10,657 research outputs found
Economic structure, development policy and environmental quality : an empirical analysis of environmental Kuznets curves with Chinese municipal data
In many cases, the relationship between environmental pollution and economic development can be generally depicted by an inverted U-shaped curve, or an environmental Kuznets curve, where pollution increases with income at the beginning and decreases after a certain level of income. However, what determine the shape of an enviornmental Kuznets curve, such as the height and the turning point of the curve, have not been thoroughly studied. A good understanding of the determinants is vitally important to the development community, especially for the developing world, where income growth is a high priority and yet environmental pollution also needs to be carefully controlled. This study analyzes the impacts of economic structure, development strategy and environmental regulation on the shape of the environmental Kuznets curve with a city-level panel dataset obtained from China. The results show that economic structure, development strategy and environmental regulation can all have important implications on the relationship between environmental environmental quality and economic development but the impacts can be different at different development stages.Environmental Economics&Policies,Economic Theory&Research,Emerging Markets,Population Policies,Green Issues
Complete Study of Hadroproduction of a Meson Associated with a Prompt
We present the first complete study of and prompt
production from single-parton scattering, including the complete
color-singlet contribution, the
electroweak contribution, the complete
nonrelativistic S-wave and P-wave color-octet contribution as well as the
feeddown contribution. Our study was motivated by the recent evidence reported
by D0 Collaboration of prompt and simultaneous production
at the Tevatron. With our complete evaluation, we are able to refine the
determination of the double parton scattering contribution made by D0
Collaboration. We find that the effective cross section characterizing the
importance of double-parton scatterings is mb at
confidence level from the D0 measurement.Comment: 11 pages, 4 figures, 4 tables; v2: journal version, update the
references and fix a few typo
Segmentation of ultrasound images of thyroid nodule for assisting fine needle aspiration cytology
The incidence of thyroid nodule is very high and generally increases with the
age. Thyroid nodule may presage the emergence of thyroid cancer. The thyroid
nodule can be completely cured if detected early. Fine needle aspiration
cytology is a recognized early diagnosis method of thyroid nodule. There are
still some limitations in the fine needle aspiration cytology, and the
ultrasound diagnosis of thyroid nodule has become the first choice for
auxiliary examination of thyroid nodular disease. If we could combine medical
imaging technology and fine needle aspiration cytology, the diagnostic rate of
thyroid nodule would be improved significantly. The properties of ultrasound
will degrade the image quality, which makes it difficult to recognize the edges
for physicians. Image segmentation technique based on graph theory has become a
research hotspot at present. Normalized cut (Ncut) is a representative one,
which is suitable for segmentation of feature parts of medical image. However,
how to solve the normalized cut has become a problem, which needs large memory
capacity and heavy calculation of weight matrix. It always generates over
segmentation or less segmentation which leads to inaccurate in the
segmentation. The speckle noise in B ultrasound image of thyroid tumor makes
the quality of the image deteriorate. In the light of this characteristic, we
combine the anisotropic diffusion model with the normalized cut in this paper.
After the enhancement of anisotropic diffusion model, it removes the noise in
the B ultrasound image while preserves the important edges and local details.
This reduces the amount of computation in constructing the weight matrix of the
improved normalized cut and improves the accuracy of the final segmentation
results. The feasibility of the method is proved by the experimental results.Comment: 15pages,13figure
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