作者：
Yang LiJiang ZhouHong Guo[]CREAM Group
State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics School of Electronics Engineering and Computer Science and Center for Computational Science and Engineering (CCSE) Peking University Beijing 100871 People’s Republic of China
Using a nonperturbative method, we study the exact entanglement dynamics of two two-level dipole-dipole interacting atoms coupled to a common non-Markovian reservoir with different coupling strengths. Besides analyzin...
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Using a nonperturbative method, we study the exact entanglement dynamics of two two-level dipole-dipole interacting atoms coupled to a common non-Markovian reservoir with different coupling strengths. Besides analyzing the conditions for the existence of a steady state, we find that, although the dipole-dipole interaction could destroy the stationary entanglement, a relatively strong dipole-dipole interaction does suppress disentanglement in the initial period of time. These results are helpful for the practical engineering of entanglement in the future.
The query optimization is a very big field in the context of database *** has been studied in a great variety of contexts and from many different perspectives, giving rise to several diverse solutions in each case. Th...
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The query optimization is a very big field in the context of database *** has been studied in a great variety of contexts and from many different perspectives, giving rise to several diverse solutions in each case. The purpose of this paper is to primarily provide a comprehensive review and discussion of the core problems which the techniques of query optimization generally cope with by simulating a parallel database environment in different processing units. In addition to that this paper focuses on the skewing problem in parallel database architectures with proper survey of literature.
The so-called PageRank algorithm has been used at Google for properly ranking search *** quantifies the importance of each page by the structure of links in the *** our recent work,we have proposed a distributed rando...
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The so-called PageRank algorithm has been used at Google for properly ranking search *** quantifies the importance of each page by the structure of links in the *** our recent work,we have proposed a distributed randomized approach for the PageRank computation,where the pages find their own values by communicating with linked *** paper builds upon this approach to improve the computation and communication load for the algorithm by systematically aggregating the webpages while maintaining performance.
There is a growing body of experimental evidence suggesting that the Ca2+ signaling in ventricular myocytes is characterized by a high gradient near the cell membrane and a more uniform Ca2+ distribution in the cell i...
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There is a growing body of experimental evidence suggesting that the Ca2+ signaling in ventricular myocytes is characterized by a high gradient near the cell membrane and a more uniform Ca2+ distribution in the cell interior [1]--[7]. An important reason for this phenomenon might be that in these cells the t-tubular system forms a network of extracellular space, extending deep into the cell interior. This allows the electrical signal, that propagates rapidly along the cell membrane, to reach the vicinity of the sarcoplasmic reticulum (SR), where intracellular Ca2+ required for myofilament activation is stored [1], [8]--[11]. Early studies of cardiac muscle showed that the t-tubules are found at intervals of about 2 lm along the longitudinal cell axis in close proximity to the Z-disks of the sarcomeres [12]. Subsequent studies have demonstrated that the t-tubular system has also longitudinal extensions [9]--[11], [13].
We study the statistical properties of return intervals r between successive energy dissipation rates above a certain threshold Q in three-dimensional fully developed turbulence. We find that the distribution function...
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We study the statistical properties of return intervals r between successive energy dissipation rates above a certain threshold Q in three-dimensional fully developed turbulence. We find that the distribution function PQ(r) scales with the mean return interval RQ as PQ(r)=RQ−1f(r/RQ) for RQ∊[50,500], where the scaling function f(x) has two power-law regimes. The scaling behavior is statistically validated by the Cramér–von Mises criterion. The return intervals are short-term and long-term correlated and possess multifractal nature. The Hurst index of the return intervals decays exponentially against RQ, predicting that rare extreme events with RQ→∞ are also long-term correlated with the Hurst index H∞=0.639. These phenomenological findings have potential applications in risk assessment of extreme events at very large RQ.
Geographic data sets are often very large in size. Interactive visualization of such data at all scales is not easy because of the limited resolution of the monitors and inability of visualization applications to hand...
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ISBN:
(纸本)9781424445622
Geographic data sets are often very large in size. Interactive visualization of such data at all scales is not easy because of the limited resolution of the monitors and inability of visualization applications to handle the volume of data. This is especially true for large vector datasets. The end user's experience is frequently unsatisfactory when exploring such data over the Web using a naive application. Network bandwidth is another contributing factor to the low performance. In this paper, a quadtree based technique to visualize extremely large spatial network datasets over the Web is described. It involves using custom developed methods leveraging a PostGIS database as the data source and Google Earth as the visualization client. The methodology supports both point and range queries along with non-spatial queries. It is demonstrated on a network dataset consisting of several million links. The implementation of the methodology is based on using some of the powerful features of KML (Keyhole Markup Language). Keyhole Markup Language (KML) is an Open Geospatial Consortium (OGC) standard for displaying geospatial data on Earth browsers. One of the features of KML is the notion of network links. Using network links, a wide range of geospatial data sources such as geodatabases, static files and geospatial data services can be simultaneously accessed and visualized seamlessly. Using the network links combined with level of detail principle, view based rendering and intelligent server and client-side caching, scalability in visualizing extremely large spatial datasets can be achieved.
We present advances on the development of a mechatronically and algorithmically automated framework for the data-driven identification of constitutive material models based on energy density considerations. These mode...
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We present advances on the development of a mechatronically and algorithmically automated framework for the data-driven identification of constitutive material models based on energy density considerations. These models can capture both the linear and nonlinear constitutive response of multiaxially loaded composite materials in a manner that accounts for progressive damage.
The design of optimal separation flow sheets for multi-component mixtures is still not a solved problem. This is especially the case when non-ideal or azeotropic mixtures or hybrid separation processes are considered....
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The design of optimal separation flow sheets for multi-component mixtures is still not a solved problem. This is especially the case when non-ideal or azeotropic mixtures or hybrid separation processes are considered. We review recent developments in this field and present a systematic framework for the design of separation flow sheets. This framework proposes a three-step approach. In the first step different flow sheets are generated. In the second step these alternative flow sheet structures are evaluated with shortcut methods. In the third step a rigorous mixed-integer nonlinear programming (MINLP) optimization of the entire flow sheet is executed to determine the best alternative. Since a number of alternative flow sheets have already been eliminated, only a few optimization runs are necessary in this final step. The whole framework thus allows the systematic generation and evaluation of separation processes and is illustrated with the case study of the separation of ethanol and water.
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