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ABSTRACT: We take sorting of large data sets as case study for making data-intensive applications more energy-efficient. Using a low-power processor, solid state disks, and efficient algorithms, we beat the current records in the JouleSort benchmark for 10 GB to 1 TB of data by factors of up to 5.1. Since we also use parallel processing, this usually comes without a performance penalty.
Green Computing Conference, 2010 International; 09/2010
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S. Chekanov,
M. Derrick,
D. Krakauer,
J. H. Loizides,
S. Magill,
S. Miglioranzi,
B. Musgrave,
J. Repond,
R. Yoshida,
M. C. K. Mattingly, [......],
W. H. Smith,
A. Deshpande,
S. Dhawan,
S. Bhadra,
C. D. Catterall,
S. Fourletov,
G. Hartner,
S. Menary,
M. Soares,
J. Standage
Physical review D: Particles and fields 08/2006; 74(5):59906.
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S. Chekanov, M. Derrick, D. Krakauer, J. H. Loizides,
S. Miglioranzi S. Magill,
M. C. K. Mattingly,
P. Antonioli,
G. Bari,
M. Basile,
L. Bellagamba,
D. Boscherini,
A. Bruni,
G. Bruni, [......],
W. H. Smith,
A. Deshpande,
S. Dhawan,
S. Bhadra,
C. D. Catterall,
S. Fourletov,
G. Hartner,
S. Menary,
M. Soares,
J. Standage
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ABSTRACT: The photoproduction of bottom quarks in events with two jets and a muon has been measured with the ZEUS detector at HERA using an integrated luminosity of 110 pb-1. The fraction of jets containing b quarks was extracted from the transverse momentum distribution of the muon relative to the closest jet. Differential cross sections for bottom production as a function of the transverse momentum and pseudorapidity of the muon, of the associated jet and of xγjets, the fraction of the photon’s momentum participating in the hard process, are compared with MC models and QCD predictions made at next-to-leading order. The latter give a good description of the data.
Phys. Rev. D. 07/2004; 70(1).
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S Chekanov,
M Derrick,
D Krakauer,
J H Loizides,
S Magill,
S Miglioranzi,
B Musgrave,
J Repond,
R Yoshida,
M C K Mattingly, [......],
O Kind, U Meyer,
E Paul,
J Rautenberg,
R Renner,
A Stifutkin,
J Tandler,
K C Voss,
M Wang,
A Weber
Physics Letters B. 01/2004; 583:231-246.
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Zeus Collaboration,
S Chekanov,
M Derrick,
D Krakauer,
J H Loizides,
S Magill,
B Musgrave,
J Repond,
R Yoshida,
M C K Mattingly, [......],
O Kind, U Meyer,
E Paul,
J Rautenberg,
R Renner,
A Stifutkin,
J Tandler,
K C Voss,
M Wang,
A Weber
Physics Letters B. 01/2004; 578:33-44.
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Kh Khayyat,
T Weber,
R Dörner,
M Achler,
V Mergel,
L Spielberger,
O Jagutzki, U Meyer,
J Ullrich,
R Moshammer, [......],
U Mikkelsen,
P Aggerholm,
E Uggerhoej,
S P Moeller,
V D Rodríguez,
S F C O'Rourke,
R E Olson,
P D Fainstein,
J H McGuire,
H Schmidt-Böcking
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ABSTRACT: Cross sections are presented for the first time for antiproton-helium collisions at an energy of 945 keV differential in longitudinal electron and recoil-ion momenta. The longitudinal momentum distributions for antiproton impact are compared with 1 MeV proton-helium collision. The electron and the recoil-ion momentum distributions for antiprotons agree with those for protons to within 10%. We did not observe a difference between antiproton impact and proton impact. A comparison with CDW and CTMC theories is presented.
Journal of Physics B Atomic Molecular and Optical Physics 12/1998; 32(4):L73. · 1.88 Impact Factor
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ABSTRACT: The coherent state model (CSM) and the triaxial rotation-vibration model (TRVM) are alternatively used to describe the ground, γ and β bands of 228Th. CSM is also applied to the nuclei 126Xe and 130Ba, which were recently considered in TRVM. The two models are compared with respect to both their underlying assumptions and to their predicted results for energy levels and E2 branching ratios. Both models describe energies and quadrupole transitions of 228Th equally well and in good agreement with experiment, if the 03+ level at 1120 keV is interpreted as the head of the β band. The other two 0+ levels at 832 and 939 keV are most likely not of a pure quadrupole vibration nature as has been already pointed out in the literature.
Nuclear Physics A 12/1998; 637(3):321-334. · 1.54 Impact Factor
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Zeus Collaboration,
S Chekanov,
M Derrick,
S Magill,
S Miglioranzi,
B Musgrave,
J Repond,
R Yoshida,
M C K Mattingly,
N Pavel, [......],
P Irrgang,
H.-P Jakob,
O Kind, U Meyer,
E Paul,
J Rautenberg,
R Renner,
K C Voss,
M Wang,
M Wlasenko
01/2002;
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ABSTRACT: Two Tube immunoassays have been developed for the detection and quantification of fungal antigens in grape juice. One for Botrytis, the main cause of Bunch rot in grapes in California, and the other for Botrytis plus rot caused by species of Aspergillus and Penicillium, fungi that can also be involved in Bunch rot. The assays, which are rapid, user friendly and do not require laboratory facilities were designed and tested for on-site use at wineries during harvest. Both assays employ highly specific monoclonal antibodies, BC12.CA4, for Botrytis and an hitherto unreported antibody, AF-CA2, for all species of Aspergillus and Penicillium. The protocol for both assays is the same and mirrors that used in plate-trapped antigen (PTA) ELISAs. The antibodies detect water-soluble fungal antigens present in juice from infected grapes that bind rapidly to the walls of Nunc immunosorbent tubes. Saline extracts from freeze-dried mycelial cultures of Botrytis cinerea and Aspergillus niger are used as standards. The assays are very sensitive detecting between 1 and 3% levels of rot in grapes corresponding to 10–30 μg/ml extracts from freeze-dried mycelium. Absorbance values from the Tube assays parallel but do not equal those from PTA-ELISA tests. No problems were encountered with tests carried out on the testing stands at wineries at harvest time by personnel with no scientific background.
Analytica Chimica Acta.
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ABSTRACT: The primary purpose of the Space VLBI Geodesy Demonstration Experiment (GEDEX) is to test how this new potential space geodetic technique works in practice using data from the first dedicated space VLBI satellite HALCA. Here we present our experience with a test observation made in December 1997. The data flow and pre-processing procedure is outlined. Initial results of preliminary data reduction using GINS, the CNES/GRGS software for analysis of space geodetic technique data, are presented.
Advances in Space Research.
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ABSTRACT: Collective quadrupole degrees of freedom give rise to vibrations and rotations in nuclei. The axial Rotation Vibration Model (RVM) is here extended to describe also triaxial equilibrium shapes with β and γ vibrations allowing for the interaction between vibrations and rotations. This Triaxial Rotation Vibration Model (TRVM( is applied to Ba and Xe isotopes with A ≈ 120 to 130. This are has recently been pointed out to be a region for the O(6) limit of the Interacting Boson Approximation (IBA). The present work shows that the TRVM can equally well describe these nuclei concerning their excitation energies and E2 branching ratios.
Nuclear Physics A.
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ABSTRACT: The aim of the study was to compare two ozone exposure patterns with different peak concentrations under equal dose conditions. Spring wheat (Triticum aestivum cv. ‘Nandu’) was ‘pre-cultivated’ under glasshouse conditions and exposed to two different ozone exposure scenarios (A: 1700–0900 h: 20 ppb, 0900–1700 h: 65 ppb; B: 1600–1200 h: 20 ppb, 1200–1600 h: 110 ppb) in large fumigation chambers for two weeks during anthesis. Control plants received charcoal filtered ambient air (<5 ppb ozone 24 h/day) (CF). Chlorophyll content as well as chlorophyll fluorescence (Fv : Fm ratio) and carbohydrate composition (hexoses, sucrose, starch) were monitored in flag leaves and in the case of carbohydrate content also in the penultimate internode during and after ozone exposure. Thousand grain weight (TGW) was determined for estimating yield effects. Photosynthesis decreased markedly in both treatments expressed as Fv : Fm ratio. In treatment B chlorophyll content (a + b) of leaves was reduced by 40% after 7 and 14 days of exposure (p ≤ 0.001). Carbohydrate content decreased significantly as compared with CF-plants to 20% (p ≤ 0.001) in the case of sucrose and starch. Effects were especially pronounced in treatment B (110 ppb for 4 h) and could be observed even seven days after exposure under CF conditions. After 14 days of exposure during anthesis, plants were incapable of recovery as shown by a significant reduction in thousand grain weight of ozone treated plants compared with CF-plants (treatment B: 22% at p ≤ 0.001). Effects on photosynthesis and carbon content even under moderate daily ozone peaks as in treatment A induced a significant yield loss of 11% (p ≤ 0.001) as well, when applied during anthesis. It can be concluded that under equal dose conditions ozone treatments with comparatively high peak concentration induce more pronounced effects than ozone patterns with moderate peaks.
Agriculture, Ecosystems & Environment.
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ABSTRACT: The survival of loaded implants is critically dependent on their biomechanical stability. We have used a computer-guided navigation technique to evaluate the accuracy of computer-assisted insertion for immediately-loaded implants in minipigs. On the basis of computed tomographical data, the Robodent system was used for preoperative planning and guidance of inserting the implant. An optical tracking system allowed positioning of the implant and immediate prosthetic rehabilitation by inserting it in a plaster model and during the operation. Postoperative computed tomograms (CT) showed that the implants were placed precisely in the preoperatively planned position. The accuracy achieved corresponded well with the spatial resolution of the CT used. Immediate placement of the prefabricated crowns resulted in favourable occlusal positioning. Histological cross-sections showed that the implants were biomechanically stable. The accuracy of insertion of oral implants illustrated here suggests that insertion and prosthetic modelling of implants may benefit from computer-assisted navigation.
British Journal of Oral and Maxillofacial Surgery.
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S. Chekanov,
M. Derrick,
J.H. Loizides,
S. Magill,
S. Miglioranzi,
B. Musgrave,
J. Repond,
R. Yoshida,
M.C.K. Mattingly,
N. Pavel, [......],
A.A. Savin,
W.H. Smith,
S. Dhawan,
S. Bhadra,
C.D. Catterall,
S. Fourletov,
G. Hartner,
S. Menary,
M. Soares,
J. Standage
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ABSTRACT: First measurements of cross sections for isolated prompt photon production in deep inelastic ep scattering have been made using the ZEUS detector at the HERA electron–proton collider using an integrated luminosity of 121 pb−1. A signal for isolated photons in the transverse energy and rapidity ranges and −0.7<ηγ<0.9 was observed for virtualities of the exchanged photon of . Cross sections are presented for inclusive prompt photons and for those accompanied by a single jet in the range and −1.5⩽ηjet<1.8. Calculations at order α3αs describe the data reasonably well.
Physics Letters B.
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S. Chekanov,
M Derrick,
J.H. Loizides,
S Magill,
S. Miglioranzi,
B Musgrave,
J Repond,
R Yoshida,
M.C.K. Mattingly,
N Pavel, [......],
R Carlin,
F Dal Corso,
S Dusini,
A Garfagnini,
S Limentani,
A. Longhin,
A Parenti,
M Posocco,
L Stanco,
M Turcato
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ABSTRACT: The beauty production cross section for deep inelastic scattering events with at least one hard jet in the Breit frame together with a union has been measured, for photon virtualities Q(2) gt 2 GeV2, with the ZEUS detector at HERA using integrated luminosity of 72 pb(-1) The total visible cross section is sigma(bb)- (ep → e jet muX) = 40.9 +/- 5.7 (stat.) (+6.0)(-4.4) (syst) pb. The next-to- leading order QCD prediction lies about 2.5 standard deviations below the data. The differential cross sections are in general consistent with the NLO QCD predictions; however at low values of Q(2), Bjorken x, and muon transverse momentum, and high values of jet transverse energy and muon pseudorapidity, the prediction is about two standard deviations below the data. (C) 2004 Published by Elsevier B.V
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S. Chekanov,
M Derrick,
D Krakauer,
J.H. Loizides,
S Magill,
B Musgrave,
J Repond,
R Yoshida,
M.C. Mattingly,
P. Antonioli, [......],
F Dal Corso,
S Dusini,
A Garfagnini,
S Limentani,
A. Longhin,
A Parenti,
M Posocco,
L Stanco,
M Turcato,
E.A. Heaphy
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ABSTRACT: The cross-section for deeply virtual Compton scattering in the reaction ep → egammap has been measured with the ZEUS detector at HERA using integrated luminosities of 95.0 pb(-1) of e(+) p and 16.7 pb(-1) of e(-) p collisions. Differential cross-sections are presented as a function of the exchanged- photon virtuality, Q(2), and the centre-of-mass energy, W, of the gamma*p system in the region 5 lt Q(2) lt 100 GeV2 and 40 lt W lt 140 GeV. The measured cross-sections rise steeply with increasing W. The measurements are compared to QCD-based calculations. (C) 2003 Elsevier B.V. All rights reserved
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S. Chekanov,
M Derrick,
D Krakauer,
J.H. Loizides,
S Magill,
B Musgrave,
J Repond,
R Yoshida,
M.C.K. Mattingly,
P. Antonioli, [......],
R Carlin,
F Dal Corso,
S Dusini,
A Garfagnini,
S Limentani,
A. Longhin,
A Parenti,
M Posocco,
L Stanco,
M Turcato
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ABSTRACT: Cross sections for e (+) p charged current deep inelastic scattering at a centre-of-mass energy of 318 [LF]GeV have bee n determined with an integrated luminosity of 60.9 pb(-1) collected with the ZEUS detector at HERA. The differential cross sections dsigma/dQ(2), dsigma/dx and dsigma/dy for Q(2) > 200 GeV are presented. In addition, d(2)sigma/d x d Q(2) has been measured in the kinematic range 280 GeV2 < Q(2) < 17 000 Gev(2) and 0.008 << x < 0.42. The predictions of the Standard Model agree well with the measured cross sections. The mass of the W boson propagator is determined to be M-W = 78.9 [LF]+/- 2.0 (stat.) +/- 1.8(syst.)(-1.8)(+2.0) (PDF) GeV from a fit to dsigma/dQ(2). The chiral structure of the Standard Model is also investigated in terms of the (1-y)(2) dependence of the double-differential cross section. The structure-function F- 2(CC) has been extracted by combining the measurements presented here with previous ZEUS results from e(-)p scattering, extending the measurement obtained in a neutrino- nucleus scattering experiment to a significantly higher Q(2) region.
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S. Chekanov,
M Derrick,
D Krakauer,
J.H. Loizides,
S Magill,
B Musgrave,
J Repond,
R Yoshida,
M.C.K. Mattingly,
P. Antonioli, [......],
R Carlin,
E. Dal Corso,
S Dusini,
A Garfagnini,
S Limentani,
A. Longhin,
A Parenti,
M Posocco,
L Stanco,
M Turcato
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ABSTRACT: Production of D*+/-(2010) mesons in diffractive deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb(-1). Diffractive events were identified by the presence of a large rapidity gap in the final state. Differential cross sections have been measured in the kinematic region 1.5 lt Q(2) lt 200 GeV2 0.02 lt y lt 0.7, x(P) lt 0.035, beta lt 0.8, P-T (D*+/-) gt 1.5 GeV and \eta(D*+/-)\ lt 1.5. The measured cross sections are compared to theoretical predictions. The results are presented in terms of the open- charm contribution to the diffractive proton structure function. The data demonstrate a strong sensitivity to the diffractive parton densities.
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S. Chekanov,
M Derrick,
D Krakauer,
J.H. Loizides,
S Magill,
B Musgrave,
J Repond,
R Yoshida,
M.C.K. Mattingly,
P. Antonioli, [......],
R Brugnera,
R Carlin,
F Dal Corso,
S Dusini,
A Garfagnini,
S Limentani,
A. Longhin,
A Parenti,
M Posocco,
L Stanco
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ABSTRACT: A search for narrow-width resonances that decay into electron+jet or neutrino+jet has been performed with the ZEUS detector at the DESY ep collider HERA operating at center-of- mass energies of 300 and 318 GeV. An integrated e(+)p luminosity of 114.8 pb(-1) and e(-)p luminosity of 16.7 pb(-1) were used. No evidence for any resonance was found. Limits were derived on the Yukawa coupling lambda as a function of the mass of a hypothetical resonance that has arbitrary decay branching ratios into eq or nuq. These limits also apply to squarks predicted by R-parity-violating supersymmetry. Limits for the production of leptoquarks described by the Buchmuller-Ruckl- Wyler model were also derived for masses up to 400 GeV. For lambda=0.1, leptoquark masses up to 290 GeV are excluded.
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S. Chekanov,
M Derrick,
D Krakauer,
J.H. Loizides,
S Magill,
B Musgrave,
J Repond,
R Yoshida,
M.C.K. Mattingly,
P. Antonioli, [......],
R Carlin,
F Dal Corso,
S Dusini,
A Garfagnini,
S Limentani,
A. Longhin,
A Parenti,
M Posocco,
L Stanco,
M Turcato
[show abstract]
[hide abstract]
ABSTRACT: A search for single-top production, ep to et X, has been made with the ZEUS detector at HERA using an integrated luminosity of 130.1 pb/sup -1/. Events from both the leptonic and hadronic decay channels of the W boson resulting from the decay of the top quark were sought. For the leptonic mode, the search was made for events with isolated high-energy leptons and significant missing transverse momentum. For the hadronic decay mode, three-jet events in which two of the jets had an invariant mass consistent with that of the W were selected. No evidence for top production was found. The results are used to constrain single-top production via flavour-changing neutral current (FCNC) transitions. The ZEUS limit excludes a substantial region in the FCNC tu gamma coupling not ruled out by other experiments.
