289,787 research outputs found
Ricci flow on K\"ahler-Einstein manifolds
In our previous paper math.DG/0010008, we develop some new techniques in
attacking the convergence problems for the K\"ahler Ricci flow. The one of main
ideas is to find a set of new functionals on curvature tensors such that the
Ricci flow is the gradient like flow of these functionals. We successfully find
such functionals in case of Kaehler manifolds. On K\"ahler-Einstein manifold
with positive scalar curvature, if the initial metric has positive bisectional
curvature, we prove that these functionals have a uniform lower bound, via the
effective use of Tian's inequality. Consequently, we prove the following
theorem: Let be a K\"ahler-Einstein manifold with positive scalar
curvature. If the initial metric has nonnegative bisectional curvature and
positive at least at one point, then the K\"ahler Ricci flow will converge
exponentially fast to a K\"ahler-Einstein metric with constant bisectional
curvature. Such a result holds for K\"ahler-Einstein orbifolds.Comment: 49 pages. This is a revised version. Sections 4 and 5 are simplified
and streamline
Strongly Coupled Inflaton
We continue to investigate properties of the strongly coupled inflaton in a
setup introduced in arXiv:0807.3191 through the AdS/CFT correspondence. These
properties are qualitatively different from those in conventional inflationary
models. For example, in slow-roll inflation, the inflaton velocity is not
determined by the shape of potential; the fine-tuning problem concerns the dual
infrared geometry instead of the potential; the non-Gaussianities such as the
local form can naturally become large.Comment: 12 pages; v3, minor revision, comments and reference added, JCAP
versio
Network support for integrated design
A framework of network support for utilization of integrated design over the Internet has been developed. The techniques presented also applicable for Intranet/Extranet. The integrated design system was initially developed for local application in a single site. With the network support, geographically dispersed designers can collaborate a design task through out the total design process, quickly respond to clients’ requests and enhance the design argilty. In this paper, after a brief introduction of the integrated design system, the network support framework is presented, followed by description of two key techniques involved: Java Saverlet approach for remotely executing a large program and online CAD collaboration
Privacy-Preserving Outsourcing of Large-Scale Nonlinear Programming to the Cloud
The increasing massive data generated by various sources has given birth to
big data analytics. Solving large-scale nonlinear programming problems (NLPs)
is one important big data analytics task that has applications in many domains
such as transport and logistics. However, NLPs are usually too computationally
expensive for resource-constrained users. Fortunately, cloud computing provides
an alternative and economical service for resource-constrained users to
outsource their computation tasks to the cloud. However, one major concern with
outsourcing NLPs is the leakage of user's private information contained in NLP
formulations and results. Although much work has been done on
privacy-preserving outsourcing of computation tasks, little attention has been
paid to NLPs. In this paper, we for the first time investigate secure
outsourcing of general large-scale NLPs with nonlinear constraints. A secure
and efficient transformation scheme at the user side is proposed to protect
user's private information; at the cloud side, generalized reduced gradient
method is applied to effectively solve the transformed large-scale NLPs. The
proposed protocol is implemented on a cloud computing testbed. Experimental
evaluations demonstrate that significant time can be saved for users and the
proposed mechanism has the potential for practical use.Comment: Ang Li and Wei Du equally contributed to this work. This work was
done when Wei Du was at the University of Arkansas. 2018 EAI International
Conference on Security and Privacy in Communication Networks (SecureComm
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