5,493 research outputs found
An eclectic approach to real exchange rate: Determination
We present a model of bilateral real exchange rate determination based on different theories that can be combined into a common statistical framework. Although eclectic, the approach is successfully used to shape a final specification which performs surprisingly well when out of sample exercises are carried out. Among the desirable features of the model there is the achievement of a high level of cross-currency consistency and the full interpretation of the coefficients from an economic point of view. Joint estimation by SURE, through the extraction of relevant interrelations among currencies, turns out to be an optimal tool to compute their historical fair values. --Real Exchange Rates,SURE,Fair Value
Global Equilibrium Exchange Rates: Euro, Dollar, "Ins," "Outs," and Other Major Currencies in a Panel Cointegration Framework
This paper presents a methodology for the calculation of bilateral equilibrium exchange rates for a panel of currencies in a way that guarantees consistency at the global level. A theoretical model, which encompasses the balance of payments and the Balassa-Samuelson approaches to real exchange rate determination, shows that the stock of net foreign assets and the evolution of sectoral prices are the fundamentals underlying the behavior of the real exchange rate. An unobserved components methodology in a cointegration framework allows us to identify a time-varying equilibrium real exchange rate, and deviations from this equilibrium provide an estimate of the degree of multilateral misalignment. Finally, an algebraic transformation converts these multilateral equilibrium real rates into bilateral equilibrium nominal rates. The results uncover, inter alia, that by the start of Stage III of EMU the euro was significantly undervalued against the dollar and even more against the pound, but overvalued relative to the yen. Regarding EMU currencies, it is shown that the four major EMU currencies locked their parities with the euro at a rate close to equilibrium.
MODELLING TOURISM DEMAND: A COMPARATIVE STUDY BETWEEN ARTIFICIAL NEURAL NETWORKS AND THE BOX-JENKINS METHODOLOGY
This study seeks to investigate and highlight the usefulness of the Artificial Neural Networks (ANN) methodology as an alternative to the Box-Jenkins methodology in analysing tourism demand. To this end, each of the above-mentioned methodologies is centred on the treatment, analysis and modelling of the tourism time series: âNights Spent in Hotel Accommodation per Monthâ, recorded in the period from January 1987 to December 2006, since this is one of the variables that best expresses effective demand. The study was undertaken for the North and Centre regions of Portugal. The results showed that the model produced by using the ANN methodology presented satisfactory statistical and adjustment qualities, suggesting that it is suitable for modelling and forecasting the reference series, when compared with the model produced by using the Box?Jenkins methodology.Artificial Neural Networks; ARIMA Models; Time Series Forecasting
La suerte del fracaso. Lo fallido en la prĂĄctica artĂstica contemporĂĄnea
El anĂĄlisis que se presenta a continuaciĂłn parte de la viabilidad de la elecciĂłn de lo fallido âfracasoâcomo posibilidad realizativa de una expresiĂłn exitosa en el campo de la prĂĄctica contemporĂĄnea de las artes visuales. Con dicha finalidad, la de estudiar la praxis de esta ejecuciĂłn creativa, se expondrĂĄn tres enfoques âla obra inacabada, la obra imposible y la comunicaciĂłn fallidaâ como ejes principales sobres los que estas prĂĄcticas artĂsticas se desarrollan, siendo su modus operandi posible Ășnicamente a travĂ©s de la experiencia del espectador(lector) implĂcito.The analysis presented below works on the feasibility of choosing failure as a performative possibility of a successful expression within the field of contemporary practices in visual arts. To this purpose, that of studying the praxis in this creative execution, three approaches will be exposed âthe unfinished work, the impossible work,and the failed communicationâ as principal centralconcepts on which theses artistic practices are developed, being their modus operandi only possible through the experience of empirical spectator (reader).
A Poisson hierarchical modelling approach to detecting copy number variation in sequence coverage data.
BACKGROUND: The advent of next generation sequencing technology has accelerated efforts to map and catalogue copy number variation (CNV) in genomes of important micro-organisms for public health. A typical analysis of the sequence data involves mapping reads onto a reference genome, calculating the respective coverage, and detecting regions with too-low or too-high coverage (deletions and amplifications, respectively). Current CNV detection methods rely on statistical assumptions (e.g., a Poisson model) that may not hold in general, or require fine-tuning the underlying algorithms to detect known hits. We propose a new CNV detection methodology based on two Poisson hierarchical models, the Poisson-Gamma and Poisson-Lognormal, with the advantage of being sufficiently flexible to describe different data patterns, whilst robust against deviations from the often assumed Poisson model. RESULTS: Using sequence coverage data of 7 Plasmodium falciparum malaria genomes (3D7 reference strain, HB3, DD2, 7G8, GB4, OX005, and OX006), we showed that empirical coverage distributions are intrinsically asymmetric and overdispersed in relation to the Poisson model. We also demonstrated a low baseline false positive rate for the proposed methodology using 3D7 resequencing data and simulation. When applied to the non-reference isolate data, our approach detected known CNV hits, including an amplification of the PfMDR1 locus in DD2 and a large deletion in the CLAG3.2 gene in GB4, and putative novel CNV regions. When compared to the recently available FREEC and cn.MOPS approaches, our findings were more concordant with putative hits from the highest quality array data for the 7G8 and GB4 isolates. CONCLUSIONS: In summary, the proposed methodology brings an increase in flexibility, robustness, accuracy and statistical rigour to CNV detection using sequence coverage data
GResilient index to assess the greenness and resilience of the automotive supply chain
Purpose: The purpose of this paper is to suggest an Index entitled GResilient Index to assess the greenness and resilience of the automotive companies and corresponding supply chain. Design/methodology/approach: An integrated assessment model is proposed based on Green and Resilient practices. These practices are weighted according to their importance to the automotive supply chain competitiveness. The Delphi technique is used to obtain the weights for the focused supply chain paradigms and corresponding practices. The model is then tested using a case study approach in the automotive supply chain. Findings: The case study results confirmed the applicability of this Index in a real-world supply chain. The results show that the Resilient supply chain management paradigm is the one considered as the one that more contributes for the automotive supply chain competitiveness. Research limitations/implications: The proposed Index was developed in the automotive sector context therefore it could not be adjusted to a different one. Future research could consider other aggregation methods for the Index construction. Practical implications: Supply chain participants will be able to evaluate the performance of their companies or supply chain in terms of Green and Resilient paradigms. Also, the Index can be effectively employed for functional benchmarking among competing companies and supply chains.Green; resilient; supply chain management; index; automotive industry
Lattice-Boltzmann Method for Non-Newtonian Fluid Flows
We study an ad hoc extension of the Lattice-Boltzmann method that allows the
simulation of non-Newtonian fluids described by generalized Newtonian models.
We extensively test the accuracy of the method for the case of shear-thinning
and shear-thickening truncated power-law fluids in the parallel plate geometry,
and show that the relative error compared to analytical solutions decays
approximately linear with the lattice resolution. Finally, we also tested the
method in the reentrant-flow geometry, in which the shear-rate is no-longer a
scalar and the presence of two singular points requires high accuracy in order
to obtain satisfactory resolution in the local stress near these points. In
this geometry, we also found excellent agreement with the solutions obtained by
standard finite-element methods, and the agreement improves with higher lattice
resolution
Patterns of antenal sensilla of Panstrongylus megistus from three Brazilian states
The objective of the present study was to analyze and describe the phenotype of the antennal sensilla of Panstrongylus megistus, one of the epidemiologically most important species of triatomines in Brazil. Specimens from the Brazilian states of GoiĂĄs (GO), Minas Gerais (MG), and Rio Grande do Sul (RS) were compared, based on studies of four types of sensilla on three antennal segments: thick-walled trichoid (TK), thin-walled trichoid (TH), bristles (BR), and basiconica (BA). Discriminant analysis allowed the separation of the RS specimens from those of GO and MG. Multivariate discriminant analysis demonstrated that the sensilla of males differed from those of females, the variables with greatest weight being the BA of all three segments and the TK of flagellum 1. The basiconica sensilla were significantly more abundant in females, on all three segments. Antennal sensilla patterns also demonstrated significant differences among P. megistus specimens.Fil: Villela, M. M.. FundaciĂłn Oswaldo Cruz; BrasilFil: Catala, Silvia Susana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - SecretarĂa de Industria y MinerĂa. Servicio GeolĂłgico Minero Argentino. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones CientĂficas y Transferencia TecnolĂłgica de La Rioja; ArgentinaFil: Juberg, J.. Instituto Oswaldo Cruz; Brasil. FundaciĂłn Oswaldo Cruz; BrasilFil: Silva, I. G.. Universidade Federal de GoiĂĄs; BrasilFil: Dias, J. C. P.. FundaciĂłn Oswaldo Cruz; Brasi
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