1,936 research outputs found

    Beneficial and Harmful Agile Practices for Product Quality

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    There is the widespread belief that Agile neglects the product quality. This lack of understanding how Agile processes assure the quality of the product prevents especially companies from regulated domains from an adoption of Agile. This work aims to identify which Agile Practices contribute towards product quality. Hence, data from a survey study is analyzed to identify Ag-ile Practices which are beneficial or harmful for the quality of the product. From 49 practices that were used in the survey so far, 36 were perceived to have a positive impact on product quality, while four practices were rated as being harmful. The results enrich understanding of how product quality can be achieved in Agile, and support selection of practices to improve quality

    Noncontact electrical metrology of Cu/low-k interconnect for semiconductor production wafers

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    We have demonstrated a technique capable of in-line measurement of dielectric constant of low-k interconnect films on patterned wafers utilizing a test key of ~50x50 \mu m in size. The test key consists of a low-k film backed by a Cu grid with >50% metal pattern density and <250 nm pitch, which is fully compatible with the existing dual-damascene interconnect manufacturing processes. The technique is based on a near-field scanned microwave probe and is noncontact, noninvasive, and requires no electrical contact to or grounding of the wafer under test. It yields <0.3% precision and 2% accuracy for the film dielectric constant

    Real-time prediction with U.K. monetary aggregates in the presence of model uncertainty

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    A popular account for the demise of the U.K.’s monetary targeting regime in the 1980s blames the fluctuating predictive relationships between broad money and inflation and real output growth. Yet ex post policy analysis based on heavily revised data suggests no fluctuations in the predictive content of money. In this paper, we investigate the predictive relationships for inflation and output growth using both real-time and heavily revised data. We consider a large set of recursively estimated vector autoregressive (VAR) and vector error correction models (VECM). These models differ in terms of lag length and the number of cointegrating relationships. We use Bayesian model averaging (BMA) to demonstrate that real-time monetary policymakers faced considerable model uncertainty. The in-sample predictive content of money fluctuated during the 1980s as a result of data revisions in the presence of model uncertainty. This feature is only apparent with real-time data as heavily revised data obscure these fluctuations. Out-of-sample predictive evaluations rarely suggest that money matters for either inflation or real output. We conclude that both data revisions and model uncertainty contributed to the demise of the U.K.’s monetary targeting regime

    Hybrid Software Development Approaches in Practice: A European Perspective

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    Agile and traditional development approaches are used in combination in todays software development. To improve the understanding and to provide better guidance for selecting appropriate development approaches, it is important to analyze such combinations in practice. Results obtained from an online survey strongly confirm that hybrid development approaches are widely used in industry. Our results show that hybrid development approaches: (i) have become reality for nearly all companies; (ii) are applied to specific projects even in the presence of company-wide policies for process usage; (iii) are neither planned nor designed but emerge from the evolution of different work practices; and, (iv) are consistently used regardless of company size or industry secto

    Weak decays of 4He-Lambda

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    We measured the lifetime and the mesonic and non-mesonic decay rates of the 4He-Lambda hypernucleus. The hypernuclei were created using a 750 MeV/c momentum K- beam on a liquid 4He target by the reaction 4He(K-,pi-)4He-Lambda. The 4He-Lambda lifetime was directly measured using protons from Lambda p -> n p non-mesonic decay (also referred to as proton-stimulated decay) and was found to have a value of tau = 245 +/- 24 ps. The mesonic decay rates were determined from the observed numbers of pi-'s and pi0's as Gamma_pi-/Gamma_tot = 0.270 +/- 0.024 and Gamma_pi0/Gamma_tot = 0.564 +/- 0.036, respectively, and the values of the proton- and neutron-stimulated decay rates were extracted as Gamma_p/Gamma_tot = 0.169 +/- 0.019 and Gamma_n/Gamma_tot <= 0.032 (95% CL), respectively. The effects of final-state interactions and possible 3-body Lambda N N decay contributions were studied in the context of a simple model of nucleon-stimulated decay. Nucleon-nucleon coincidence events were observed and were used in the determination of the non-mesonic branching fractions. The implications of the results of this analysis were considered for the empirical Delta I = 1/2 rule and the decay rates of the 4H-Lambda hypernucleus.Comment: 15 pages, 11 figures, published in PRC, revised content to match published versio

    Monetary policy uncertainty spillovers in time and frequency domains

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    We use the recently created monthly Interest Rate Uncertainty measure, to investigate monetary policy uncertainty across the US, Germany, France, Italy, Spain, UK, Japan, Canada, and Sweden in both the time and frequency domains. We find that the largest spillover indices are from innovations in the country itself; however, there are some instances where spillover indices between countries are large. These relationships change over time and we observe large variances in pairwise spillovers during the global financial crisis. We find that most of the volatility is confined to the crisis period. Policy makers should consider accounting for the spillovers from the US, Germany, France and Spain, as we found that they are the most consistent net transmitters of monetary policy uncertainty

    Structure and apparent topography of TiO2 (110) surfaces

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    We present self-consistent ab-initio total-energy and electronic-structure calculations on stoichiometric and non-stoichiometric TiO2 (110) surfaces. Scanning tunneling microscopy (STM) topographs are simulated by calculating the local electronic density of states over an energy window appropriate for the experimental positive-bias conditions. We find that under these conditions the STM tends to image the undercoordinated Ti atoms, in spite of the physical protrusion of the O atoms, giving an apparent reversal of topographic contrast on the stoichiometric 1x1 or missing-row 2x1 surface. We also show that both the interpretation of STM images and the direct comparison of surface energies favor an added-row structure over the missing-row structure for the oxygen-deficient 2x1 surface.Comment: 6 pages, two-column style with 5 postscript figures embedded. Uses REVTEX and epsf macros. Also available at http://www.physics.rutgers.edu/~dhv/preprints/index.html#ng_tio

    Properties of the electron-doped infinite-layer superconductor Sr1x_{1-x}Lax_{x}CuO2_{2} epitaxially grown by pulsed laser deposition

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    Thin films of the electron-doped infinite-layer cuprate superconductor Sr1x_{1-x}Lax_xCuO2_2 (SLCO) with doping x0.15x \approx 0.15 were grown by means of pulsed laser deposition. (001)-oriented KTaO3_3 and SrTiO3_3 single crystals were used as substrates. In case of SrTiO3_3, a BaTiO3_3 thin film was deposited prior to SLCO, acting as buffer layer providing tensile strain to the SLCO film. To induce superconductivity, the as-grown films were annealed under reducing conditions, which will be described in detail. The films were characterized by reflection high-energy electron diffraction, atomic force microscopy, x-ray diffraction, Rutherford backscattering spectroscopy, and electric transport measurements at temperatures down to T=4.2T = 4.2\,K. We discuss in detail the influence of different process parameters on the final film properties.Comment: 16 pages, 14 figure

    Inheritance of gene density–related higher order chromatin arrangements in normal and tumor cell nuclei

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    A gene density–related difference in the radial arrangement of chromosome territories (CTs) was previously described for human lymphocyte nuclei with gene-poor CT #18 located toward the nuclear periphery and gene-dense CT #19 in the nuclear interior (Croft, J.A., J.M. Bridger, S. Boyle, P. Perry, P. Teague, and W.A. Bickmore. 1999. J. Cell Biol. 145:1119–1131). Here, we analyzed the radial distribution of chromosome 18 and 19 chromatin in six normal cell types and in eight tumor cell lines, some of them with imbalances and rearrangements of the two chromosomes. Our findings demonstrate that a significant difference in the radial distribution of #18 and #19 chromatin is a common feature of higher order chromatin architecture in both normal and malignant cell types. However, in seven of eight tumor cell lines, the difference was less pronounced compared with normal cell nuclei due to a higher fraction of nuclei showing an inverted CT position, i.e., a CT #18 located more internally than a CT #19. This observation emphasizes a partial loss of radial chromatin order in tumor cell nuclei
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