Normal Forms and Equivalence of K-periodically Routed Graphs

We introduce K-periodically Routed Graphs, which are extensions of Marked Graphs with routing nodes, governed by ultimately periodic binary sequences. We study data relations and dependencies, as well as equational transformations of the network topology. We show the existence of expanded normal forms. We prove that some transformations preserve external flow equivalence. Issues arising from internal flow interleavings and permutations are also tackled

Dynamic Variable Stage Pipeline: an Implementation of its Control

RR-6918Energy efficient computing is a major concern in all EDA industry, due mainly to cost, reliability and feasibility: temperature and power are themain performance limiters. Dynamic Variable Stages Pipelines allows to improve processors and data-paths throughput while reducing their energy consumptions. When the clock frequency is lowered, more computations can be performed in a combinatorial way. In such case, signals can go farther away than the fixed pipelines boundaries needed to ensure correct behaviour at high-frequency clock. Dynamic Variables Stages Pipelines allow to save dynamic power when stalling clock on bypassed pipeline buffers. This paper copes with the control for such Dynamic Variable Stages Pipelines. The control must ensure correct mode switches from/to Long Pipeline High Frequency and Short Pipeline Low Frequency. We provide an implementation with distributed control, and another one with centralized control, allowing to cope with very long pipelines where physical latencies can cause feasibility issues

Throughput and FIFO Sizing: an Application to Latency-Insensitive Design

RR-6919On-chip communications are a key concern for high end designs. Since latency issues cannot be avoided in deep-submicron technologies, design methodologies need to cope with it. In such a case, precise FIFO sizings are of high interest, to find the right trade-off in between area, power and throughput. This paper provides means to size optimally FIFOs while reaching maximum achievable throughput. We apply our algorithms to Latency-Insensitive Designs. Such algorithms can also be used to size FIFOs in other application fields, as for instance Networks-on-Chips. We also revisit the equalization process, which introduces as much latencies as possible in the system while preserving global system throughput. This algorithm point out where it is possible to introduce more stage of pipelines while ensuring the maximum throughput of the system. It allows for instance to postpone execution of IP(s) to limit dynamic power peak. We provide a modified algorithm that globally minimizes the number of such introduced latencies

LID: Retry Relay Station and Fusion Shell

This paper is electronically published in Electonic Notes In Theoretical Computer Science http://dx.doi.org/10.1016/j.entcs.2009.07.026This paper introduces a new variant implementation of Latency-Insensitive Design elements. It optimizes area footprint of so-called Shell-Wrappers being partially fused with their input Relay-Stations. The modified Relay-Station is called a Retry Relay-Station. We show correctness of this implementation and provide comparative results between a regular implementation and our new one on both FPGA and ASIC

Kahn-extended Event Graphs

Process Networks have long been used as formal Models of Computation in the design of dedicated hardware and software embedded systems and Systems-on-Chip. Choice-less models such as Marked/Event Graphs and their Synchronous Data Flow extensions have been considered to support periodic scheduling analysis. Those models do not hide dependency informations like regular sequential languages: they capture the communication topology through point-to-point channels. Those models are concurrent, formally defined, have a clear semantic but are limited due to static point-to-point channels. Then, further extensions such as Cyclo-Static Data Flow or Boolean-controlled Dataflow (BDF) graphs introduced routing switches, allowing internal choices while preserving conflict-freeness, in the tradition of Kahn Process Networks. We introduce a new model, which we term Kahn-extended Event Graphs (KEG). It can be seen as a specialization of both Cyclo-Static and BDF processes. It consists merely in the addition of Merge/Select routing nodes to former Marked/Event Graphs; but, most importantly, these new nodes are governed by explicit (ultimately periodic) binary-word switching patterns for routing directions. We introduce identities on Merge/Select expressions, and show how they build a full axiomatization for the flow-equivalence between the computation nodes. The transformations carry a strong intuitive meaning, as they correspond to sharing/unsharing the interconnect links. Such interconnect defines each time a precise Network-on-Chip topology, and the switching patterns drive the traffic. One can also compute the buffering space actually required at the various fifo locations. The example of a Sobel edge filter is discussed to illustrate the importance of this model

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Search for High-Mass Resonances Decaying to τν in pp Collisions at √s=13 TeV with the ATLAS Detector

A search for high-mass resonances decaying to τν using proton-proton collisions at √s=13 TeV produced by the Large Hadron Collider is presented. Only τ-lepton decays with hadrons in the final state are considered. The data were recorded with the ATLAS detector and correspond to an integrated luminosity of 36.1 fb−1. No statistically significant excess above the standard model expectation is observed; model-independent upper limits are set on the visible τν production cross section. Heavy W′ bosons with masses less than 3.7 TeV in the sequential standard model and masses less than 2.2–3.8 TeV depending on the coupling in the nonuniversal G(221) model are excluded at the 95% credibility level