Uso de software en la enseñanza de la matemática

Las clases de matemáticas no debieran tener como objetivo fundamental el aprendizaje de contenidos (definiciones, teoremas, axiomas…) que posteriormente serán aplicados a la resolución de un gran listado de ejercicios y problemas propuestos por el profesor y que justificará el aprendizaje de dichos contenidos, sino que, por el contrario, debieran partir con un problema concreto y familiar para el alumno. Una vez planteado éste y discutido por todos, estudiantes y profesor, traerá como consecuencia la obligación de resolverlo y por tanto la necesidad del aprendizaje de las técnicas que son necesarias para ello y recurrir al uso de tecnología disponible. Es muy importante destacar que durante todo el proceso el alumno hace conjeturas que irá verificando en cada paso. Se dará cuenta que algunas de las conjeturas que hizo son correctas y que otras no lo son, es decir, cometerá errores y aciertos, en función de los cuales irá cimentando su aprendizaje. Pero, por sobre todo, debe aprender que “va al colegio a equivocarse”, pero que no debe quedarse en el error, que en la discusión con sus compañeros y el profesorado encontrará la(s) solucione(s), que es probable que más de una sirva, pero que también unas son mejores que otras, que en algunos casos hay una solución óptima, en definitiva irá “aprendiendo a aprender”. Se ilustra lo anterior planteando resolver un clásico problema de construcción de cajas utilizando como herramienta de aprendizaje el software DERIVE 5

En busca de un modelo matemático

El objetivo de nuestra investigación fue ajustar un modelo matemático a un problema real. Específicamente centramos nuestra atención en determinar un modelo matemático referente al aprendizaje de una rata de laboratorio en resolver un laberinto, es decir controlamos el tiempo que invierte la rata en completar el recorrido del laberinto y el número de veces que se repetía la experiencia. Después de aplicar la interpolación Lagrangeana el comportamiento de las ratas se ajustó a una rama de una función hiperbólica, naturalmente se realizaron algunas restricciones para concluir con una expresión (modelo) más compacta

Comunicación bluetooth para sensores utilizados en aplicaciones de control de tráfico

1 archivo PDF (40 páginas)Exposición del diseño e implementación de la plataforma de desarrollo Bluetooth para sensores inalámbricos orientados a aplicaciones lIS

La geometría dinámica con CABRI II

La utilización de una herramienta nueva, de cualquier tipo que sea, necesita de una reflexión sobre lo que hacemos, muchas veces cambia nuestro modo de trabajar (actitud) y hace surgir problemas sobre las verdades que teníamos. En matemática los conocimientos utilizados pueden ser diferentes: comparar una construcción geométrica con regla y compás o con regla y escuadra (mecánica) o solamente con compás. En este curso se explora de manera activa el software Cabri II. En una primera etapa se realiza la construcción de triángulos -sus elementos secundarios- y circunferencias inscritas y circunscritas así como exploraciones de simetría. En una segunda etapa se elaboran macro construcciones o construcciones que podemos grabar, para luego reutilizar en figuras más complejas, sin necesidad de rehacerlas. A través de la exploración ya descrita se reflexiona sobre el aporte de esta herramienta al quehacer pedagógico y/o científico. El uso del software es muy cercano a la forma de pensar en la geometría clásica, lo que permite a los estudiantes acercarse a esta disciplina y hacer conjeturas. Corresponde advertir que, como Cabri II no es un software de dibujo ni de demostración sino que está basado en un ambiente numérico, hay errores de aproximación. aunque leves. Se inicia el curso explicando brevemente el funcionamiento del software Cabri II para pasar a realizar actividades de construcción y comprobación de relaciones geométricas

Doctor of Philosophy

dissertationThis dissertation consists of three independent essays on cyclical fluctuations of functional income distribution and effective demand in the Post-Keynesian tradition. The first essay investigates the longer run relationship between wage share and measurements of economic activity. Our main tools are wavelet covariance and multiresolution analysis. Results indicate that (1) Goodwin type cycles are observed even at longer run and (2) when considering smooth trends for periodicities longer than 32 years, a long Goodwin cycle seems to appear from the 1940s to mid-1990s that collapses afterwards. The second and third essays are related in the sense that they empirically investigate the possibility of strong internal dynamics in the business cycle model of effective demand and income distribution. Specifically, in the second essay, we study wage share and output gap in an univariate setting. Each time series is examined through chaos theory. The main tools are the nonlinear autoregressive neural network model, the dominant Lyapunov exponent, coefficient of determination, and local Lyapunov exponent. Results indicate that output gap might behave quasi-chaotically and wage share noisy-stable. Finally, the third essay inquires into the possibility of limit cycle in the two-dimensional model on wage share and output gap. For that, we use the multivariate nonlinear autoregressive neural network model. Our results indicate that limit cycle behavior describes well their dynamics and, furthermore, the instability is located on the wage share isocline. Chapters 1 through 3 open several questions that we hope further research will address. In Chapter 1, we conjecture that globalization plays a crucial role in the stagnation of the trends in the late 1990s. However, further research is required. Chapter 2 concludes that instability is rooted in the goods market dynamics rather than the distributive dynamics. Results on Chapter 3 indicate that the demand regime is stable and wage share locally unstable. This possibility remains largely unexplored both in the theoretical and empirical literature, and it creates a contradiction with the results found in Chapter 2. Further research is necessary on the robustness of the result, and possible mechanisms

Study of phytopathogenesis regulation through chromatine modification

Chromatin is a structure formed by DNA and protein found in eukaryotic cells. This structure serves to package and condense the DNA. Histones are the main proteins forming part of this structure. The histones have aminoacidic tails which modifications are highly involved in transcriptional control of genetic programs that lead essentials processes like mitosis or more complex processes as can be cell differentiation. We have done a phylogenetic study and have found 3 genes which can encode the enzymes in charge of histone H3 methylation at its lysine resides 9 (KMT1) and 36 (KMT3 and KMT2H). The lysine 9 methylation in H3 is the main hallmark of constitutive heterochromatin (1,2) and the H3 lysine 36 methylation is generally associated with active transcription (3). We have deleted these putative methyltransferases in Ustilago maydis. While KMT1 deletion has not showed a significant virulence phenotype, both H3K36 methyltransferases mutants present infection defects. Interestingly, meanwhile KMT3 deletion shows a reduction in virulence, KMT2H deletion improve pathogenesis. In addition, by western blot analysis we have observed a reduction of H3K36 trimethylation in both mutants respect the wild type strain, indicating there are two H3K36 methyltransferases with opposite roles in infection. These observations are in agreement with a recent publication where the fungus Fusarium fujikuroi is methylating H3K36 in heterochromatin and euchromatin area through two different methyltransferases (4). We are currently studying the differences between these methyltrasnferases at the molecular and cellular level during the pathogenesis process

A new forward-scatter visibility sensor based on a universal frequency-to-digital converter

Traffic delays attributable to weather conditions may cause an increase in fuel consumption and then an increase in CO2 emissions to the environment. Visibility reduction in roads due to dense fog is a main cause of traffic accidents and possible environmental pollution, hence the importance of deploying fog warning systems. In this article, we present a forward-scatter visibility sensor that uses a quasi-digital photodetector and a universal frequency-to-digital converter instead of a conventional analog-to-digital converter as data acquisition system. This feature has allowed the design of a low-cost, robust, and simple sensor-to-microcontroller interface as demanded by Intelligent Transportation Systems (ITS) applications. An optical system to limit light interference is proposed. The visibilimeter was calibrated from a self-calibrated transmissometer using the same frequency-to-digital technique. This new instrument is capable of a 41 662.5m visibility range detection and to transmit the information wirelessly to a 100m distance.The authors would like to thank the Universidad Autonoma Metropolitana-Azcapotzalco and the Universidad Politecnica de Valencia for their support.Barrales Guadarrama, R.; Mocholí Salcedo, A.; Rodríguez Rodríguez, M.; Barrales Guadarrame, VR.; Vázquez Cerón, ER. (2013). A new forward-scatter visibility sensor based on a universal frequency-to-digital converter. Instrumentation Science and Technology. 41:445-462. doi:10.1080/10739149.2013.780250S44546241News Section, p. 8, (April-March 2009), ITS International Electronic Magazine [Online]. Available: www.itsinternational.comBandivadekar , A. ; Bodek , K. ; Cheah , L. ; Evans , C. ; Groode , T. ; Heywood , J. ; Kasseris , E. ; Kromer , M. ; Weiss , M. On the Road in 2035: Reducing Transportation's Petroleum Consumption and GHG Emissions. Report No. LFEE 2008–05 RP, MIT Laboratory for Energy and the Environment, Cambridge, Massachusetts, 2008.Schrank , D. ; Lomax , T. ; Turner , S. TTI's Urban Mobility Report 2010 [Online]. Avalaible: http://tti.tamu.edu/publications/catalog/record/?id=36580.Bradley , J. T. ; Kraus , K. ; Townshend , T. Federal Citing Criteria for Automated Surface Weather Observations. 7th Symp. On Meteorological Observations and Instrumentation, New Orleans, LA, 1991, 207–210.Winstanley, J. V., & Adams, M. J. (1975). Point Visibility Meter: a forward scatter instrument for the measurement of aerosol extinction coefficient. Applied Optics, 14(9), 2151. doi:10.1364/ao.14.002151Horner, J. L. (1976). Analog visibility computer. Applied Optics, 15(4), 999. doi:10.1364/ao.15.000999Twomey, S., & Howell, H. B. (1965). The Relative Merit of White and Monochromatic Light for the Determination of Visibility by Backscattering Measurements. Applied Optics, 4(4), 501. doi:10.1364/ao.4.000501Vogt, H. (1968). Visibility Measurement Using Backscattered Light. Journal of the Atmospheric Sciences, 25(5), 912-918. doi:10.1175/1520-0469(1968)0252.0.co;2Tjugum, S. A., Vaagen, J. S., Jakobsen, T., & Hamre, B. (2005). Use of optical scatter sensors for measurement of visibility. Journal of Environmental Monitoring, 7(6), 608. doi:10.1039/b414327bNebuloni, R. (2005). Empirical relationships between extinction coefficient and visibility in fog. Applied Optics, 44(18), 3795. doi:10.1364/ao.44.003795Kirianaki, N. V., Yurish, S. Y., Shpak, N. O., & Deynega, V. P. (2002). Data Acquisition and Signal Processing for Smart Sensors. doi:10.1002/0470846100Hlupic, N., Butorac, J., & Kresic, M. (2005). Improved Frequency Measurement by Means of DMM and Verification of its Specifications. IEEE Transactions on Instrumentation and Measurement, 54(5), 1957-1963. doi:10.1109/tim.2005.853561Prokin, M. (1991). Double buffered wide-range frequency measurement method for digital tachometers. IEEE Transactions on Instrumentation and Measurement, 40(3), 606-610. doi:10.1109/19.87027Yurish, S. Y., Reverter, F., & Pallàs-Areny, R. (2005). Measurement error analysis and uncertainty reduction for period- and time-interval-to-digital converters based on microcontrollers. Measurement Science and Technology, 16(8), 1660-1666. doi:10.1088/0957-0233/16/8/018Kirianaki, N. V., Yurish, S. Y., & Shpak, N. O. (2001). Methods of dependent count for frequency measurements. Measurement, 29(1), 31-50. doi:10.1016/s0263-2241(00)00026-9Barrales-Guadarrama , R. ; Mocholí-Salcedo , A. ; Vázquez-Cerón , E. R. ; Rodríguez-Rodríguez , M. E. ; Barrales-Guadarrama , V. R. A Technique for Adapting a Quasi-digital Photodetector to a Frequency-to-digital Converter. Proceedings 2012 IEEE Electronics, Robotics and Automotive Mechanics Conference, CERMA 2012, Cuernavaca, Morelos, México, Nov. 20–23, 2012.(2011) 700–999 nm Bandpass Interference Filters, [Online]. Available: http://www.edmundoptics.com/products/displayproduct.cfm?productid=3198&PageNum=6&Sort=displayOrder&Order=asc#products.AeroGrapher's Mate, Module 05—Basic Meteorology, Ch. 5, Atmospheric Phenomena, Radiation Fog, [Online]. Available: http://www.tpub.com/content/aerographer/14312/css/14312_143.htm

Exaptation and vulnerability to introduced mammal herbivores on Balearic endemic flora

Aim: Introduced mammal herbivores are predicted to negatively affect insular flora. However, disentangling which particular traits (1) developed from exaptations and (2) are functional to avoid herbivory remains mainly unknown. This study aims to assess if the flora of continental islands with historic native herbivores are exapted to the introduction of new mammal herbivores and to predict the potential vulnerability of endemic species from islands where mammal herbivores have not been introduced. Location: Balearic Islands. Taxon: 96 Balearic endemic plant species. Methods: We investigated whether the endemic flora on continental islands maintains functional traits that resist introduced mammal herbivores by analysing the chemical and morphological traits related to plant resistance of five individuals for each of 98 species. Also, we measured plant-size variables to assess plant escape strategies. Overall, we combined these traits with the accessibility to goats. Predictive models were generated for species that inhabit islands where goats have not been introduced to assess their potential vulnerability. Results: Endemic species may defend against new herbivores (e.g. goats) if they contain highly toxic compounds (alkaloids, glycosides, coumarins), spinescent and urticating structures, or specific plant architecture (low plant size, high specific leaf area). If such traits are absent, the species may become extinct—unless they inhabit areas inaccessible to goats. On continental islands, some endemic species are expected to resist the introduction of herbivores, while others may be significantly affected. Main Conclusions: From the ancient connection with the mainland, exaptations may allow the plants to resist the presence of introduced herbivores. However, non-exapted species could be threatened by the introduction of non-native ungulatesDireccio General de Politica Universitaria i Recerca (Govern de les Illes Balears) FPI/1925/2016Spanish Government CGL2015-70449-REuropean Union (NextGenerationEU