oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

时间不限

2017 ( 17 )

2016 ( 40 )

2015 ( 200 )

2014 ( 479 )

自定义范围…

匹配条件: “Zapata Elizabeth” ,找到相关结果约10206条。
列表显示的所有文章,均可免费获取
第1页/共10206条
每页显示
CARACTERIZACIóN DEL SOI USANDO ANFIS CON RESIDUALES HETEROCEDáSTICOS
Zapata,Elizabeth C; Velásquez,Juan D; Smith Q,Ricardo;
Ingeniare. Revista chilena de ingeniería , 2007, DOI: 10.4067/S0718-33052007000300010
Abstract: in this paper, we propose the representation of the southern oscillation index (soi) dynamics using a new class of nonlinear hybrid model. in this new model, the non-linearity in the mean is represented by an adaptive neurofuzzy inference system (anfis), while the variance is represented using an autoregressive conditional heterocedastic (arch) component. in addition, a specification strategy for the proposed model, which is based on a battery of statistical tests is developed. the results indicate that the proposed model captures in a better way the main features of the studied time series, when compared to other competitive models.
CARACTERIZACIóN DEL SOI USANDO ANFIS CON RESIDUALES HETEROCEDáSTICOS SOI CHARACTERIZATION USING ANFIS WITH HETEROCEDASTIC RESIDUALS
Elizabeth C Zapata,Juan D Velásquez,Ricardo Smith Q
Ingeniare : Revista Chilena de Ingeniería , 2007,
Abstract: En este trabajo se propone la representación de la dinámica del índice de Oscilación del Sur usando una nueva clase de modelo híbrido no lineal. En este nuevo modelo, la no-linealidad en la media es representada usando un sistema adaptativo neurodifuso de inferencia (ANFIS), mientras que la varianza es representada usando una componente autoregresiva heterocedástica condicional. En adición, una estrategia de especificación es desarrollada para el modelo propuesto, la cual está basada en una batería de pruebas estadísticas. Los resultados indican que el modelo propuesto captura de mejor forma las principales características de la serie de tiempo estudiada, en comparación con otros modelos competitivos. In this paper, we propose the representation of the Southern Oscillation Index (SOI) dynamics using a new class of nonlinear hybrid model. In this new model, the non-linearity in the mean is represented by an adaptive neurofuzzy inference system (ANFIS), while the variance is represented using an autoregressive conditional heterocedastic (ARCH) component. In addition, a specification strategy for the proposed model, which is based on a battery of statistical tests is developed. The results indicate that the proposed model captures in a better way the main features of the studied time series, when compared to other competitive models.
Sistemas adaptativos de inferencia neurodifusa con errores heterocedásticos para el modelado de series financieras
Zapata Gómez,Elizabeth Catalina; Velásquez Henao,Juan David; Smith Quintero,Ricardo Agustín;
Cuadernos de Administración , 2008,
Abstract: this paper proposes a new kind of non-linear hybrid model. in the proposed model, mean non-linearity is represented by using an adaptive neuro-fuzzy inference system (anfis) whereas variance is represented using a conditional self-regressive heteroscedastic component. the mathematical formula for this type of model is shown and a method to estimate it is proposed. in addition, a specification strategy is developed for the proposed model, based on a battery of statistical soft transaction regression (str) tests and on verosimility radius testing. as a case study, the ibm stock closing price series dynamics were modeled, which is commonly used as a benchmark in the literature on time series. results indicate that the model developed represents the dynamics of the studied series better than other models with similar characteristics.
EVALUACIóN DE RESISTENCIA DE GENOTIPOS DE PLáTANO Y BANANO A LA SIGATOKA NEGRA (MYCOSPHAERELLA FIJIENSIS MORELET.)
Cuéllar Quintero,Alejandra; álvarez Cabrera,Elizabeth; Casta?o Zapata,Jairo;
Revista Facultad Nacional de Agronomía, Medellín , 2011,
Abstract: a study was conducted to evaluate plantain and banana genotypes with mycosphaerella fijiensis morelet isolates of different virulence and geographic origin. the pathogenicity test and morphological characterization of the m. fijiensis populations were performed with a group of fifty monosporic isolates representative of the geographic growing areas in colombia. for the pathogenicity and resistance assays an aqueous spore suspension of 5.000 conidias ml-1 was used to inoculate seedlings of plantain and banana genotypes, disease response of genotypes was rated by measuring the variables incubation period (ip), time of evolution of symptoms (tes), area under disease progress curve (audpc) and rate of disease development (r).the inoculation of fifty isolates on dominico harton cultivar allowed to establish five levels of virulence (very high, high, medium, low and very low), which were not related to their geographic origin nor to genotype of the isolates. isolates with different virulence level were present in the same zone and in the same genotype. the resistance assay showed that plantain and banana genotypes can present a differential behavior to the m. fijiensis isolates. the disease severity measured in the genotypes allowed to classify the in three disease reactions levels, resistance, intermediate and susceptible genotypes the plantain genotypes topocho, maqueno, fhia 20 and fhia 21, and the banana genotype sedita and fhia 23 were characterized for having a higher level of resistance, that was expressed as a lower disease severity and slower disease progress as compared with the other genotypes.
FORMACIóN DE DOCENTES UNIVERSITARIOS PARA LA EDUCACIóN MORAL Y VALORES.
Montilva Mariela,García Milagros,Torres González Aída Pastora,Zapata Elizabeth
Salud, Arte y Cuidado , 2012,
Abstract: In order to educate both in moral and values to university students in regards to Health Sciences, a course was designed and implemented to train professors belonging to Medicine and Nursing undergraduate programs of a Venezuelan public university (UCLA).A qualitative evaluation study was carried out with the aim of evaluating the course. The course program included basic concepts, models of moral education and values (EMV),emphasizing the Construction model of the Moral Personality, the role of the teacher,educational strategies, instructional design for the EMV and learning assessment. The coursewas anonymously evaluated by 82 participants through an instrument of 6 open questions regarding: usefulness and relevance of the topics and resources used, educational strategies used, key learning and recommendations. The majority of participants expressed that thetopics were very useful and relevant to their teaching activities; they almost unanimously considered materials very useful. Among the main learning they highlighted the EMV models, academic work and personal re ection, moral dilemmas and the basic concepts.Professors expressed recommendations about time spent on the course, theory and practice content relationship, continuity, and expectations about the courses, curriculum changes development, strategies for each subject, continuous education on EMV and participants work follow-up. In conclusion, the course was valued positively; it promoted re ection on the exercised values internally, professionally and academically. Standpoints allowed knowing the course strengths and weaknesses to eventually adjust it to the needs of the deanship.
EVALUACIóN DE RESISTENCIA DE GENOTIPOS DE PLáTANO Y BANANO A LA SIGATOKA NEGRA (MYCOSPHAERELLA FIJIENSIS MORELET.) EVALUATION OF RESISTANCE OF PLANTAIN AND BANANA GENOTYPES TO BLACK SIGATOKA (MYSCOSPHAERELLA FIJIENSIS MORELET.)
Alejandra Cuéllar Quintero,Elizabeth álvarez Cabrera,Jairo Casta?o Zapata
Revista Facultad Nacional de Agronomía, Medellín , 2011,
Abstract: Con el objetivo de evaluar bajo condiciones de invernadero genotipos de plátano y banano frente a poblaciones de Mycosphaerella fijiensis Morelet de diferente virulencia y origen, se estableció una colección de 125 aislamientos monospóricos obtenidos en 10 departamentos de Colombia. Se seleccionaron 50 aislamientos por área geográfica y genotipo hospedante, para la caracterización morfológica y patogénica del hongo en Dominico Hartón. En las pruebas de patogenicidad y resistencia se realizaron inoculaciones de una suspensión acuosa de 5.000 conidias mL-1, la respuesta de las plántulas a la enfermedad se determinó mediante las variables periodo de incubación (PI), tiempo de evolución de los síntomas (TES), área bajo la curva del desarrollo de la enfermedad (ABCDE) y tasa de desarrollo de la enfermedad (r). La inoculación de los 50 aislamientos en plántulas de Dominico Hartón, permitió establecer cinco niveles de virulencia (muy alta, alta, media, baja y muy baja). La virulencia de los aislamientos no se relacionó con su origen geográfico ni con el genotipo del cual se obtuvieron; encontrándose en una misma zona y en un mismo genotipo, aislamientos de diferente virulencia. Los genotipos de plátano y banano mostraron un comportamiento diferencial frente a cinco aislamientos de diferente virulencia y origen, resultados que permitieron establecer tres niveles de reacción de los genotipos frente a los aislamientos (resistente, intermedio y susceptible), destacándose los genotipos Topocho, Maque o, FHIA 20, FHIA 21 de plátano y los genotipos Sedita y FHIA 23 de banano por presentar un mayor nivel de resistencia, expresada como un progreso lento y menos severo de la enfermedad. A study was conducted to evaluate plantain and banana genotypes with Mycosphaerella fijiensis Morelet isolates of different virulence and geographic origin. The pathogenicity test and morphological characterization of the M. fijiensis populations were performed with a group of fifty monosporic isolates representative of the geographic growing areas in Colombia. For the pathogenicity and resistance assays an aqueous spore suspension of 5.000 conidias mL-1 was used to inoculate seedlings of plantain and banana genotypes, disease response of genotypes was rated by measuring the variables incubation period (IP), time of evolution of symptoms (TES), area under disease progress curve (AUDPC) and rate of disease development (r).The inoculation of fifty isolates on Dominico Harton cultivar allowed to establish five levels of virulence (very high, high, medium, low and very low), which were not r
Sistemas adaptativos de inferencia neurodifusa con errores heterocedásticos para el modelado de series financieras Sistemas adaptativos de inferência em neuro difus o com erros heterecedásticos para o modelado de séries financeiras Adaptive neuro-fuzzy inference systems with heteroscedastic errors for financial series modeling
Elizabeth Catalina Zapata Gómez,Juan David Velásquez Henao,Ricardo Agustín Smith Quintero
Cuadernos de Administración , 2008,
Abstract: En este trabajo se propone una nueva clase de modelos híbridos no lineales. En el modelo propuesto, la no linealidad en la media se representa usando un sistema adaptativo neurodifuso de inferencia (ANFIS, por su sigla en inglés), mientras la varianza se representa usando una componente autorregresiva heterocedástica condicional. Se presenta la formulación matemática de este tipo de modelos y se propone un método para su estimación; adicionalmente, se desarrolla para el modelo propuesto una estrategia de especificación basada en una batería de pruebas estadísticas que incluyen pruebas para la especificación de los modelos de regresión con transición suave (STR, por su sigla en inglés) y la prueba del radio de verosimilitud. Como un caso de estudio, se modela la dinámica de la serie de los cambios en los precios de cierre de las acciones de IBM, la cual se usa comúnmente como referente en la literatura de series de tiempo. Los resultados indican que el modelo desarrollado representa mejor que otros modelos de características similares la dinámica de la serie estudiada. Neste trabalho prop em-se uma nova classe de modelos híbridos n o lineais. No modelo proposto, a n o linearidade em média representa-se utilizando um sistema adaptativo de neuro difus o de inferência (ANFIS, por sua sigla em inglês), enquanto a varia o se representa usando um componente auto-regressivo heterecedástico condicional. Apresenta-se a formula o matemática deste tipo de modelos e prop em-se um método para sua estima o; adicionalmente, desenvolve-se para o modelo proposto uma estratégia de especifi ca o baseada em uma bateria de provas estatísticas que incluem provas para a especifica o dos modelos de regress o com transi o suave (STR, por sua sigla em inglês), e a prova de rádio de verosimilitude. Como um caso de estudo, modela-se a dinamica da série dos cambios nos cambios nos pre os de feixe nas a es de IBM, a qual utiliza-se comummente como referente na literatura de séries de tempo. Os resultados indicam que o modelo desenvolvido representa melhor que outros modelos de características similares a dinamica da série estudada. This paper proposes a new kind of non-linear hybrid model. In the proposed model, mean non-linearity is represented by using an adaptive neuro-fuzzy inference system (ANFIS) whereas variance is represented using a conditional self-regressive heteroscedastic component. The mathematical formula for this type of model is shown and a method to estimate it is proposed. In addition, a specification strategy is developed for the proposed model, based on a
Morphometric, Physicochemical, Thermal, and Rheological Properties of Rice (Oryza sativa L.) Cultivars Indica × Japonica  [PDF]
Laura Elizabeth Morales-Martínez, Luis Arturo Bello-Pérez, Mirna María Sánchez-Rivera, Elsa Ventura-Zapata, Antonio Ruperto Jiménez-Aparicio
Food and Nutrition Sciences (FNS) , 2014, DOI: 10.4236/fns.2014.53034
Abstract:

The anther culture technical was applied to produce haploid lines of rice (Oryza sativa L.). The hybrids (K/ A92VM061, K/A92VM067, K/A92VM0611, K/A92VM719, K/A92VM720 and K/A92VM721) were obtained in order to generate new varieties from Indica and Japonica cultivars. Morphometric parameters of the grains were evaluated by image analysis. Flours were prepared from the whole rice grains and physicochemical, thermal and rheological properties, X-ray diffraction pattern and evaluation of color using the CIELAB system were assessed. The hybrids lines showed long (061, 611, 721), medium (719 and 720) and short (067) grains. The rice samples presented lipids (2.6% - 3.2%), protein (11% - 15%), total dietary fiber (8.4% - 10.2%), total starch (65% - 74%) and apparent amylose (5% - 32%) contents. Gelatinization temperature (Tp) was found in the range of 66.1℃ - 79.4℃ with enthalpy (ΔH) value between 3.4 - 8.1 J/g. The retrogradation parameters (temperature and ΔH) were lower than those for gelatinization in all samples. The rice samples presented A-type X-ray diffraction pattern. Rice pastes showed a non-Newtonian behavior and the brightness (L*) characterize the color of the samples. Hybrid rice grains presented morphometric properties more similar to Japonica than Indica variety. Rice hybrid had higher protein content than Indica variety. Apparent amylose, viscosity and gelatinization temperature varied significantly among hybrids and varieties.

LA INVERSIóN EXTRANJERA DIRECTA DE LA UNIóN EUROPEA HACIA AMéRICA LATINA: EL MéTODO DE ENTRADA DE LAS PRINCIPALES MULTINACIONALES ELéCTRICAS
ZAPATA,YUDIRA;
Estudios Gerenciales , 2007,
Abstract: in a scope so explored as the one of the foreing direct invesment, fdi, still exist aspects to approach. in spite of the importance of the services sector, the researchers are limited trying to explain the flows of fdi towards latin america . the diversity of subjects which they can influence in this explanation, turn it an extremely complex task, as much for the academic investigation as for the enterprise management. being conscious of this fact, this work represents an attempt to reduce this complexity, trying to define the relation between flows of fdi and entry methods. the entry methods fdi has played an important role in the internationalization of services companies, particularly in the case of the european electrical multinationals, which have been the responsible of the increase in the flows of investment towards the region.
Elementos para una paideia política en Hannah Arendt
Zapata,Guillermo;
Papel Politico , 2010,
Abstract: with this text we want to point out the contribution to modern western politics, or to the spirit of the polis, from hannah arendt, whose posture is a radical and participative democracy. arendt proposes that each citizen be formed in the spirit of citizenship, implementing a political action from the logic of freedom. to be formed in this dynamic of freedom is to be conscientious of the difference between logic of necessity of the homo faber responsible for the labor, work, and action, better understood as praxis, and the logic of free-dom, which is the foundation of politics. to enter into the spirit of polis presupposes being formed in the action within the framework of vita activa where the citizens, who are the creators of public space, emerge to the new beginning of a free, representative and democratic humanity in which people have a sense for forgiveness and promise. the homo faber transforms him or herself into homo civilis when he or she cultivates the spirit of plurality in citizenship, and decides to become an active and responsible subject; a subject who is responsible of his or her own birth for the polis; this is realized out of the grandness of his actions. this transformation happens in what arendt calls vita activa, and it makes sense in the realm of action. to be formed in this radical, democratic action is una paideia politica, which means, to qualify a political praxis marked by the greatness of a plural, democratic, and free spirit.
第1页/共10206条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.