4,317 research outputs found
Models of public-private partnerships in megaprojects: the Spanish case
This article provides a
literature review of PPP Models, where the clarification of this current
confusion and ambiguity constitute the fundamental issue addressed
by our research. The systematization of the PPP models is performed by
applying six classification criteria based on organizational and financial
aspects and focused on the Spanish experience. Additionally, a comparative
study of the various schemes applied in European countries is
carried out, whereby the concession model implemented successfully
in Spain is studied in greater detail. To this end, a megaproject, the first
metro line of Seville (Spain) forms the basis of a case-study. When the
megaproject is viable through user fees, the public sector can use PPPs
to defer payments and as a way to control their deficits and debt without
cutting investments in infrastructures and public services. Nevertheless,
certain drawbacks should be borne in mind, such as the expenditure
commitments of future budgets, the higher cost of private funding, and
the necessity for transparency and accountability of PPP contractual
arrangements to be improved. Therefore, the aim of this article is to
analyze the various forms of PPPs in megaprojects in order to determine
the potential efficiency gains that can be achieved in the implementation
of these models
Kernel alternatives to aproximate operational severity distribution: an empirical application
The estimation of severity loss distribution is one the main topic in operational
risk estimation. Numerous parametric estimations have been suggested
although very few work for both high frequency small losses and low frequency
big losses. In this paper several estimation are explored. The good performance
of the double transformation kernel estimation in the context of operational risk
severity is worthy of a special mention. This method is based on the work of
Bolancé and Guillén (2009), it was initially proposed in the context of the cost of
claims insurance, and it means an advance in operational risk research
Porous Soil Structure as Heterogeneous Complex Networks
In this paper we present a complex network model based on a heterogeneous preferential attachment scheme as a new way to quantify the porous structure of soils and to relate them with soil texture. We consider the pores as nodes, the properties of which, such as position and size, are described by fixed states in a metric space. An affinity function is introduced to bias the attachment probabilities of links according to these properties. We perform an analytical study of the degree distributions in the model and develop a numerical analysis of the degree distributions in the model for a combination of parameters corresponding to eleven empirical soil samples with different physical properties and five different textures
The financial performance of an innovative megaproject
The financial structure of megaprojects, known in the literature as project finance, is characterized by the creation of a legally
independent project company financed with a concentrated equity ownership and a high level of non-recourse debt. Research in
this field may yield new ideas and theories about the existing theoretical framework on capital structure, stakeholder
management and risk management. A case-study is analyzed in this paper: the financial performance of the first metro line in
Seville (Spain). In spite of previous cost overruns in the construction stage, the present operation stage is considered successful
from the point of view of social and financial profitability, whereby the risks have been theoretically transferred to stakeholders,
as defined by Value for Money considerations.
The objective of this study involves: first to determine whether this megaproject meets the expectations for which it was created
in terms of hope of return of the shareholders, and the expectations of the economic and financial feasibility under a change of
subsidy policies; and secondly to determine whether the conditions remain for not including the investment as public debt. This
issue is crucial in a budgetary constraint context for the planning of future metro lines. By taking this first experience into
account, this article also provides information for potential participants in the projects of the new metro lines, which are
currently in the planning stage
Improving bankruptcy prediction in micro-entities by using nonlinear effects and non-financial variables
The use of non-parametric methodologies, the introduction of non-financial variables,
and the development of models geared towards the homogeneous characteristics of
corporate sub-populations have recently experienced a surge of interest in the bankruptcy
literature. However, no research on default prediction has yet focused on micro-entities
(MEs), despite such firms’ importance in the global economy. This paper builds the first
bankruptcy model especially designed for MEs by using a wide set of accounts from 1999
to 2008 and applying artificial neural networks (ANNs). Our findings show that ANNs
outperform the traditional logistic regression (LR) models. In addition, we also report
that, thanks to the introduction of non-financial predictors related to age, the delay
in filing accounts, legal action by creditors to recover unpaid debts, and the ownership
features of the company, the improvement with respect to the use of solely financial
information is 3.6%, which is even higher than the improvement that involves the use
of the best ANN (2.6%)
Cerámicas emirales y califales en la excavación arqueológica del Antiguo Conservatorio (Onda, Castelló)
Los materiales estudiados proceden de la excavación realizada en el solar del Antiguo Conservatorio, en la Plaza de San Cristóbal nº 21 de Onda, donde se documentaron los restos de dos viviendas andalusíes datadas entre mediados del siglo X – primer tercio del siglo XIII. Los materiales cerámicos hallados en los rellenos de nivelación, donde aparecen cimentados los muros de la primera fase constructiva documentada, constituyen un conjunto muy homogéneo en el que encontramos cerámicas comunes modeladas a mano y a torno. Muchas de estas piezas comparten características comunes con las documentadas en otros yacimientos emirales y califales de la zona del Sharq Al-andalus y de la Meseta,
mientras que en otras encontramos elementos que remiten a una producción local, con abundantes paralelos con las cerámicas del Mas de Pere, yacimiento cercano a Onda, donde se documentó una alfarería datada entre la segunda mitad del siglo IX y el siglo X.The materials studied come from the excavation carried out on the site of the Old Conservatory, in Plaza de San Cristobal nº 21 in Onda, where the remains of two Andalusian houses dating to the end of the 10th-13th century were documented. The ceramic materials found in the leveling fills, where the walls of the first documented constructive phase appear cemented, constitute a very homogeneous set in which we find a wide set of common ceramics, modeled by hand and to the lathe. Many of these pieces share common characteristics with those documented in other emirates and caliphs of the Sharq Al-Andalus and Meseta area, while in others we find elements that refer to local production, with abundant parallels with the ceramics of the Mas of Pere, just 3 km from the town of Onda, where Montmessin located a test that ranks between the second half of the 9th century and the 10th century
Integration of Computers in the Classroom. The Use of the UNIX Operating System as a Tool
In this paper we present our ESP teaching experience to computer science students at the Escuela Universitaria de Informática at the UAB using the UNIX operating system as a leaming tool. Concretely we detall the new approach adopted for our practice classes
Hybrid model using logit and nonparametric methods for predicting micro-entity failure
Following the calls from literature on bankruptcy, a parsimonious hybrid bankruptcy model is developed in this paper
by combining parametric and non-parametric approaches.To this end, the variables with the highest predictive power to
detect bankruptcy are selected using logistic regression (LR). Subsequently, alternative non-parametric methods
(Multilayer Perceptron, Rough Set, and Classification-Regression Trees) are applied, in turn, to firms classified as
either “bankrupt” or “not bankrupt”. Our findings show that hybrid models, particularly those combining LR and
Multilayer Perceptron, offer better accuracy performance and interpretability and converge faster than each method
implemented in isolation. Moreover, the authors demonstrate that the introduction of non-financial and macroeconomic
variables complement financial ratios for bankruptcy prediction
Integration of Computers in the Classroom. The Use of the UNIX Operating System as a Tool
In this paper we present our ESP teaching experience to computer science students at the Escuela Universitaria de Informática at the UAB using the UNIX operating system as a leaming tool. Concretely we detall the new approach adopted for our practice classes
Multiscaling properties on sequences of turbulent plumes images
A multifractal analysis on a finite-range-scale of the plume concentration images at different experimental conditions (the height of the source Ho), where the measure is the grey value of the image (from 0 to 255), was applied to study its structure through time. The multifractal spectrum showed the characteristic inverse U-shape and a similar evolution in all Ho. The variation of the Hölder exponent (¿a) presented different amplitudes at different moments and increased with time. The symmetry of the spectrum (¿f) decreased with time achieving negative values (from left hand asymmetry evolving to right asymmetry). We show the different behaviour of axial velocity (W) with ¿a and ¿f. There is a linear relation of entrainment coefficient (ae) and the entropy dimension (a1). Therefore, the multifractal spectrum and the derived parameters can be used as markers of plume evolution as well as to study the effect of experimental conditions.Postprint (published version
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