Emilian Szczepański

Genetic algorithms based approach for transhipment hub location in urban areas

Points of distribution, sales or service are important elements of the supply chain. These are the final elements which are responsible for proper functioning of the whole cargo distribution process. Proper location of these points in the transport network is essential to ensure the effectiveness and reliability of the supply chain. The location of these points is very important also from the consumers point of view. In this paper developed method of points location was present on the example of urban transport network. The developed approach is based on the Vehicle Routing Problem in the multistage distribution systems. The proposed method uses a genetic algorithm. Article also presents a mathematical model of delivery cost as a criterion function. The article presents an example calculations which illustrating the operation of the developed method.

Analysis of the traffic stream distribution in terms of identification of areas with the highest exhaust pollution

Transport is a sector that is said to be negatively affecting the environment. The continuous development of transport increases the negative impact on the environment and civilization. In the article authors present the parameters that were used to describe the size of harmful transport exhaust emissions, in particular by means of road transport and the factors affecting their size. The areas where the level of concentrations of air pollutants are exceeded in Poland were characterized and analysed. Also examples of the stream traffic distribution in the selected area of the transport network were presented.

Implementation of the model of proecological transport system

Paper presents assumptions to build simulation model allowing computational experimentation and inference on impact of various factors on transport modal split and the impact that transport has on environment. It presents a general mathematical model of environmentally friendly transport system and characterizes particular elements of this model. The structure of transport network is mapped with a graph. The characteristics describing elements of this structure, vehicles, and characteristics of harmful compounds emission are given. Model will be implemented in PTV VISUM environment – a tool supporting planning of transport processes as well as analysis and designing of transport systems. The model of proecological transport system developed in PTV VISUM will consist of model of demand for both passenger and freight transport, and model of transport network cooperating with various means of transport. Road and rail vehicles for passenger and freight transport are characterized and divided into groups according to type of fuel and harmful emission. The demand for transport services and emission of exhaust gases components are reflected in model of proecological transport system of Poland. The last part of paper presents a sample of preliminary research on estimating emission from particular type of vehicle.

Assessment of the Method Effectiveness for Choosing the Location of Warehouses in the Supply Network

This paper describes the problem of determining the location of warehouses in the logistics network supplying different type of entities with raw materials. Was presented a mathematical model, i.e. were defined decision variables, were specified constraints and objective function that minimizes the total cost of transporting raw materials from suppliers to the recipients. Were included costs of flow of raw materials between network facilities and costs associated with salaries for drivers engaged in the realization of this flow. Was developed a method of determining the location of storage facilities based on genetic algorithm. In order to check the efficiency of the method was proposed algorithm for evaluating its effectiveness.

The method for evaluation of efficiency of the concept of centrally managed distribution in cities

AbstractThe paper describes proecological solution dedicated for organizing logistics services in urban areas. Proposed solution is based on cross-docking processes combined with consolidation centres. Authors proposed new method of estimating economic and social benefits from implementing centrally managed cooperation of logistics operators using common city consolidation hubs. Developed mathematical model bases on Vehicle Routing Problem (VRP) with vehicles of different types, limited loading capacities and multiply depots characterized by limited throughput. Proposed approach was supported by case study of integration of distribution processes in Warsaw (Poland) performed by three medium-size logistics operators. The central management of distribution was investigated in variants assuming using existing warehouses and with new configuration of logistics network developed with using SIMMAG 3D tools. As it was proved for analysed case, total costs of distribution in the city after implementation of centr...

Computer Aided Implementation of Logistics Processes – Selected Aspects

The paper presents selected aspects of the application of information technology to support the implementation of logistics processes. The general discussion about optimization logistics processes precedes basics of designing procedure for logistics systems of different scale which are the foundation for three examples of applications tailored for micro-, and mezo-scale logistics systems. Applications are presented and discussed as tools to optimize logistics processes in aspect of their simultaneous usage to create advanced and comprehensive planning tools. Presented tools enable not only the design of selected elements of the logistics system but also allow assessing their effectiveness. An example of the possible use of applications LogMND to support shaping and dimensioning of point and linear logistic network elements and SCHED to support designing warehousing processes are given.

The influence of road transport on emission of toxic substances in Poland against the EU countries

The paper is a result of research work carried out under the project EMITRANSYS for shaping ecological transport system. The paper presents selected aspects of emission and concentration of harmful compounds of exhaust gases generated by road transport. It also presents the share of harmful compounds emitted by road transport in comparison with the emission from other sectors of economy. Transport policy should encourage the usage of energyefficient and less environmentally damaging modes of transport and their efficient use. The paper analyses the emissions of selected pollutants and their estimated contribution to the total emissions of road transport. It also presents selected aspects of the identification of areas with the highest emissions of harmful compounds in Poland against the European Union. This analysis provides a basis to identify the instruments to prevent and reduce pollution arising from transport activities. In particular, variable emission of selected components of fumes according to the velocity of passenger vehicle. the measured values for NO2 concentration in the UE countries in 2011, the measured values for CO concentration in UE countries in 2011, the measured values for PM10 concentration in UE countries in 2011, the measured values for PM2.5 concentration in UE countries in 2011 are presented in the paper.

The assessment of supply chain effectiveness

This paper presents the problem of the assessment of the supply chains in the context of their effectiveness. In this paper the concepts of a supply chain and effectiveness were characterized. The supply chain is a structure of entities which are connected with each other by the use of material and financial flows and functional, structural, technological, economic and information dependencies. Entities such as: suppliers, final recipients, entrepreneurs, warehouse facilities, supply centers, logistics operators, carriers, etc. perform material flows from suppliers to recipients. The concept of efficiency, in general terms, refers to economic rationality and means the relationship between the achieved or expected effects and the expenditures incurred. Additionally, indicators of measuring the effectiveness of the supply chain were described. In order to assess the effectiveness of the supply chain the decision model was developed. Optimization is crucial in decision support systems. The development of an appropriate model for mapping the behavior of a real object or system and formulating an optimization task is a necessary activity in effective management. This is even more important if we want to be competitive. Along with the development of decision support systems, as well as the development of systems for data acquisition on the system functioning, which feed optimization models in ever more detailed form, complex decision models are created that take into account many optimization criteria and require a large amount of data. It allows, however, to ensure the sustainable development of the system and simultaneous implementation of its basic tasks. The main aim of this paper is to present the stages and assumptions of the model for assessing the effectiveness of the supply chain. The main data input, constraints of the model, the criteria functions were determined.

The Influence Of The External Costs Of Modal Split In The Transport Network, With Particular Reference To Rail Transport

Vehicles have an impact on environmental pollution through emissions. Thus, they generate different carbon footprints, or emit different amounts of carbon dioxide into the atmosphere. This article attempts to determine the effects of carbon dioxide on the distribution of the traffic stream in the selected part of the transport network. For the analysis the Warsaw–Krakow route was chosen. The movement between these two cities can be performed with different modes of transport. The distribution of the passenger streams was conducted for three variants of the three sub-criteria: minimum average costs, minimum marginal costs and the costs of environmental pollution. The unitary cost of carbon dioxide emission was determined using a CO₂ Calculator. The selection of the variant of the passenger stream distribution was carried out using a multi-criteria evaluation method called MAJA.

The Role Of Railway Transport In Designing A Proecological Transport System

This paper is prepared as a part of the scientific project “Proecological transport system designing” (EMITRANSYS). It presents the selected aspects and roles of railway transport in realization of the tasks set out by the national transport system. Particular attention is paid to the ecological aspects of railway transport, especially to the emission of pollutants in comparison to road transport. The ecological aspects are crucial for a systemic approach to the designing of transport and are important in developing a sustainable economy. One of the criteria for designing a large scale transport system is the external cost of environmental degradation. Two partial criteria considering external costs related to harmful emissions resulting from cargo and passenger streams distribution onto a network are discussed in the paper. These criteria are implemented into the PTV Visum environment for simulation experiments.