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1

The efficiency of food supply chain engineering (case study in Ukraine)

Kush Yevhen, Tonkoshkur Maksym, Vakulenko Kateryna, Ryabev Anton, Davidich Natalia, Galkin Andrii

Archives of Transport

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2020

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Vol. 55, iss. 3

51--71

EN

The basic conceptual idea of logistics is the need to adapt the company to an ever-changing market situation, while spending a minimum of funds in these conditions. The concept of logistics is a system of views on the rationalization of economic activity by optimizing material flows. The paper investigates the change of the main indicators of the functioning of the supply chain, depending on the organization of distribution of the material flow. The supply systems of food products that form the consumer basket at the stage of distribution is considered. The conceptual schemes of freight flow distribution with and without distribution center is presented. The field research was conducted to determine and initial data were collected. The paper investigate the functioning of the supply chain in two cases: in a situation "proposed scenario" and in a situation "without a project". The situation "existing scenario" implies that no action to change the parameters of the supply chain during the period specified for the research does not take place. In this case, it is necessary to assess the effectiveness of the logistics chain under existing conditions. An integrated approach to evaluate the efficiency of the functioning of the logistics system and the consumer had been used. The efficiency of existing of the supply chain functioning were analysed. Also, certain measures will be implemented to improve the chain through investments and by bringing logistics infrastructure with the needs. A modelling of the supply chain was made. The effect of parameters of participants on the supply chain efficiency was analysed. The planned effect from the reorganization of distribution channels is calculated. The technological and economic feasibility of introducing a distribution center into the existing distribution channel based on modeling is calculated. The object of the research is the process of food products distribution in the supply chain. The aim of the research is to evaluate the effectiveness of the food supply chain scheme.

2

Mechanisms for increasing of transportation efficiency using joint service of logistics systems

Galkin Andrii

Archives of Transport

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2019

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Vol. 49, iss. 1

7--24

EN

More and more attention become to Transport Company’s functioning efficiency due to growing of goods’ nomenclature and specific requirements for their service. Existing scientific and practical approaches to managing of transportation process consider separate service of each contract individually. Up-today requirements for transportation services complicate such evaluation. These requirements primarily include transportation frequency and volumes variation in each logistics system due to seasonal consumption of material flows. Different seasonality leads to irrational use of vehicles and decrees of their efficiency. All this gives rise to the mechanism of compatible transportation service of numerous logistics systems and their material flows by any enterprise. The paper consist of next sections the analysis of scientific framework and methods on the transportation services, fleet estimation, efficiency evaluations, analysis of requirements of transportation services; Mechanism of joint transportation services; Modelling of transportation services in logistics systems, where joint efficiency estimation of transportation functioning and logistics system and conclusions. The proposed methods and tools in the complex allow to identify and evaluate the effectiveness of the joint motor transport service of logistic systems by own and hired vehicles compared to the separate on the basis of performance indicators, which vary depending on the technological parameters: transport distances, runway usage factor, cargo class, load capacity of motor vehicles . The offered approach will reveal: regularities of change of indicators of efficiency of variants of the joint motor transport service between the traditional approach (a separate calculation of efficiency for each logistics system) and the proposed (calculation of compatible services), which allows to determine the equivalent cost of transport services during motor transport maintenance of material flows. The calculations confirm the effect of use compared to the separate combined transportation of material flows, which will be shown in reducing the required amount of vehicles by 31,8% and increasing efficiency from 5% to 60%, depending on the initial values of the transportation services parameters. The results of the project can be used in the formation of a freight vehicle fleet of any enterprise that is faced with the issue of hiring transport or have its own, PL providers, transport companies, and others.

3

The present value of a portfolio of assets with present values determined by trapezoidal ordered fuzzy numbers

Łyczkowska-Hanćkowiak A., Piasecki K.

Operations Research and Decisions

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2018

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Vol. 28, No. 2

41--56

EN

We consider the obvious thesis that the present value of a portfolio is equal to the sum of the present values of its components. The main goal of this paper is the implementation of this thesis in the case when present values are determined by trapezoidal ordered fuzzy numbers. We apply the revised sum of ordered fuzzy numbers. The associativity of such a revised sum is investigated here. In addition, we show that the multiple revised sum of a finite sequence of trapezoidal ordered fuzzy numbers depends on the ordering of its summands. Without any obstacles, the results obtained can be generalized to the case of any ordered fuzzy numbers.

4

The portfolio problem with present value modelled by a discrete trapezoidal fuzzy number

Piasecki K., Siwek J.

Operations Research and Decisions

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2018

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Vol. 28, No. 1

57--74

EN

A multi-asset portfolio in the case of its present value estimated by a discrete trapezoidal fuzzy number has been assessed. The benefits of owning a security have been evaluated according to an expected fuzzy discount factor. The ambiguity risk has been assessed by an energy measure and indistinctness risk has been evaluated by Kosko’s entropy measure. The relationship between the expected fuzzy discount factor for a portfolio and the expected fuzzy discount factors for its components has been derived. An analogous relationship between the values of the energy measure has been presented. The model has been illustrated by means of a profound numerical case study.

5

On simulation of maintenance costs for water distribution system with fuzzy parameters

Romaniuk M.

Eksploatacja i Niezawodność

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2016

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Vol. 18, no. 4

514--527

EN

In this paper we propose a model for evaluation of maintenance costs of a water distribution system (WDS). The set of possible states of each connection (i.e. a pipeline in the WDS) is related to various possible degrees of quality of the pipe and types of its malfunctions. The process of transitions between these states forms a semi-Markov process. Using Monte Carlo simulations, the length of services and the times of necessary replacements and repairs of the connections are obtained. These values are then used as an input for estimation of the maintenance costs of the whole WDS. During this step we take into account the concept of present value of money. Contrary to other approaches, instead of a constant yield, a stochastic process (the one-factor Vasicek model) of an interest rate is assumed. Then various simulated measures of reliability and the maintenance costs can be analysed, like an influence of various parameters of the pipes (e.g. intensities of damages) on the final costs of the performed services. They can be crucial in the analysis of risk for various possible decisions. Apart from the crisp approach, the Monte Carlo simulations are also applied, if some of the parameters of the WDS are fuzzified. Therefore uncertainty and experts’ knowledge can be easily incorporated into the proposed procedure of the estimation of the maintenance costs. Observed differences between the crisp and the fuzzy output are highlighted. Simulation algorithms, necessary for both of these approaches, are also provided.

PL

W niniejszym artykule przedstawiono model obliczający koszty utrzymania i konserwacji dla systemu dystrybucji wody (WDS). Zbiór możliwych stanów każdego połączenia (tzn. odcinku rurociągu w WDS) jest zdefiniowany przez różne poziomy jakości rury oraz występujące typy uszkodzeń. Proces przejść pomiędzy tymi stanami jest opisany procesem semi-Markowa. Wykorzystując symulacje Monte Carlo, uzyskano długości okresów obsługi oraz momenty niezbędnych wymian i napraw. Wartości te są następnie wykorzystywane do estymowania kosztów utrzymania całego WDS. W kroku tym brana jest pod uwagę wartość pieniądza w czasie. W przeciwieństwie do innych podejść, zamiast stałej stopy procentowej, założono stochastyczny proces stopy (dany jednowymiarowym modelem Vasicka). Następnie na podstawie przeprowadzonych symulacji wykonano analizę opartą o różne miary niezawodności i obliczone koszty obsługi, np. zbadano wpływ parametrów połączenia (takich jak intensywność uszkodzeń) na ostateczne koszty konserwacji. Analizy tego typu mogą pełnić istotną rolę w ocenie ryzyka dla różnych możliwych do podjęcia decyzji. Poza podejściem typu crisp, zastosowano również symulacje Monte Carlo gdy niektóre z parametrów WDS zostały określone w sposób rozmyty. Dzięki temu można wykorzystać niepewność oraz wiedzę ekspercką w proponowanej metodzie estymacji kosztów obsługi. Zwrócono uwagę na różnice występujące pomiędzy podejściem crisp i rozmytym. Zostały również opisane niezbędne dla obydwu podejść odpowiednie algorytmy symulacyjne.

6

Acceleration of Economic Growth by Technological Change and Knowledge Management

Kulikowski R.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2003

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Vol. 51, nr 3

323-333

EN

The paper deals with the methodology of knowledge management which is aimed at the acceleration of economic growth. The methodology is based on the subjective utility concept, introduced by Kulikowski [1998], which enables one to estimate the present value benefits resulting from the technological change and the cost of change. It enables also to derive, in an explicite form, the optimum strategies connected with alocation of a budget among the research institutes and research projects. The support of negotiations, connected with joint ventures, between the research institutes and business organizations, based on Nash principle and subjective utility, is also presented.