6 research outputs found
An investigation of the association between sources of competence and affect in physically active college students
No full textHarter’s competence motivation theory (Harter, 1978) describes factors that can increase motivation to enhance participation in physical activity. Important factors are sources of competence information, perceptions of competence, and affect. As young people age, they move from emphasizing external sources of competence information (e.g., parents and coaches) to internal sources (e.g., effort and improvement). This study examined sources of competence information used by young adults in college physical activity classes and the impact of those sources on their affect. It was hypothesized that students who used multiple sources of competence information (i.e., scored high on both internal and external sources) would have higher positive affect than students who used only internal sources of competence information. It was also hypothesized that perceptions of competence would mediate the relationship between multiple sources of competence information and positive affect. One hundred and fifty-one college students from various physical activity classes were included in the sample. A cluster analysis was utilized to create groups of students based on their reliance on internal and external sources. Two distinct groups were found – Cluster 1, who favored internal sources and Cluster 2, who preferred multiple sources (internal and external). A One-Way ANOVA was used to compare the two clusters on positive affect. The hypothesis was not supported, as there were no significant differences between the clusters on positive affect. A mediational analysis was used to determine if perceptions of competence would mediate the relationship between multiple sources of competence and affect. This hypothesis was also not supported, signifying a direct relationship between sources of competence and positive affect. In addition, since there was no difference between multiple and internal sources on positive affect, it may be important for college-aged physical activity participants to focus on using internal sources of competence information to have the highest enjoyment in physical activity. Having college-aged students enjoy physical activity is an important factor for students to stay motivated to participate in physical activity during their transition into adulthood. Guidelines for personnel at colleges and universities are provided.Psy. D.Includes bibliographical referencesby Jenya C. Gaski
A length comparison theorem for geodesic currents
No full textWe work with the space of geodesic currents on a closed
surface of negative Euler characteristic. By prior work of the author with
Sebastian Hensel, each filling geodesic current has a unique
length-minimizing metric in Teichm\"uller space. In this paper, we show
that, on so-called thick components of , the geometries of and are
comparable, up to a scalar depending only on and the topology of . We
also characterize thick components of the projection using only the length
function of .Comment: 46 pages, 29 figures. Added results on identifying short curves,
thick subsurfaces of projectio
Antimalarial Peptide and Polyketide Natural Products from the Fijian Marine Cyanobacterium Moorea producens
No full textA new cyclic peptide, kakeromamide B (1), and previously described cytotoxic cyanobacterial natural products ulongamide A (2), lyngbyabellin A (3), 18E-lyngbyaloside C (4), and lyngbyaloside (5) were identified from an antimalarial extract of the Fijian marine cyanobacterium Moorea producens. Compounds 1 and 2 exhibited moderate activity against Plasmodium falciparum blood-stages with EC50 values of 0.89 and 0.99 M, respectively, whereas 3 was more potent with an EC50 value of 0.15 nM. Compounds 1, 4, and 5 displayed moderate liver-stage antimalarial activity against P. berghei liver schizonts with EC50 values of 1.1, 0.71, and 0.45 M, respectively. The threading-based computational method FINDSITEcomb2.0 predicted the binding of 1 and 2 to potentially druggable proteins of Plasmodium falciparum, prompting formulation of hypotheses about possible mechanisms of action. Kakeromamide B (1) was predicted to bind to several Plasmodium actin-like proteins and a sortilin protein suggesting possible interference with parasite invasion of host cells. When 1 was tested in a mammalian actin polymerization assay, it stimulated actin polymerization in a dose-dependent manner, suggesting that 1 does, in fact, interact with actin
Sentiment Analysis in the News
No full textRecent years have brought a significant growth in the volume of research in sentiment analysis, mostly on highly subjective text types (movie or product reviews). The main difference these texts have with news articles is that their target is clearly defined and unique across the text. Following different annotation efforts and the analysis of the issues encountered, we identified three subtasks for news opinion mining: definition of the target; separation of the good and bad news content from the good and bad sentiment expressed on the target; and analysis of clearly marked opinion that is expressed explicitly, not needing interpretation or the use of world knowledge. Furthermore, we distinguish three different possible views on newspaper articles � author, reader and text, which have to be addressed differently at the time of analysing sentiment. Given these definitions, we present work on mining opinions about entities in English language news, in which (a) we test the relative suitability of various sentiment dictionaries and (b) we attempt to separate positive or negative opinion from good or bad news. We tested in the experiments described here whether or not subject domain-defining vocabulary should be ignored. Results showed that this idea is more appropriate in the context of news opinion mining and that the approaches taking this into consideration have a better performance.JRC.DG.G.2 - Global security and crisis managemen
Search for the exclusive boson hadronic decays , and with the ATLAS detector
No full textA search for the exclusive hadronic decays , and is performed using up to of proton-proton collisions recorded with the ATLAS detector at a center-of-mass energy of . These rare processes provide a test bench for the quantum chromodynamics factorization formalism used to calculate cross sections at colliders, as well as a probe of boson coupling to quarks and a new way to measure the boson mass through fully reconstructed decay products. The search results in the most stringent upper limit to date on the branching fractions \mathcal{B}(W^{\pm}\to \pi^{\pm}\gamma) W±→π±γ, W±→K±γ, and W±→ρ±γ is performed using up to 140 fb-1 of proton-proton collisions recorded with the ATLAS detector at a center-of-mass energy of s=13 TeV. If observed, these rare processes would provide a unique test bench for the quantum chromodynamics factorization formalism used to calculate cross sections at colliders. Additionally, at future colliders, these decays could offer a new way to measure the W boson mass through fully reconstructed decay products. The search results in the most stringent upper limits to date on the branching fractions B(W±→π±γ)<1.9×10-6, B(W±→K±γ)<1.7×10-6, B(W±→ρ±γ)<5.2×10-6 at 95% confidence level.A search for the exclusive hadronic decays W^{\pm}\to \pi^{\pm}\gammaW^{\pm}\to K^{\pm}\gammaW^{\pm}\to \rho^{\pm}\gamma140\, \text{fb}^{-1}\sqrt{s}=13\,\text{TeV}WW\mathcal{B}(W^{\pm}\to \pi^{\pm}\gamma) < 1.9\times10^{-6}\mathcal{B}(W^{\pm}\to K^{\pm}\gamma) < 1.7\times10^{-6}\mathcal{B}(W^{\pm}\to \rho^{\pm}\gamma) < 5.2\times10^{-6}$ at 95% confidence level
Modelado y simulación de sistemas fotovoltaicos bajo condiciones de sombreado parcial
No full textgraficas, tablasThis thesis introduces a methodology for modeling commercial photovoltaic panels at the cell
level operating under partial shading conditions. In the first part, a review of the literature
is presented, focusing on the proper representation of the current-voltage characteristics in
both forward and reverse bias, the mathematical formulation, the circuit model, and the
estimation of parameters for photovoltaic cells.
In the second part, the single diode model (SDM), the direct-reverse model (DRM), and
Bishop’s model are introduced, emphasizing their current-voltage relationship, mathematical
formulation, circuit model, and parameter requirements.
In the third part of the thesis, a procedure to obtain I-V curves in panel terminals without
the need for any physical intervention is detailed. This procedure is necessary to compare
the behavior of the three models analyzed in both quadrants. The procedure requires a panel
without a bypass diode and measurement equipment capable of acquiring current, voltage,
temperature, and irradiation.
After considering the evaluation of some metrics such as root mean square error (RMSE)
and mean absolute percentage error (MAPE), Bishop’s model is selected for use in the
methodology.
In the fourth part, a methodology to estimate the parameters of Bishop’s model is proposed, which formulates the estimation of the parameters as an optimization problem. The metho-
dology uses a genetic algorithm, and it is validated using information from two commercial
panels. The curve reconstructions for each technology are evaluated using metrics such as
RMSE and MAPE to assess the accuracy of the models (Texto tomado de la fuente)Esta tesis presenta una metodología de modelado de paneles fotovoltaicos comerciales a nivel
de celda operando bajo condiciones de sombreado parcial. En la primera parte se realiza
una revisión de la literatura sobre la representación de celdas fotovoltaicas, en la que se
consideran características importantes como la formulación matemática, el modelo circuital,
la representación apropiada del comportamiento en modo directo e inverso y la estimación
de parámetros.
En la segunda parte, se exponen algunos de los modelos m ́as utilizados en la literatura para
el modelado de celdas fotovoltaicas, Modelo de un solo diodo (SDM), Modelo DRM y el
modelo de Bishop, prestando especial atención a la relación corriente-voltaje, la formulación
matemática, el modelo circuital y los parámetros necesarios para su evaluación. Para modelar
los paneles a nivel de celda, la tercera parte se enfoca en detallar un procedimiento para
obtener las curvas I-V en terminales de un panel, sin necesidad de ninguna intervención
física. Para lo se requiere un panel sin diodo de bypass, información del panel obtenida al
sombrear el panel y algunos equipos de medida que permitan adquirir corriente, voltaje,
temperatura e irradiación.
En la tercera parte de la tesis se detalla un procedimiento para obtener curvas I-V en terminales del panel sin necesidad de intervención física alguna. Este procedimiento es necesario
para comparar el comportamiento de los tres modelos analizados en ambos cuadrantes. El
procedimiento requiere un panel sin diodo de derivación y un equipo de medición capaz de
adquirir corriente, voltaje, temperatura e irradiación.
Después de considerar la evaluación de algunas métricas como el error cuadrático medio
(RMSE) y el error porcentual absoluto medio (MAPE), se selecciona el modelo de Bishop
para su uso en la metodología.
En la cuarta parte, se propone una metodología para estimar los parámetros del modelo de
Bishop, formulando el problema de estimación de parámetros como un problema de optimización. La metodología utiliza un algoritmo genético y se valida con información de dos
paneles comerciales. Las reconstrucciones de curvas para cada tecnología se evalúan utilizando métricas como RMSE y MAPE para evaluar la precisión de los modelos.DoctoradoDoctor en IngenieríaEléctrica, Electrónica, Automatización Y Telecomunicaciones.Sede Manizale
