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The contribution deals with the evaluation of the influence of the change of the fare amount on the size of the demand for the urban public transport. In this context, it also deals with the impact of this change on the size of the sales of a relevant transport company. The assumption is that the primary task of the municipal transport company is to transport as many passengers as requested by the contracting authority. Like this, the transport company will comply with the definition of the city public transport as a public service from the long-term sustainability point of view with regard to the limited funds provided from public sources. Possibilities of funding public city transport are compared 1) with a hundred percent, 2) partial and 3) zero amount of subsidy with regard to different sizes of the elasticity of demand. Comparisons are made on the basis of a simplified assumption of changes only in the prices of the individual types of tickets. [ABSTRACT FROM AUTHOR]

The development of a portfolio of investment projects is a relatively underestimated economic practice, which often leads to wrong investment decisions with a negative impact on the corporate performance. This development is often done under certainty, which means with the only one possible scenario. The multi-criteria nature of the task character is also rarely respected. The evaluation of projects is usually done in isolation, without any connection to other projects or without taking into account dependencies between the projects. This paper aims to specify the problem of optimization of development of a project portfolio under risk (optimal allocation of scarce resources). The article offers two approaches to the optimization. The first approach is based on deterministic equivalents with application of bivalent programming (multi-criteria and mono-criteria optimization). The second one uses stochastic optimization based on the Monte Carlo simulation. The application of these model approaches can greatly improve the quality of the project portfolio development under risk. [ABSTRACT FROM AUTHOR]

The construction of the urban transport line network is one of the fundamental problems in the traffic practice. Efficient functioning of the public mass transportation supported from the public sources in the towns is more urgent at present, when the individual automobile traffic leads to congestions in central parts of the cities. The demand to increase the culture of travelling in the public mass transportation requires, however, substantial costs. Therefore it is necessary to solve the balance between the inhabitants' requirements and the economy of the transportation system. The operation of the public mass transportation must be rational; the vehicles must not show unreasonable waiting times, etc. One of the possible ways how to rationalise the public mass transportation is to minimise the number of vehicles in operation complying with the requirements of the travellers. The paper deals with the problem of minimising the number of vehicles needed to operate the lines of the public mass transportation network. To solve this problem the methods of linear programming are used. There are four mathematical models described in which the vehicles are assigned to the individual lines. The models arise from the mathematical model PRIVOL [4], and they vary from this model especially by the variety of the rolling-stock the transport company has at disposal. By means of the constructed models a number of numerical experiments concerning the network corresponding to a medium-sized town were performed using the four constructed models. These numerical experiments demonstrated the functionality of the designed models. The main contribution of the presented modifications of the original model PRIVOL consists in the fact, that instead of the optimal number of seats the new models are able to directly find an optimal number of vehicles needed to operate the particular lines to meet the expected demand of the passengers. That way the proposed approach allows to objectify the decision making of the transport company concerning the allocation of vehicles to the network lines. [ABSTRACT FROM AUTHOR]