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Showing 6 results for Functions

Gh. Yari , M. D Jafari ,
Volume 17, Issue 4 (11-2006)
Abstract

Main result of this paper is to derive the exact analytical expressions of information and covariance matrix for multivariate Pareto, Burr and related distributions. These distributions arise as tractable parametric models in reliability, actuarial science, economics, finance and telecommunications. We showed that all the calculations can be obtained from one main moment multidimensional integral whose expression is obtained through some particular change of variables. Indeed, we consider that this calculus technique for that improper integral has its own importance.


 


Gh. Yari, A.m. Djafari ,
Volume 19, Issue 6 (8-2008)
Abstract

Main result of this paper is to derive the exact analytical expressions of information and covariance matrices for multivariate Burr III and logistic distributions. These distributions arise as tractable parametric models in price and income distributions, reliability, economics, Human population, some biological organisms to model agricultural population data and survival data. We showed that all the calculations can be obtained from one main moment multi dimensional integral whose expression is obtained through some particular change of variables. Indeed, we consider that this calculus technique for improper integral has its own importance .


A Azizi, V. Boppana , A.c. Clement,
Volume 22, Issue 4 (12-2011)
Abstract

  This paper demonstrates a preliminary investigation of geometry, function and its relation to DFX principles, namely DFM (Design for Manufacturing). This is the starting point for research on the development of an expert system that assesses design goals along DFX principles in a feature-based CAD environment. There is a need for a deeper level of understanding of the relationship between geometry and its effects on function, in order to correct and improve the product concept before large amounts of resources are invested in the product’s development.

This paper is a preliminary investigation into geometry and function involving DFM as part of an early stage of research into geometric effects on function and DFX through the use of CAD/CAE/CAM.In this paper, a concept is chosen to develop a parametric solid model that will be used to investigate a set of defined function attributes using model variants, which are evaluated in terms of the defined function attributes and DFM. The investigation found that for the functions defined, geometric parameters had less of an effect than expected. This is mainly due to the fact that the defined function attributes under investigation were associated with material properties. This paper demonstrates a preliminary investigation at the early stage of research to develop a more detailed relationship structure between geometry and functional attributes and their relationship with DFX. The end goal is to develop an integrated methodology involving geometry, function and DFX principles through the use of CAD/CAE/CAM .
Romina Madani, Amin Ramezani, Mohammad Taghi Madani Beheshti,
Volume 25, Issue 4 (10-2014)
Abstract

Today, companies need to make use of appropriate patterns such as supply chain management system to gain and preserve a position in competitive world-wide market. Supply chain is a large scaled network consists of suppliers, manufacturers, warehouses, retailers and final customers which are in coordination with each other in order to transform products from raw materials into finished goods with optimal placement of inventory within the supply chain and minimizing operating costs in the face of demand fluctuations. Logistics is the management of the flow of goods between the point of origin and the point of consumption. One issue in Logistics management is the presence of possible long delays in goods transportation. In order to handle long delays, there are two possible solutions proposed in this paper. One solution is to use Model Predictive Controllers (MPCs) using orthonormal functions (Laguerre functions) and the other is to change supply chain model in which an integrator is imbedded. To this end, the two mentioned solutions will be implemented on a supply chain with long logistics delays and the results will be compared to classical MPC without using orthonormal basis and augmented model for different type of customer demand (constant, pulse and random demand).
Zahra Touni, Ahmad Makui, Emran Mohammadi,
Volume 30, Issue 1 (3-2019)
Abstract

Financial decision-making is the principal part of any decisions hence great efforts are done to improve the methods to assess and analyze the stock in financial markets as a part of the financial decision. This paper addresses the stock selection by discovering investor's utility function .Investors in the Stock Exchange consider diverse criteria to buy shares and bonds. Due to the criteria development in stock selection, understanding the investor's behavior by a consultant is a prominent issue. Recognizing an exclusive utility function according to the characteristics of the investors facilitates acquiring each share's value for the decision maker (DM) when it is required. In this study, UTASTAR method is used to estimate the marginal value function, using 3 appropriate criteria (risk, return, liquidity) and finally fit out the total utility function. It provides the opportunity to make a rational decision fit to investor's mentality and allowing their ranking, prioritization, selection or classification. The ranking of the options is as compatible as possible to the original one. The method is applied to an example from Iran Stock Exchange.


Hamiden Khalifa,
Volume 31, Issue 2 (6-2020)
Abstract

   This paper aims to study multi- objective assignment (NMOAS) problem with imprecise costs instead of its prices information. The NMOAS problem is considered by incorporating single valued trapezoidal neutrosophic numbers in the elements of cost matrices. After converting the NMOAS problem into the corresponding crisp multiobjective assignment (MOAS) problem based on the score function, an approach to find the most preferred neutrosophic solution is discussed. The approach is used through a weighting Tchebycheff problem which is applied by defining relative weights and ideal targets.  The advantage of this approach is more flexible than the standard multi- objective assignment problem, where it allows the decision maker (DM) to choose the targets he is willing. Finally, a numerical example is given to illustrate the utility, effectiveness and applicability of the approach.
 
  
 

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