1,874 research outputs found
The diffusion of new technology: adoption subsidies, spillovers, and transaction costs.
We establish the relation between optimal subsidy rates and spillovers from the sequential adoption of a new technology, we find that they evolve in the same direction over time. We show that spillovers, hence the subsidy rates, need not be monotonic. We show that when subsidy rates are increasing, their growth rate has to be paced by the growth rate of the present cost of the adoption of the new technology. We also show that increasing subsidies rates cannot produce the desired effect of accelerating adoption if the social cost of public funds is relatively high; hence first-best subsidy adoptions are not always viable.Adoption subsidies, Adoption spillovers, Technology adoption, Technology diffusion.
A Sliding Mode Multimodel Control for a Sensorless Photovoltaic System
In this work we will talk about a new control test using the sliding mode
control with a nonlinear sliding mode observer, which are very solicited in
tracking problems, for a sensorless photovoltaic panel. In this case, the panel
system will has as a set point the sun position at every second during the day
for a period of five years; then the tracker, using sliding mode multimodel
controller and a sliding mode observer, will track these positions to make the
sunrays orthogonal to the photovoltaic cell that produces more energy. After
sunset, the tracker goes back to the initial position (which of sunrise).
Experimental measurements show that this autonomic dual axis Sun Tracker
increases the power production by over 40%
Complementarity between private and public investment in R&D: A Dynamic Panel Data analysis
This paper investigates the relationship between private and public investment in R&D, while taking into account the effect of several instruments policies such as subsidies and taxes. We design a new look of knowledge spillovers and R&D cooperation to explain the contribution of public and private R&D on growth. We propose a heterogeneous dynamic panel data model to consider the endogenous effect of R&D investment. We also distinguish between the estimated long and short run results. Our results based on a sample of 23 countries over the period 1992-2004 indicate that both public and private investments in R&D are complementary. By establishing an endogenous growth model, the estimates indicate that public and private R&D depends on the host country's human capital investment. Results indicate that foreign direct investment is a more significant spillover channel than imports.R&D investment; Technology Spillovers; Complementarities; Economic growth; Dynamic Panel Data; Cointegration; Unit root test; Private investment; Public investment; R&D cooperation
Complementarity or substitutability between private and public investment in R&D: An empirical study
In this paper, we investigate the relationship between private and public investment in R&D. Various models proposed in the literature to take account for several instruments policies as: (subsidies, taxesâŠ) are estimated to verify if private and public R&D spending are complement or substitute. Our empirical study is based on a dynamic panel model for a sample of (23) countries over the period 1992-2004. This research is dealing with the relationship between private and public investment in R&D. Results based on the GMM method of Arellano and Bond (1991) and the tests of causality and unit root applied to the panel data show a positive and significant relation between private and public R&D.R&D; Complementarity; Substituability; GMM; Dynamic Panel Data
Synthesis, characterization, antibacterial, antioxidant and anti-inflammatory activities of new 4-Aryl-2-amino-6-(4-hydroxy coumarin-3-yl) pyridine-3-carbonitriles derivatives
This study aimed for the synthesis of 4-Aryl-2-amino-6-(4-hydroxy coumarin-3-yl) pyridine-3-carbonitriles 4 suitable for use as antibacterial, anti-oxidant and anti-inflammatory activities via a versatile, readily accessibleĂÂ 3-((2E)-3(aryl)prop-2-enoyl)-2H-chromen-2-one 3ĂÂ which were prepared by refluxing 3-acetyl-4-hydroxy coumarin with aromatic aldehydes in chloroform in the presence of a catalytic amount of piperidine. Then the direct reaction of the obtained chalcones 3 with malonitrile in the presence of ammonium acetate in one step gave products 5 .The structures of the new compounds 3-4 were confirmed by elemental analysis, IR, and multinuclear/multidimensional NMR spectroscopy (1H, 13C-NMR, NOESY, HMBC) which allowed assignment of the complete network of proton and carbon atoms. Most of the new compounds 4 exhibit moderateĂÂ antibacterialĂÂ activity against Gram Negative bacterial strains (E. coli, K.ĂÂ pneumonia,ĂÂ S. typhiĂÂ andĂÂ S. flexneri). In addition, the compounds 4 were investigated forĂÂ anti-oxidantĂÂ activitiesĂÂ byĂÂ super oxide radical, DPPH (2,2-Diphenyl-1-picrylhydrazyl), and hydroxyl radical scavenging assays,ĂÂ whereĂÂ most of the compoundsĂÂ displayed significant antioxidant activities.ĂÂ Furthermore,ĂÂ these 4-Aryl-2-amino-6-(4-hydroxy coumarin-3-yl) pyridine-3-carbonitriles 4 were evaluated for anti-inflammatoryĂÂ activity byĂÂ indirect haemolytic and lipoxygenase inhibition assays where compounds revealed good activity
Etude comparative de la dureté (hardness) des détecteurs p+ n- n+ et n+ p- p+ au Silicium
Dans ce travail, lâeffet des radiations sur une diode au silicium utilisĂ©e comme dĂ©tecteur de particule est simulĂ© numĂ©riquement. Ces radiations crĂ©ent des dĂ©fauts qui ont des effets indĂ©sirables et donc on peuvent dĂ©grader les performances des dĂ©tecteurs. LâĂ©tude est une comparaison de la duretĂ© des dĂ©tecteurs ayant diffĂ©rentes structures : p+ n- n+ et n+ p- p+. La duretĂ© est caractĂ©risĂ©e par les taux dâintroduction des dĂ©fauts (α) et (ÎČ). En partant des valeurs expĂ©rimentales de α et ÎČ, la tension de dĂ©plĂ©tion (Vdep) est Ă©valuĂ©e Ă partir des caractĂ©ristiques capacitĂ©-tension en polarisation inverse pour diffĂ©rentes fluences dâirradiations (Ί) pour les deux structures. La densitĂ© des dĂ©fauts crĂ©e par lâirradiation est proportionnelle Ă la fluence. La comparaison entre les deux structures (Ă rĂ©gions actives de types n et p) est rĂ©sumĂ©e dans les points suivants :
-Dans la structure p+ n- n+, la rĂ©gion active de type n se convertie au type p mais la rĂ©gion active p du dĂ©tecteur n+ p- p+ devient fortement de type p avec lâaugmentation de la densitĂ© du piĂ©ge accepteur. Au contraire avec lâaugmentation de la densitĂ© du piĂ©ge donneur oĂč le type n devient fortement de type n mais le type p se convertie au type n.
-la variation de la tension de déplétion du détecteur p+ n- n+ est plus important que celle du détecteur n+ p- p+. Donc, le détecteur n+ p- p+ est plus robuste vis-à -vis des radiations. Donc, il plus dure et peut avoir une durée de vie plus longue.
-Lâeffet des centres de recombinaison devient important lorsque les piĂ©ges accepteurs sont plus Ă©loignĂ© de la bande de valence tandis que les piĂ©ges donneurs sont plus Ă©loignĂ© de la bande de conduction
The Impact of Political Risk on the Volatility of Stock Returns: the Case of Canada
This paper examines the impact of political risk in Canada on the volatility of stock returns. Our results suggest that political news associated with a possible separation of Quebec from Canada plays an important role in the volatility of stock returns. We also show that the volatility of stock returns varies with the degree of a firmâs exposure to political risk, namely, the structure of assets and the extent of foreign involvement.
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