Institution
University of Bremen
Education•Bremen, Germany•
About: University of Bremen is a education organization based out in Bremen, Germany. It is known for research contribution in the topics: Population & Context (language use). The organization has 14563 authors who have published 37279 publications receiving 970381 citations. The organization is also known as: Universität Bremen.
Papers published on a yearly basis
Papers
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22 May 2008TL;DR: RevLib is introduced, an online resource for reversible functions and reversible circuits that provides a large database of functions with respective circuit realizations and tools are introduced to support researchers in evaluating their algorithms and documenting their results.
Abstract: Synthesis of reversible logic has become an active research area in the last years. But many proposed algorithms are evaluated with a small set of benchmarks only. Furthermore, results are often documented only in terms of gate counts or quantum costs, rather than presenting the specific circuit. In this paper RevLib (www.revlib.org) is introduced, an online resource for reversible functions and reversible circuits. RevLib provides a large database of functions with respective circuit realizations. RevLib is designed to ease the evaluation of new methods and facilitate the comparison of results. In addition, tools are introduced to support researchers in evaluating their algorithms and documenting their results.
449 citations
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20 Jun 2004TL;DR: This paper adopts lattice-reduction-aided schemes to the MMSE criterion and proposes an alternative method based on an extended system model, which in conjunction with simple successive interference cancellation nearly reaches the performance of maximum-likelihood detection.
Abstract: In recent publications the use of lattice-reduction for signal detection in multiple antenna systems has been proposed. In this paper, we adopt these lattice-reduction-aided schemes to the MMSE criterion. We show that an obvious way to do this is infeasible and propose an alternative method based on an extended system model, which in conjunction with simple successive interference cancellation nearly reaches the performance of maximum-likelihood detection. Furthermore, we demonstrate that, a sorted QR decomposition can significantly reduce the computational effort associated with lattice-reduction. Thus, the new algorithm clearly outperforms existing methods with comparable complexity.
449 citations
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TL;DR: In this paper, the authors investigate the crossover regime from three-dimensional topological insulators to two-dimensional insulators with quantum spin Hall effect when the layer thickness is reduced.
Abstract: We investigate the crossover regime from three-dimensional topological insulators ${\text{Bi}}_{2}{\text{Te}}_{3}$ and ${\text{Bi}}_{2}{\text{Se}}_{3}$ to two-dimensional topological insulators with quantum spin Hall effect when the layer thickness is reduced. Using both analytical models and first-principles calculations, we find that the crossover occurs in an oscillatory fashion as a function of the layer thickness, alternating between topologically trivial and nontrivial two-dimensional behavior.
447 citations
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TL;DR: It is concluded that changes in ocean circulation, and hence sea surface temperature patterns, were important in modulating atmospheric moisture transport onto the central African continent.
Abstract: Past hydrological changes in Africa have been linked to various climatic processes, depending on region and timescale. Long-term precipitation changes in the regions of northern and southern Africa influenced by the monsoons are thought to have been governed by precessional variations in summer insolation(1,2). Conversely, short-term precipitation changes in the northern African tropics have been linked to North Atlantic sea surface temperature anomalies, affecting the northward extension of the Intertropical Convergence Zone and its associated rainbelt(3,4). Our knowledge of large-scale hydrological changes in equatorial Africa and their forcing factors is, however, limited(5). Here we analyse the isotopic composition of terrigenous plant lipids, extracted from a marine sediment core close to the Congo River mouth, in order to reconstruct past central African rainfall variations and compare this record to sea surface temperature changes in the South Atlantic Ocean. We find that central African precipitation during the past 20,000 years was mainly controlled by the difference in sea surface temperatures between the tropics and subtropics of the South Atlantic Ocean, whereas we find no evidence that changes in the position of the Intertropical Convergence Zone had a significant influence on the overall moisture availability in central Africa. We conclude that changes in ocean circulation, and hence sea surface temperature patterns, were important in modulating atmospheric moisture transport onto the central African continent.
446 citations
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Ohio State University1, Rega Institute for Medical Research2, University of Exeter3, Université Paris-Saclay4, University of Paris5, Utrecht University6, École Normale Supérieure7, Laval University8, University of Bremen9, Shirshov Institute of Oceanology10, University of Maine11, Wellcome Trust12, Massachusetts Institute of Technology13, Stazione Zoologica Anton Dohrn14, Bigelow Laboratory For Ocean Sciences15, Université catholique de Louvain16, University of Arizona17, Swiss Institute of Bioinformatics18, Radboud University Nijmegen19
TL;DR: An ∼12-fold expanded global ocean DNA virome dataset is established of 195,728 viral populations, now including the Arctic Ocean, and it is validated that these populations form discrete genotypic clusters.
441 citations
Authors
Showing all 14961 results
Name | H-index | Papers | Citations |
---|---|---|---|
Roger Y. Tsien | 163 | 441 | 138267 |
Klaus-Robert Müller | 129 | 764 | 79391 |
Ron Kikinis | 126 | 684 | 63398 |
Ulrich S. Schubert | 122 | 2229 | 85604 |
Andreas Richter | 110 | 769 | 48262 |
Michael Böhm | 108 | 755 | 66103 |
Juan Bisquert | 107 | 450 | 46267 |
John P. Sumpter | 101 | 266 | 46184 |
Jos Lelieveld | 100 | 570 | 37657 |
Michael Schulz | 100 | 759 | 50719 |
Peter Singer | 94 | 702 | 37128 |
Charles R. Tyler | 92 | 325 | 31724 |
John P. Burrows | 90 | 815 | 36169 |
Hans-Peter Kriegel | 89 | 444 | 73932 |
Harald Haas | 85 | 750 | 34927 |