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111.
Investigation of the conformational properties of a SAW polymer chain near an impenetrable, non-interacting flat surface showed that the chain at first contracted and orientated itself to slightly parallel when it pulled close to the surface and at last elongated and reoriented itself to slightly perpendicular to the surface at very small distance from the surface. Simulation showed that most of the disappeared configurations were of large size at moderate distance from the surface while they were of small size at very small distance from the surface; and that the mean-square end-to-end distance was much more prone to be influenced by the surface than the mean-square radius of gyration . The orientational correlation between the direction of the longest principal axis of the moment of inertia and end-to-end vector was also discussed. 相似文献
112.
Keith?KoenigEmail author Nan?Davis?Mitchell Thomas?E.?Hannigan J.?Keith?Clutter 《Sports Engineering》2004,7(2):105-117
The speed at which a player can swing a bat is central to the games of baseball and softball, determining, to a large extent,
the hit speed of the ball. Experimental and analytical studies of bat swing speed were conducted with particular emphasis
on the influence of bat moment of inertia on swing speed. Two distinct sets of experiments measured the swing speed of colege
baseball and fast-pitch softball players using weighted rods and modified bats. The swing targets included flexible targets,
balls on a tee and machine pitched balls. Internal mass alterations provided a range of inertial properties. The average measured
speeds, from 22 to 31 m s−1, are consistent with previous studies. Bat speed approximately correlates with the moment of inertia of the bat about a vertical
axis of rotation through the batter's body, the speed generally decreasing as this moment of inertia increases. The analytical
model assumes pure rotation of the batter/bat system about a vertical axis through the batter's body. Aerodynamic drag of
the batter's arms and the bat is included in the model. The independent variable is bat moment of inertia about the rotation
axis. There is reasonable agreement between the model and the measured speeds. Detailed differences between the two suggest
the importance of additional degrees of freedom in determining swing speed. 相似文献
113.
Guido?Candela Paolo?Figini Antonello?E.?ScorcuEmail author 《Journal of Cultural Economics》2004,28(4):285-302
This paper proposes a price index for artists adjusted for the quality of the paintings, based on the ratio between the average market price and the average pre-sale estimate for paintings. We apply this methodology to a group of selected artists and schools presented in auctions worldwide in the period 1990–2001. A comparison with quality unadjusted and hedonic indices is also conducted.JEL Classification: C10, Z11 相似文献
114.
Martin?VeselyEmail author Thomas?Baron Jean-Yves?Le?Meur Tibor?Simko 《Publishing Research Quarterly》2004,20(1):77-83
Conclusion In this paper we briefly described the current status of research in the field of digital libraries interoperability, mainly
with respect to federated data processing such as permitted within the Open Archive Initiative framework. We then presented
the CERN Document Server Software suite that is a free software package main-tained by CERN providing an online digital library
solution for mid- to large-sized document repositories. The set of CDSware modules was described and the differ-ences with
other existing tools briefly mentioned. Finally we have mentioned a typical usage statistics illustrating the scope of grey
literature and networked con-ditions of the CERN Document Server.
We pointed out that the current trend in grey literature management goes toward institutional repositories build upon the
distributed and federated model. Further research is going on within the CDS collaboration in this area, focused particularly
on (i) semantic interoperability using ontologies in distributed and federated data processing and (ii) ranking technologies
when searching grey literature in OAI compliant repositories. 相似文献
115.
Summary What will be the future of ONIX? Some argue that wider industry acceptance will lead to increased efficiencies in the transfer
of book data, which will ultimately benefit book sales. ONIX still has to overcome many challenges: its implementation cost
is high, whole-salers and aggregators are still using different spreadsheets and information sources. Furthermore, MS Excel
as an alternative solution is widely available and accepted by the industry. Small publishers need more education and a straightforward
demonstration of ONIX’s return on investment. An outreaching of the helping hand of professional organizations is strongly
suggested to foster the adoption process among small players. It is the role of the AAP and BISG to get their memberships
to think about what is good for all members as a whole throughout the industry. As an organization BISG can recommend, educate,
and promote the standard. It cannot, however, bring pressure or demand organizations use it. Publishers, retailers, and wholesalers
make those decisions for themselves and quite apparently the majority do not yet see the rewards. Market players need to determine
the cost versus benefit and as long as distributors and retailers agree on receiving other formats, ONIX will never take a
strong hold in the marketplace. After all, publishers should compete against each other with good books and not with multiple
computer codes. 相似文献
116.
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119.
Conclusions We are living a deep change in the information transfer process involving the different actors of the editorial scene (from
authors to editors, web-editors, e-publishers and readers), who occasionally play different roles at the same time (e.g.,
authors sometimes bypass the editor thus assuming direct responsibilities in the diffusion of documents in the Internet).
Furthermore, information producers, managers or seekers often show twofold personalities like Dr. Jekyll and Mr. Hyde. They
would like to find all documents free on the Internet and be able to read original, reliable, and high quality information,
but they are sometimes reluctant to spread their papers through online nonofficial channels as they care for the impact factor,
prestige, and career advancement.
It is a revolutionary period in which new and alternative forms of scholarly communication live together with more traditional
ones and the future is difficult to define. Recent initiatives of open access—such as Pubmed Central, Public Library of Science,
Budapest Open Access Initiative—are contributing to define new trends in the editorial market, challenging the traditional
distribution channels, mainly managed by commercial editors, and placing the authors’ role and publication copyrights under
severe discussion.
In this landscape, GL now has new dignity and becomes closer and closer to innovative scientific publications supported by
researchers in view of a generalised movement towards open access. The nuances of grey are becoming lighter and lighter. The
questions are many, the answers few, but, in any case, the ethical responsibility of producing and issuing quality documents
can never be disregarded. 相似文献
120.