Online Fault Classification in HPC Systems through Machine Learning

As High-Performance Computing (HPC) systems strive towards the exascale goal, studies suggest that they will experience excessive failure rates. For this reason, detecting and classifying faults in HPC systems as they occur and initiating corrective actions before they can transform into failures will be essential for continued operation. In this paper, we propose a fault classification method for HPC systems based on machine learning that has been designed specifically to operate with live streamed data. We cast the problem and its solution within realistic operating constraints of online use. Our results show that almost perfect classification accuracy can be reached for different fault types with low computational overhead and minimal delay. We have based our study on a local dataset, which we make publicly available, that was acquired by injecting faults to an in-house experimental HPC system.Comment: Accepted for publication at the Euro-Par 2019 conferenc

You can't see what you can't see: Experimental evidence for how much relevant information may be missed due to Google's Web search personalisation

The influence of Web search personalisation on professional knowledge work is an understudied area. Here we investigate how public sector officials self-assess their dependency on the Google Web search engine, whether they are aware of the potential impact of algorithmic biases on their ability to retrieve all relevant information, and how much relevant information may actually be missed due to Web search personalisation. We find that the majority of participants in our experimental study are neither aware that there is a potential problem nor do they have a strategy to mitigate the risk of missing relevant information when performing online searches. Most significantly, we provide empirical evidence that up to 20% of relevant information may be missed due to Web search personalisation. This work has significant implications for Web research by public sector professionals, who should be provided with training about the potential algorithmic biases that may affect their judgments and decision making, as well as clear guidelines how to minimise the risk of missing relevant information.Comment: paper submitted to the 11th Intl. Conf. on Social Informatics; revision corrects error in interpretation of parameter Psi/p in RBO resulting from discrepancy between the documentation of the implementation in R (https://rdrr.io/bioc/gespeR/man/rbo.html) and the original definition (https://dl.acm.org/citation.cfm?id=1852106) as per 20/05/201

Phase diagram of Eu magnetic ordering in Sn-flux-grown Eu(Fe1−x_{1-x}Cox_{x})2_{2}As2_{2} single crystals

The magnetic ground state of the Eu$^{2+}$ moments in a series of Eu(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ single crystals grown from the Sn flux has been investigated in detail by neutron diffraction measurements. Combined with the results from the macroscopic properties (resistivity, magnetic susceptibility and specific heat) measurements, a phase diagram describing how the Eu magnetic order evolves with Co doping in Eu(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ is established. The ground-state magnetic structure of the Eu$^{2+}$ spins is found to develop from the A-type antiferromagnetic (AFM) order in the parent compound, via the A-type canted AFM structure with some net ferromagnetic (FM) moment component along the crystallographic $\mathit{c}$ direction at intermediate Co doping levels, finally to the pure FM order at relatively high Co doping levels. The ordering temperature of Eu declines linearly at first, reaches the minimum value of 16.5(2) K around $\mathit{x}$ = 0.100(4), and then reverses upwards with further Co doping. The doping-induced modification of the indirect Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between the Eu$^{2+}$ moments, which is mediated by the conduction $\mathit{d}$ electrons on the (Fe,Co)As layers, as well as the change of the strength of the direct interaction between the Eu$^{2+}$ and Fe$^{2+}$ moments, might be responsible for the change of the magnetic ground state and the ordering temperature of the Eu sublattice. In addition, for Eu(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ single crystals with 0.10 $\leqslant$ $\mathit{x}$ $\leqslant$ 0.18, strong ferromagnetism from the Eu sublattice is well developed in the superconducting state, where a spontaneous vortex state is expected to account for the compromise between the two competing phenomena.Comment: 10 pages, 9 figure

Probing the magnetic ground state of the molecular Dysprosium triangle

We present zero field muon spin lattice relaxation measurements of a Dysprosium triangle molecular magnet. The local magnetic fields sensed by the implanted muons indicate the coexistence of static and dynamic internal magnetic fields below $T^* ~35$ K. Bulk magnetization and heat capacity measurements show no indication of magnetic ordering below this temperature. We attribute the static fields to the slow relaxation of the magnetization in the ground state of Dy3. The fluctuation time of the dynamic part of the field is estimated to be ~0.55 $\mu$s at low temperaturesComment: 5 pages, 5 figures, accepted for publication in Phys. Rev.

Leukemia-related chromosomal loss detected in hematopoietic progenitor cells of benzene-exposed workers.

Benzene exposure causes acute myeloid leukemia and hematotoxicity, shown as suppression of mature blood and myeloid progenitor cell numbers. As the leukemia-related aneuploidies monosomy 7 and trisomy 8 previously had been detected in the mature peripheral blood cells of exposed workers, we hypothesized that benzene could cause leukemia through the induction of these aneuploidies in hematopoietic stem and progenitor cells. We measured loss and gain of chromosomes 7 and 8 by fluorescence in situ hybridization in interphase colony-forming unit-granulocyte-macrophage (CFU-GM) cells cultured from otherwise healthy benzene-exposed (n=28) and unexposed (n=14) workers. CFU-GM monosomy 7 and 8 levels (but not trisomy) were significantly increased in subjects exposed to benzene overall, compared with levels in the control subjects (P=0.0055 and P=0.0034, respectively). Levels of monosomy 7 and 8 were significantly increased in subjects exposed to <10 p.p.m. (20%, P=0.0419 and 28%, P=0.0056, respectively) and ≥ 10 p.p.m. (48%, P=0.0045 and 32%, 0.0354) benzene, compared with controls, and significant exposure-response trends were detected (P(trend)=0.0033 and 0.0057). These data show that monosomies 7 and 8 are produced in a dose-dependent manner in the blood progenitor cells of workers exposed to benzene, and may be mechanistically relevant biomarkers of early effect for benzene and other leukemogens

Data-driven urban management: Mapping the landscape

Big data analytics and artificial intelligence, paired with blockchain technology, the Internet of Things, and other emerging technologies, are poised to revolutionise urban management. With massive amounts of data collected from citizens, devices, and traditional sources such as routine and well-established censuses, urban areas across the world have – for the first time in history – the opportunity to monitor and manage their urban infrastructure in real-time. This simultaneously provides previously unimaginable opportunities to shape the future of cities, but also gives rise to new ethical challenges. This paper provides a transdisciplinary synthesis of the developments, opportunities, and challenges for urban management and planning under this ongoing ‘digital revolution’ to provide a reference point for the largely fragmented research efforts and policy practice in this area. We consider both top-down systems engineering approaches and the bottom-up emergent approaches to coordination of different systems and functions, their implications for the existing physical and institutional constraints on the built environment and various planning practices, as well as the social and ethical considerations associated with this transformation from non-digital urban management to data-driven urban management

Determination of the photodisintegration reaction rates involving charged particles: systematical calculations and proposed measurements based on Extreme Light Infrastructure - Nuclear Physics (ELI-NP)

Photodisintegration reaction rates involving charged particles are of relevance to the p-process nucleosynthesis that aims at explaining the production of the stable neutron-deficient nuclides heavier than iron. In this study, the cross sections and astrophysical rates of (g,p) and (g,a) reactions for about 3000 target nuclei with 10<Z<100 ranging from stable to proton dripline nuclei are computed. To study the sensitivity of the calculations to the optical model potentials (OMPs), both the phenomenological Woods-Saxon and the microscopic folding OMPs are taken into account. The systematic comparisons show that the reaction rates, especially for the (g,a) reaction, are dramatically influenced by the OMPs. Thus the better determination of the OMP is crucial to reduce the uncertainties of the photodisintegration reaction rates involving charged particles. Meanwhile, a gamma-beam facility at ELI-NP is being developed, which will open new opportunities to experimentally study the photodisintegration reactions of astrophysics interest. Considering both the important reactions identified by the nucleosynthesis studies and the purpose of complementing the experimental results for the reactions involving p-nuclei, the measurements of six (g,p) and eight (g,a) reactions based on the gamma-beam facility at ELI-NP and the ELISSA detector for the charged particles detection are proposed, and the GEANT4 simulations are correspondingly performed. The minimum required energies of the gamma-beam to measure these reactions are estimated. It is shown that the direct measurements of these photonuclear reactions within the Gamow windows at T_9=2.5 for p-process are fairly feasible and promising at ELI-NP. The expected experimental results will be used to constrain the OMPs of the charged particles, which can eventually reduce the uncertainties of the reaction rates for the p-process nucleosynthesis.Comment: 14 pages, 8 figures, Phys. Rev. C accepte

A Randomized, Double-Blind Study of Larazotide Acetate to Prevent the Activation of Celiac Disease During Gluten Challenge

OBJECTIVES: In patients with celiac disease, enteropathy is caused by the entry of gluten peptides into the lamina propria of the intestine, in which their immunogenicity is potentiated by tissue transglutaminase (tTG) and T-helper type 1–mediated immune responses are triggered. Tight junction disassembly and paracellular permeability are believed to have an important role in the transport of gluten peptides to the lamina propria. Larazotide acetate is a tight-junction regulator peptide that, in vitro, prevents the opening of intestinal epithelial tight junctions. The aim of this study was to evaluate the efficacy and tolerability of larazotide acetate in protecting against gluten-induced intestinal permeability and gastrointestinal symptom severity in patients with celiac disease. METHODS: In this dose-ranging, placebo-controlled study, 86 patients with celiac disease controlled through diet were randomly assigned to larazotide acetate (0.25, 1, 4, or 8 mg) or placebo three times per day with or without gluten challenge (2.4 g/day) for 14 days. The primary efficacy outcome was the urinary lactulose/mannitol (LAMA) fractional excretion ratio. Secondary endpoints included gastrointestinal symptom severity, quality-of-life measures, and antibodies to tTG. RESULTS: LAMA measurements were highly variable in the outpatient setting. The increase in LAMA ratio associated with the gluten challenge was not statistically significantly greater than the increase in the gluten-free control. Among patients receiving the gluten challenge, the difference in the LAMA ratios for the larazotide acetate and placebo groups was not statistically significant. However, larazotide acetate appeared to limit gluten-induced worsening of gastrointestinal symptom severity as measured by the Gastrointestinal Symptom Rating Scale at some lower doses but not at the higher dose. Symptoms worsened significantly in the gluten challenge–placebo arm compared with the placebo–placebo arm, suggesting that 2.4 g of gluten per day is sufficient to induce reproducible gluten toxicity. Larazotide acetate was generally well tolerated. No serious adverse events were observed. The most common adverse events were headache and urinary tract infection. CONCLUSIONS: LAMA variability in the outpatient setting precluded accurate assessment of the effect of larazotide acetate on intestinal permeability. However, some lower doses of larazotide acetate appeared to prevent the increase in gastrointestinal symptom severity induced by gluten challenge

Confined Interfacial Monomicelle Assembly for Precisely Controlled Coating of Single-Layered Titania Mesopores

The development of core-shell structures has been in great demand recently owing to their integrated functionalities. However, the progress in reliable coating of porous semiconductors remains unproductive. Here, we have demonstrated a confined interfacial monomicelle assembly method for controlled coating of ordered single-layered mesoporous TiO2. The coating method can be well controlled with tunable coated layers, mesopore size, and switchable coated surfaces. The resulting mesoporous TiO2 exhibit excellent electrochemical properties as a sodium-ion anode, which is attributed to their unique mesostructures associated with accessible high surface area and ultrathin layers. Such accurately designed mesoporous core-shell nanostructures are expected to provide a useful platform to produce numerous delicate core-shell nanostructures with integrated functionalities and mesoporosities for potential applications, such as catalysts, sensors, energy storage, and energy conversion. - 2019 Elsevier Inc.Mesoporous core-shell nanostructures have recently been receiving extensive scientific interest; however, reliable approaches for coating mesoporous materials still remain exciting challenges, except for amorphous silica. We report, for the first time, a confined interfacial monomicelle assembly method for controlled coating of anatase TiO2 with single-layered ordered mesopores on diverse surfaces, opening up the area of coating ordered mesoporous crystalline materials that possess mesopores originating from self-assembled surfactant instead of accumulated nanocrystals. This facile and repeatable methodology relies on the solvent-confinement effect of glycerol during the assembly process and monomicelle hydrogel preformation by selective evaporation of double-solvent precursors. This assembly process shows precise controllability and great versatility, endowing the coated TiO2 layers with highly tunable thickness, mesopore size, and switchable coated surfaces. The ultrathin monolayered mesopores of such mesoporous TiO2 shells, in combination with their high surface area and highly crystalline nature, afford them excellent rate capability and superior cyclability for sodium-ion storage. - 2019 Elsevier Inc.We have demonstrated a confined interfacial monomicelle assembly approach for accurately coating ordered monolayered TiO2 mesopores on diverse surfaces. By regulating the synthetic conditions, the coated mesoporous TiO2 layers can be well controlled with desired thickness, mesopore size, and switchable coated surfaces. The resulting monolayered mesoporous TiO2 exhibit excellent sodium-storage properties. This unique mesoporous TiO2 coating strategy affords great potential in constructing multicomponent nanostructures with mesoporosities for advanced technologies. - 2019 Elsevier Inc.This work is supported by the State Key Basic Research Program of China ( 2017YFA0207303 ), the National Natural Science Foundation of China ( 21733003 ), the Shanghai Leading Academic Discipline Project ( B108 ), and the Science and Technology Commission of Shanghai Municipality ( 17JC1400100 ). K.L. acknowledges the financial support by the China Scholarship Council ( 201806100112 ). A.E. acknowledges Qatar University under GCC Co-Fund Program grant GCC-2017-001