30,158 research outputs found
Introduction to measures of inequality and concentration in tourism
There are many statistical measures available in the literature for the analysis of inequality and
concentration. The most common measure in this field is the Gini index (Roselló Nadal et al.,2004), which is associated to the Lorenz curve. Both were developed at the beginning of the 20th century: the Lorenz curve in 1905 and the Gini index in 1914 (Giorgi,!1993).
A revision of recent applications of these measures in the field of tourism can be found in Cisneros Martín and Fernández Morales (2015)and Duro (2016)
Good practices, innovation or scientific research in education? A conceptual reflection
In this work a conceptual delimitation of "good teaching practices", "educational innovation" and "educational research" is proposed, based on both the experimental design and the quality of the evidence provided by these studies. This terminological clarification should help teachers to recognize the scientific research specific to pedagogy, in order to distinguish them from studies that do not have enough elements to be considered fully scientific although, occasionally, they may work for some teachers. Thus, in a near future, an educational science should be established in which teachers can trust.Peer ReviewedPostprint (published version
Complete minimal surfaces in R3 with a prescribed coordinate function
In this paper we construct complete simply connected minimal surfaces with a
prescribed coordinate function. Moreover, we prove that these surfaces are dense
in the space of all minimal surfaces with this coordinate function (with the topol-
ogy of the smooth convergence on compact sets).Ministerio de Educación y Ciencia MTM2007-61775Ministerio de Educación y Ciencia MTM2007-6450
Automating SLA-Driven API Development with SLA4OAI
The OpenAPI Specification (OAS) is the de facto standard
to describe RESTful APIs from a functional perspective. OAS has been
a success due to its simple model and the wide ecosystem of tools supporting the SLA-Driven API development lifecycle. Unfortunately, the
current OAS scope ignores crucial information for an API such as its
Service Level Agreement (SLA). Therefore, in terms of description and
management of non-functional information, the disadvantages of not having a standard include the vendor lock-in and prevent the ecosystem to
grow and handle extra functional aspects.
In this paper, we present SLA4OAI, pioneering in extending OAS not
only allowing the specification of SLAs, but also supporting some stages
of the SLA-Driven API lifecycle with an open-source ecosystem. Finally,
we validate our proposal having modeled 5488 limitations in 148 plans
of 35 real-world APIs and show an initial interest from the industry with
600 and 1900 downloads and installs of the SLA Instrumentation Library
and the SLA Engine.Ministerio de Economía y Competitividad TIN2015-70560-RMinisterio de Ciencia, Innovación y Universidades RTI2018-101204-B-C21Ministerio de Educación, Cultura y Deporte FPU15/0298
Quid Pro Quo: A Mechanism for Fair Collaboration in Networked Systems
Collaboration may be understood as the execution of coordinated tasks (in the
most general sense) by groups of users, who cooperate for achieving a common
goal. Collaboration is a fundamental assumption and requirement for the correct
operation of many communication systems. The main challenge when creating
collaborative systems in a decentralized manner is dealing with the fact that
users may behave in selfish ways, trying to obtain the benefits of the tasks
but without participating in their execution. In this context, Game Theory has
been instrumental to model collaborative systems and the task allocation
problem, and to design mechanisms for optimal allocation of tasks. In this
paper, we revise the classical assumptions and propose a new approach to this
problem. First, we establish a system model based on heterogenous nodes (users,
players), and propose a basic distributed mechanism so that, when a new task
appears, it is assigned to the most suitable node. The classical technique for
compensating a node that executes a task is the use of payments (which in most
networks are hard or impossible to implement). Instead, we propose a
distributed mechanism for the optimal allocation of tasks without payments. We
prove this mechanism to be robust event in the presence of independent selfish
or rationally limited players. Additionally, our model is based on very weak
assumptions, which makes the proposed mechanisms susceptible to be implemented
in networked systems (e.g., the Internet).Comment: 23 pages, 5 figures, 3 algorithm
Fostering SLA-Driven API Specifications
Software architecture tendencies are shifting to a microservice paradigm. In this context, RESTful APIs are being established the standard of integration. API designer often identifies two key issues to be competitive in such growing market. On the one hand, the generation of accurate documentation of the behavior and capabilities of the API to promote its usage; on the other hand, the design of a pricing plan that fits into the potential API user’s needs. Besides the increasing number of API modeling alternatives is emerging, there is a lack of proposals on the definition of flexible pricing plans usually contained in the Service Level Agreements (SLAs). In this paper we propose two different modeling techniques for the description of SLA in a RESTful API context: iAgree and SLA4OAI.Ministerio de Economía y Competitividad TIN2015-70560-RJunta de Andalucía P12-TIC-1867Ministerio de Economía y Competitividad TIN2014-53986-RED
Evaluation of the mechanical properties of self compacting concrete using current estimating models. Estimating the modulus of elasticity, tensile strength, and modulus of rupture of self compacting concrete
This study includes an analysis of the applicability of current models used for estimating the mechanical properties of conventional concrete to self-compacting concrete. The mechanical properties evaluated are: modulus of elasticity, tensile strength, and modulus of rupture. An extensive database which included the dosifications and the mechanical properties of 627 mixtures from 138 different references, was used. The models considered are: ACI, EC-2, NZS 3101:2006 (New Zealand code) and the CSA A23.3-04 (Canadian code). The precision in estimating the modulus of elasticity and tensile strength is acceptable for all models; however, all models are less precise in estimating the modulus of rupture
Resistance to SDHI fungicides in Botrytis cinerea from strawberry fields in Spain
Gray mold, caused by Botrytis cinerea Pers., is one of the most economically important
diseases of strawberries and its control involves the application of fungicides throughout the
strawberry growing season. Succinate dehydrogenase inhibitors (SDHIs) constitute a novel class of
fungicides representing new alternatives for strawberry growers. In the present study, B.
cinerea isolates were used to determine the effective concentration that reduces mycelial
growth by 50% (EC50) and to obtain discriminatory doses to monitor SDHI fungicides over the
course of three-year monitoring period. The overall frequencies of resistance to the SDHI
fungicides boscalid, fluopyram, fluxapyroxad and penthiopyrad were 56.9, 6.9, 12.9, and
24.6%, respectively. Four SDHI resistance patterns were observed in our population.
Patterns I (resistance to boscalid) and II (resistance to boscalid and penthiopyrad) were
associated with the amino acid substitutions H272R/Y; pattern III (resistance to boscalid,
fluxapyroxad, and penthiopyrad) was associated only with the H272Y mutation; and finally,
pattern IV (resistance to boscalid, fluopyram, fluxapyroxad and penthiopyrad) was associated with
the N230I allele in the SdhB subunit. For gray mold management, it is suggested that the
simultaneous use of boscalid and penthiopyrad should be limited to one application per season.
The use of fluxapyroxad and fluopyram could be used as valid SDHI alternatives for our strawberry
growers, but they should be applied with caution.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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