oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 22 )

2019 ( 227 )

2018 ( 242 )

2017 ( 242 )

Custom range...

Search Results: 1 - 10 of 144893 matches for " Leiva B "
All listed articles are free for downloading (OA Articles)
Page 1 /144893
Display every page Item
Financial risks after the subprime crisis Riesgos financieros después de la crisis subprime
Rodrigo Leiva Büchi
Contabilidad y Negocios : Revista del Departamento Académico de Ciencias Administrativas , 2009,
Abstract: The subprime financial crisis revealed some of risks that were not considered as a priority. Among others, a liquidityrisk is now considered as one of the main risks to work with by all institutions. Apart from that, it became obviousthat traditional risk management focused only on what was known and expected, ignoring analysis and testing eventswith low probability but high impact. Lastly, the subprime crisis left a number of lessons in relation to the regulationfor financial markets that must be considered when creating a new regulatory system. La crisis subprime dejó al descubierto una serie de riesgos financieros que, hasta antes de la crisis, no eran consideradoscomo prioritarios. Entre otros, el riesgo de liquidez se ve ahora como uno de los principales temas a abordar por partede todas las instituciones. Adicionalmente, quedó en evidencia que la administración de riesgos se enfocaba solamenteen lo conocido y esperado, dejando de lado el análisis y evaluación de eventos de baja probabilidad de ocurrencia, peroalto impacto. Por último, la crisis subprime deja ciertas lecciones en torno a la regulación de los mercados financierosque se deben tener en cuenta al momento de redactar nuevos marcos regulatorios.
A Generalization of Cramer’s Rule  [PDF]
Hugo Leiva
Advances in Linear Algebra & Matrix Theory (ALAMT) , 2015, DOI: 10.4236/alamt.2015.54016
Abstract:

In this paper, we find two formulas for the solutions of the following linear equation \"\"\"\", where \"\" is a \"\" real matrix. This system has been well studied since the 1970s. It is known and simple proven that there is a solution for all \"\" if, and only if, the rows of A are linearly independent, and the minimum norm solution is given by the Moore-Penrose inverse formula, which is often denoted by \"\" ; in this case, this solution is given by \"\". Using this formula, Cramer’s Rule and Burgstahler’s Theorem (Theorem 2), we prove the following representation for this solution

\"\"

\"\", where \"\" are the row vectors of the matrix A. To the best of our knowledge and looking in to many Linear Algebra books, there is not formula for this solution depending on determinants. Of course, this formula coincides with the one given by Cramer’s Rule when \"\".

APORTE DEL PAN A LA NUTRICION DE YODO DEL ESCOLAR CHILENO
Leiva B,Laura; Braverman,Lewis; Muzzo B,Santiago;
Revista chilena de nutrición , 2002, DOI: 10.4067/S0717-75182002000100009
Abstract: the evolution of iodine nutrition in chilean school age children belonging to 4 censorial areas is described. the excesive urinary iodine excretion, in spite that food sanitary regulations decreased iodine concentration in salt from 100 to a range of 20 to 60 ppm, is noted. we were interested in studying why iodine in urine did not decreased. iodine content in bread was measured due to its high intake in chile (250 ug/day). iodine concentration in different types of breads was around 0.5 ug/g, a value 10 times the determinations done in england and spain. however it was estimated that bread consumption in chile contributed around 130 ug i/ day, which does not explain completely current high urinary iodine excretions. it is important continue searching the cause of this high intake to avoid posible complications.
MASA óSEA MáXIMA DE ADULTOS JOVENES CHILENOS COMPARADA CON LOS VALORES DE LA LUNAR
Muzzo B.,Santiago; Leiva B.,Laura; Ramirez M.,Ivan;
Revista chilena de nutrición , 2003, DOI: 10.4067/S0717-75182003000100007
Abstract: achievement of a high peak bone mass (pbm) in the young adult constitute the most important safeguard to prevent bone mineralization (bm) problems of the elderly. we were interested to know if young healthy chilean adults, with all the positive factors that favors a normal bm, had a pbm similar to the lunar's reference values, that are used to determine the adequation of bm in lunar's densitometers. twelve men and 11 women, 27 to 29 years of age were studied. bone mineral density (bmd) of whole body, spine and hips were determined with a lunar-dexa densitometer. no significant differences were found in bmd of whole body, spine and hips of this young chilean adults compared with lunar's reference values. these results point out that lunar's references values can be used as the gold standard to achieve early in the adult life in order to prevent osteoporosis
Peso, talla y perímetro craneano de escolares de la Región Metropolitana de Chile, de acuerdo al nivel socioeconómico Weight, height and skull circumference of school age children from the Metropolitan Region of Chile, according to socioeconomic level
Raquel Burrows A,Laura Leiva B,Santiago Muzzo B
Revista chilena de pediatría , 1992,
Abstract:
Perímetro, áreas magra y grasa braquiales, pliegue tricipital y nivel socioeconómico en escolares de la Región Metropolitana de Chile Brachial circumference, lean and fat area, triceps skin fold and socioeconomic condition in school children
Raquel Burrows A,Laura Leiva B,Santiago Muzzo B
Revista chilena de pediatría , 1993,
Abstract:
MASA óSEA MáXIMA DE ADULTOS JOVENES CHILENOS COMPARADA CON LOS VALORES DE LA LUNAR PEAK BONE MASS VALUES OF YOUNG CHILEAN ADULTS COMPARED WITH LUNAR′S VALUES
Santiago Muzzo B.,Laura Leiva B.,Ivan Ramirez M.
Revista Chilena de Nutricíon , 2003,
Abstract: La masa ósea máxima (MOM) del adulto joven constituye el capital de reserva para prevenir trastornos de la mineralización ósea (MO) en la vida de adulto mayor. Nos interesó conocer si adultos jóvenes chilenos, sanos y que reunieran todos los factores favorecedores de una adecuada MO, tenían una MOM similar a los valores de referencia de los densitómetros LUNAR, que se usan para determinar la adecuación de la MO. Se estudiaron 23 jóvenes cuyas edades fluctuaron entre 27 y 29 a os (12 varones y 11 mujeres), a los cuales se les determinó la densidad mineral ósea (DMO) en cuerpo entero, columna y caderas con un densitómetro LUNAR-DEXA. No se encontraron diferencias significativas entre los valores determinados en estos adultos jóvenes chilenos con los valores de referencia de la LUNAR. Estos resultados indicarían que los valores de MOM de la LUNAR pueden usarse como meta a obtener especialmente en programas de prevención de osteoporosis Achievement of a high peak bone mass (PBM) in the young adult constitute the most important safeguard to prevent bone mineralization (BM) problems of the elderly. We were interested to know if young healthy Chilean adults, with all the positive factors that favors a normal BM, had a PBM similar to the Lunar's reference values, that are used to determine the adequation of BM in Lunar's densitometers. Twelve men and 11 women, 27 to 29 years of age were studied. Bone mineral density (BMD) of whole body, spine and hips were determined with a LUNAR-DEXA densitometer. No significant differences were found in BMD of whole body, spine and hips of this young Chilean adults compared with Lunar's reference values. These results point out that Lunar's references values can be used as the gold standard to achieve early in the adult life in order to prevent osteoporosis
APORTE DEL PAN A LA NUTRICION DE YODO DEL ESCOLAR CHILENO CONTRIBUTION OF BREAD TO IODINE INTAKE IN CHILEAN SCHOOL CHILDREN
Laura Leiva B,Lewis Braverman,Santiago Muzzo B
Revista Chilena de Nutricíon , 2002,
Abstract: Se describe la evolución de la nutrición de yodo en el escolar chileno perteneciente a 4 zonas censorias del país, destacando la excesiva excreción urinaria de yodo a pesar que el Reglamento Sanitario de los Alimentos disminuyó el a o 2000 la concentración de yodo en la sal de 100 ppm a un rango de 20 a 60 ppm. Nos interesó estudiar porque no disminuyeron las yodurias en los escolares. Para ello se midió el contenido de yodo en el pan, por tener un alto consumo en Chile (en promedio 250 g por día). En diferentes tipos de pan se determinó la concentración de yodo que fue alrededor de 0.5 ug /g, valor 10 veces mas alta que en mediciones efectuadas en Inglaterra y Espa a. Sin embargo se estimó que el consumo de pan en Chile aportaría alrededor de 130 ug I/día, lo que no explicaría totalmente las altas cifras de excreción de yodo actuales. De importancia es continuar indagando las causas de este alto consumo para evitar sus posibles complicaciones The evolution of iodine nutrition in chilean school age children belonging to 4 censorial areas is described. The excesive urinary iodine excretion, in spite that Food Sanitary regulations decreased iodine concentration in salt from 100 to a range of 20 to 60 ppm, is noted. We were interested in studying why iodine in urine did not decreased. Iodine content in bread was measured due to its high intake in Chile (250 ug/day). Iodine concentration in different types of breads was around 0.5 ug/g, a value 10 times the determinations done in England and Spain. However it was estimated that bread consumption in Chile contributed around 130 ug I/ day, which does not explain completely current high urinary iodine excretions. It is important continue searching the cause of this high intake to avoid posible complications.
Assessing the Performance of Two Hydrologic Models for Forecasting Daily Streamflows in the Cazones River Basin (Mexico)  [PDF]
Fernando González-Leiva, Rodrigo Valdés-Pineda, Juan B. Valdés, Laura A. Ibá?ez-Castillo
Open Journal of Modern Hydrology (OJMH) , 2016, DOI: 10.4236/ojmh.2016.63014
Abstract: Floods have caused significant human and economic losses in the Cazones River Basin, located on the Gulf of Mexico. Despite this knowledge, steps towards the design and implementation of an early warning system for the Cazones are still a pending task. In this study we contributed by establishing a hydrological scheme for forecasting mean daily discharges in the Cazones Basin. For these purposes, we calibrated, validated and compared the HyMod model (HM) which is physics-based, and an autoregressive-based model coupled with the Discrete Kalman Filter (ARX-DKF). The ability of both models to accurately predict discharges proved satisfactory results during the validation period with RMSEHYMOD = 2.77 [mm/day]; and RMSEARX-DKF = [2.38 mm/day]. Further analysis based on a Streamflow Assimilation Ratio (SAR) revealed that both models underestimate the discharges in a similar proportion. This evaluation also showed that, under the most common conditions, the simpler stochastic model (ARX-DKF) performs better; however, under extreme hydrological conditions the deterministic HM model reveals a better performance. These results are discussed under the context of future applications and additional requirements needed to implement an early warning hydrologic system for the Cazones Basin.
A Characterization of Semilinear Surjective Operators and Applications to Control Problems  [PDF]
Edgar Iturriaga, Hugo Leiva
Applied Mathematics (AM) , 2010, DOI: 10.4236/am.2010.14033
Abstract: In this paper we characterize a broad class of semilinear surjective operators given by the following formula where Z are Hilbert spaces, and is a suitable nonlinear function. First, we give a necessary and sufficient condition for the linear operator to be surjective. Second, we prove the following statement: If and is a Lipschitz function with a Lipschitz constant small enough, then and for all the equation admits the following solution .We use these results to prove the exact controllability of the following semilinear evolution equation , , where , are Hilbert spaces, is the infinitesimal generator of strongly continuous semigroup in the control function belong to and is a suitable function. As a particular case we consider the semilinear damped wave equation, the model of vibrating plate equation, the integrodifferential wave equation with Delay, etc.
Page 1 /144893
Display every page Item


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