1,720,963 research outputs found
Design and optimization of inductive-coupling links for 3-D-ICs
No full textRecent research in the field of 3-D system integration has looked to the use of inductive-coupling links (ICLs) to provide vertical connectivity without incurring the inflated fabrication and testing costs associated with through-silicon vias. For power-efficient ICL design, optimization of the utilized physical inductor geometries is essential, but currently must be performed manually in a process that can take several hours. As a result, the generation of optimized inductor designs poses a significant challenge. In this paper, we address this challenge in three main contributions: 1) a novel, nonuniform planar inductor layout that exhibits enhanced performance when compared with conventional uniform inductors; 2) a rapid solver for evaluating inductor layouts; and 3) a high-speed optimization algorithm for determining best performing coil pairs. These three contributions are combined as a CAD tool for optimization of ICLs for 3-D-ICs (COIL-3-D). Results demonstrate that COIL-3-D achieves an average accuracy within 7.8% of finite-element tools consuming a small fraction of the time (1.5x 10E-3 %), significantly ameliorating the design of ICL-based 3-D-ICs. We also demonstrate that using COIL-3-D to optimize ICL inductor layouts can yield significant performance (up to 41.5% bandwidth improvement) and power (up to 8.1% power improvement) benefits, when compared with layouts used in prior ICL implementations. For these reasons, this paper unlocks new potential for low-cost, power-efficient 3-D integration using ICLs.</p
Globally Wireless Locally Wired (GloWiLoW): A clock distribution network for many-core systems
No full textModern high-performance systems are now facing critical issues on delivering power-efficient and globally interconnected clock networks. Conventional metal-based interconnect has gradually reached its bottleneck with the technology scaling which limits system performance as the interconnect delay has already overweighed circuit gate delay. A typical clock distribution network (CDN) might consume up to 50% of the total chip power and could generate large phase delay and clock uncertainties due to its RC characteristic and unbalanced load. This paper proposes a novel hybrid wire-wireless CDN, which improves the performance of on-chip clock distribution significantly using embedded wireless clock transmitter and receiver fabrics. In particular, On-Off-Keying (OOK) transceivers are implemented for overall system simplicity and has achieved significant power-efficiency. Results indicate that the total propagation delay can be reduced to 39.4ps, which is 57 times lower than the conventional H-tree. Besides, the system clock skew can be predictable and limited only by the displacement of clock receivers. Less than 26.9ps of clock skew (6.7% of a clock period at 2.5GHz) could be found within the proposed CDN and hence, shows the promising potential of future high-performance on-chip clock distribution.</p
A high-speed design methodology for inductive coupling links in 3D-ICs
No full textInductive coupling links (ICLs) are gaining traction as an alternative to through silicon vias (TSVs) for 3D integration, promising high-bandwidth connectivity without the inflated fabrication costs associated with TSV-enabled processes. For power-efficient ICL design, optimisation of the utilised physical inductor geometries is essential, however typically necessitates the use of finite element analysis (FEA) in addition to manual parameter fitting, a process that can take several hours even for a single geometry. As a result, the generation of optimised inductor designs poses a significant challenge. In this paper, we address this challenge, presenting a CAD-Tool for Optimisation of Inductive coupling Links for 3D-ICs (COIL-3D1). COIL-3D uses a rapid solver based upon semi-empirical expressions to quickly and accurately characterise a given link, in conjunction with a high-speed refined optimisation flow to find optimal inductor geometries for use in ICL-based 3D-ICs. The proposed solver achieves an average accuracy within 9.1% of commercial FEA software tools, and the proposed optimisation flow reduces the search time by 26 orders of magnitude. This work unlocks new potential for power-efficient 3D integration using inductive coupling links.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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