurtosis) of actual versus planned duration and cost (log) ratios are analyzed by project, phase of execution, and activity type. Results suggest that, contrary to common wisdom, construction activities do not end late on average. Instead, the large variability in the activity duration is the major factor causing significant project delays and cost overruns. The values of average activity duration and cost variability gathered in this study will also serve as a reference for construction managers to improve future construction planning and project simulation studies with more realistic data

A mobile application to report and detect 3D body emotional poses

Most research into automatic emotion recognition is focused on facial expressions or physiological signals, while the exploitation of body postures has scarcely been explored, although they can be useful for emotion detection. This paper first explores a mechanism for self-reporting body postures with a novel easy-to-use mobile application called EmoPose. The app detects emotional states from self-reported poses, classifying them into the six basic emotions proposed by Ekman and a neutral state. The poses identified by Schindler et al. have been used as a reference and the nearest neighbor algorithm used for the classification of poses. Finally, the accuracy in detecting emotions has been assessed by means of poses reported by a sample of users

On the practical usefulness of the Hardware Efficient Ansatz

Variational Quantum Algorithms (VQAs) and Quantum Machine Learning (QML) models train a parametrized quantum circuit to solve a given learning task. The success of these algorithms greatly hinges on appropriately choosing an ansatz for the quantum circuit. Perhaps one of the most famous ansatzes is the one-dimensional layered Hardware Efficient Ansatz (HEA), which seeks to minimize the effect of hardware noise by using native gates and connectives. The use of this HEA has generated a certain ambivalence arising from the fact that while it suffers from barren plateaus at long depths, it can also avoid them at shallow ones. In this work, we attempt to determine whether one should, or should not, use a HEA. We rigorously identify scenarios where shallow HEAs should likely be avoided (e.g., VQA or QML tasks with data satisfying a volume law of entanglement). More importantly, we identify a Goldilocks scenario where shallow HEAs could achieve a quantum speedup: QML tasks with data satisfying an area law of entanglement. We provide examples for such scenario (such as Gaussian diagonal ensemble random Hamiltonian discrimination), and we show that in these cases a shallow HEA is always trainable and that there exists an anti-concentration of loss function values. Our work highlights the crucial role that input states play in the trainability of a parametrized quantum circuit, a phenomenon that is verified in our numerics

Inflaton dark matter from incomplete decay

We show that the decay of the inflaton field may be incomplete, while nevertheless successfully reheating the Universe and leaving a stable remnant that accounts for the present dark matter abundance. We note, in particular, that since the mass of the inflaton decay products is field dependent, one can construct models, endowed with an appropriate discrete symmetry, where inflaton decay is kinematically forbidden at late times and only occurs during the initial stages of field oscillations after inflation. We show that this is sufficient to ensure the transition to a radiation-dominated era and that inflaton particles typically thermalize in the process. They eventually decouple and freeze out, yielding a thermal dark matter relic. We discuss possible implementations of this generic mechanism within consistent cosmological and particle physics scenarios, for both single-field and hybrid inflation

Guidelines to design tangible tabletop activities for children with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder is one of the most frequent neurodevelopmental disorders among children. In spite of this, there is a lack of HCI research specifically devoted to these children. This paper describes efforts to transfer previous experience with other neurodiverse children in the field of tangible tabletops to ADHD children. The results of evaluation sessions carried out in conjunction with an ADHD association, complemented with an in-depth study of their special characteristics and needs, have led to a set of guidelines oriented to the design of tangible tabletop activities. These guidelines are mostly general and applicable to the design of any interactive application oriented to ADHD children. They are also appropriate for applications for other neurodiverse children or, in fact, any child from a more inclusive perspective

Factorization and criticality in finite XXZ systems of arbitrary spin

We analyze ground state (GS) factorization in general arrays of spinss_iwithXXZcouplings immersed in nonuniform fields. It is shown that an exceptionally degenerate set of completely separable symmetry-breaking GS's can arise for a wide range of field configurations, at a quantum critical point where all GS magnetization plateaus merge. Such configurations include alternating fields as well as zero bulk field solutions with edge fields only and intermediate solutions with zero field at specific sites, valid ford-dimensional arrays. The definite magnetization projected GS's at factorization can be analytically determined and depend only on the exchange anisotropies, exhibiting critical entanglement properties. We also show that some factorization compatible field configurations may result in field-induced frustration and nontrivial behavior at strong fields.Facultad de Ciencias Exacta