Ilona Jacyna-Gołda

Models of traffic flow distribution for various scenarios of the development of proecological transport system

The paper is a result of a research work concerning the development of an environmentally friendly transport system Project EMITRANSYS. The publication contains the issues of shaping the transport system, where important factor due to the aspect of sustainable development is including the external costs in transport activity. This paper presents a mathematical model of the distribution of the traffic flow in the transport network. The paper presents selected aspects of the problem of multi-variant distribution of the traffic stream on the network transport for defined scenarios for the transport system development. Traffic distribution on the network has been made due to the criterion function – external cost connected with air pollution. The paper presents modal split of traffic ecological flow for chosen scenarios of the development domestic transport system.

Vehicle routing in an urban area: environmental and technological determinants

This paper discusses selected environmental and technological issues of routing freight vehicles in urban areas. The conditions of organizing distribution minimizing not only realization time but also the emission of harmful components of exhaust gases are described. Time-dependant traffic conditions characteristic for densely populated urban areas are defined and discussed according to ecological aspects. Theoretical information about CO2 emission in urban conditions are gathered and used to formulate the base of a mathematical model of a Time-Dependant Vehicle Routing Problem with emission criteria function, as a version of the Capacitated Vehicle Routing Problem. The model comprises selected characteristics of urban transport infrastructure such as distances, speed limits, zones, or the effect of rush hours. It allows considering different types of vehicles according to the task requirements and emission characteristics, and changing traffic conditions. The model is implemented onto a representation of a real transport network and solved for given data with two-step heuristics based on a modified A-star algorithm and genetic programming. Appropriate results, future research directions and other potential uses are presented and discussed.

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.

Identification and analysis of parameters for the areas of the highest harmful exhaust emissions in the model emitransys

The development of human civilisation has always been related to an increase in energy demand. The growth of transportation and an increase in the number of automobile vehicles in service produce a rising demand for fuel. Before piston IC engine is replaced with a different effective power source, it is necessary to use gaseous fuels on a larger scale than ever before. The natural resources of gaseous fuels are estimated to be much higher than crude oil reserves. Additionally, engines can run on biogas, i.e. gaseous renewable fuel. The use of gaseous fuels means lowering the harmful effect engines produce on the natural environment. Multi-fuelling, i.e. switching from one fuel to another, could be an advantageous feature of automobile combustion engine, both from the user’s standpoint and with respect to environmental concerns. Gaseous fuels have desirable properties that are especially suitable for fuel of spark ignition engines. The paper presents the engine test bench constructed at the Laboratory of Heat Engines of the Kielce University of Technology. The test stand comprises modern spark ignition engine Fiat 0.9 MultiAir and the eddy-current brake. At the test stand, the engine was converted to fuelling with three fuels, namely petrol, LPG gas blends and compressed natural gas (CNG). The engine could run alternatively on the three fuels mentioned above. The stand is equipped with an external unit to control the engine work, which makes it possible to extend the range of the engine investigations.

Decision-making model for supporting supply chain efficiency evaluation

This paper presents some approach for the formulation of the decision-making model in supporting the assessment of supply chain efficiency. Were presented factors affecting the efficiency of the functioning of individual links of supply chain. Was pointed out the technical, economic, organizational and reliability aspects affecting the efficiency and reliability of functioning of the supply chain both in terms of supply and distribution. Having regard to a comprehensive approach to assessing efficiency of the functioning of supply chains were proposed indicators for assessing the quality of functioning. Were distinguished technical, economic and quality indicators for which also were presented a formal record.

Some aspects of risk assessment in the logistics chain

The paper presents selected aspects of the evaluation of the effectiveness and risks of the logistics chain that supports the enterprise. It was assumed that the logistics chain includes all activities associated with the flow of materials from the sourcing of raw materials for sale to the ultimate purchaser of the product and the disposal of used products. It was found that the elements of the supply chain are usually unstable which generates difficulties in determining the appropriate level of the risk of the chain. The paper presents a formal record of risk and performance. There is proposed determination of the effectiveness of individual links of the logistics chain. The task of the logistics chain is to provide goods from producers to the final customers, thereby making available these goods in a place and time suited to the needs and expectations of customers. The movement of goods in the logistics chains is determined by the sequence of interrelated actions. In the logistics chains, many entities are involved to different extents. This determines the spatial distribution of different configuration of individual users of the whole logistics chain. In particular, example of a logistics chain of production company, stages of the procedures for quantitative risk analysis, the problems in the logistics chains, assessment of the risk of the task in the logistics chain, the concept of risk, effectiveness and risk in logistics chains are presented in the paper.

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.

Decision making strategies for warehouse operations

The paper presents issues related to design and organization of warehouse processes. Draws attention to problems of modelling logistics facilities and processes occurring in them. Paper also points out the essence of correct operation of warehouses and associated with this risks for supply chain. Warehouse processes have been properly defined and divided into smaller components, like: phases of process, activities, sets of procedures, procedures or working movements. Paper presents various possible configurations of warehouse processes, which were named as warehouse strategies. Warehouse process strategy is a part of warehousing. It determines the sequence of warehouse operations. These operations are related to internal transport, cargo form transformation and cargo buffering. In paper it is noted that the warehouse strategy depends on the several technical and organizational factors and is associated with a certain probability. This probability can be estimated based on data analysis concerning logistics processes in the specified warehouse facility. As shown in case study, appropriate selection of warehouse strategies determines possibility of fulfilling customer order in time and costs that are acceptable for him.

The application of genetic algorithm for warehouse location in logistic network

The paper presents a certain approach to solving the problem of warehouse locations based on the application of a genetic algorithm. The main objective is to indicate a location of warehouses from among those that already exist, which are most likely to assure the best value of the adopted criterion function, concurrently meeting recipients’ needs. A formal notation was presented of the mathematical model, allowing for the indispensable data, decisionrelated variables of limitations and the criterion function. The problem is to determine the location of warehouses taking into account minimising costs of transport and storage of forwarded cargo between determined facilities within the network. To allow solving the problem related to warehouse location within the logistics network of a manufacturing enterprise the use of a genetic algorithm was proposed. The structure of the algorithm was adapted to the mathematical model. A genetic algorithm was used to determine the volume of cargo stream flows between particular facilities in the network. To form a genetic algorithm it is advisable to define the chromosome structure, the adaptation function, cross-linking process and mutation. The location problem is solved in such a way that if for any day within the analysed period flows take place from a given warehouse or to a given warehouse, such a logistics facility should constitute an element of the target logistics network. If there are no such flows, no warehouse is necessary in the given location.

A NEW ECOLOGICAL RESEARCH – REAL DRIVING EMISSIONS

In the assumptions, regarding to the transport policy both at the level of country and Europe there is the concept of sustainable development of transport. Warsaw University of Technology in cooperation with Poznan University of Technology performs research work concerning the shaping of environmentally friendly transport system – Project EMITRANSYS. In this project, one of the conditions is to reduce exhaust emissions by means of transport. The paper presents the reasons for the testing of the exhaust emissions under Real Driving Emissions testing (RDE). Research potential of Institute of Combustion Engines and Transport at Poznan University of Technology in the area of road testing of passenger and heavy-duty vehicles has been presented in the paper. Example test results have been shown in the aspect of the emission-related classification of vehicles. The major challenge of worldwide emission standards, engine operating parameters in various emissions tests, the test potential under real operating conditions, the view of the analyser for on-road emission testing of vehicles, the test results for road emission of CO, HC and NOx, detailed characteristics of the averaged particle number for the entire test run (vehicles with different mileage and different emission class) for: Euro 4 class and 75,000 km; Euro 4 class and 500,000 km; Euro 5 class and 75,000 km; Euro 5 class and 500,000 km are presented in the paper.