11,211 research outputs found
Involuntary Resettlement in Hydroelectric Projects: A Comparison of Chinese and Canadian Case Studies and Implications for Best Practice
This paper examines the political systems of China and Canada with respect to involuntary resettlement induced by hydroelectric projects. It uses case studies from the two countries – namely the Three Gorges Dam in China and a series of dams in James Bay, Quebec – to analyze the similarities and differences found under each system. The findings reveal that, with regards to similarities, in both countries, certain marginalized groups were further disadvantaged as a result of resettlement and the organized resettlement practices in the two countries are relatively short, although the history of dam construction is relatively long. With regards to differences, the findings reveal that the cultural and historical legacy of land for Aboriginal peoples in Canada has been given more attention than the land concerns of peasants in China, the approval process of dam construction and resettlement takes more time in Canada, and the central-local government relationship tends to be more hierarchical in China
A Web-GIS Online Vector Data Editing Method Based on Multi-scale Representation Data Structure
From analysis of the factors affecting the service quality of Web GIS, the key factor in the efficiency of online vector data interactive editing is to control the size of the relevant data set. This paper puts forward an online vector data editing method based on the multi-scale representation data structure DBLG-tree. It designs WindowingQuery for large geometric features. Combined with SimplifyQuery, it can effectively control the vertex scale of the geometric features. At the same time, the sub-feature resulting from WindowingQuery retains the connection with the original feature and can be merged and updated. It provides DownsizeQuery which can directly control the volume of query result from the data set, so as to adapt to the performance of different browsers and mobile devices. Research shows that the execution time of DownsizeQuery under the support of multi-scale representation data structure is stable, and the size of the queried and updated data set is also stable. The upper bounded query time and query results ensure the response time of online interactive visualization and updating of the vector features
The most plausible explanation of the cyclical period changes in close binaries: the case of the RS CVn-type binary WW Dra
We searched the orbital period changes in 182 EA-type (including the 101
Algol systems used by \cite{hal89}), 43 EB-type and 53 EW-type binaries with
known both the mass ratio and the spectral type of their secondary components.
We reproduced and improved the same diagram as Hall's (1989) according to the
new collected data. Our plots do not support the conclusion derived by
\cite{hal89} that all cases of cyclical period changes are restricted to
binaries having the secondary component with spectral types later than F5. The
presence of period changes also among stars with secondary component of early
type indicates that the magnetic activity is one cause, but not the only one,
for the period variation. It is discovered that cyclic period changes, likely
due to the presence of a third body are more frequent in EW-type binaries among
close binaries. Therefore, the most plausible explanation of the cyclical
period changes is the LTTE via the presence of a third body. By using the
century-long historical record of the times of light minimum, we analyzed the
cyclical period change in the Algol binary WW Dra. It is found that the orbital
period of the binary shows a cyclic variation
with an amplitude of . The cyclic oscillation
can be attributed to the LTTE via a third body with a mass no less than . However, no spectral lines of the third body were discovered
indicating that it may be a candidate black hole. The third body is orbiting
the binary at a distance shorter than 14.4 AU and it may play an important role
in the evolution of this system.Comment: 9 pages, 5 figures, published by MNRA
First R and I Lights and Their Photometric Analyses of GSC 02393-00680
We obtained complete and light curves of GSC 02393-00680 in 2008 and
analyzed them with the 2003 version of the W-D code. It is shown that GSC
02393-00680 is a W-type shallow contact binary system with a high mass ratio
and a degree of contact factor . It will be a good
example to check up on the TRO theory. A period investigation based on all
available data suggests that the system has a small-amplitude period
oscillation (; years). This may indicate it has a
moderate mass close third body, which is similar to XY Leo
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