Piotr Sawicki

Technical diagnostic of a fleet of vehicles using rough set theory

The paper presents a process of technical diagnostic applied to a fleet of vehicles utilized in the delivery system of express mail. It is focused on evaluation of diagnostic capacity of particular characteristics, reduction of a set of initially selected characteristics to a minimal and satisfactory subset, recognition of a technical condition of vehicles resulting in their condition-based classification. In addition, the decision rules facilitating technical diagnostic and management of a fleet of vehicles are generated and utilized. N-fold cross validation is applied to estimate the efficiency of the decision rules. The rough set theory is applied to support the diagnostic process of vehicles. Classical rough set (CRS) theory is compared with the dominance-based rough set (DRS) approach. The results of computational experiments for both approaches are compared.

Selection of the most adequate trip-modelling tool for integrated transport planning system

This paper deals with the problem of selection the most suitable trip-modelling tool (TMT), which is a part of the more complex integrated transport planning system (ITPS) at the regional scale. Since an application of TMT is not autonomous and several different users exist the selection problem is not a trivial. In this paper, an original five-phase selection procedure is presented. The first phase consists in specification of both, detailed expectations of all identified users and technical requirements of ITPS. Second phase deals with research on available TMT while a third one is concentrated on defining a comprehensive set of criteria. In this phase critical criteria as well as selection criteria are defined. First one is utilised to eliminate unacceptable TMTs in phase four and second one to evaluate and select most adequate TMT in phase five. In the paper an exemplary application of this procedure is presented. The authors have defined 2 critical criteria and a set of 19 selection criteria. The last one is divided into 3 main subsets, i.e. functional, technical and financial contexts of selection process. All the selection criteria are characterised by 43 sub-criteria and some of them are more detailed extended. Using this procedure 3 out of 6 alternative TMTs including Emme, Aimsun and Visum have been initially accepted and next evaluated. Finally, Visum has been selected and recommended for application into ITPS.

The impact of long-term travel demand changes on mixed decision problems of mass transit lines construction and vehicles' depots location

Abstract The paper is concentrated on solving a mixed decision problem of mass transit line construction and vehicles’ depots location (MTLC&VDL). The authors have iteratively solved this problem as a function of scenario-based, long-term travel demand changes, and finally have analysed the generated results. As a product of the computations, it has been proved that the solution of the mixed MTLC&VDL decision problem depends on changes in travel demand, both in terms of the line construction and the location of the depot. 5 and 10% increase of travel demand leads to changes in the optimal mass transit line’s configuration, while the change of the optimal depot location takes place with 10% of the travel demand change. The results have implied a conclusion that to make strategic decisions on transport systems and solving mixed decision problems, forecasting travel demand changes (its volume and structure) over the long-term horizon has to be performed.

Mixed Public Transport Lines Construction and Vehicle’s Depots Location Problems

The paper deals with the problem of simultaneous consideration of transport lines construction and decision on vehicle’s depots location problems in the public transport system. The authors have proposed a cost oriented mathematical model for solving a complex problem and application of macro-simulation based modified four-stage procedure for defining transportation tasks on the network. The proposed methodology is verified on a medium size testing transport network and conclusions have been finally formulated.

The Application of Dominance-based Rough Sets Theory to Evaluation of Transportation Systems☆

The paper presents an original procedure of evaluation of a transportation system, resulting in its assignment into a predefined class, representing the overall standard of the considered system and the level of transportation service. The method relies on the application of the dominance-based rough set theory (DRST), allows for thorough data exploration, evaluation of informational content of the considered characteristics and generation of certain decision rules that support t he evaluation process. In the analysis different characteristics (criteria and attributes) describing various aspects of a transportation system operations are taken into account. The assignment of a transportation system to a specific quality class is performed based on the values of characteristics which are compared with the evaluation pattern, i.e. the set of decision rules generated through the analysis of customers’ opinions and expectations concerning a transportation system. The method is composed of three major steps, including: 1) identification of the most important characteristics, 2) generation of the evaluation pattern, and 3) assignment of the transportation system to the appropriate class. In the evaluation process five key components of a transportation system, including: transportation means, human resources, informational resources, transportation infrastructure and technical equipment as well as organizational rules are considered.