2,972 research outputs found
National Administered Protection Agencies: Their Role in the Post-Uruguay Round World
International Relations/Trade,
NATIONAL ADMINISTERED PROTECTION AGENCIES: THEIR ROLE IN THE POST-URUGUAY ROUND WORLD
This paper reviews the role of national administered protection agencies, whose responsibility is the enforcement of national trade remedy laws. After reviewing four recent trade remedy cases we argue that the role of the national administered protection agencies should be changed. Given the additional responsibilities the WTO has assumed in administering the Agreement on Agriculture, the growth of regional integration agreements and the increasing use of anti-dumping and countervailing duty actions against fairly traded imports, we argue that all trade actions should be taken to the WTO for settlement. The role of the national administered protection agencies should be changed to make them agents for trade liberalization. This would involve them taking on three primary functions: 1) as transparency agents; 2) as investigatory agents; and 3) as advocacy agents.International Relations/Trade,
Spin-Charge Separation and Kinetic Energy in the t-J Model
I show that spin-charge separation in 2-D t-J model leads to an increase of
kinetic energy. Using a sum rule, I derive an exact expression for the lowest
possible KE (E_{bound}) for any state without doubly occupied sites. KE of
relevant slave-boson and Schwinger-boson mean-field states -- which exhibit
complete spin-charge separation -- are found to be much larger than E_{bound}.
Examination of n(k) shows that the large increse in KE is due to excessive
depletion of electrons from the bottom of the band (Schwinger boson) and of
holes from the top (slave boson). To see whether the excess KE is simply due to
poor treatment of the constraints, I solve the constraint problem analytically
for the Schwinger boson case in the J = 0 limit. This restores gauge
invariance, incorrectly violated in MF theories. The result is a generalized
Hartree-Fock state of the Hubbard model, but one that includes spin waves. Even
after constraints are imposed correctly, the KE remains much larger than
E_{bound}. These results support the notion, advanced earlier [PRB 61, 8663
(2000)] that spin-charge separation in the MF state costs excessive KE, and
makes the state unstable toward recombination processes which lead to
superconductivity in d = 2 and a Fermi liquid state in higher dimensions.Comment: 13 pages, LateX plus three figures. To appear in Phys Rev B Typos
correcte
ANALYZING THE POTENTIAL FOR INCREASED TRADE IN DAIRY PRODUCTS: A CANADIAN PERSPECTIVE
International Relations/Trade,
Economic Performance of Bt Cotton Varieties in Pakistan
Farmers in Pakistan have been growing cotton that contains the first generation of Bt gene since 2002. The cultivation of these varieties, although formally unapproved and unregulated, increased rapidly after 2005. In 2007, nearly 60 percent of the cotton area was under BT varieties. This paper examines the economic performance of Bt cotton in Pakistan based on data collected through a structured questionnaire survey in January-February 2009 in two districts (Bahawalpur and Mirpur Khas). The extent of the impact of Bt cotton on costs of production and yield gains are different across the two districts with their diverse agro-climatic conditions and pest pressures. Seed expenditures increase in both districts, but a decline in the number of bollworm sprays and hence in the expenditure for pesticides is observed and total pesticide control costs (for bollworms and non bollworm pests) declines in both districts. Total production costs decline in Bahawalpur but rise in Mirpur Khas. The yield increases are higher in Mirpur Khas as well, resulting in total revenue and gross margins improving more than in Bahawalpur. The results are similar to other studies of Bt cotton in India and suggest gains for Pakistan from progressing to a regulated national market for Bt cotton technologies.Bt cotton, economic performance, Pakistan, Bahawalpur, Mirpur Khas, Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,
Schwinger-Boson Mean-Field Theory of Mixed-Spin Antiferromagnet
The Schwinger-boson mean-field theory is used to study the three-dimensional
antiferromagnetic ordering and excitations in compounds , a large
family of quasi-one-dimensional mixed-spin antiferromagnet. To investigate
magnetic properties of these compounds, we introduce a three-dimensional
mixed-spin antiferromagnetic Heisenberg model based on experimental results for
the crystal structure of . This model can explain the experimental
discovery of coexistence of Haldane gap and antiferromagnetic long-range order
below N\'{e}el temperature. Properties such as the low-lying excitations,
magnetizations of and rare-earth ions, N\'{e}el temperatures of different
compounds, and the behavior of Haldane gap below the N\'{e}el temperature are
investigated within this model, and the results are in good agreement with
neutron scattering experiments.Comment: 12 pages, 6 figure
Distribution of Benefits and Adoption of Bt Cotton in Pakistan: Ex-ante Analysis
This poster presents the potential impact of Bt cotton adoption in Pakistan. The size and distribution of economic benefits from the commercial adoption of Bt cotton in Pakistan are examined under four hypothetical scenarios. The adjusted economic surplus model is used to measure total benefits and their distribution between producers, consumers and technology innovators. To account for uncertainty in key parameters, the stochastic simulation techniques is applied. The results show that the total net benefits of adopting Bt cotton in Pakistan are large. As a result of increase in production, farmers get considerable benefits despite a decline in price. The share of benefits to innovators is small. The results indicate that the total cost of adopting latest Bt technology to the government of Pakistan is less than the benefits that farmers and consumers of all cotton-textile chain can receive. This is true even if the decline in pesticide expenditure and increase in yield are not very large.Bt cotton, economic surplus model, Pakistan, Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,
Hydrogen absorption properties of amorphous (Ni0.6Nb0.4−yTay)100−xZrx membranes
Ni based amorphous materials have great potential as hydrogen purification membranes. In the present work
the melt spun (Ni0.6Nb0.4−yTay)100−xZrx with y=0, 0.1 and x=20, 30 was studied. The result of X-ray diffraction
spectra of the ribbons showed an amorphous nature of the alloys. Heating these ribbons below T < 400 °C, even
in a hydrogen atmosphere (1−10 bar), the amorphous structure was retained. The crystallization process was
characterized by differential thermal analysis and the activation energy of such process was obtained. The
hydrogen absorption properties of the samples in their amorphous state were studied by the volumetric method,
and the results showed that the addition of Ta did not significantly influence the absorption properties, a clear
change of the hydrogen solubility was observed with the variation of the Zr content. The values of the
hydrogenation enthalpy changed from ~37 kJ/mol for x=30 to ~9 kJ/mol for x=20. The analysis of the
volumetric data provides the indications about the hydrogen occupation sites during hydrogenation, suggesting
that at the beginning of the absorption process the deepest energy levels are occupied, while only shallower
energy levels are available at higher hydrogen content, with the available interstitial sites forming a continuum
of energy levels
CuisineNet: Food Attributes Classification using Multi-scale Convolution Network
Diversity of food and its attributes represents the culinary habits of
peoples from different countries. Thus, this paper addresses the problem of
identifying food culture of people around the world and its flavor by
classifying two main food attributes, cuisine and flavor. A deep learning model
based on multi-scale convotuional networks is proposed for extracting more
accurate features from input images. The aggregation of multi-scale convolution
layers with different kernel size is also used for weighting the features
results from different scales. In addition, a joint loss function based on
Negative Log Likelihood (NLL) is used to fit the model probability to multi
labeled classes for multi-modal classification task. Furthermore, this work
provides a new dataset for food attributes, so-called Yummly48K, extracted from
the popular food website, Yummly. Our model is assessed on the constructed
Yummly48K dataset. The experimental results show that our proposed method
yields 65% and 62% average F1 score on validation and test set which
outperforming the state-of-the-art models.Comment: 8 pages, Submitted in CCIA 201
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