eng
Poznan School of Logistics
Logforum
1734459X
2013-12-30
9
4
article
Modelling of contact problems involved in ensuring the safety of rail transport
Edward Rydygier
1
Zygmunt Strzyżakowski
2
Kazimierz Pulaski University of Technology and Humanities in Radom, Poland
Municipal Office of Capital City of Warsaw, Poland
Background: Mathematical modelling aids diagnostics the track and rolling stock, as it often for technical reasons it is not possible to obtain a complete set of measurement data required to diagnose the rail and wheel deformation caused by the impact of a rail vehicle on the track. The important issue in a railway diagnostics is to study the effects of contact wheel and rail. Diagnostics investigations of track and rolling stock have a fundamental role in ensuring the safety of transport of passengers and goods.
The aim of the study presented in the paper was to develop simulation methods of mathematical modelling of the wheel-rail system useful in the diagnostics of the track and a railway vehicle.
Methods: In the paper two ways of modelling were presented and discussed. One of these ways is the method which consists in reducing the contact issue to field issue and solving the identification of the field source in 2-D system. Also presented a different method designed on the basis of the methods using one period energy concept. This method is adapted for modelling the dynamics of the contact wheel-rail for the normal force. It has been shown that the developed modelling methods to effectively support the study on the effects of mechanical and thermal of contact wheel-rail and contribute to the safety of operations.
Results and conclusions: In the case of field sources identifications two specific issues were examined: the issue of rail torsion and the identification of heat sources in the rail due to exposure the rolling contact wheel-rail. In the case of the method using one period energy concept it was demonstrated the usefulness of this method to the study of energy processes in the contact wheel-rail under the normal periodic force. The future direction of research is to establish cooperation with research teams entrusted with the diagnostic measurements of track and rolling stock.
http://www.logforum.net/vol9/issue4/no1/9_4_1_13.pdf
contact wheel-rail
diagnostics of tract and rolling stock
numerical methods
one period energy
eng
Poznan School of Logistics
Logforum
1734459X
2013-12-30
9
4
article
Selection and application of the touchable elements for blind and people in the Warsaw underground
Janusz Poliński
1
Krzysztof Ochociński
1
Railway Institute, Warsaw, Poland
Background: The aim of this work was to design a warning belt for blind people as well as an inclusion of the requirements in the normative document.
Methods: A diagnostic survey using the questionnaires and the interviews with disabled people (especially with blind and visually impaired people).
Results and Conclusion: As a result of the research and a participation of the blind and visually impaired people, the tactile elements were chosen and parameterized for use in the underground buildings in Warsaw. The relevant information in this filed, which should correspond to Warsaw underground buildings, were included in the regulations of the Minister of Infrastructure. On this basis, all the edges of the Warsaw underground platforms were indicated.
http://www.logforum.net/vol9/issue4/no2/9_4_2_13.pdf
underground platform
danger zone
touchable element
eng
Poznan School of Logistics
Logforum
1734459X
2013-12-30
9
4
article
Optimizing sales areas of combined transport chains
Philip Michalk
1
Technical University of Applied Sciences Wildau, Wildau, Germany
Background: Combined transport chains (such as intermodal transport), have certain advantages. The main advantage from customer points of view is the possibility to bundle freight and thereby decrease transport costs. On the other hand, a combined transport chain can cause longer transport times, due to the necessary transshipment processes.
Methods: The area around a terminal, in which a combined service has favourable properties to a customer in comparison to a direct transport, can be understood as a sales-area, in which a combined transport product is marketable. The aim of this paper was to find a method to determine the best shape and size of this area.
Results and conclusions: The paper at hand lined out a method in order to calculate such a sales area and determine which geographical points around a terminal have an advantage in comparison to a direct transport service.
http://www.logforum.net/vol9/issue4/no3/9_4_3_13.pdf
sales area
intermodal transport
marketing
eng
Poznan School of Logistics
Logforum
1734459X
2013-12-30
9
4
article
The tools for evaluating logistics processes
Michał Adamczak
1
Roman Domański
1
Piotr Cyplik
1
Żaneta Pruska
1
Poznan School of Logistics, Poznan, Poland
Background: The growing importance of business process approach and dynamic management
is triggered by market expectations for lead time reductions and the pressure for cost cuts. An efficient process management requires measurement and assessment skills. This article is intended to present the tools used in evaluating processes and the way in which they work together under simulated conditions.
Methods: The project's Authors believe that a process can be assessed by measuring its attributes: cost, time and quality. An assessment tool has been developed for each of those attributes. For costs - it could be activity based costing, for time - value stream mapping; for quality - statistical process control. Each tool allows for evaluating one of the attributes,
any element in the process hierarchy. The methods presented in the paper have been supplemented with process modelling and simulation.
Results: In order to show how process assessment tools are combined with process simulation the Authors show a sample process in three versions (serial, parallel and mixed). A variant simulation (using iGrafx software) allows
for determining the values of attributes in the entire process based on the data set for its components (activities).
In the example under investigation the process variant has no impact on its quality. Process cost and time are affected.
Conclusions: The tools for identifying attribute values, in combination with process modelling and simulation, can prove very beneficial when applied in business practice. In the first place they allow for evaluating a process based on the value of the attributes pertaining to its particular activities, which, on the other hand, raises the possibility of process configuration at the design stage. The solution presented in the paper can be developed further with a view to process standardization and best variant recommendation.
http://www.logforum.net/vol9/issue4/no4/9_4_4_13.pdf
process assessment
process modelling
process simulation
process management
eng
Poznan School of Logistics
Logforum
1734459X
2013-12-30
9
4
article
Logistics potentials in business competitive advantage creation
Rafał Matwiejczuk
1
Opole University, Opole, Poland
Background: Companies constantly search for ways to achieve and sustain long-term competitive advantage. Among the factors influencing the competitive advantage creation there are so called logistics potentials, which constitute a component part of a business strategic potentials. Logistics resources, logistics capabilities and logistics competences are the main components of the logistics potentials structure and hierarchy.
Methods: In order to recognize the logistics potentials which determine the competitive advantage creation one may use the assumptions and elements of contemporary management concepts, including strategic management. In particular the article deals with Resource-Based View (RBV), Dynamic Capabilities Concept (DCC) and - first of all - Competence-Based Management (CBM).
http://www.logforum.net/vol9/issue4/no5/9_4_5_13.pdf
logistics
competitive advantage
potentials
resources
capabilities
competences
eng
Poznan School of Logistics
Logforum
1734459X
2013-12-30
9
4
article
A measure of internal synergy of the collective system
Novikov V.A.
1
Sapun O.L.
1
Shipulina L.G.
2
Belarusian State Agrarian Technical University
International University "MITSO"
Background: The authors examine the methodology of HRM personnel management based on ratings. Proposed to represent a collective system that uses a matrix of pair relations as a system of linear differential equations. The condition of auto generation of an autonomous system can be determined by the application of the Laplace transformation to the system. This condition mainly depends on the main eigenvalue of dating relationships matrix. Assuming the oscillation frequency is straightly proportional to the system's synergy rating, a special algorithm of comparative evaluation of several collective systems was suggested.
Methods: The calculation of the rating of internal synergies is based on the representation of the collective system as a system of linear differential equations, the coefficients of which are obtained by questionnaire survey of all members of the team. Internal representation of the system's synergism as a stimulation of an autonomous system allows using the eigenvector of the system as a measure of internal synergies.
Results: The result of this method is the rating of members of interacting collective systems in terms of their contribution to the self-organization sharing behavior.
Conclusions: Using a matrix of pair relations allows without direct programming and only using MathCad determines the measure of internal synergy of a collective system.
http://www.logforum.net/vol9/issue4/no6/9_4_6_13.pdf
synergy
rating
matrix of pair relations
autonomous system
differential equation
Laplace transform
frequency of auto generation
eigenvalue
eigenvector
eng
Poznan School of Logistics
Logforum
1734459X
2013-12-30
9
4
article
Cyclic delivery scheduling to customers with different priorities
Katarzyna Zofia Gdowska
1
Roger Książek
1
AGH University of Science and Technology, Krakow, Poland
Background: In this paper a cyclic delivery scheduling problem for customers with different priorities is presented. Shops, which are provided with deliveries, are occasionally located in places which are crucial for the proper flow of traffic. In such places coordination of deliveries is crucial; therefore it allows to completely eliminate the phenomenon of the simultaneous arrivals of suppliers.
Methods: In this paper the cyclic delivery scheduling problem for customers with different priorities was presented. To this theoretical problem a mix integer programming model was developed. Specific approach to the cyclic delivery scheduling problem is inspired by timetabling problem for urban public transport.
Results: Mixed integer programming model was employed for solving four cases of cyclic delivery scheduling problem for customers with different priorities. When the value of the synchronization priority assigned to a single customer raised then the total number of synchronizations in the whole network decreased. In order to compare solutions a synchronization rate was utilized. A simple factor was utilized - the proportion of number of synchronizations of deliveries to a given customer to the total number of synchronizations obtained for the whole network. When the value of synchronization priority raised then the value of synchronization rate of this customer improved significantly.
Conclusions: The mixed integer programming model for the cyclic delivery scheduling problem for customers with different priorities presented in this paper can be utilized for generating schedules of serving customers located in places where only one delivery can be received and unloaded at one go and where there is no space for other suppliers to wait in a queue. Such a schedule can be very useful for organizing deliveries to small shops united in a franchising network, since they operate in a way that is very similar to the network presented in this paper. Moreover, in a franchising network it is possible to implement and control coordination between deliveries.
http://www.logforum.net/vol9/issue4/no7/9_4_7_13.pdf
cyclic delivery scheduling problem
mixed-integer programming
optimization
time windows
eng
Poznan School of Logistics
Logforum
1734459X
2013-12-30
9
4
article
Trends in logistics in the german e-commerce and the particular relevance of managing product returns
Michael Brusch
1
Eva Stüber
2
Anhalt University of Applied Sciences, Köthen, Germany
E-Commerce-Center Köln, Cologne, Germany
Background: There are several trends in logistics Internet retailers have to face nowadays, e.g. addressing and reaching customers through different sales channels (multi- or cross-channel management), integration of new payment alternatives (combined online and/or mobile payment methods), ordering and delivery of products from an Internet retailer at the same day (same-d
http://www.logforum.net/vol9/issue4/no8/9_4_8_13.pdf
E-Commerce
Empirical Investigation
Product Returns
Trends in Logistics