Effort estimation is always quite a challenge, especially for agile software development projects. This paper describes the process of building a Bayesian network model for effort prediction in agile development. Very few studies have addressed the application of Bayesian networks to assess agile development efforts. Some research has not been validated in practice, and some has been validated on one or two projects. This paper aims to bring the implementation and use of Bayesian networks for effort prediction closer to the practitioners. This process consists of two phases. The Bayesian network model for task effort estimation is constructed and validated in the first phase on real agile projects. A relatively small model showed satisfactory estimation accuracy, but only five output intervals were used. The model was proven to be useful in daily work, but the project manager wanted to obtain more output intervals, although increasing the number of output intervals reduces the prediction accuracy. In the second phase, the focus is on increasing the number of output intervals while maintaining satisfactory accuracy. The advanced model for task effort estimation is developed and tested on real projects of two software firms.

Turnover of the personnel represents a serious issue for management of software projects. The buildup of competences and phasing in of the people into the project requires both time and effort. This paper presents a case study of a large in-house agile software development project. The research goal was to determine the effects that turnover has on the expert effort estimation. In order to do this, paper examines relations across empirical data on a studied project. Study findings are the following: a) it is necessary to distinguish types of turnover, b) the general and planned turnover do not necessarily have a negative effect on estimation accuracy, and c) the unplanned turnover can have a significant negative impact on the reliability of the estimates and therefore should be treated with special attention. Results suggest that these facts should be taken into account both by the management and human resources.

Charged kaon-deuteron interactions offer a sensitive probe of the strangeness sector of QCD at low energy, particularly through their scattering parameters. Despite available theoretical predictions, experimental constraints remain absent, particularly for the K − d system. The first measurement of femtoscopic correlation functions for K − d ⊕ K + d ¯ and K + d ⊕ K − d ¯ particle pairs in Pb-Pb collisions at s NN = 5.02 TeV recorded by ALICE at the LHC is presented. Correlation functions for both systems are analyzed in three centrality classes and fitted using the Lednický-Lyuboshitz model to extract the source size and strong interaction scattering lengths. The K − d scattering length is found to be ℜ f 0 = − 1.44 ± 0.15 ( stat ) − 0.10 + 0.10 ( stat ) fm and ℑ f 0 = 1.34 ± 0.33 ( stat ) − 0.15 + 0.21 ( syst ) fm , while for K + d the value ℜ f 0 = − 0.68 ± 0.16 ( stat ) − 0.09 + 0.09 ( syst ) fm is obtained. These results provide the first constraints on the K ± d interaction modeling at low energy, delivering a long-awaited experimental benchmark for testing chiral QCD dynamics.

This paper presents the measurement of $$\pi ^{\pm }$$ π ± , $$\text {K}^{\pm }$$ K ± , and p( $$\bar{\text {p}}$$ p ¯ ) production in high-multiplicity proton–proton collisions at $$\sqrt{s}=13$$ s = 13 TeV at midrapidity ( $$|y| < 0.5$$ | y | < 0.5 ) using the ALICE detector at the LHC. The transverse-momentum ( $$p_\textrm{T} $$ p T ) spectra of these particles are reported for three high-multiplicity classes. The results show a mass- and multiplicity-dependent hardening of the $$p_\textrm{T} $$ p T spectra and an enhancement of the p/ $$\pi $$ π ratio at intermediate $$p_\textrm{T} $$ p T . These features are similar to those observed in heavy-ion collisions, where quark–gluon plasma formation is expected. The new measurements have extended the highest average charged-particle multiplicity density per unit of pseudorapidity achieved in pp collisions, roughly a factor five higher than that in average inelastic pp collisions, thereby reducing the multiplicity gap between small and large collision systems. In addition, the results are further compared with previously published measurements and with model calculations obtained using distinct tunes of the PYTHIA 8 Monte Carlo generator, as well as with predictions from the EPOS4. The comparison of the $$p_\textrm{T}$$ p T -integrated K/ $$\pi $$ π and p/ $$\pi $$ π ratios across different collision systems and energies suggests that particle production scales with charged-particle multiplicity, rather than with collision energy or system size. While the PYTHIA 8 tunes and the EPOS4 model are able to reproduce some of these measurements, either quantitatively or qualitatively, none of them consistently describes all observed features of the data.

A bstract: The measurement of hyperon (Λ and $$\overline{\Lambda }$$ ) polarization along the beam axis in Pb-Pb collisions at $$\sqrt{{s}_{\text{N}\text{N}}}=5.36$$ TeV using the ALICE detector is presented. The polarization, arising from vorticity components induced by anisotropic flow, is studied relative to the second- and third-order event planes. The measured polarization exhibits clear azimuthal sine modulations, providing the first observation of polarization along the beam direction measured relative to the third-order event plane at the Large Hadron Collider. The values of the polarization measured with respect to the second-order event plane are consistent with previous measurements at $$\sqrt{{s}_{\text{N}\text{N}}}=5.02$$ TeV and show improved statistical precision owing to the larger data sample. Comparisons with hydrodynamic calculations indicate that the measured polarization is sensitive to the bulk viscosity and the vortical structure of the quark-gluon plasma, offering new constraints on its transport properties. In particular, the polarization measured relative to the third-order event plane is expected to provide an additional and independent input to constrain both bulk and shear viscosities of the quark-gluon plasma.

This paper presents the first measurements of $$\Xi $$ Ξ and $$\Omega $$ Ω hyperon yields at the highest multiplicities reached in pp collisions at $$\sqrt{s}=13$$ s = 13 TeV. This measurement exploits the high-multiplicity pp collisions collected by ALICE with dedicated triggers. The selected collisions are characterised by about 30 charged particles per unit of rapidity, over four times more than in minimum-bias pp collisions at the same centre-of-mass energy, and about twice as many as in minimum-bias p–Pb or very peripheral Pb–Pb collisions at similar energies. The production yields and average transverse momenta of the hyperons agree with trends indicated by previous measurements in pp collisions at lower multiplicities. The difference in average transverse momenta between pp and p–Pb collisions, observed with the new high-multiplicity pp data, provides additional insight into the underlying particle production mechanisms in small collision systems. The results support a strong correlation between multi-strange hadron yields and final-state multiplicity regardless of the collision system at the LHC energies, extending this observation to the highest multiplicity reached in pp collisions. The comparison with several state-of-the-art models suggests that the description of strange-hadron production is improved by recently introduced features such as interactions between overlapping strings in Pythia 8.2 with Ropes and the collective expansion of high-density string regions in EPOS4.