JOINT MODELING AND SIMULATION OF AUTOCORRELATED NON-NORMAL TIME SERIES: AN APPLICATION TO RISK AND RETURN ANALYSIS

This study presents a technique that can jointly model and simulate the expected values, variances, and covariances of sets of correlated time-series dependent variables that are autocorrelated and non-normal (right or left skewed and/or kurtotic). It illustrates the method by applying it to risk analysis of diversified tropical agroforestry systems.Resource /Energy Economics and Policy, Risk and Uncertainty,

RISK AND RETURNS OF DIVERSIFIED CROPPING SYSTEMS UNDER NONNORMAL, CROSS-, AND AUTOCORRELATED COMMODITY PRICE STRUCTURES

This study analyzes the risks of diversified tropical cropping systems that combine cocoa, plantain, and tree-crop components in different proportions versus traditional monocultures. A technique for modeling the expected values, variances, and covariances of correlated time-series variables that are autocorrelated and nonnormal (right or left skewed and kurtotic) is applied to simulate commodity prices. The importance of using simulated cumulative density functions (cdf's) which reflect the most important characteristics of the stochastic behavior of prices for analyzing risk and returns of diversified agricultural systems is demonstrated. The analysis priovides evidence in favor of diversified cocoa-plantain-Cordia agroforestry system technologies versus the traditional monocultures.Demand and Price Analysis,

Off The Farm: An Evaluation Of Non-Farm Earnings And Employment On Poverty Alleviation In Rural Nicaragua

In Nicaragua, poverty disproportionately affects the rural population. Over the last two decades, rural inhabitants have increased their participation in the Rural Non-Farm (RNF) sector. This study uses four waves of data from the Living Standard Measurement Survey (LSMS) between 2001 and 2014 to test whether the transition to the RNF sector decreases poverty rates and increases consumption. To account for the endogeneity of RNF participation and measures of well-being like consumption, I use an instrumental variables approach. I use a policy enacted in 2006 that induced plausibly exogenous variation in electrification rates over the same period to instrument for the RNF decision. Results suggest that an additional member of the household employed in the RNF sector increase household consumption by 17-25 percent and reduces the household’s likelihood to be in a poverty status by 15-21 percentage points. These effects are greater among municipalities with higher levels of consumption prior to the electrification expansion, which implies that households engage in RNF taking advantage of the surrounding opportunities

On the Analysis of the Contact Conditions in Temporomandibular Joint Prostheses

Temporomandibular joint replacement (TMJR) is a complex surgical procedure in which the artificial joints available must assure the anatomical reconstruction and guarantee a good range of the natural temporomandibular joint (TMJ) movements. With this aim, different types of TMJ prostheses, including the stock prosthetic system and custom-made prostheses, are being currently implanted. Although temporomandibular joint replacements (TMJRs) are expected to accomplish their function during a number of years, they might actually fail and need to be replaced. This paper analyzes different design factors affecting the contact stress distributions within the TMJ prosthesis interface, which are consequently involved in their deterioration and final failure of the prosthetic device. With this purpose, a numerical model based on finite elements has been carried out in order to evaluate the stress states attained in different prosthesis configurations corresponding to general types of TMJ prostheses. On the other hand, the actual degradation of resected implants has been evaluated via optical microscopy. The linkage between the numerical simulations performed and experimental evidence allowed the authors to establish the different wear and damage mechanisms involved in the failure of stock TMJ prostheses. Indeed, the results obtained show that the contact stresses at the interface between the mandible and the glenoid fossa components play a key role in the failure process of the TMJR devices

Pack Rust: Mitigation Strategy Effectiveness

As of 2013, the damage caused by corrosion on highway bridges has been estimated to cost approximately 14 billion dollars annually, and this cost has been increasing over the years. Corrosion is one of the natural phenomena that has been slowly deteriorating infrastructure systems across the United States. One of the most problematic types of corrosion is crevice corrosion, which is defined as the formation of rust between overlapping surfaces, such as the case of a splice connection where flanges are attached by splice plates. A significant number of steel bridges in Indiana have developed crevice corrosion in splice connections. Therefore, this research focuses on the crevice corrosion, or “pack rust,” occurring in these structural elements. The application of coatings alone has not been enough to stop pack rust at these connections. In an attempt to look for approaches that can effectively mitigate this problem and maintain the designed service life of bridges, different strategies have been studied and tested. It was found that the proper use of penetrating sealers can be effective in delaying the development of further corrosion, while the use of caulk alone may be problematic as a repair method

Evaluación de riesgos laborales empresariales en el beneficio de café seco La Providencia S, A, Municipio de Matagalpa, Departamento de Matagalpa, segundo semestre del año 2016

La evaluación de riesgos busca identificar y eliminar riesgos presentes en el entorno de trabajo, así como la valoración de la urgencia de actuar. La evaluación de riesgos laborales es una obligación empresarial y una herramienta fundamental para la prevención de daños a la salud y la seguridad de los trabajadores. Su objetivo es identificar los peligros derivados de las condiciones de trabajo para: 1. Eliminar de inmediato los factores de riesgo que puedan suprimirse fácilmente, 2. Evaluar los riesgos que no van a eliminarse inmediatamente, y 3. Planificar la adopción de medidas correctoras. Su núcleo central consiste en examinar detalladamente todos los aspectos del trabajo que puedan causar daños a los trabajadores. Este examen no estará completo si no recoge la opinión de los trabajadores, porque son los y las que mejor conocen su puesto de trabajo. Para poder evaluar, hay que estar capacitado para reconocer las condiciones de trabajo que generan riesgos. También a veces es necesario realizar mediciones (y algunas de estas sólo pueden ser realizadas por personal con titulación específica). Muchos criterios de riesgo están recogidos en normativa, pero también se pueden mejorar mediante negociación colectiva, e incluso pueden ser acordados en el comité de seguridad y salud de una empresa. La evaluación de riesgos laborales engloba los siguientes pasos: 1. Identificar los peligros presentes, por áreas y/o por puestos de trabajo. 2. Identificar quién puede sufrir daños, contemplando la posibilidad de que haya colectivos especialmente sensibles a determinados riesgos. 3. Evaluar los riesgos e identificar medidas que se deben adoptar. 4. Documentar los hallazgos, detallando las medidas ya adoptadas y las pendientes. 5. Planificar las medidas pendientes e implementarlas. 6. Revisar la evaluación y actualizarla cuando sea necesari