2,491 research outputs found
Tough Policies, Incredible Policies?
We revisit the question of what determines the credibility of macroeconomic policies here, of promises to repay public debt. Almost all thinking on the issue has focused on governments' strategic decision to default (or erode the value of outstanding debt via inflation/devaluation). But sometimes governments default not because they want to, but because they cannot avoid it: adverse shocks leave them no option. We build a model in which default/devaluation can occur deliberately (for strategic reasons) or unavoidably. If such unavoidable fiscal crises a) have pecuniary costs and b) occur with possible probability, much conventional wisdom on the determinantes of credibility need no longer hold. For instance, appointing a conservative policymaker or denominating public debt in foreign currency may reduce, not increase, credibility.
Environmental Information for Aviation Passengers
Purpose - Review of tools that inform passengers about the environmental impact of their flight. Review of tools that allow passengers to compare flying with other means of transportation. Improve already existing tools and develop new ways to determine the environmental impact of passenger transport. --- Methodology - Continue work previously done on the ecolabel for aircraft. Study how the scientific community, governmental institutions, passengers, and the general public think about the environmental impact of aviation. Perform a survey that shows how airlines are perceived with respect to their environmental action and how environmental information should be presented to passengers. --- Findings - The majority of people are willing to make changes in their travelling behavior in order to make it more environmentally friendly. Taxes or even restrictions would be accepted if fairness and transparency were felt. Passengers would like to be informed with an ecolabel for aircraft. Offsetting carbon emissions would be accepted, if the scheme is explained in detail. The bad reputation of airlines after years of not taking any measures for reducing their absolute environmental impact has made people skeptical about any airline initiative. In the corona pandemic it became apparent that airline associations were never in favor of reducing the number of flights. --- Practical Implications - Methods for airline passenger to compare their travel emissions are proposed. --- Social Implications - If passengers are able to compare travel options in terms of environmental impact, it will open up a new type of competition among airlines. --- Originality - It is the first time that tools are collected and compared to allow airline passengers making an educated choice about their way of travelling regarding its environmental impact
Software-based methods for Operating system dependability
Guaranteeing correct system behaviour in modern computer systems has become essential, in particular for safety-critical computer-based systems. However all modern systems are susceptible to transient faults that can disrupt the intended operation and function of such systems. In order to evaluate the sensitivity of such systems, different methods have been developed, and among them Fault Injection is considered a valid approach widely adopted.
This document presents a fault injection tool, called Kernel-based Fault-Injection Tool Open-source (KITO), to analyze the effects of faults in memory elements containing kernel data structures belonging to a Unix-based Operating System and, in particular, elements involved in resources synchronization. This tool was evaluated in different stages of its development with different experimental analyses by performing Faults Injections in the Operating System, while the system was subject to stress from benchmark programs that use different elements of the Linux kernel. The results showed that KITO was capable of generating faults in different
elements of the operating systems with limited intrusiveness, and that the data structures belonging to synchronization aspects of the kernel are susceptible to an appreciable set of possible errors ranging from performance degradation to complete system failure, thus preventing benchmark applications to perform their task.
Finally, aiming at overcoming the vulnerabilities discovered with KITO, a couple of solutions have been proposed consisting in the implementation of hardening techniques in the source code of the Linux kernel, such as Triple Modular Redundancy and Error Detection And Correction codes. An experimental fault injection analysis has been conducted to evaluate the effectiveness of the proposed solutions. Results have shown that it is possible to successfully detect and correct the noxious effects generated by single faults in the system with a limited performance overhead in kernel data structures of the Linux kernel
Labour flexibility and productivity in the hotel sector
In this paper, we analyze the effect of labour flexibility on productivity in the Andalusian hotel industry using raw data of our own database and applying an expanded version of the standard production function by distinguishing between part-time, temporary, and full-time labour inputs. Our results show that productivity is lower the higher the percentage of temporary and part-time workers and there are no differences between the impacts on productivity of both types of labour contract. Future studies should analyze the differential impact of all the types of contracts discussed on the mean cost per employee in this sector.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Dynamically programmable virtual profiles as a service
Many devices in our daily environments are being connected to the network, building what has been called the Web of Things. Although these things offer a web interface to interact with, this interaction must be performed manually and for each one of them. In a near future in which we will be surrounded by dozens of connected devices, technology must evolve to make the interactions automatically and adapt the behavior of these devices considering the needs and context of their users. To this extent, in previous work we proposed the Internet of People model to empower the smartphones with the capability of automatically inferring virtual profiles of their owners. However, in order to build complete virtual profiles with information about the user’s environment and context, we also need the contribution of these surrounding devices. In this paper, we propose a framework in which users and smart devices are integrated seamlessly and in real time, allowing programmatic adaptation and update of both virtual user profiles and connected devices. We present the architecture of this framework and define how the virtual profiles should be, coming from our experience in the field. Virtual profiles are the key element in the way to an effective Programmable World, in which everyday things connected to the network can be programmatically adapted to their users.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Diseño de las líneas de vapor para el calentamiento de los tanques de almacenamiento de combustible de la central térmica Miraflores
La presente tesis describe el diseño de un sistema para vapor, que deberá suplir el
calentamiento del sistema de almacenaje y distribución de combustible, en el área de
tanques de la central termoeléctrica.
El primer capítulo presenta la teoría de generación de vapor para sistemas de
calentamiento industrial con vapor de agua, comprende la normativa internacional de
sistema vapor ASME B31.1 POWER PIPING, normativa de tubería para sistemas de
vapor ASTM A53., y recomendaciones de los fabricantes de los equipos a utilizarse.
En el segundo capítulo se analiza los recursos disponibles en la central térmica,
específicamente en el área de tanques de almacenamiento, y del área en referencia.
En el tercer capítulo se diseña el sistema para vapor, los diámetros requeridos para
transportar el vapor atreves del sistema, dimensionar los distribuidores de vapor
necesarios, selección de las líneas tracer y diseño del sistema de retorno de
condensado, con sus respectivos accesorios.
En el cuarto capítulo se realiza el análisis de costos requeridos, para la construcción
del diseño propuesto
Efeitos do solo e clima numa vinha de uva de mesa com cultura de cobertura. Gestão da rega utilizando redes de sensores
[ENG] TThe use of mulches in vineyards and orchards is a traditional agricultural practice used with the aim of saving moisture, reducing weed growth and improving organic matter content in the soil. In table grape vineyards trained to overhead system in Puglia region (Southeastern Italy), plastic sheets covering the canopy are often used to either advance ripening or delay harvest. In this environment, the living mulches could contribute to the modification of the microclimate around the canopy below the plastic sheets. This condition has an influence on the climatic demand and on both the vegetative and productive activities, mainly in stages with a high evapotranspiration. However, the presence of living mulches could increase the demand of available water and nutrient resources and this could cause a lower yield. The aim of this study was to acquire a suitable knowledge to manage irrigation and verify the influences of living mulches on the vine by using wireless sensor networks to measure the vapor pressure deficit, soil water potential and content.[POR] A utilização de coberturas do solo em vinhas e pomares é uma prática agrícola tradicional, utilizada com o objetivo de preservar a humidade do solo, reduzir o crescimento de infestantes e melhorar o teor de matéria orgânica no solo. Em vinhas de uva de mesa, conduzidas em sistema de pérgula na região de Puglia (sudeste da Itália), são frequentemente usadas coberturas de plástico para promover o avanço da maturação ou o atraso da colheita. Neste ambiente a utilização de enrelvamentos pode contribuir para a modificação do microclima do copado. Esta condição pode influenciar a demanda atmosférica, bem como a atividade vegetativa e reprodutiva da videira, principalmente em períodos de elevada evapotranspiração. No entanto, a presença do enrelvamento pode originar um aumento da demanda dos recursos disponíveis, nomeadamente água e nutrientes, o que poderá provocar uma quebra de produção. O objetivo deste estudo foi adquirir conhecimento para a gestão da rega e, simultaneamente, verificar a influência dos enrelvamentos na atividade da videira, usando para o efeito redes de sensores “sem fio” para medir o déficit de pressão de vapor, o potencial e o conteúdo de água no solo.The development of this work was supported by: The Spanish Ministry of Science and Innovation through the project RIDEFRUT (ref. AGL2013-49047-C2-1-R), the “Fundacion Seneca, Agencia de Ciencia y Tecnologia” of the Region of Murcia under the “Excelence Group Program”, and the Technical University of Cartagena under the PMPDI Program
Estudio de factibilidad para la construcción de un proyecto inmobiliario "dorms" para estudiantes universitarios de provincia y extranjeros que deseen estudiar en la Universidad San Francisco da Quito.
Now a day, thousands of people from other provinces and other countries come
to Quito to complete their third level studies or for an Exchange program. It’s
very complicated for them to find a place where they can live or stay during this
period of time because apartments or suites that can be rented are relatively
according to the students’ budget, and they usually lack of facilities that the
students need.
Mountain View Guest House is a Real State project with a unique concept in the
city of Quito; it’s a building that has dorms for exchange students or for students
that come from other provinces to study at Universidad San Francisco de
Quito.The reason why we have decided to make this feasibility research and
study is because we have detected a need in our target market. We would like
our project to become true in order to fulfill this need offering at the same time a
service that will be different, fun, comfortable and efficient for all the students
that choose to live in Mountain View Guest House
Política descentralizadora del agua potable
Hablar de política descentralizadora en relación con la gestión del agua potable implica aclarar el significado de descentralización y su aplicación en México. En este trabajo se ofrecen algunas aportaciones al concepto y se describe el proceso que, de hecho, ha ocurrido en la política de descentralización del agua en el país.Hablar de política descentralizadora en relación con la gestión del agua potable implica aclarar el significado de descentralización y su aplicación en México. En este trabajo se ofrecen algunas aportaciones al concepto y se describe el proceso que, de hecho, ha ocurrido en la política de descentralización del agua en el país
Equivariant Versions of Higher Order Orbifold Euler Characteristics
There are (at least) two different approaches to define an equivariant analogue of the Euler characteristic for a space with a finite group action. The first one defines it as an element of the Burnside ring of the group. The second approach emerged from physics and includes the orbifold Euler characteristic and its higher order versions. Here we give a way to merge the two approaches together defining (in a certain setting) higher order Euler characteristics with values in the Burnside ring of a group. We give Macdonald type equations for these invariants. We also offer generalized (“motivic”) versions of these invariants and formulate Macdonald type equations for them as well
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