Search results for "EXPANSION"
showing 10 items of 630 documents
Data from: On the origin of mongrels: evolutionary history of free-breeding dogs in Eurasia
2015
Although a large part of the global domestic dog population is free-ranging and free-breeding, knowledge of genetic diversity in these free-breeding dogs (FBDs) and their ancestry relations to pure-breed dogs is limited, and the indigenous status of FBDs in Asia is still uncertain. We analyse genome-wide SNP variability of FBDs across Eurasia, and show that they display weak genetic structure and are genetically distinct from pure-breed dogs rather than constituting an admixture of breeds. Our results suggest that modern European breeds originated locally from European FBDs. East Asian and Arctic breeds show closest affinity to East Asian FBDs, and they both represent the earliest branching…
¿Puede un factor réplica del crecimiento económico futuro (PIB) explicar los rendimientos de los activos financieros cotizados en la bolsa española?
2020
El objetivo de este trabajo es analizar si un factor con capacidad predictiva sobre el crecimiento económico futuro, captura los rendimientos de los activos cotizados en la bolsa española. A su vez, se analiza la posible interpretación racional económica de los factores de Fama y French y momentum, como variables con información sobre dicho crecimiento económico futuro. Se cuantifican estos efectos para las etapas de crisis (económica: 1993-1997 y financiera: 2008-2011) y de expansión económica (1998-2007). Los resultados subrayan la relevancia y capacidad explicativa de este factor predictivo pero se encuentra una interpretación económica débil de los factores tamaño y ratio book-to-market…
Job protection deregulation in good and bad times
2019
Abstract This paper explores the short-term employment effect of deregulating job protection for regular workers and how it varies with prevailing business cycle conditions. We apply the local projection method to a newly constructed dataset of major regular job protection reforms covering 26 advanced economies over the past four decades. The analysis relies on country-sector-level data, using as identifying assumption the fact that stringent dismissal regulations are more binding in sectors that are characterized by a higher ‘natural’ propensity to make regular adjustments to the workforce. We find that the response of sectoral employment to deregulation depends crucially on the state of t…
Expansion of Private Secondary Education: Lessons from Recent Experience in Tanzania
1998
International audience; The private sector's role in education has been the subject of much analysis and policy debate in recent years. In developing countries, public resources for education are limited and governments have traditionnally relied on private education, particularly at the post-basic levels, to meet the excess demand for education. Even when excess demand is not a major issue, advocates of private education note that private schools can be more efficient than their public sector counterparts, delivering more value in terms of student achievement per investment of resources. In this article we explore Tanzania's experience with private education during the early 1990s, a perio…
A method of variation of boundaries for waveguide grating couplers
2008
We describe a method for calculating the solution of the electromagnetic field in a non-rectilinear open waveguide by using a series expansion, starting from the field of a rectilinear waveguide. Our approach is based on a method of variation of boundaries. We prove that the obtained series expansion converges and we provide a radiation condition at infinity in such a way that the problem has a unique solution. Our approach can model several kinds of optical devices which are used in optical integrated circuits. Numerical examples will be shown for the case of finite aperiodic waveguide grating couplers.
High order normal form construction near the elliptic orbit of the Sitnikov problem
2011
We consider the Sitnikov problem; from the equations of motion we derive the approximate Hamiltonian flow. Then, we introduce suitable action–angle variables in order to construct a high order normal form of the Hamiltonian. We introduce Birkhoff Cartesian coordinates near the elliptic orbit and we analyze the behavior of the remainder of the normal form. Finally, we derive a kind of local stability estimate in the vicinity of the periodic orbit for exponentially long times using the normal form up to 40th order in Cartesian coordinates.
Design, assembly and characterization of silicide-based thermoelectric modules
2016
ID: 1143 In: Energy conversion and management, 13-21. Summary: Highlights•Novel silicide-based thermoelectric modules were experimentally investigated.•The modules produced high power of 1.04 W at 405 °C and 3.24 W at 735 °C.•An estimated module efficiency of 5.3% represent the highest reported for silicide systems.AbstractSilicides have attracted considerable attention for use in thermoelectric generators due mainly to low cost, low toxicity and light weight, in contrast to conventional materials such as bismuth and lead telluride. Most reported work has focused on optimizing the materials properties while little has been done on module testing. In this work we have designed and tested mod…
Vibration of damaged beams under a moving mass: theory and experimental validation
2004
Abstract A theoretical and experimental study of the response of a damaged Euler–Bernoulli beam traversed by a moving mass is presented. Damage is modelled through rotational springs whose compliance is evaluated using linear elastic fracture mechanics. The analytical solution is based on the series expansion of the unknown deflection in a basis of the beam eigenfunctions. The latter are calculated using the transfer matrix method, taking into account the effective mass distribution of the beam. The convective acceleration terms, often omitted in similar studies, are considered here for a correct evaluation of the beam–moving mass interaction force. The analytical solution is then validated…
On Thermoeconomic Diagnosis of a Fouled Direct Expansion Coil: Effects of Induced Malfunctions on Quantitative Performance of the Diagnostic Technique
2017
Thermoeconomic diagnosis represents a promising technique for the detection of common faults in refrigeration systems, which are responsible of degradation in their energetic performance. Recently, the authors have carried out a sensitivity analysis of the performance of this method to the thermodynamic conditions of inlet air and to the geometry of the direct expansion coil, in case of degradation induced by evaporator fouling. The analysis showed that the method is able to detect this fault, but sometimes its quantitative assessments are not satisfactory. In order to understand more in-depth the origin of such results and identify margins for refinement of the technique, this paper is aim…
Wideband modeling of cascaded H-plane waveguide junctions using the generalised impedance matrix representation
2009
A strong interest in H-plane waveguide components composed of a large number of cascaded planar junctions is recently renewed. Therefore, the more efficient development of full-wave analysis tools of such devices is again receiving consideration, specially for its potential use within modern design tools. A novel technique for providing the wideband generalised impedance matrix representation of the inductive devices in the form of pole expansions, thus extracting the most expensive computations from the frequency loop is proposed. For such purpose, the whole device is first decomposed into simpler building blocks, i.e. planar junctions and uniform waveguides, which are modelled in terms of…