35,002 research outputs found
Cost-Effective TSV Grouping for Yield Improvement of 3D-ICs
Three-dimensional Integrated Circuits (3D-ICs) vertically stack multiple silicon dies to reduce overall wire length, power consumption, and allow integration of heterogeneous technologies. Through-silicon-vias (TSVs) which act as vertical links between layers pose challenges for 3D integration design. TSV defects can happen in fabrication process and bonding stage, which can reduce the yield and increase the cost. Recent work proposed the employment of redundant TSVs to improve the yield of 3D-ICs. This paper presents a redundant TSVs grouping technique, which partition regular and redundant TSVs into groups. For each group, a set of multiplexers are used to select good signal paths away from defective TSVs. We investigate the impact of grouping ratio (regular-to-redundant TSVs in one group) on trade-off between yield and hardware overhead. We also show probabilistic models for yield analysis under the influence of independent and clustering defect distributions. Simulation results show that for a given number of TSVs and TSV failure rate, careful selection of grouping ratios lead to achieving 100% yield at minimal hardware cost (number of multiplexers and redundant TSVs) in comparison to a design that does not exploit TSV grouping ratios
Asymptotically Optimal Approximation Algorithms for Coflow Scheduling
Many modern datacenter applications involve large-scale computations composed
of multiple data flows that need to be completed over a shared set of
distributed resources. Such a computation completes when all of its flows
complete. A useful abstraction for modeling such scenarios is a {\em coflow},
which is a collection of flows (e.g., tasks, packets, data transmissions) that
all share the same performance goal.
In this paper, we present the first approximation algorithms for scheduling
coflows over general network topologies with the objective of minimizing total
weighted completion time. We consider two different models for coflows based on
the nature of individual flows: circuits, and packets. We design
constant-factor polynomial-time approximation algorithms for scheduling
packet-based coflows with or without given flow paths, and circuit-based
coflows with given flow paths. Furthermore, we give an -approximation polynomial time algorithm for scheduling circuit-based
coflows where flow paths are not given (here is the number of network
edges).
We obtain our results by developing a general framework for coflow schedules,
based on interval-indexed linear programs, which may extend to other coflow
models and objective functions and may also yield improved approximation bounds
for specific network scenarios. We also present an experimental evaluation of
our approach for circuit-based coflows that show a performance improvement of
at least 22% on average over competing heuristics.Comment: Fixed minor typo
Non-diffractive mechanisms in the meson photoproduction on nucleons
We examine the non-diffractive mechanisms in the meson photoproduction
from threshold up to a few GeV using an effective Lagrangian in a constituent
quark model. The new data from CLAS at large angles can be consistently
accounted for in terms of {\it s}- and {\it u}-channel processes. Isotopic
effects arising from the reactions and , are investigated by comparing the cross sections and polarized beam
asymmetries. Our result highlights an experimental means of studying
non-diffractive mechanisms in meson photoproduction.Comment: 4 eps figures, version accepted by Phys. Lett.
The Heteronormative Frame in Chinese Yaoi: Integrating Female Chinese Fan Interviews with Sinophone and Anglophone Survey Data
This article addresses the research question: How do Chinese Yaoi fans read Yaoi stories? Yaoi is a female-oriented genre of Japanese popular culture which describes romantic and erotic relationships between men. We interviewed twenty Chinese nationals who are self-defined fans of Yaoi (mean age=23.5 years). Although men were not excluded, none volunteered. A Yaoi fandom survey was created in Chinese and in English with five sections: demographics, Yaoi materials, feelings about Yaoi, social relationships, and other erotic materials (Chinese N=1085; Anglophone N=1615). Thematic Analysis of the interviews produced five themes suggesting the existence of a heteronormative frame: social and family approval, everlasting romantic relationship, heteronormative couple, dislike reversible relationship, and gay relationships in reality. We then selected questions from the survey for statistical analysis on the rationale that these items might inform this frame and help us interpret and contextualise the qualitative analysis. Our survey results support our thematic analysis that Chinese Yaoi fans tend to read Yaoi through a heteronomative frame and, importantly, that in comparison with Anglophone fans, this is differential to Chinese culture
Organoaluminium complexes derived from Anilines or Schiff bases for ring opening polymerization of epsilon-caprolactone, delta-valerolactone and rac-lactide
Reaction of R¹R²CHN=CH(3,5-tBu₂C₆H₂-OH-2) (R¹ = R² = Me L¹H; R¹ = Me, R² = Ph L²H; R¹ = R2 = Ph L³H) with one equivalent of R³3Al (R³ = Me, Et) afforded [(L¹-³)AlR³₂] (L¹, R³ = Me 1, R³ = Et 2; L², R³ = Me 3, R³ = Et 4; L³ R³ = Me 5, R³ = Et 6); complex 1 has been previously reported. Use of the N,O-ligand derived from 2,2/-diphenylglycine afforded either 5 or a by-product [Ph₂NCH₂(3,5-tBu₂C₆H₂-O-2)AlMe₂] (7). The known Schiff base complex [2-Ph₂PC₆H4CH₂(3,5-tBu₂C₃H₂-O-2)AlMe₂] (8) and the product of the reaction of 2-diphenylphosphinoaniline 1-NH₂,2-PPh₂C₆H4 with Me3Al, namely {Ph₂PC₆H4N[(Me₂Al)₂mu-Me](mu-Me₂Al)} (9) were also isolated. For structural and catalytic comparisons, complexes resulting from interaction of Me₃Al with diphenylamine or benzhydrylamine, namely {Ph₂N[(Me₂Al)2mu-Me]} (10) and [Ph₂CHNH(mu-Me₂Al)]₂·MeCN (11), were prepared. The molecular structures of the Schiff pro-ligands derived from Ph₂CHNH₂ and 2,2/-Ph2C(CO₂H)(NH₂), together with complexes 5, 7 and 9 - 11·MeCN were determined. All complexes have been screened for their ability to ring opening polymerization (ROP) epsilon-caprolactone, delta-valerolactone or rac-lactide, in the presence of benzyl alcohol, with or without solvent present. The co-polymerization of epsilon-caprolactone with rac-lactide has also been studied
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