Wyniki wyszukiwania - BazTech

1

Optimization of an EPQ model in an imprecise environment with defuzzification by the centroid method under inflation

Arora Ritu, Chauhan Anand, Sharma Renu, Singh Anubhav Pratap

Operations Research and Decisions

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2022

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Vol. 32, No. 3

32--48

EN

The awareness of making decisions in an imprecise environment has resulted in considering the inventory system under a fuzzy approach. The effects of uncertain demand have been finding increased application in many inventory systems. Uncertainty creates complicated situations for the manufacturer in making decisions. Markets have become more competitive as a result of technological advancements. The effect of inflation on the overall cost of the inventory system is useful in providing a tool for the analysis of inventory decisions. This study intended to estimate the effect of different fuzzy numbers on a manufacturer's annual joint expected total cost. The comparative study of this proposed model has been considered for two different fuzzy numbers with the defuzzification technique as the centroid method. The optimization technique has been used to minimize the producer’s joint expected total cost under the condition mentioned earlier, and the model is validated numerically.

2

Reliability study on non-contact traction power supplysystem based on fuzzy grey relational FTA

Pei Yanxia, Li Xin

Archives of Electrical Engineering

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2021

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Vol. 70, nr 2

253--270

EN

The traction power supply system based on Inductively Coupled Power Transfer (ICPT) technology is one of the new traction power supply technologies that will bedeveloped in the future. As the core part of rail transit energy transfer and conversion, thetraction power supply system is not only the critical system for the safe operation of railtransit, but also the main source of its failures, so it is of great significance to study itsreliability. In this paper, the reliability analysis of the non-contact traction power supplysystem based on mobile ICPT technology is carried out using the method of (Fault Tree Analysis) FTA combined with triangular fuzzy theory and grey relational theory. Firstly,the fault tree of the system is established, and the minimum cut sets and structure functionof the fault tree are obtained. Then the triangular fuzzy numbers are introduced to representthe probability of the bottom events, and the fuzzy probability of the top event and the fuzzyimportance of the bottom events are determined, after that, the maximum probability offailure of the top event is obtained. Finally, the grey relational degrees of each minimum cutset are obtained and ranked. Furthermore, in order to prove the correctness of this method,the trapezoidal fuzzy FTA is introduced and compared with it. Both research results showthat the loosely coupled transformer and Insulated Gate Bipolar Transistor (IGBT) moduleare the weak links of the system. The results obtained are consistent and realistic, whichproves the correctness of the method selected in this article.

3

Two-storage inventory model for deteriorating items with price dependent demand and shortages under partial backlogged in fuzzy approach

Indrajitsingha Susanta Kumar, Samanta Padmanava, Raju Lakshmi Kanta, Misra Umakanta

LogForum

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2019

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Vol. 15, no. 4

487--499

EN

Background: In this paper we developed a fuzzy two-warehouse (one is OW, the own warehouse and other is RW, the rented warehouse) inventory model of deteriorating items with price dependent demand rate and allowed shortages under partially backlogged conditions. Since the capacity of any warehouse is limited, the supplier has to rent a warehouse for keeping the excess units over the fixed capacity W of the own warehouse in practice. The rented warehouse owed higher holding cost than the own warehouse. In this paper we considered holding cost, deterioration rate, shortages cost and lost sales as triangular fuzzy numbers. Methods: Graded Mean Integration Representation is used to defuzzify the total cost function. The result obtained by this method is compared with crisp model with the help of a numerical example. Sensitivity analysis is accomplished to changing one parameter at a time and keeping others at their archetypal. Results and conclusions: It has been proved that graded mean integration representation method gives more accurate result as compare to crisp model.

PL

Wstęp: W pracy zaprezentowano rozmyty model układu dwumagazynowego, składającego się z własnego magazynu (OW) oraz magazyny wynajmowanego (RW) dla asortymentów podlegających psuciu oraz o popycie zależnym od ceny przy dopuszczenia częściowych braków. Ze względu na ograniczoną powierzchnię własną magazynu, dostawca był zmuszony wynająć drugi magazyn w celu magazynowania nadwyżki. Koszt magazynu wynajmowanego jest wyższy niż koszt magazynu własnego. W pracy uwzględniono koszt utrzymywania obiektu, współczynnik psucia, koszt ubytków oraz koszt utraty sprzedaży jak liczby rozmyte. Metody: W celu odwrócenia rozmycia funkcji całkowitego kosztu użyto metody Graded Mean Integration Representation. Otrzymane wyniki porównano z modelem Crisp przy pomocy przykładu liczbowego. Następnie wykonano analizę wrażliwości zmieniają jeden z parametrów przy utrzymaniu niezmienionych pozostałych. Wyniki i wnioski: Wykazano, że wyniki uzyskane przy zastosowaniu metody Graded Mean Integration Representation są dokładniejsze aniżeli przy zastosowaniu modelu Crisp.

4

Evaluating organizational antifragility via fuzzy logic : the case of an Iranian company producing banknotes and security paper

Ghasemi A., Alizadeh M.

Operations Research and Decisions

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2017

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Vol. 27, No. 2

21--43

EN

The concept of antifragility has received much attention from researchers in recent years. Contrary to fragile systems which fail when exposed to stressors, antifragile systems prosper and improve in response to unpredictability, volatility, randomness, chaos and disturbance. The implications of antifragility goes beyond resilience or robustness. A resilient system resists stress and remains the same; while an antifragile system improves. Taleb argues that antifragility is required for dealing with events that he called black swans or X-events, which are scarce, unpredictable, and extreme events. Such events come as a surprise and have major consequences. The concept of antifragility was developed by Taleb in a socioeconomic context, not in industrial production. However, the authors think that this concept may have its greatest practical utilization when applied to industrial environments. Thus, they focused on this concept in the article aiming to investigate the level of antifragility in an organization. In order to perform this, the authors used a case study based on an Iranian manufacturer of banknotes and security paper (TAKAB). Firstly, a questionnaire was designed based on 7 criteria related to antifragility using the five-point Likert scale and a triangular fuzzy number for each linguistic term is defined. In the next phase, the weight of each component was obtained using the entropy technique. In the final stage, the Euclidean distance between the aggregated fuzzy antifragility index (FAI) and each linguistic term used during this case study was calculated. Finally, based on these results, the level of the organization’s antifragility was assessed as satisfactorily antifragile, based on the minimum Euclidean distance.

5

Non-probabilistic Solutions of Uncertain Fractional Order Diffusion Equations

Tapaswini S., Chakraverty S.

Fundamenta Informaticae

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2014

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Vol. 133, nr 1

19--34

EN

This paper investigates the numerical solution of uncertain fractional order diffusion equation subject to various external forces. Homotopy Perturbation Method (HPM) is used for the analysis. Uncertainties present in the system are modelled through triangular convex normalised fuzzy sets. A new computational technique has been proposed based on double parametric form of fuzzy numbers to handle the fuzzy fractional diffusion equation. Using the single parametric form of fuzzy numbers, the original fuzzy fractional diffusion equation is converted first to an interval fuzzy fractional differential equation. Next this equation is transformed to crisp form by applying double parametric form of fuzzy numbers. Finally the same is solved by HPM symbolically to obtain the uncertain bounds of the solution. Obtained results are depicted in term of plots. Results obtained by the proposed method are compared with existing results in special cases.

6

Effect of demand boosting policy on optimal inventory policy for imperfect lot size with backorder in fuzzy environment

Yadav D., Singh S. R., Kumari R.

Control and Cybernetics

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2012

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Vol. 41, no. 1

191-212

EN

This paper investigates an Economic Order Quantity (EOQ) model with backorder by taking imprecise demand rate with dependence upon the frequency of advertisement. The formulated model also incorporates learning effects on percentage of defective items present in each lot. Due to imprecision in demand, the obtained profit function is fuzzy. To determine the optimal values, we determine the equivalent crisp profit function by applying the signed distance method. Optimal order quantity and backorder level are obtained by using algebraic method in place of differential calculus. A numerical example is used to study the behavior of the model with respect to different inventory parameters. All calculations are performed with MATLAB 7.4.