Анализ обеспеченности подвижным составом региональных железнодорожных пассажирских перевозок Польши

This article assesses the impact of socio-economic factors and the amount of transport work done on the capacity of rolling stock used in passenger transport on selected railway lines located in various regions of Poland. The purpose of this article was to check the relationship between the capacity of rolling stock running on a railway line in regional passenger transport, and the socio-economic factors occurring in the area through which the analyzed railway line runs, and between volume of transport on this line. The analysis was carried out for 32 railway lines located in different voivodeships, with one main line and one local line selected from each voivodeship. The average number of seats in regional trains running on it was calculated for each of the analyzed lines. Then calculations of partial correlation coefficients were performed. During calculations, the average number of seats was used as a dependent variable, while socio-economic factors affecting the size of passenger flows and the amount of transport work done were used as independent values. The calculation used the transport data and socio-economic factors that occurred in 2018. The calculations showed that there is a clear relationship between the rolling stock capacity and the amount of transport work done. On lines where more transport work is done, more capacious rolling stock also runs. On the other hand, the dependence of rolling stock capacity on socio-economic factors affecting the size of passenger flows is small.Представлены результаты оценки влияния социально-экономических факторов и объёма выполненной транспортной работы на вместимость подвижного состава, используемого на региональных железнодорожных пассажирских перевозках Польши. Исследование проводилось для железнодорожных линий, расположенных в различных регионах страны. Цель статьи – проверка наличия и оценка связей между вместимостью подвижного состава, используемого на региональных железнодорожных линиях, и показателями социально-экономической среды регионов, обслуживаемых этими линиями. Анализ проводился для 32 железнодорожных линий, расположенных в разных регионах (воеводствах) Польши. Для исследования в каждом воеводстве были выбраны по одной главной и местной линии. Средняя вместимость региональных поездов рассчитывалась для каждой из анализируемых линий. Выполнен расчёт значений частных коэффициентов корреляции между исследуемыми величинами. В расчётах среднее число мест в поездах использовалось как зависимая переменная, а социально-экономические показатели, влияющие на величину пассажиропотоков и объём выполненной транспортной работы, – как независимые. Расчёты выполнены с использованием статистических данных об объёмах перевозок и показателях социально-экономической среды за 2018 год. Результаты расчётов показали наличие сильной связи между вместимостью используемого подвижного состава и объёмом выполненной транспортной работы. На линиях с большим объёмом пассажирских перевозок используется более вместительный подвижной состав. С другой стороны, связь вместимости подвижного состава и социально-экономических факторов, определяющих размер пассажиропотоков, невелика

Quantum collapse rules from the maximum relative entropy principle

We show that the von Neumann--Lueders collapse rules in quantum mechanics always select the unique state that maximises the quantum relative entropy with respect to the premeasurement state, subject to the constraint that the postmeasurement state has to be compatible with the knowledge gained in the measurement. This way we provide an information theoretic characterisation of quantum collapse rules by means of the maximum relative entropy principle.Comment: v2: some references added, improved presentation, result generalised to cover nonfaithful states; v3: cross-ref to arXiv:1408.3502 added, v4: some small corrections plus reference to a published version adde

Observables for General Relativity related to geometry

We present a new scheme of defining invariant observables for general relativistic systems. The scheme is based on the introduction of an observer which endowes the construction with a straightforward physical interpretation. The observables are invariant with respect to spatial diffeomorphisms which preserve the observer. The limited residual spatial gauge freedom is studied and fully understood. A full canonical analysis of the observables is presented: we analyze their variations, Poisson algebra and discuss their dynamics. Lastly, the observables are used to solve the vector constraint, which triggers a possible considerable reduction of the degrees of freedom of general relativistic theories.Comment: 33 pages, 1 figur

Addendum: Observables for General Relativity related to geometry

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SL(2,C) Chern-Simons Theory, a non-Planar Graph Operator, and 4D Loop Quantum Gravity with a Cosmological Constant: Semiclassical Geometry

We study the expectation value of a nonplanar Wilson graph operator in SL(2,C) Chern-Simons theory on $S^3$. In particular we analyze its asymptotic behaviour in the double-scaling limit in which both the representation labels and the Chern-Simons coupling are taken to be large, but with fixed ratio. When the Wilson graph operator has a specific form, motivated by loop quantum gravity, the critical point equations obtained in this double-scaling limit describe a very specific class of flat connection on the graph complement manifold. We find that flat connections in this class are in correspondence with the geometries of constant curvature 4-simplices. The result is fully non-perturbative from the perspective of the reconstructed geometry. We also show that the asymptotic behavior of the amplitude contains at the leading order an oscillatory part proportional to the Regge action for the single 4-simplex in the presence of a cosmological constant. In particular, the cosmological term contains the full-fledged curved volume of the 4-simplex. Interestingly, the volume term stems from the asymptotics of the Chern-Simons action. This can be understood as arising from the relation between Chern-Simons theory on the boundary of a region, and a theory defined by an $F^2$ action in the bulk. Another peculiarity of our approach is that the sign of the curvature of the reconstructed geometry, and hence of the cosmological constant in the Regge action, is not fixed a priori, but rather emerges semiclassically and dynamically from the solution of the equations of motion. In other words, this work suggests a relation between 4-dimensional loop quantum gravity with a cosmological constant and SL(2,C) Chern-Simons theory in 3-dimensions with knotted graph defects.Comment: 54+11 pages, 9 figure

Four-dimensional Quantum Gravity with a Cosmological Constant from Three-dimensional Holomorphic Blocks

Prominent approaches to quantum gravity struggle when it comes to incorporating a positive cosmological constant in their models. Using quantization of a complex $\mathrm{SL}(2,\mathbb{C})$ Chern-Simons theory we include a cosmological constant, of either sign, into a model of quantum gravity.Comment: 5 pages and 2 figure

RSA Keys Quality in a Real-world Organizational Certificate Dataset: a Practical Outlook

This research investigates the intricacies of X.509 certificates within a comprehensive corporate infrastructure. Spanning over two decades, the examined enterprise has heavily depended on its internal certificate authority and Public Key Infrastructure (PKI) to uphold its data and systems security. With the broad application of these certificates, from personal identification on smart cards to device and workstation authentication via Trusted Platform Modules (TPM), our study seeks to address a pertinent question on how prevalent are weak RSA keys within such a vast internal certificate repository. Previous research focused primarily on key sets publicly accessible from TLS and SSH servers or PGP key repositories. On the contrary, our investigation provides insights into the private domain of an enterprise, introducing new dimensions to this problem. Among our considerations are the trustworthiness of hardware and software solutions in generating keys and the consequential implications of identified vulnerabilities on organizational risk management. The obtained results can contribute to enhancing security strategies in enterprises

Comparison of forecasting methods for freight transportation by Polish railways

Abstract In Poland problem related to lack of rolling stock occurred recently. This article presents a comparison between two forecasting methods of realized transport work and transported freight mass by railway. The obtained results are also compared on a monthly and quarterly data basis. Knowing the exact values of forecasts railway carriers can plan the number of rolling stock. The calculations show that using the data as a monthly basis, the most reliable results can be obtained using the Holt model, while calculating data for quarterly basis results is closer to the real values using the Winters model