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1

Road vehicle sequencing problem in a railroad intermodal terminal – simulation research

Jacyna M., Jachimowski R., Szczepański E., Izdebski M.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2020

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Vol. 68, nr 5

1135--1148

EN

The paper presents the issue of container handling processes at a railroad intermodal terminal. The main purpose of this paper is the assessment of the handling equipment utilization and the associated energy consumption. The authors analyze how the road vehicle availability at the moment specified in the containers loading schedule influences the total handling equipment operation time as well as the necessary number of handling equipment. It is assumed that vehicles planned for loading of import containers may be late for loading, which causes some interruptions in the loading schedule. Such interruptions are identified with the necessity to handle the next container for which the road vehicle is already waiting, which influences the handling equipment utilization and, finally, energy consumption. The general mathematical model of the problem developed in the FlexSim simulation software was presented. Based on the simulation research, it pointed out that proper road vehicles loading sequencing can significantly reduce handling equipment operation time, and thus energy consumption, costs, and CO2 emissions. The literature analysis presented in the paper indicates that most of the research in the field of intermodal transport is focused on operations optimization in container ports. There are differences between two types of intermodal terminals in operation procedures and rules. That is why the authors decided to undertake the problem of road vehicle sequencing including their random availability and its influence on handling device operation time, which has not been considered in the literature so far.

2

The optmization tool supporting supply chain management in the multi-criteria approach

Izdebski M., Jacyna-Gołda I., Gołębiowski P., Plandor J.

Archives of Civil Engineering

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2020

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Vol. 66, nr 3

505--524

PL

W artykule przedstawiono nowe narzędzie optymalizacyjne wspierające zarządzanie łańcuchem dostaw w aspekcie wielokryterialnym. To narzędzie zostało wdrożone w systemie EPLOS (Europejski Portal Usług Logistycznych). System EPLOS to zintegrowany system informatyczny wspierający proces tworzenia sieci dostaw i dystrybucji w łańcuchach dostaw. Ten system składa się z wielu modułów, np. moduł optymalizacji odpowiedzialny za przetwarzanie danych, generowanie wyników, moduł danych wejściowych, moduł kalibracji parametrów algorytmu optymalizacyjnego. Głównym celem badań było opracowanie systemu do określania parametrów łańcucha dostaw, które wpływają na jego efektywność w procesie zarządzania przepływem towarów między poszczególnymi ogniwami łańcucha. Parametry te zostały uwzględnione w modelu matematycznym jako zmienne decyzyjne w celu ustalenia ich w procesie optymalizacji. W modelu matematycznym zdefiniowano dane wejściowe adekwatne do analizowanego problemu, przedstawiono główne ograniczenia związane z wyznaczaniem efektywnego sposobu zarządzania łańcuchem dostaw oraz opisano funkcje kryterium. Problem zarządzania przepływem towarów w łańcuchu dostaw został przedstawiony w ujęciu wielokryterialnym. Ocenę efektywności zarządzania łańcuchem dostaw przeprowadzono na podstawie globalnej funkcji kryterium składającej się z częściowych funkcji kryteriów opisanych w modelu matematycznym. Główne funkcje kryteriów na podstawie których wyznaczane jest końcowe rozwiązane to współczynnik wykorzystania wewnętrznych środków transportu, współczynnik wykorzystania zewnętrznych środków transportu, koszty pracy środków transportu wewnętrznego i personelu, całkowity koszt realizacji zadań transportowych, współczynnik wykorzystania czasu zaangażowania pojazdów, całkowity czas poświęcony na wykonanie zadań, czy liczba pojazdów. Punktem wyjścia do badania było założenie, że o skuteczności zarządzania łańcuchem decydują dwa problemy decyzyjne ważne dla menedżerów w procesie zarządzania łańcuchem dostaw, tj. problem przydziału pojazdów do zadań i problem lokalizacji obiektów logistycznych w łańcuchu dostaw. Aby rozwiązać badany problem, zaproponowano innowacyjne podejście w postaci opracowania algorytmu genetycznego, który został dostosowane do przedstawionego modelu matematycznego. W pracy szczegółowo opisano poszczególne kroki konstruowania algorytmu. Zaproponowana struktura przetwarzana przez algorytm jest strukturą macierzową, dzięki której wyznaczane są optymalne parametry łańcucha dostaw. Procesy krzyżowania i mutacji zostały opracowane adekwatnie do przyjętej struktury macierzowej. W procesie kalibracji algorytmu wyznaczono takie wartości parametrów algorytmu tj. prawdopodobieństwo krzyżowania czy mutacji, które generują optymalne rozwiązanie. Poprawność algorytmu genetycznego oraz efektywność zaproponowanego narzędzia wspomagającego proces zarządzania łańcuchem dostaw została potwierdzona w procesie jego weryfikacji.

EN

The article presents a new optimization tool supporting supply chain management in the multi-criteria aspect. This tool was implemented in the EPLOS system (European Logistics Services Portal system). The EPLOS system is an integrated IT system supporting the process of creating a supply and distribution network in supply chains. This system consists of many modules e.g. optimization module which are responsible for data processing, generating results. The main objective of the research was to develop a system to determine the parameters of the supply chain, which affect its efficiency in the process of managing the goods flow between individual links in the chain. These parameters were taken into account in the mathematical model as decision variables in order to determine them in the optimization process. The assessment of supply chain management effectiveness was carried out on the basis of the global function of the criterion consisting of partial functions of the criteria described in the mathematical model. The starting point for the study was the assumption that the effectiveness of chain management is determined by two important decision-making problems that are important for managers in the supply chain management process, i.e. the problem of assigning vehicles to tasks and the problem of locating logistics facilities in the supply chain. In order to solve the problem, an innovative approach to the genetic algorithm was proposed, which was adapted to the developed mathematical model. The correctness of the genetic algorithm has been confirmed in the process of its verification.

3

Frequency dependence of the Kerr constant in Nynas Nytro 3000 oil determined by the polarimetric method

Poborska J., Dąbrówka D., Chwirot M., Ledzion R., Izdebski M., Kucharczyk W.

Scientific Bulletin. Physics / Lodz University of Technology

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2018

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Vol. 39

37--44

EN

A frequency dependence of the Kerr constant K in transformer oil Nynas Nytro 3000 within a frequency range 117-5017 Hz is determined. An averaged value (2.30 ± 0.03) 10-15 m/V2 for K is obtained. The constant is found to be weakly frequency dependent and approaches its maximum 2.37·10-15 m/V2 at about 3000 Hz. The Kerr constant is of comparable value to that observed in other mineral oils employed previously in measurements of the quadratic electro-optic effect and the electrostriction in crystals.

PL

W zakresie częstotliwości 117 Hz – 5017 Hz przeprowadzono pomiary stałej Kerra K oleju transformatorowego Nynas Nytro 3000. Otrzymana średnia wartość stałej wynosi (2.30 ± 0.03)·10-15 m/V2 a w okolicach 3000 Hz osiąga ona maksymalną wartość 2.37·10-15 m/V2. Wyniki pokazują, że wielkość stałej Kerra w badanym oleju jest zbliżona do wartości obserwowanych w poprzednio badanych olejach więc może on być wykorzystany jako ciecz immersyjna w pomiarach współczynników kwadratowego efektu elektrooptycznego oraz elektrostrykcji w kryształach.

4

The Organization of Municipal Waste Collection: the Decision Model

Izdebski M., Jacyna M.

Rocznik Ochrona Środowiska

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2018

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Tom 20, cz. 1

919--933

EN

The paper presents the problem of organizing municipal waste collection from individual residents. A waste collection organization is defined as the designation of vehicle routes for a given collection. In order to solve this problem, a decision model for determining driving routes has been proposed. The organization of municipal waste collection may be considered in a single or multi-criteria approach. This study presents a collection of municipal waste in the context of a multi-criteria decision problem. In this work, the decision model of the municipal waste collection organization is based on multi-criteria optimization. In this case, the optimization algorithm was an ant algorithm. This algorithm has been specially modified to solve the problem of making decisions based on many criteria. The authors of this publication have not found application of this approach and this algorithm in the literature to designate the municipal waste collection organization. The municipal waste collection organization is a complex decision problem and refers to the traveling salesman problem. This problem belongs to NP-hard problems. To solve the problem of the traveling salesman, a heuristic algorithm should be applied. Fast time of generating the result by the ant algorithm is its main feature, which is desirable in the process of designating the municipal waste collection organization. This process depends on many factors, e.g. vehicle capacity, size of tasks. The algorithm for determining this type of problem must be adapted to frequent changes of these factors and quick generation of solutions. The time of solution generation plays the most important role in municipal companies. The ant algorithm generates results in a quick way and therefore this algorithm was chosen in this problem. The presented decision model concerns the collection of waste from individual residents. The car visits the loading points (inhabitants) and collects waste. The main goal is to designate this route. This fact additionally emphasizes the use of the heuristic algorithm in this problem. The work defines the mathematical model of the problem of municipal waste collection, the input data entered into the model are given, e.g. distances between objects of the transport network have been defined, driving times between these objects are given, loading times, unloading of waste, crossing time. The decision variable defines the connection between individual network objects implemented by the vehicle in a given route. Decision variables are binary type. Limitations have been introduced for working time and for the capacity of vehicles that collect waste. The criteria functions concern the minimization of the time of completion of all routes and the costs of fuel consumption. In order to check the correctness of the ant algorithm, its results were compared with random values. The ant algorithm in each case generated a better solution than a random algorithm. It should be emphasized that the form algorithm belongs to heuristic algorithms. The solution generated by these algorithms for complex decision problems is a suboptimal solution. However, taking into account the complexity of the municipal waste collection organization, the solution is accepted from a practical point of view.

PL

W pracy przedstawiono problem organizacji zbiórki odpadów komunalnych od indywidualnych mieszkańców. Organizacja zbiórki odpadów jest zdefiniowana jako wyznaczenie tras jazdy pojazdów realizujących daną zbiórkę. W celu rozwiązania tego problemu zaproponowano model decyzyjny wyznaczania tras jazdy pojazdów. Organizacja zbiórki odpadów komunalnych może być rozpatrywany w ujęciu jedno lub wielokryterialnym. W niniejszym opracowaniu przedstawiono zbiórkę odpadów komunalnych w kontekście wielokryterialnego problemu decyzyjnego. W niniejszej pracy model decyzyjny organizacji zbiórki odpadów komunalnych opiera się na optymalizacji wielokryterialnej. W tym przypadku algorytm optymalizacji był algorytmem mrówkowym. Algorytm ten został specjalnie zmodyfikowany w celu rozwiązania problemu podejmowania decyzji w oparciu o wiele kryteriów. Autorzy tej publikacji nie znaleźli zastosowania tego podejścia i tego algorytmu w literaturze do wyznaczenia organizacji zbiórki odpadów komunalnych. Organizacja zbiórki odpadów komunalnych jest złożonym problemem decyzyjnym i odnosi się do problemu komiwojażera. Problem ten należy do problemów NP-trudnych. Aby rozwiązać problem komiwojażera, należy zastosować algorytm heurystycznych. Szybki czas generowania wyniku przez algorytm mrówkowy jest jego główną cechą, co jest pożądane w procesie wyznaczania organizacji zbiórki odpadów komunalnych. Proces ten zależy od wielu czynników, np. pojemność pojazdów, wielkość zadań. Algorytm wyznaczania tego typu problemu musi być dostosowany do częstych zmian tych czynników i szybkiego generowania rozwiązań. W firmach komunalnych najważniejszą rolę odgrywa czas generowania rozwiązania. Algorytm mrówkowy generuje wyniki w szybki sposób i dlatego ten algorytm został wybrany w tym problemie. Przedstawiony model decyzyjny dotyczy zbiórki odpadów od poszczególnych mieszkańców. Samochód odwiedza punkty załadunku (mieszkańców) i zbiera odpady. Głównym celem jest wyznaczenie tej trasy. Fakt ten dodatkowo podkreśla zastosowanie algorytmu heurystycznego w tym problemie. W pracy zdefiniowano model matematyczny problemu zbiórki odpadów komunalnych, podano dane wejściowe wprowadzane do modelu np. zdefiniowano odległości pomiędzy obiektami sieci transportowej, podano czasy jazdy pomiędzy tymi obiektami, czasy załadunku, wyładunku odpadów, czas przejazdu przez skrzyżowania. Zmienna decyzyjna określa połączenie pomiędzy poszczególnymi obiektami sieci realizowane przez pojazd w danej trasie. Zmienne decyzyjne są typu binarnego. Wprowadzono ograniczenia na czas pracy oraz na pojemność pojazdów realizujących zbiórkę odpadów. Funkcje kryteriów dotyczą minimalizacji czasu realizacji wszystkich tras oraz kosztów zużycia paliwa. W pracy szczegółowo scharakteryzowano algorytm mrówkowy rozwiązujący wielokryterialny problem decyzyjny zbiórki odpadów komunalnych. W celu sprawdzenia poprawności algorytmu mrówkowego jego wyniki porównano z wartościami losowymi. Algorytm mrówkowy w każdym przypadku generował lepsze rozwiązanie niż losowy algorytm. Należy podkreślić, że algorytm mrówkowy należy do algorytmów heurystycznych. Rozwiązanie wygenerowane przez te algorytmy dla złożonych problemów decyzyjnych jest rozwiązaniem nieoptymalnym. Biorąc jednak pod uwagę złożoność organizacji zbiórki odpadów komunalnych, rozwiązanie jest akceptowane z praktycznego punktu widzenia.

5

The car fleet management model with including expectations of the users

Szczepański E., Nivette M., Jacyna-Gołda I., Izdebski M.

Journal of KONES

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2018

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Vol. 25, No. 4

489--500

EN

The paper presents a certain approach to fleet management in the company, taking into account the mobility of employees and the selection of vehicles for tasks. The main objective is to indicate the factors that significantly affect the proper selection of vehicles for the task, as well as concurrently meeting recipients' needs. The general model for fleet management was presented, taking into account not only the mobility of employees but also the method of obtaining funds for the replacement of greener cars. The current approach is based on the car purchase model in the form of credit, low-purchase leasing, and supervision over the use process and operating costs by the company's internal resources. The problem solved in the article concerns the analysis of entrusting fleet management to specialized Car Fleet Management (CFM) companies. It was pointed out that in this calculation model, CFM companies have to take into account many variables related to vehicle selection and mobility of employees in order to perform tasks. In this article, particular attention has been paid to the areas that CFM analyses when choosing a vehicle for a given company.

6

The application of genetic algorithm in the assignment problems in the transportation company

Izdebski M., Jacyna M.

Journal of KONES

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2018

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Vol. 25, No. 4

133--140

EN

The article presents the problem of the task assignment of the vehicles for the transportation company, which deals with the transport of the cargo in the full truckload system. The presented problem is a complex decision making issue which has not been analysed in the literature before. There must be passed through two stages in order to solve the task assignment problem of the vehicles for the transportation company. The first stage is to designate the tasks, the other one is to determine the number of the vehicles that perform these tasks. The task in the analysed problem is defined as transporting the cargo from the suppliers to the recipients. The transportation routes of the cargo must be determined. In order to solve the task assignment problem of the vehicles, the genetic algorithm has been developed. The construction stages of this algorithm are presented. The algorithm has been developed to solve the multi-criteria decision problem. What is more, the algorithm is verified by the use of the real input data.

7

The application of ant algorithm in the assignment problem of aircrafts to stops points on the apron

Gołda P., Izdebski M., Szczepański E.

Journal of KONES

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2018

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Vol. 25, No. 4

479--487

EN

The article refers to the problem of assigning the aircrafts to stops points on the apron. The aim of this paper is to develop the algorithm, which will be used to this assignment. The assignment problem of aircrafts to stops points is the complex decision problems, which refer to the problems of designating the minimal path in the graph. The assignment model was described, i.e. decision variables, constraints and the criterion function. Decision variables take the binary form and determine the connections between the elements of infrastructure of the apron, i.e. touchdown points, intermediate points and stop points. Constraints take into account the number of aircrafts in the given period, the number of unoccupied stop points. The criterion function determines the minimum driving time of the aircraft on the apron. In order to designate the routes in international transport the heuristic algorithm, i.e. ant algorithm was developed. The steps of building this algorithm were presented. This algorithm was verified in the C# programming language. The results generating by the presented algorithm were compared with the results generating by the random algorithm.

8

Exhaust emission estimation in freight transport systems

Szczepański E., Gołda P., Jacyna-Gołda I., Izdebski M.

Journal of KONES

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2018

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Vol. 25, No. 1

395--406

EN

Modelling of transport systems is a complex issue requiring taking into account many factors that allow for the mapping of the real system and thus allowing decision support. In the era of increasingly higher requirements for services, transport also faces the challenges of sustainable development. Therefore, it is necessary to conduct research both in the sphere of technical and organizational solutions aimed at limiting pollutant emissions. Mapping in the model the negative impact of transport on the environment allows for planning the implementation of the transport service taking into account the pro-ecological criterion. This is particularly important in urban areas where traffic and especially heavy goods vehicles are particularly onerous for inhabitants and require limiting transport work in the city area and the use of environmentally friendly rolling stock. The aim of the article is to present the considerations regarding the modelling of transport systems including pollutant emissions. The article introduces the problem of cargo distribution and a review of the models of estimation of pollution emission in the micro and macro scale was carried out. Next, a mathematical model was proposed which is a variant of the Vehicle Routing Problem of the so-called Green VRP. In the distribution model was used COPERT methodology for estimation of harmful substance emission. In article examples of calculations carried out on the example of the city of Warsaw for the organization of cargo distribution due to the CO emission criterion was presented. The article ended with a short synthesis of the work carried out.

9

Innowacyjny algorytm pomiaru temperatury uzwojenia wirnika generatora

Izdebski M.

Energetyka

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2018

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nr 2

101--110

PL

Zaprezentowano klasyczną metodę pomiaru temperatury uzwojenia wirnika generatora synchronicznego oraz przeanalizowano jej błędy pomiarowe. W artykule opisano koncepcję, algorytm oraz badania innowacyjnej metody pomiaru temperatury uzwojenia wirnika w procesorze regulatora napięcia statycznego tyrystorowego układu wzbudzenia. Badania przeprowadzono w środowisku Matlab/Simulink. Nowa metoda pomiaru temperatury uzwojenia wirnika została opracowana przez Instytut Energetyki Oddział Gdańsk w ramach pracy statutowej.

EN

Presented is a classical method for measurement of a synchronous generator rotor winding temperature and analysed are its measurement errors. Described is an idea, algorithm and research on the innovative method for measurement of a generator rotor winding temperature in the processor of a static voltage regulator in a thyristor excitation system. Reasearch was conducted in the Matlab/Simulink environment. The new method of a rotor winding temperature measurement has been developed by the Instytut Energetyki Oddział Gdańsk as a part of its statutory activity.

10

The assessment of supply chain effectiveness

Jacyna-Gołda I., Izdebski M., Szczepański E., Gołda P.

Archives of Transport

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2018

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Vol. 45, iss. 1

43--52

EN

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.

11

Characteristics of event recorders in automatic train control systems

Jacyna M., Szczepański E., Izdebski M., Jasiński S., Maciejewski M.

Archives of Transport

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2018

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Vol. 46, iss. 2

61--70

EN

The development of railway transport in the current times is very noticeable, it is connected with the growing needs of movement as well as the development of information engineering. The increase in the demand for transport requires the implementation of solutions that increase the efficiency of the transport system. Both long-distance, agglomeration and metro railways can use different systems due to their specificity. Nevertheless, there is a noticeable trend in the development of systems supporting or even replacing the driver by the automation of selected activities. Such systems allow to reduce trains headway and thus increase the capacity of the line. CBTC class systems (Communications-based train control) belong to automatic train systems and are based on wireless transmission. The main purpose of using such systems is to increase the frequency of running trains while maintaining the level of safety. Computers that are on the system equipment record, process and analyse very large amounts of data. An essential element of such systems are recording units. The parameter recorders can be divided into technical and legal ones. However, for CBTC class systems, there is no obligation or requirement to use legal recorders as it is in the case of ETCS. However, it is necessary to use event recorders, and these are subject to the requirements set out in the PN-EN 62625-1: 2014 standard. The recorders are a very important component of safety systems, which is why they were analysed in this article. Both the driver, the vehicle and the infrastructure should be subject of continuous monitoring. The occurrence of an adverse event (not necessarily leading to an incident or accident) should be analysed and used to improve safety procedures. Currently, automatic systems are still developing and we are not able to accurately assess what the causes and effects of certain events may be, which is why data collection and analysis is particularly important. The article presents the general specification of the CBTC system. The parameters and properties of driving recorders should be presented. This article is cofinanced by the European Union POIR.01.01.01-00-0276/17

12

Verification of one-dimensional models describing anisotropy of step growth

Izdebski M., Ledzion R.

Scientific Bulletin. Physics / Lodz University of Technology

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2017

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Vol. 38

11--26

EN

Models that allow to obtain directional dependencies of normal velocity of a straight step on the (001) face of Kossel crystal and its edge free energy are reviewed. The dependencies were considered in a wide range of crystal growth conditions, which showed some significant discrepancies between the models and limitations in the scope of their applicability. The results presented concern on one-dimensional kinetic and thermodynamic models of a single step.

PL

Dokonano przeglądu modeli znanych z literatury, które umożliwiają otrzymanie kierunkowych zależności prędkości normalnej prostoliniowego stopnia wzrostu na ścianie (001) kryształu Kossela oraz jego krawędziowej energii swobodnej. Zależności zostały rozważone w szerokim zakresie warunków wzrostu kryształu, co umożliwiło ukazanie niezgodności pomiędzy modelami oraz ograniczeń w zakresie ich stosowalności. Przedstawione wyniki koncentrują się na jednowymiarowych kinetycznych i termodynamicznych modelach pojedynczego stopnia wzrostu.

13

Możliwość produkcji biogazu z osadów komunalnych na obszarach wiejskich

Izdebski W., Chibowski P., Izdebski M., Kassar F. H., Tanaś W., Szymanek M.

Przemysł Chemiczny

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2017

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T. 96, nr 5

1030--1033

14

Zasady konstruowania i graficznej prezentacji procesu magazynowego

Wasiak M., Kłodawski M., Lewczuk K., Izdebski M.

Prace Naukowe Politechniki Warszawskiej. Transport

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2017

|

z. 119

493--503

PL

W artykule przedstawiono podstawowe założenia do konstruowania i prezentacji procesów magazynowych w różnych typach obiektów logistycznych. Proces magazynowy rozumiany i odwzorowywany jest, jako sekwencja faz magazynowania, zadań magazynowych, zestawów operacji magazynowych, operacji oraz czynności. Ich struktura, jak również sposób i zakres realizacji zależą od rodzaju obiektu logistycznego i postaci oraz zakresu jego zadania logistycznego. Podstawowe założenia przedstawione w referacie zostaną wykorzystane do budowy matematycznych modeli symulacyjnych przepływu materiałów w określonych typach obiektów logistycznych.

EN

Paper presents basic assumptions for modelling warehouse processes in different types of logistic facilities. These processes are mapped as sequences of warehousing phases, warehouse tasks, material transformations, warehouse operations and activities. Their structure, as well as manner and range of implementation are dependent on type of logistic facility and its main logistic task. Basic assumptions presented in the paper will be used to build a mathematical simulation model of the materials flow in certain types of logistics facilities.

15

Optimizing the number of docks at transhipment terminals using genetic algorithm

Izdebski M., Jacyna-Gołda I.

Journal of KONES

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2017

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Vol. 24, No. 4

369--376

EN

This article presents the issue of designating the number of docks at the transhipment terminals using genetic algorithm. Transhipment terminals refer to cross-docking terminals. The main factor that influences on the number of these docks is the stream of cargo flowing into the given terminal. In order to determine this flow of cargo the mathematical model of the distribution of this flow was developed. This model takes into account constraints like those that e.g. processing capacity at the transhipment terminal cannot be exceeded or demand of recipients must be met. The criterion function in this model determines the minimum cost of the flow of cargo between all objects in the transport network. To designate the optimal stream of cargo flowing into the transport network the genetic algorithm was developed. In this article, the stages of construction of this algorithm were presented. The structure processed by the algorithm, the process of crossover and mutation were described. In the article in order to solve the problem of designating the number of docks at the transhipment terminals the genetic algorithm was developed.

16

Heuristic algorithms applied to the problems of servicing actors in supply chains

Izdebski M., Jacyna-Gołda I., Markowska K., Murawski J.

Archives of Transport

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2017

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Vol. 44, iss. 4

25--34

EN

The paper discusses main decision problems analysed in the subject matter of servicing actors operating in the supply chains, i.e. the vehicle routing problem, vehicles-to-task assignment problem and the problem of entities’ localization in the supply chain. The input data used to describe supply chains is given as well as the basic constraints and the criterion functions used in the development of mathematical models describing the supply chains. Servicing actors in supply chains is the complex decision making problem. Operators in the supply chains are constrained by: production capacity of the suppliers, the demand of the customers in particular working days, storage capacities of warehouses, handling capacities of warehouses, suppliers’ and warehouses’ time windows and other. The efficiency of supply chain is described by cost of transport between operators, costs of passing cargoes through warehouses and delivery time to the recipient. The heuristic algorithms, like genetic and ant algorithms are detailed and used to identify issues related to the operation of actors operating in the supply chains are described. These algorithms are used for solving localization problems in supply chains, vehicle routing problems, and assignment problems. The complexity of presented issues (TSP is known as NP-hard problem) limits the use of precise algorithms and implies the need to use heuristic algorithms. It should be noted that solutions generated by these algorithms for complex decision instances are sub-optimal solutions, but nonetheless it is accepted from the practical point of view.

17

Designing and efficiency of database for simulation of processes in systems. Case study for the simulation of warehouse processes

Jachimowski R., Gołębiowski P., Izdebski M., Pyza D., Szczepański E.

Archives of Transport

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2017

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Vol. 41, iss. 1

31--42

EN

The basis of each IT system is data exchange both between individual modules of program and between program and user. The number of exchanged data and the number of operations on the data, which should be performed, require application of professional tools allowing for collecting and performing operations on multiple types of data. One of these tools are databases, which are an essential part of any IT system. With database designing are connected many decision problems which can occur both during the construction of database management system and at the stage of integration of entire user application with developed database. The article presents typical decision problems connected with designing of databases. These problems mainly concern sphere of information technology (including the programming language or recovery mechanism of database after the failure). Database architecture for typical IT system from the point of view possible paths for users were discussed, and role of catalogues played in development of database were presented. In addition, modular structure of the database, which was developed for the system SIMMAG3D for modelling and visualization of warehouse facilities in 3D was shown. This system is being developed under a project financed by the National Centre for Research and Development. We discussed in detail one of the essential elements in developed database - catalogues of means of external and internal transport, non-mechanical equipment and accessories which are essential from the point of view of the work load.

18

Temperature dependence of the Kerr constant of Fomblin M03

Ledzion R., Górski P., Izdebski M., Kucharczyk W.

Scientific Bulletin. Physics / Lodz University of Technology

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2016

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Vol. 37

75--82

EN

The Kerr constant B of perfluoropolyether Fomblin M03 has been determined within the temperature range 295-370K. At 300K the constant B was found to be equal to 2.8·10-15 m/V2. The measurements indicate that B varies inversely with temperature. Relatively low electro-optic response of the perfluoropolyether shows its usability in measurements of the quadratic electrooptic effect and the electrostriction in crystals.

PL

W zakresie temperatur 295- 323 K przeprowadzono pomiary stałej Kerra B polimeru Fomblin M03. Stwierdzono, że stała B jest odwrotnie proporcjonalna do temperatury. W temperaturze 300 K jej wielkość wynosi 2.8·10-15 m/V2. Wyniki pokazują, że ze względu na małą wartość stałej Kerra Fomblin M03 może być wykorzystany jako ciecz immersyjna w pomiarach współczynników kwadratowego efektu elektrooptycznego oraz elektrostrykcji w kryształach.

19

Study of electrically induced orientational ordering in mineral oils on the example OF ORLEN OIL TRAFO EN

Izdebski M., Adamus M., Jóźwiak E., Ledzion R.

Scientific Bulletin. Physics / Lodz University of Technology

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2016

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Vol. 37

31--47

EN

A simple model of orientational ordering of molecules in the liquid under the influence of an applied sinusoidal electric field of low frequency is presented. The predicted theoretical dependencies of linear birefringence and light transmission coefficients on the intensity of the applied field were confirmed by experimental data obtained for transformer oil ORLEN OIL TRAFO EN. It was found that the intensity of orientational effects in the oil depends strongly not only on the current conditions, but also on the thermal history of the sample. Furthermore it is shown that the minimum amount of dissolved contaminants (e.g. polyethylene) strongly increases the effects. The results suggest that it is necessary to reconsider the techniques for measuring the Kerr effect in liquids associated with deformation of electron cloud, because the traditional approach does not take into account the orientational effects occurring simultaneously with the Kerr effect.

PL

Przedstawiono prosty model orientacyjnego porządkowania molekuł cieczy pod wpływem przyłożonego sinusoidalnie zmiennego pola elektrycznego niskiej częstotliwości. Teoretyczne zależności liniowej dwójłomności oraz współczynników transmisji światła od natężenia przyłożonego pola zostały potwierdzone przez dane doświadczalne otrzymane dla oleju transformatorowego ORLEN TRAFO EN. Stwierdzono, że intensywność efektów orientacyjnych w tym oleju zależy silnie nie tylko od bieżących warunków, lecz także od termicznej historii próbki. Ponadto pokazano, że minimalny dodatek rozpuszczonych zanieczyszczeń (np. polietylenu) może zdecydowanie wzmocnić te efekty. Otrzymane wyniki sugerują, że należy ponownie rozważyć techniki pomiaru efektu Kerra w cieczach, związanego z deformacją chmury elektronowej, gdyż tradycyjne podejście nie uwzględnia efektów orientacyjnych, które występują jednocześnie z efektem Kerra.

20

Improving Investment Efficiency by Using Renewable Energy Sources

Grzeszczyk T. A., Izdebski M.

Research in Logistics & Production

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2016

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Vol. 6, No. 4

331--342

EN

The reduction of natural resources and the ever increasing demand for energy forces research on new energy sources. In the case of obtaining energy from non-renewable sources of energy, natural resources are used as fuel in the combustion process. This way relatively high calorific value is achieved but it is associated with the number of fundamental flaws. Among other things, this may include destruction of the environment in the vicinity of extraction of conventional fuels’ sources, emission of large amounts of harmful substances during the combustion of conventional fuels causing the pollution of natural environment and there is a danger of life or health loss for people working in the extraction of fossil fuels. The use of renewable energy sources is related to interesting investment opportunities in the energy field and there are no problems mentioned above. For these reasons, it is worthwhile to conduct research on improving investment efficiency by using new, renewable sources. Therefore, the purpose of this paper is showing the opportunities of improving efficiency of electric power investment by using renewable energy sources. This article presents a comprehensive overview of renewable technologies used to produce electricity. Then, the attention was focused on assessing the financial efficiency of wind turbines. The considerations were illustrated with the examples of calculation of financial ratios NPV and IRR for a hypothetical investment in the production of electric power using the wind farm. The calculations and analysis conducted can provide interesting basis for further research on improving electric power investment efficiency by using renewable energy sources and new comprehensive evaluation methods of such investments. Comprehensive evaluation methods should take into consideration multifaceted nature of the projects.