15,646 research outputs found
Institutions, infrastructure, and trade
We examine the influence of infrastructure, institutional quality, colonial and geographic context, and trade preferences on the pattern of bilateral trade. We are interested in threshold effects, and so emphasize those cases where bilateral country pairs do not actually trade. We depart from the institutions and infrastructure literature in this respect, using selection-based gravity modeling of trade flows. We also depart from this literature by mixing principal components (to condense our institutional and infrastructure measures) with a focus on deviations in the resulting indexes from expected values for given income cohorts to control for multicollinearity. We work with a panel of 284,049 bilateral trade flows from 1988 to 2002. Matching bilateral trade and tariff data and controlling for tariff preferences, level of development, and standard distance measures, we find that infrastructure, and institutional quality, are significant determinants not only of export levels, but also of the likelihood exports will take place at all. Our results support the notion that export performance, and the propensity to take part in the trading system at all, depends on institutional quality and access to well developed transport and communications infrastructure. Indeed, this dependence is far more important, empirically, than variations in tariffs in explaining sample variations in North-South trade
Measure and interpretation of effective protection in the presence of high capital costs : evidence from India
This paper is derived from a previous working paper prepared within a comprehensive review of India's trade regime and protection policies. One striking feature of India's protection structure has been the very high tariffs and protection on capital goods, thereby harming industrial competitiveness (and export potential) and distorting industrial incentives as they are indicated by Effective Protection Rates (EPRs). This paper presents three main themes. First, it provides a brief refresher on the definition of EPR and its limited interpretation as a measure of the scope for inefficiency or extra-profit resulting from protection, with a simple geometrical representation. In the second part, the paper introduces the notions and formulae of Corrected Effective Protection Rates (CEPR) and Net Effective Protection (NEPR), also with a geometrical representation. Finally, the paper tests the relevance of these notions, and assesses their magnitude -- in the case of India on the basis of a sample of some 60 industrial projects. A brief conclusion summarizes the major findings and draws some tentative conclusions.Globalization and Financial Integration,International Terrorism&Counterterrorism,Economic Theory&Research,Environmental Economics&Policies,Banks&Banking Reform
Adsorption of Alkali, Alkaline Earth and Transition Metal Atoms on Silicene
The adsorption characteristics of alkali, alkaline earth and transition metal
adatoms on silicene, a graphene-like monolayer structure of silicon, are
analyzed by means of first-principles calculations. In contrast to graphene,
interaction between the metal atoms and the silicene surface is quite strong
due to its highly reactive buckled hexagonal structure. In addition to
structural properties, we also calculate the electronic band dispersion, net
magnetic moment, charge transfer, workfunction and dipole moment of the metal
adsorbed silicene sheets. Alkali metals, Li, Na and K, adsorb to hollow site
without any lattice distortion. As a consequence of the significant charge
transfer from alkalis to silicene metalization of silicene takes place. Trends
directly related to atomic size, adsorption height, workfunction and dipole
moment of the silicene/alkali adatom system are also revealed. We found that
the adsorption of alkaline earth metals on silicene are entirely different from
their adsorption on graphene. The adsorption of Be, Mg and Ca turns silicene
into a narrow gap semiconductor. Adsorption characteristics of eight transition
metals Ti, V, Cr, Mn, Fe, Co, Mo and W are also investigated. As a result of
their partially occupied d orbital, transition metals show diverse structural,
electronic and magnetic properties. Upon the adsorption of transition metals,
depending on the adatom type and atomic radius, the system can exhibit metal,
half-metal and semiconducting behavior. For all metal adsorbates the direction
of the charge transfer is from adsorbate to silicene, because of its high
surface reactivity. Our results indicate that the reactive crystal structure of
silicene provides a rich playground for functionalization at nanoscale.Comment: 8 Figures, 1 Table. under publication Physical Review B (2013
Economics and politics of water resources development: Uda Walawe Irrigation Project, Sri Lanka
Water resources development / Irrigation programs / History / River basins / Rehabilitation / Costs / Crop production / Domestic water / Water use / Reservoirs / Fisheries / Decision making / Cost benefit analysis / Cost recovery / Water requirements / Water demand / Sri Lanka / Uda Walawe Irrigation Project
Engineering applications of heuristic multilevel optimization methods
Some engineering applications of heuristic multilevel optimization methods are presented and the discussion focuses on the dependency matrix that indicates the relationship between problem functions and variables. Coordination of the subproblem optimizations is shown to be typically achieved through the use of exact or approximate sensitivity analysis. Areas for further development are identified
Characterization of the size and position of electron-hole puddles at a graphene p-n junction
The effect of an electron-hole puddle on the electrical transport when
governed by snake states in a bipolar graphene structure is investigated. Using
numerical simulations we show that information on the size and position of the
electron-hole puddle can be obtained using the dependence of the conductance on
magnetic field and electron density of the gated region. The presence of the
scatterer disrupts snake state transport which alters the conduction pattern.
We obtain a simple analytical formula that connects the position of the
electron-hole puddle with features observed in the conductance. Size of the
electron-hole puddle is estimated from the magnetic field and gate potential
that maximizes the effect of the puddle on the electrical transport.Comment: This is an author-created, un-copyedited version of an article
published in Nanotechnology. IOP Publishing Ltd is not responsible for any
errors or omissions in this version of the manuscript or any version derived
from it. The Version of Record is available online at
doi:10.1088/0957-4484/27/10/10520
Protection and industrial structure in India
Effective protection rates in India are so high and vary so greatly that anything short of low uniform tariffs and the complete elimination of quantitative restrictions would not make the industrial incentive scheme transparent, as it needs to be. The authors produce evidence to show that there is ample scope for reducing tariffs and quantitative restrictions and that most industries could coexist with much less protection than they now have. By eliminating all surcharges on inputs (tariffs on imported inputs, price differentials on local inputs, nondeductible excise taxes) - even without correcting for the effects of high investment costs - most projects (including import substitution projects) would earn from current international prices a positive profit margin on their marginal as well as full production costs. The proportion of projects with a positive profit margin would triple, from 20 to 63 percent. Among import-substituting projects that are not candidates for export under the present trade regime, under the proposed new regime half would be candidates for export if they would procure their inputs at international prices. Lower tariffs would fulfill their primary purpose more effectively: providing protection and incentive signals. The function of generating public revenues, another critical issue in India, should be fulfilled not through tariffs but through more efficient and protection-neutral instruments - in particular direct taxation (income tax) and nontariff indirect taxation (neutral excise taxes, MODVAT, and preferably the value-added tax on consumption).Environmental Economics&Policies,Economic Theory&Research,Access to Markets,Markets and Market Access,Consumption
Electronic and Vibrational Properties of PbI 2 : From Bulk to Monolayer
Using first-principles calculations, we study the dependence of the
electronic and vibrational properties of multi-layered PbI 2 crystals on the
number of layers and focus on the electronic-band structure and the Raman
spectrum. Electronic-band structure calculations reveal that the direct or
indirect semiconducting behavior of PbI 2 is strongly influenced by the number
of layers. We find that at 3L-thickness there is a direct-to-indirect band gap
transition (from bulk-to-monolayer). It is shown that in the Raman spectrum two
prominent peaks, A 1g and E g , exhibit phonon hardening with increasing number
of layers due to the inter-layer van der Waals interaction. Moreover, the Raman
activity of the A 1g mode significantly increases with increasing number of
layers due to the enhanced out-of-plane dielectric constant in the few-layer
case. We further characterize rigid-layer vibrations of low-frequency
inter-layer shear (C) and breathing (LB) modes in few-layer PbI 2 . A reduced
mono-atomic (linear) chain model (LCM) provides a fairly accurate picture of
the number of layers dependence of the low-frequency modes and it is shown also
to be a powerful tool to study the inter-layer coupling strength in layered PbI
2 .Comment: To appear in Phys. Rev.
On Recommendation of Learning Objects using Felder-Silverman Learning Style Model
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The e-learning recommender system in learning institutions is increasingly becoming the preferred mode of delivery, as it enables learning anytime, anywhere. However, delivering personalised course learning objects based on learner preferences is still a challenge. Current mainstream recommendation algorithms, such as the Collaborative Filtering (CF) and Content-Based Filtering (CBF), deal with only two types of entities, namely users and items with their ratings. However, these methods do not pay attention to student preferences, such as learning styles, which are especially important for the accuracy of course learning objects prediction or recommendation. Moreover, several recommendation techniques experience cold-start and rating sparsity problems. To address the challenge of improving the quality of recommender systems, in this paper a novel recommender algorithm for machine learning is proposed, which combines students actual rating with their learning styles to recommend Top-N course learning objects (LOs). Various recommendation techniques are considered in an experimental study investigating the best technique to use in predicting student ratings for e-learning recommender systems. We use the Felder-Silverman Learning Styles Model (FSLSM) to represent both the student learning styles and the learning object profiles. The predicted rating has been compared with the actual student rating. This approach has been experimented on 80 students for an online course created in the MOODLE Learning Management System, while the evaluation of the experiments has been performed with the Mean Absolute Error (MAE) and Root Mean Square Error (RMSE). The results of the experiment verify that the proposed approach provides a higher prediction rating and significantly increases the accuracy of the recommendation
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