Vibrational spectra of condensed and gas-phase systems containing light nuclei are influenced by their quantum-mechanical behaviour. The quantum dynamics of light nuclei can be approximated by the imaginary time path integral (PI) formulation, but still at a large computational cost that increases sharply with decreasing temperature. By leveraging advances in machine-learned coarse-graining, we develop a PI method with the reduced computational cost of a classical simulation. We also propose a simple temperature elevation scheme to significantly attenuate the artefacts of standard PI approaches and also eliminate the unfavourable temperature scaling of the computational cost. We illustrate the approach, by calculating vibrational spectra using standard models of water molecules and bulk water, demonstrating significant computational savings and dramatically improved accuracy compared to more expensive reference approaches. We believe that our simple, efficient and accurate method could enable routine calculations of vibrational spectra including nuclear quantum effects for a wide range of molecular systems.

Coarse-grained models allow computational investigation of biomolecular processes occurring on long time and length scales, intractable with atomistic simulation. Traditionally, many coarse-grained models rely mostly on pairwise interaction potentials. However, the decimation of degrees of freedom should, in principle, lead to a complex many-body effective interaction potential. In this work, we use experimental data on mutant stability to parametrize coarse-grained models for two proteins with and without many-body terms. We demonstrate that many-body terms are necessary to reproduce quantitatively the effects of point mutations on protein stability, particularly to implicitly take into account the effect of the solvent.

The aim of the article is to study the features of ship repair production and, accordingly, develop recommendations for the composition of the functions of the project management office, its structure and stages of development. The characteristics of ship repair production, which determine its features and the structure of management of a ship repair enterprise, are systematically presented. The subject of the study is the models and methods of project management, programs and project portfolios of ship repair enterprises. The object of the study is the corporate project management system of a ship repair enterprise. The project-oriented nature of ship repair production, combined with a high degree of uncertainty in the planning and implementation of ship repair projects, identifies the need to use deterministic network models with a probabilistic estimate of the duration of work. To reduce risks in conditions of uncertainty, it is proposed to use Agile technologies, which organically complement the matrix organizational structure of a ship repair enterprise and ensure effective cooperation with the customer and the success of the business as a whole. The creation of a project management office is proposed to be implemented as a development system that includes four stages of maturity. The key functions of the project management office at each stage of development have been formulated. The role of the information model of the vessel in the implementation of the 6D design methodology, which provides monitoring during the operation of the vessel, predicting the degree of wear of the vessel's elements over time, is justified. The MS Project Standard package allows building interfaces with the information model of the vessel to obtain the parameters of the hull structures, characteristics of the mechanisms and equipment of the vessel, as well as recommendations for repair technology. An important function of the project management office is to participate in the strategic management of project portfolios. To implement this function in the enterprise management system, certain prerequisites for the development of portfolio management must be formed: a formalized strategy, metrics for evaluating projects for compliance with the strategy, a certain culture of management decisions. The duration of vessel repair determines the time of decommissioning. This important strategic indicator is the basis for the formulation of BS (balanced scorecard). An important task of the project management office is to implement feedback and provide information on the status of achieving the planned indicators at all levels of enterprise management. The structure of the function and tools of the project management office are determined by the management of the enterprise depending on the number and complexity of the ship repair projects, level of development of the corporate information system of the enterprise, availability of specialists with appropriate qualifications. The project management office will provide effective communication between project management and functional services of the enterprise, which will significantly improve the quality of the enterprise management system as a whole. The organization of the project management office in the management system of the ship repair enterprise will ensure the effective allocation of resources for projects, accounting for available resources of the enterprise, coordination of goals and tasks of individual projects with strategic plans of the enterprise. All this is aimed at reducing costs and increasing the competitiveness of the ship repair enterprise.