79 research outputs found

    A new view to uncertainty in Electre III method by introducing interval numbers

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    The Electre III is a widely accepted multi attribute decision making model, which takes into account the uncertainty and vagueness. Uncertainty concept in Electre III is introduced by indifference, preference and veto thresholds, but sometimes determining their accurate values can be very hard. In this paper we represent the values of performance matrix as interval numbers and we define the links between interval numbers and concordance matrix .Without changing the concept of concordance, in our propose concept, Electre III is usable in decision making problems with interval numbers

    Analysis of implementation of Tradable Green Certificates system in a competitive electricity market: A game theory approach

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    This paper investigates three models to implement Tradable Green Certificates (TGC) system with aid of game theory approach. In particular, the competition between thermal and renewable power plants is formulated in three models: namely cooperative, Nash and Stackelberg game models. The price of TGC is assumed to be determined by the legislative body (government) which is fixed. Numerical examples presented in this paper include sensitivity analysis of some key parameters and comparison of the results of different models. In all three game models, the parameters that influence pricing of the TGC based on the optimal amounts are obtained. The numerical examples demonstrate that in all models: there is a reverse relation between the price of electricity and the TGC price, as well as a direct relation between the price of electricity and the share of green electricity in total electricity generation. It is found that Stackelberg model is an appropriate structure to implement the TGC system. In this model, the supply of electricity and the production of green electricity are at the highest level, while the price of electricity is at the lowest levels. In addition, payoff of the thermal power plant is at the highest levels in the Nash model. Hence this model can be an applicatory structure for implementation of the TGC system in developing countries, where the number of thermal power plants is significantly greater than the number of renewable power plants

    Application of Controlled Source Audio Magnetotelluric (Csamt) at Geothermal

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    CSAMT or Controlled Source Audio-Magnetotelluric is one of the Geophysics methods to determine the resistivity of rock under earth surface. CSAMT method utilizes artificial stream and injected into the ground, the frequency of artificial sources ranging from 0.1 Hz to 10 kHz, CSAMT data source effect correction is inverted. From the inversion results showed that there is a layer having resistivity values ranged between 2.5 Ω.m – 15 Ω.m, which is interpreted that the layer is clay

    Emergency response network design for hazardous materials transportation with uncertain demand

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    Transportation of hazardous materials play an essential role on keeping a friendly environment. Every day, a substantial amount of hazardous materials (hazmats), such as flammable liquids and poisonous gases, need to be transferred prior to consumption or disposal. Such transportation may result in unsuitable events for people and environment. Emergency response network is designed for this reason where specialist responding teams resolve any issue as quickly as possible. This study proposes a new multi-objective model to locate emergency response centers for transporting the hazardous materials. Since many real-world applications are faced with uncertainty in input parameters, the proposed model of this paper also assumes that reference and demand to such centre is subject to uncertainty, where demand is fuzzy random. The resulted problem formulation is modelled as nonlinear non-convex mixed integer programming and we used NSGAII method to solve the resulted problem. The performance of the proposed model is examined with several examples using various probability distribution and they are compared with the performance of other existing method

    Using CSW weight’s in UTASTAR method

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    Several researchers have considered similarities between Multi-Criteria Decision Making (MCDM) and Data Envelopment Analysis (DEA), as tools for solving decision making problems. As the preferences of decision- maker (DM) on alternatives are not considered in classical DEA, some researchers have tried to consider it in DEA. The UTA-STAR method is one of the techniques widely used in Multi Criteria Decision Analysis. In this technique, the preferences of decision maker on alternatives are considered and UTA-STAR tries to compute the most suitable weights for criteria and alternatives to obtain a utility function having a minimum deviation from the preferences. The goal of this paper is interpreting decision maker’s preferences in UTA-STAR method, in a new manner, using the common set of weights (CSW) in DEA

    A new fuzzy MCDA framework for make-or-buy decisions: A case study of aerospace industry

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    One of the primary managerial decisions for manufacturing units is to find out which activity must be outsourced. A good outsourcing decision is normally involved with different criteria such as opportunity costs, cost saving, etc. In this paper, we present a multi criteria decision-making method to find a suitable solution for outsourcing activities called preference ranking organization method for enrichment evaluations (PROMETHEE). The proposed model of this paper uses fuzzy numbers to determine the relative importance of different criteria and it is implemented for a real-world case study of aerospace industry

    Parental Involvement and English Language Teaching to Young Learners: Parents\u27 Experience in Aceh

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    The interest of teaching English to young learners increased rapidly since the language has significant influence in the modern world. English is strongly associated with social and economic power in globalization\u27s context. Introducing English earlier offers opportunities to awaken the learners\u27 enthusiasm and curiosity about the language, to achieve native-like accent, and to enable them to learn the language easily at further levels. However, there are controversies, particularly, about the age to start learning a new language. In Indonesia, English roles as a foreign language and the government have set up the policy to introduce English to students at elementary school. In order to support the language learning, parent involvement is extremely important to help the children learn and acquire the language. This study explores parents\u27 perspectives toward English language teaching to young learners and further looks at their involvement in supporting their children learning the foreign language at home. An in-depth interview was conducted to parents with different educational backgrounds, professions, incomes, and gender groups in Langsa, Aceh province, Indonesia. Result revealed that parents have very positive attitude towards the language teaching to young learners. They enthusiastically support their children by helping them doing assignments, memorizing the vocabulary, providing learning medias such as English books, vocabulary pictures, English cartoon\u27s films, puzzles, and asking teachers the topic they do not understand from their children\u27s textbook. Lower education and lower income parents showed more enthusiasm in supporting their children

    Models, solution, methods and their applicability of dynamic location problems (DLPs): A gap analysis for further research

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    Determining the best location to be profitable for the facility's lifetime is the important decision of public and private firms, so this is why discussion about dynamic location problems (DLPs) is a critical significance. This paper presented a comprehensive review from 1968 up to most recent on published researches about DLPs and classified them into two parts. First, mathematical models developed based on different characteristics: type of parameters (deterministic, probabilistic or stochastic), number and type of objective function, numbers of commodity and modes, relocation time, number of relocation and relocating facilities, time horizon, budget and capacity constraints and their applicability. In second part, It have been also presented solution algorithms, main specification, applications and some real-world case studies of DLPs. At the ends, we concluded that in the current literature of DLPs, distribution systems and production-distribution systems with simple assumption of the tackle to the complexity of these models studied more than any other fields, as well as the concept of variety of services (hierarchical network), reliability, sustainability, relief management, waiting time for services (queuing theory) and risk of facility disruption need for further investigation. All of the available categories based on different criteria, solution methods and applicability of them, gaps and analysis which have been done in this paper suggest the ways for future research

    A firefly algorithm for solving competitive location-design problem: A case study

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    This paper aims at determining the optimal number of new facilities besides specifying both the optimal location and design level of them under the budget constraint in a competitive environment by a novel hybrid continuous and discrete firefly algorithm. A real-world application of locating new chain stores in the city of Tehran, Iran, is used and the results are analyzed. In addition, several examples have been solved to evaluate the efficiency of the proposed model and algorithm. The results demonstrate that the performed method provides good-quality results for the test problems

    Solving an one-dimensional cutting stock problem by simulated annealing and tabu search

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    A cutting stock problem is one of the main and classical problems in operations research that is modeled as LP problem. Because of its NP-hard nature, finding an optimal solution in reasonable time is extremely difficult and at least non-economical. In this paper, two meta-heuristic algorithms, namely simulated annealing (SA) and tabu search (TS), are proposed and developed for this type of the complex and large-sized problem. To evaluate the efficiency of these proposed approaches, several problems are solved using SA and TS, and then the related results are compared. The results show that the proposed SA gives good results in terms of objective function values rather than TS
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