Yield Management under the Real Options Scheme for Optimal Decision Making in Hotels

Yield management is the process of actively managing inventory to maximize revenues. In this paper we present a model demised to apply yield management techniques using real options to the problem of optimal decision making when assigning rooms to hotel customers. Two different methods are proposed to carry out the evaluation: numerical resolution with the PDEs and Monte Carlo simulation. The achieved results using both methods are similar demonstrating the robustness of the simulation in this field and the model lends itself to be a tool for helping the hotel manager in his operational decision of whether or not giving a room to a potential client

Valuation of patents and R&D projects using real options: a practical implementation

The correct valuation of an R&D project is a rather complex process. Aside from the fact that it can take several years to launch a new product after extensive investment, there happens to be a significant abandonment probability at each of the development and exploitation stages. Significant uncertainty is also inherently attached to both development costs and subsequent operational cash flows (be it the case of receiving final approval for commercial purposes).These cash flows need to be estimated with anticipation in order to give a reasonable value for the patent or R&D project. The approach undertaken herein is to consider the patent or R&D project as a complex option on relevant underlying stochastic variables: investment costs and operational cash flows. A model is proposed, programmed and applied to a real case

DINÂMICA DA AGRICULTURA NO ESTADO DE SÃO PAULO ENTRE 1990-2005: Uma análise através do modelo “shift share”

Este trabalho tem o objetivo de determinar quais foram as fontes de crescimento da produção agrícola no Estado de São Paulo entre 1990 e 2005. Para essa análise utilizou-se o modelo econométrico denominado “shift-share”, também conhecido como estrutural-diferencial. A análise foi dividida em subperíodos, tendo como objetivo abordar o comportamento da produção agrícola em diversos momentos da economia brasileira. Os fatores que explicam a evolução da produção nos subperíodos determinados foram os efeitos área, rendimento e localização geográfica. As alterações na área cultivada por sua vez foram subdivididas em efeito escala e substituição. A mandioca foi a cultura que apresentou maior crescimento da produção agrícola entre 1990 e 1995, o que se deu em razão do acréscimo na área cultivada. No segundo sub-período analisado (1995 a 2000), os ganhos de produção ocorreram com maior intensidade na cultura da banana (27,20% a.a) também em decorrência de acréscimos na área cultivada. E no último subperíodo (2001 a 2005), a maior crescimento da produção ocorreu no trigo (61,31% a.a). --------------------------------------------This study aims to determine what were the sources of growth of agricultural production in the state of Sao Paulo between 1990 and 2005. For this analysis used is the econometric model called "shift-share", also known as structural-differential. The analysis was divided into sub periods, with the aim address the behavior of agricultural production in various stages of the Brazilian economy. The factors that explain the evolution of production in certain sub periods were the effects area, income and geographic location. Changes in the area cultivated in turn were subdivided into effect and scale replacement. The cassava was the culture that had higher growth in agricultural production between 1990 and 1995, which occurred because of the increase in the area cultivated. In the second sub-analysis period (1995 to 2000), the gains in production occurred with greater intensity in the culture of banana (27.20% pa) also due to increases in the area cultivated. And in the last sub period (2001 to 2005), the largest growth in production occurred in the wheat (61.31% pa).São Paulo, shift-share, produção, crescimento, efeitos, shift share, production, growth, effects, Productivity Analysis,

Can we have it all? The role of grassland conservation in supporting forage production and plant diversity

Context A key global challenge is to meet both the growing demand for food and feed while maintaining biodiversity’s supporting functions. Protected grasslands, such as Natura 2000 sites in Europe, may play an important role in harmonising productivity and biodiversity goals. This work contributes to an understanding of the relationship between forage production and plant diversity in protected and non-protected grasslands. Objectives We aimed to identify differences in plant diversity and forage production between protected and non-protected grasslands by assessing the effects of land-use intensity (i.e. mowing, grazing, fertilising) on these variables. Methods Data were available for 95 managed grassland plots (50 × 50 m) in real-managed landscapes. After controlling for site conditions in the analysis, we tested for significant differences between protected and non-protected grasslands and used a multi-group structural equation modelling (SEM) framework to investigate the linkages between land-use intensity, biomass and plant diversity. Results In protected grasslands, plant diversity was significantly higher while forage production was significantly lower. In non-protected grasslands we found significantly higher land-use intensity, particularly in relation to mowing and fertilisation. Grazing intensity did not significantly differ between protected and non-protected grasslands. In non-protected grasslands we found a significant negative association between forage production and plant diversity. However, this effect was not significant in protected grasslands. We also found a negative association between land-use and plant diversity in both grassland types that was related to mowing and fertilising intensity. These two management aspects also influenced the positive association between land-use intensity and forage production. Furthermore, environmental conditions had a positive effect on forage production and a negative effect on plant diversity in protected grasslands. Conclusions Our results confirm that the protection of grassland sites is successful in achieving higher plant diversity compared to non-protected grasslands and that protected grasslands do not necessarily trade-off with forage production. This is possible under moderate grazing intensities as higher land-use intensity has a negative effect on plant diversity, particularly on rare species. However, forage production is lower in protected sites as it is driven by mowing and fertilisation intensity. Future research needs to further investigate if the nature of these relationships depends on the livestock type or other management practices

Una evaluación ambiental previa de la Universidad de León. Ecoauditoría ULE

El proyecto de Ecoauditoría ULE ha sido realizado en el Campus de Vegazana de la Universidad de León durante el período 2003-2007 por alumnos de 5º de Ciencias Ambientales. Gracias a él se han puesto de manifiesto aspectos muy relevantes en cuanto a la sostenibilidad general del campus. Concretamente, la baja conciencia de ahorro energético en sus instalaciones, la gran variabilidad de consumo eléctrico y agua en los diferentes centros, la preferencia de caminar como medio de transporte para los miembros universitarios, seguida de un uso masivo del turismo con un solo ocupante, y finalmente, la percepción global positiva del aspecto ambiental del campus, exceptuando ciertas necesidades, como mejorar la iluminación nocturna y las plazas de aparcamiento para bicicleta

A corpus-based analysis of referentiality in Mapudungun: Preliminary Report

Este artículo expone los lineamientos metodológicos y algunos resultados parciales del estudio de la referencialidad en mapudungun, una lengua aislada hablada en Chile y Argentina con distintos grados de vitalidad. La referencia en el discurso abarca dos operaciones básicas: la individuación de los referentes y su anclaje en el discurso. La presente investigación es parte de un proyecto más amplio que busca identificar los recursos estructurales utilizados por las lenguas en estas operaciones referenciales. Investigamos un conjunto de parámetros estructurales y semánticos de expresiones referenciales tal como ocurren en un corpus de textos en mapudungun pertenecientes a diferentes géneros. Algunos de los hallazgos pueden representar patrones generales de la referencia en textos naturales, otros pueden ser representativos de géneros mapuches específicos. A nivel metodológico, nuestra investigación muestra que es posible fundamentar hipótesis sobre la referencia y la estructura del discurso relacionada con la referencia cuantitativamente, caracterizar los géneros textuales mediante propiedades semánticas y estructurales medibles y descubrir nuevos fenómenos que requieren una explicación.This report presents the methodological guidelines as well as some partial results of the study of referentiality in Mapudungun, a language isolate spoken in Chile and Argentina with different degrees of vitality. Reference in discourse encompasses two basic operations: the individuation of the referents and their anchorage in the discourse. Our research is part of a wider project which seeks to identify the structural resources used by the languages in referential operations. We investigate a set of structural and semantic parameters of referential expressions as they occur in a corpus of Mapudungun texts belonging to different genres. Some of the findings may represent general patterns of reference in natural texts, while others may be representative of specific Mapudungun genres. At a methodological level, our research shows that it is possible to substantiate hypotheses on reference and on discourse structure related to reference by hard figures, to characterize text genres by measurable semantic and structural properties, and to discover new phenomena which demand an explanation.Fil: Golluscio, Lucia Angela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro Argentino de Información Científica y Tecnológica; ArgentinaFil: Lehmann, Christian. Universität Erfurt; AlemaniaFil: Hasler, Felipe. Universidad de Chile; ChileFil: Pamies, Anna. Universitat Regensburg; Alemani

Modelling landscape management scenarios for equitable and sustainable futures in rural areas based on ecosystem services

Scenario analysis is a useful technique to inform landscape planning of social-ecological systems by modelling future trends in ecosystem service supply and distribution. This is especially critical in floodplain agroecosystems of rural areas, which are at risk of losing riparian forest corridors due to increasing land use conversion for agricultural production and other ecosystem services due to rural abandonment. However, few studies investigating the effects of land management combine social and ecological modelling in scenario analyses. We estimated the supply of 16 ecosystem services under five alternative scenarios along two gradients: agricultural intensification of the floodplain and active ecological restoration of the riparian forest. We used redundancy analyses to detect ecosystem service bundles and interviews to identify societal gains and losses associated with each management scenario. Our results show how land management influences both the supply and distribution of ecosystem services. Scenarios promoting active ecological restoration supplied more services and benefited a larger range of societal sectors than scenarios focused on provisioning services. We also found two consistent bundles across scenarios, one related to less intensive food supply and another one related to outdoor activities. Interestingly, additional services were included in these bundles in the different scenarios, reflecting land management effects. Landscape scale management promoting both the conservation of ecosystem functioning and the sustainable use of provisioning services could supply a more balanced set of ecosystem services and benefit a larger number of societal sectors, contributing to more equitable and sustainable futures in rural areas

Locating modifications in signed data for partial data integrity

We consider the problem of detecting and locating modifications in signed data to ensure partial data integrity. We assume that the data is divided into $n$ blocks (not necessarily of the same size) and that a threshold $d$ is given for the maximum amount of modified blocks that the scheme can support. We propose efficient algorithms for signature and verification steps which provide a reasonably compact signature size, for controlled sizes of $d$ with respect to $n$. For instance, for fixed $d$ the standard signature size gets multiplied by a factor of $O(\log n)$, while allowing the identification of up to $d$ modified blocks. Our scheme is based on nonadaptive combinatorial group testing and cover-free families.Comment: 14 page