1,731 research outputs found

    Lessons Learned to Improve the UX Practices in Agile Projects Involving Data Science and Process Automation

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    Context: User-Centered Design and Agile methodologies focus on human issues. Nevertheless, agile methodologies focus on contact with contracting customers and generating value for them. Usually, the communication between end users and the agile team is mediated by customers. However, they do not know the problems end users face in their routines. Hence, UX issues are typically identified only after the implementation, during user testing and validation. Objective: Aiming to improve the understanding and definition of the problem in agile projects, this research investigates the practices and difficulties experienced by agile teams during the development of data science and process automation projects. Also, we analyze the benefits and the teams' perceptions regarding user participation in these projects. Method: We collected data from four agile teams in an academia-industry collaboration focusing on delivering data science and process automation solutions. Therefore, we applied a carefully designed questionnaire answered by developers, scrum masters, and UX designers. In total, 18 subjects answered the questionnaire. Results: From the results, we identify practices used by the teams to define and understand the problem and to represent the solution. The practices most often used are prototypes and meetings with stakeholders. Another practice that helped the team to understand the problem was using Lean Inceptions. Also, our results present some specific issues regarding data science projects. Conclusion: We observed that end-user participation can be critical to understanding and defining the problem. They help to define elements of the domain and barriers in the implementation. We identified a need for approaches that facilitate user-team communication in data science projects and the need for more detailed requirements representations to support data science solutions

    Using Model Cards for ethical reflection on machine learning models: an interview-based study

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    How do tools designed for documenting machine learning models contribute to developers’ ethical reflection? We set out to answer this question regarding Model Cards, a tool proposed for such purpose. We conducted a thematic analysis of eight semi-structured interviews based on speculative design sessions. Each participant assumed the role of developer of an artificial intelligence model in one of two scenarios: loan applications or university admissions. We found evidence that designers may have been selective about which ethical issues – from among those they had reflected on – they recorded in the Model Cards. While participants were hesitant to grant full autonomy to the artifact to be developed, we identified they still tended to rely on a third party (outside the design team) to mediate the relationship between the system and other stakeholders. Our findings contribute to our understanding of documentation tools, their epistemic value, and how they can be leveraged to engage in a more ethically informed design process of artificial intelligence systems

    Facility Management using digital Obeya Room by integrating BIM-Lean approaches – an empirical study

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    This paper applies a methodology for interdisciplinary Facilities Management (FM) by alingment between Building Information Modeling (BIM) and Lean. Initially, the literature review of BIM, FM and Lean principles. Afterwards, the research applies the Digital Obeya Room for improved FM and describes its application on a real-world case study. Lastly, the work presents a survey with specialists to assess the relevance of each BIM-Lean concepts and correlate their perceptions with the empirical results. The main collaborations of this work are: a conceptual framework that relates the PDCA (Plan-Do-Check-Act) cycle with BIM-Lean approaches; the identification of the most relevant BIM functionalies and Lean principles; and the real-world application of the framework procedures on FM

    Observation of two new Ξb−\Xi_b^- baryon resonances

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    Two structures are observed close to the kinematic threshold in the Ξb0π−\Xi_b^0 \pi^- mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb−1^{-1} recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content bdsbds are expected in this mass region: the spin-parity JP=12+J^P = \frac{1}{2}^+ and JP=32+J^P=\frac{3}{2}^+ states, denoted Ξbâ€Č−\Xi_b^{\prime -} and Ξb∗−\Xi_b^{*-}. Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be m(Ξbâ€Č−)−m(Ξb0)−m(π−)=3.653±0.018±0.006m(\Xi_b^{\prime -}) - m(\Xi_b^0) - m(\pi^{-}) = 3.653 \pm 0.018 \pm 0.006 MeV/c2/c^2, m(Ξb∗−)−m(Ξb0)−m(π−)=23.96±0.12±0.06m(\Xi_b^{*-}) - m(\Xi_b^0) - m(\pi^{-}) = 23.96 \pm 0.12 \pm 0.06 MeV/c2/c^2, Γ(Ξb∗−)=1.65±0.31±0.10\Gamma(\Xi_b^{*-}) = 1.65 \pm 0.31 \pm 0.10 MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of Γ(Ξbâ€Č−)<0.08\Gamma(\Xi_b^{\prime -}) < 0.08 MeV at 95% confidence level. Relative production rates of these states are also reported.Comment: 17 pages, 2 figure

    Observation of an Excited Bc+ State

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    Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+Îł decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date

    Precision measurement of CPCP violation in Bs0→J/ψK+K−B_s^0 \to J/\psi K^+K^- decays

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    The time-dependent CPCP asymmetry in Bs0→J/ψK+K−B_s^0 \to J/\psi K^+K^- decays is measured using pppp collision data, corresponding to an integrated luminosity of 3.03.0fb−1^{-1}, collected with the LHCb detector at centre-of-mass energies of 77 and 88TeV. In a sample of 96 000 Bs0→J/ψK+K−B_s^0 \to J/\psi K^+K^- decays, the CPCP-violating phase ϕs\phi_s is measured, as well as the decay widths ΓL\Gamma_{L} and ΓH\Gamma_{H} of the light and heavy mass eigenstates of the Bs0−Bˉs0B_s^0-\bar{B}_s^0 system. The values obtained are ϕs=−0.058±0.049±0.006\phi_s = -0.058 \pm 0.049 \pm 0.006 rad, Γs≡(ΓL+ΓH)/2=0.6603±0.0027±0.0015\Gamma_s \equiv (\Gamma_{L}+\Gamma_{H})/2 = 0.6603 \pm 0.0027 \pm 0.0015ps−1^{-1}, andΔΓs≡ΓL−ΓH=0.0805±0.0091±0.0032\Delta\Gamma_s \equiv \Gamma_{L} - \Gamma_{H} = 0.0805 \pm 0.0091 \pm 0.0032ps−1^{-1}, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements of those quantities to date. A combined analysis with Bs0→J/ψπ+π−B_s^{0} \to J/\psi \pi^+\pi^- decays gives ϕs=−0.010±0.039\phi_s = -0.010 \pm 0.039 rad. All measurements are in agreement with the Standard Model predictions. For the first time the phase ϕs\phi_s is measured independently for each polarisation state of the K+K−K^+K^- system and shows no evidence for polarisation dependence.Comment: 6 figure

    Observation of the Bs0→ηâ€Čηâ€ČB^0_s\to\eta'\eta' decay

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    The first observation of the Bs0→ηâ€Čηâ€ČB^0_s\to\eta'\eta' decay is reported. The study is based on a sample of proton-proton collisions corresponding to 3.03.0 fb−1{\rm fb^{-1}} of integrated luminosity collected with the LHCb detector. The significance of the signal is 6.46.4 standard deviations. The branching fraction is measured to be [3.31±0.64 (stat)±0.28 (syst)±0.12 (norm)]×10−5[3.31 \pm 0.64\,{\rm (stat)} \pm 0.28\,{\rm (syst)} \pm 0.12\,{\rm (norm)}]\times10^{-5}, where the third uncertainty comes from the B±→ηâ€ČK±B^{\pm}\to\eta' K^{\pm} branching fraction that is used as a normalisation. In addition, the charge asymmetries of B±→ηâ€ČK±B^{\pm}\to\eta' K^{\pm} and B±→ϕK±B^{\pm}\to\phi K^{\pm}, which are control channels, are measured to be (−0.2±1.3)%(-0.2 \pm1.3)\% and (+1.7±1.3)%(+1.7\pm1.3)\%, respectively. All results are consistent with theoretical expectations

    Differential branching fraction and angular analysis of Λb0→ΛΌ+Ό−\Lambda^{0}_{b} \rightarrow \Lambda \mu^+\mu^- decays

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    The differential branching fraction of the rare decay Λb0→ΛΌ+Ό−\Lambda^{0}_{b} \rightarrow \Lambda \mu^+\mu^- is measured as a function of q2q^{2}, the square of the dimuon invariant mass. The analysis is performed using proton-proton collision data, corresponding to an integrated luminosity of 3.0 \mbox{ fb}^{-1}, collected by the LHCb experiment. Evidence of signal is observed in the q2q^2 region below the square of the J/ψJ/\psi mass. Integrating over 15 < q^{2} < 20 \mbox{ GeV}^2/c^4 the branching fraction is measured as d\mathcal{B}(\Lambda^{0}_{b} \rightarrow \Lambda \mu^+\mu^-)/dq^2 = (1.18 ^{+ 0.09} _{-0.08} \pm 0.03 \pm 0.27) \times 10^{-7} ( \mbox{GeV}^{2}/c^{4})^{-1}, where the uncertainties are statistical, systematic and due to the normalisation mode, Λb0→J/ψΛ\Lambda^{0}_{b} \rightarrow J/\psi \Lambda, respectively. In the q2q^2 intervals where the signal is observed, angular distributions are studied and the forward-backward asymmetries in the dimuon (AFBlA^{l}_{\rm FB}) and hadron (AFBhA^{h}_{\rm FB}) systems are measured for the first time. In the range 15 < q^2 < 20 \mbox{ GeV}^2/c^4 they are found to be A^{l}_{\rm FB} = -0.05 \pm 0.09 \mbox{ (stat)} \pm 0.03 \mbox{ (syst)} and A^{h}_{\rm FB} = -0.29 \pm 0.07 \mbox{ (stat)} \pm 0.03 \mbox{ (syst)}.Comment: 27 pages, 10 figures, Erratum adde

    First observation and amplitude analysis of the B−→D+K−π−B^{-}\to D^{+}K^{-}\pi^{-} decay

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    The B−→D+K−π−B^{-}\to D^{+}K^{-}\pi^{-} decay is observed in a data sample corresponding to 3.0 fb−13.0~\rm{fb}^{-1} of pppp collision data recorded by the LHCb experiment during 2011 and 2012. Its branching fraction is measured to be B(B−→D+K−π−)=(7.31±0.19±0.22±0.39)×10−5{\cal B}(B^{-}\to D^{+}K^{-}\pi^{-}) = (7.31 \pm 0.19 \pm 0.22 \pm 0.39) \times 10^{-5} where the uncertainties are statistical, systematic and from the branching fraction of the normalisation channel B−→D+π−π−B^{-}\to D^{+}\pi^{-}\pi^{-}, respectively. An amplitude analysis of the resonant structure of the B−→D+K−π−B^{-}\to D^{+}K^{-}\pi^{-} decay is used to measure the contributions from quasi-two-body B−→D0∗(2400)0K−B^{-}\to D_{0}^{*}(2400)^{0}K^{-}, B−→D2∗(2460)0K−B^{-}\to D_{2}^{*}(2460)^{0}K^{-}, and B−→DJ∗(2760)0K−B^{-}\to D_{J}^{*}(2760)^{0}K^{-} decays, as well as from nonresonant sources. The DJ∗(2760)0D_{J}^{*}(2760)^{0} resonance is determined to have spin~1.Comment: 39 pages, 10 figures, submitted to Phys. Rev. D. Updated following erratum 10.1103/PhysRevD.93.11990

    Bose-Einstein correlations of same-sign charged pions in the forward region in pp collisions at √s=7 TeV

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    Bose-Einstein correlations of same-sign charged pions, produced in protonproton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the form of an enhancement of pairs of like-sign charged pions with small four-momentum difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source is investigated, determining both the correlation radius and the chaoticity parameter. The measured correlation radius is found to increase as a function of increasing charged-particle multiplicity, while the chaoticity parameter is seen to decreas
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