Работа представляет новый комбинаторный подход для анализа правил голосования.
Изучаются явные двухслойные разностные схемы на разнесенных сетках для двух известных регуляризаций 1D баротропных уравнений газовой динамики, включая схемы с дискретизациями по со свойством диссипативности по полной энергии. Выводятся критерии L^2-диссипативности в задаче Коши для их линеаризаций на постоянном решении с нулевой фоновой скоростью. Дается сравнение критериев для схем на неразнесенных и разнесенных сетках. Рассматривается также случай 1D уравнений Навье–Стокса без искусственного коэффициента вязкости. Для анализа случая 1D уравнений Навье-Стокса-Кана-Хилларда выводятся и апробируются также критерии L^2-диссипативности и устойчивости явной разностной схемы для нестационарного уравнения 4-го порядка по x со слагаемым 2-го порядка по x. Полученные критерии могут быть полезны при расчете течений при малых числах Маха.
As a result of the global warming, the situation in the Barents Sea leads to several important consequences. Firstly, oil and gas drilling becomes much easier than before. Therefore, it may raise the level of discussions on disputed shelf zones where the deposits are located, especially near to Norway-Russia sea border. Secondly, oil and gas excavation leads to potential threats to fishing by changing natural habitats, which in turn can create serious damage to the economies.
We construct a model, which helps to highlight potential disputed territories and analyze preferences of the countries interested in fossil fuels and fish resources. We also compare different scenarios of resource allocation with allocation by current agreement.
Regional authorities consider the expediency of developing a new cargo transportation hub in the region in which it would provide transshipment services. It is considered that each transportation operator working in the region will use these services only if they are competitive with the currently existing ones. This competitiveness for a particular cargo means that the total transportation tariff for moving this cargo does not exceed (substantially or in principle) the (minimal) currently existing one as a result of including a transshipment via the hub in the transportation scheme for the cargo. A verifiable sufficient condition for the transshipment service competitiveness is proposed. Its verification consists of establishing the solvability of a system of linear inequalities being part of the system of constraints in the problem of finding optimal competitive transshipment tariffs for a set of cargoes expected to be moved via the hub. The latter problem is formulated as a quadratic programming one.
In this article, we consider the problem of planning maintenance operations at a locomotive maintenance depot. There are three types of tracks at the depot: buffer tracks, access tracks and service tracks. A depot consists of up to one buffer track and a number of access tracks, each of them ending with one service track. Each of these tracks has a limited capacity measured in locomotive sections. We present a constraint programming model and a greedy algorithm for solving the problem of planning maintenance operations. Using lifelike data based on the operation of several locomotive maintenance depots in Eastern polygon of Russian Railways, we carry out numerical experiments to compare the presented approaches.
Over the past years, there is a deep interest in the analysis of different communities and complex networks. Identification of the most important elements in such networks is one of the main areas of research. However, the heterogeneity of real networks makes the problem both important and problematic. The application of SRIC and LRIC indices can be used to solve the problem since they take into account the individual properties of nodes, the possibility of their group influence, and topological structure of the whole network. However, the computational complexity of such indices needs further consideration. Our main focus is on the performance of SRIC and LRIC indices. We propose several modes on how to decrease the computational complexity of these indices. The runtime comparison of the sequential and parallel computation of the proposed models is also given.