Impact of noise on a dynamical system: prediction and uncertainties from a swarm-optimized neural network

In this study, an artificial neural network (ANN) based on particle swarm optimization (PSO) was developed for the time series prediction. The hybrid ANN+PSO algorithm was applied on Mackey--Glass chaotic time series in the short-term $x(t+6)$. The performance prediction was evaluated and compared with another studies available in the literature. Also, we presented properties of the dynamical system via the study of chaotic behaviour obtained from the predicted time series. Next, the hybrid ANN+PSO algorithm was complemented with a Gaussian stochastic procedure (called {\it stochastic} hybrid ANN+PSO) in order to obtain a new estimator of the predictions, which also allowed us to compute uncertainties of predictions for noisy Mackey--Glass chaotic time series. Thus, we studied the impact of noise for several cases with a white noise level ($\sigma_{N}$) from 0.01 to 0.1.Comment: 11 pages, 8 figure

Thermal decomposition of single hydroxychlorides of nickel, copper and cobalto

The thermal decomposition reactions of Ni(OH)Cl.l½H20 in still air and in nitrogen and β-CO2(OH)3Cl and γ-Cu2(OH)3Cl in nitrogen atmosphere, have been studied by DTA and TG analysis, and the intermediates and final products have been characterized by x-ray diffraction and infrared spectroscop. The thermal evolution ot the above indicated compounds under dynamic vacuum conditions has be en studied with the aid of an x-ray high teaperature diffraction chamber. They reveals that in these conditions, the pure metallic nickel, copper and cobalt can be obtained at comparative low temperature. The infrared spectra of thése hydroxychlorides have been tentatively assigned

Optimizing daily operation of battery energy storage systems under real-time pricing schemes

Modernization of electricity networks is currently being carried out using the concept of the smart grid; hence, the active participation of end-user consumers and distributed generators will be allowed in order to increase system efficiency and renewable power accommodation. In this context, this paper proposes a comprehensive methodology to optimally control lead-acid batteries operating under dynamic pricing schemes in both independent and aggregated ways, taking into account the effects of the charge controller operation, the variable efficiency of the power converter, and the maximum capacity of the electricity network. A genetic algorithm is used to solve the optimization problem in which the daily net cost is minimized. The effectiveness and computational efficiency of the proposed methodology is illustrated using real data from the Spanish electricity market during 2014 and 2015 in order to evaluate the effects of forecasting error of energy prices, observing an important reduction in the estimated benefit as a result of both factors: 1) forecasting error and 2) power system limitations

ETG de Referencia en Chile, simetría: Estudio de Caso

El presente artículomuestra parte de los resultados de una investigación que estudió la circulación y progresión del Espacio de Trabajo Geométrico de Referencia de Chile,en tercero y cuarto básico, en torno a las Transformaciones Isométricas. En este artículo nos referimos a una de las Actividades Sugeridas por el Ministerio de Educación de Chile, en el Programa de Estudio de cuarto año básico. En esta se identifican los elementos epistemológicos y procesos cognitivos que la actividad moviliza -a la luz de la teoría del Espacio de Trabajo Geométrico propuesta por Alain Kuzniak et al

Neurophysiological development of newborn pigs: effect of the sow’s parity number in eutocic farrowings

The objective of the present study was to determine the effect of sow parity on neonatal piglet health and vitality at birth. We evaluated 1505 neonate piglets, which were born of York–Landrace sows with the following parity distribution: primiparous (n = 202), second (n = 207), third (n = 211), fourth (n = 222), fifth (n = 225), sixth (n = 218) and seventh parity (n = 220). Piglets born to primiparous and seventh-parity sows had the lowest and highest birthweights respectively, and showed the most marked imbalances in blood gas exchanges, acid–base balance and energy profiles, as well as the highest percentage of severe meconium staining of the skin and the lowest vitality scores (P < 0.05). In contrast, the neonates from the fourth-parity sows had the highest vitality scores, required less time to reach the mother’s teat, and had the highest percentage of adhered umbilical cords and newborns with dyspnoea, apnoea and abnormal heartbeat (P < 0.05). The results of this study suggest that during eutocic farrowings, the sow’s parity number has the following effects on newborn piglets: reduced vigour and longer latencies to begin breathing, stand and take the teat. These effects are due to the presence of imbalances in gas exchanges, the acid–base balance and energy profiles that occurred when the mother was a primiparous or older sow. These signs indicate that the newborn piglet survived a process of intrapartum asphyxia.info:eu-repo/semantics/acceptedVersio

Initial learning scenarios based on the computational thinking evaluation for the course Programming fundamentals at INACAP

The paper’s objective is present the design and the planning of initial learning scenarios for the course Programming Fundamentals, from the evaluation of computational thinking to new students of the careers Computer engineering and Programmer analyst of the Technological University of Chile and Training Center Technical respectively at INACAP, to favor the motivation and autonomy of study through the recognition of skills and the use of the instructional design of the face-to-face course. The proposal is based on correspondence with three of five change trends that integrated the educational model. Regarding the Knowledge society, promote recognition of the individuality of the student as a person who will do university studies, that is, the scenarios respond to the fact that each person learns differently. In the Training of competences, contribute with preventive actions that the teacher communicates when there is a lack of specific skills. Finally, in the Flexibility and articulation, provide a diagnostic tool that favors the recognition of previous competences to have an articulated beginning of studies based on the needs of the student. Consequently, contribute to the INACAP´s educational model

Effect of pores on the mechanical and durability properties on high strength recycled fine aggregate mortar

[EN] Larger consumption of natural fine aggregates (NFA) leads to an increase in cost, energy, and negative environmental impact. On the contrary, the larger production of construction waste results in the generation of recycled fine aggregate (RFA), which requires safe disposal. The aim of study, is to the hunt for such alternatives, compares the mortar mechanical and durability properties with and without RFA. High strength mortar specimens were produced with mix proportion as 1:3 using RFA as partial replacement for NFA as 0%, 25%, 50% and 100%. The mechanical and durability performance of all specimens was assessed in the terms of compressive strength, flexural strength, water absorption and mercury intrusion porosimetry. Mechanical performance is confirmed by microscopic studies. The main results display that the mortar with 25% of RFA, performed better, which are related to pore structures and their distribution. It is noted that the, pores also increase with the increase in RFA content. The effect of pores on the strength and their relationships are assessed.SIAuthor wish to thank for the supports and guidance given by faculties from University of Leon, Leon, Spain and Coimbatore Institute of Technology, Coimbatore, Indi

Operating conditions of lead-acid batteries in the optimization of hybrid energy systems and microgrids

The promotion and deployment of storage technologies in autonomous and grid-connected systems plays a relevant part in the massive integration of renewable power sources required for the worldwide development of a sustainable society. In this regard, analyzing the behavior of electrochemical storage devices such as lead-acid batteries installed on hybrid energy systems and microgrids in terms of their lifetime and economic profitability is an important research topic. Since renewable generation is characterized by its random nature, lead-acid batteries typically work under stress conditions, which directly influence their lifetime in a negative way by increasing the net present cost. Due to the fast growing of renewable sources as a consequence of governmental policies and incentives, the number of manufacturers to be considered worldwide is becoming really high, so that optimization techniques such as genetic algorithms (GAs) are frequently used in order to consider the performance of a high number of manufacturers of wind turbines, photovoltaic panels and lead-acid batteries subject to the environmental conditions of the location under analysis to determine a cost-effective design. In this paper, GA method combined with weighted Ah ageing model is improved by including expert experiences by means of stress factors and the categorization of operating conditions, as a new contribution to earlier studies. The effectiveness of the proposed method is illustrated by analyzing a hybrid energy system to be installed in Zaragoza, Spain, resulting in a near-optimal design in a reduced computational time compared to the enumerative optimization method

Applets In Physics And Their Impact On The Development Of Thought

RESUMEN: En este trabajo se presenta una propuesta de enseñanza que involucra el uso de applets en las asignaturas de física mecánica de los programas ingeniería civil e ingeniería de sistemas de la Universidad Cooperativa de Colombia - sede Ibagué. El propósito de este estudio es conocer la incidencia de una estrategia didáctica centrada en el uso de applets y apoyada en la mediación de Feuerstein (1986,1988) como referente teórico. Se presenta un breve análisis tanto cuantitativo como cualitativo de la información recolectada, de donde se puede inferir que los estudiantes adquieren una motivación hacia el aprendizaje de conceptos físicos a partir de la interacción con estas potenciales herramientas, además de algunos indicios de aprendizaje significativo de dichos conceptos.ABSTARCT: In this work we present a teaching proposal that involves the use of applets in the courses of mechanical physics of the programs Civil Engineering and Systems Engineering in the Cooperative University of Colombia - Ibague. The purpose of this study is to know the incidence of a didactic strategy centered in the use of applets and supported in the mediation of Feuerstein (1986, 1988) as theoretical refeernce. It is presented a brief analysis, quantitative and qualitative, of the gathered information, from which we can infer that the students acquire a motivation toward the learning of physical concepts starting from the interaction with these potential tools, besides some indications of significant learning of these concepts

Cabibbo-suppressed non-leptonic B- and D-decays involving tensor mesons

The Cabibbo-suppressed non-leptonic decays of B (and D) mesons to final states involving tensor mesons are computed using the non-relativistic quark model of Isgur-Scora-Grinstein-Wise with the factorization hypothesis. We find that some of these B decay modes, as B --> (K^*, D^*)D^*_2, can have branching ratios as large as 6 x 10^{-5} which seems to be at the reach of future B factories.Comment: Latex, 11 pages, to appear in Phys. Rev.