List of articles (by subject) Mathematical Engineering
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Open Access Article
1 - Risk Assessment of Investments with Fuzzy Efficiency Indicators for Oil and Gas Production Industry
Ali Zebardast Kiumars Shahbazi Amir AminiIn the process of investment decision making, next to financial indicators many other aspects of investment projects are increasingly often considered. This leads to the multi-criteria evaluation of a project. The advantage of multi-criteria methods is the ability to ta MoreIn the process of investment decision making, next to financial indicators many other aspects of investment projects are increasingly often considered. This leads to the multi-criteria evaluation of a project. The advantage of multi-criteria methods is the ability to take into account all (not only financial) aspects of the attractiveness of an investment project. The selection of criteria of project assessment must take into account the specificity of organization that makes a decision. Along with traditional method this paper introduces new approach for risk assessment based on each criterion characterizing the investment project on hydrocarbon resources exploitation. Manuscript profile -
Open Access Article
2 - Forecast of climatologically events using improved grey model (Case Study: Qazvin Province Climatology)
مریم کریمی خواجه قیاسی علیرضا علینژادThe theory of grey system is used when sufficient information of the community under study is not in hand. The grey forecast model is proper when the information variety is fix and certain. Grey model can apply some additional computations to improve forecasting activit MoreThe theory of grey system is used when sufficient information of the community under study is not in hand. The grey forecast model is proper when the information variety is fix and certain. Grey model can apply some additional computations to improve forecasting activities when data is insufficient. Through using improved grey model, the assessment error decreases significantly. This study made use of the mean maximum daily temperature data collected by Qazvin meteorological station, from August 2001 to August 2013. The findings revealed that the grey model metabolism method can reduce errors and improve the precision of forecasting the mean variable of maximum daily temperature. Manuscript profile -
Open Access Article
3 - A novel study on nonlinear fractional differential equations: general solution
موسی ایلی علی خوش کنارIn the present article, the Abel's technique has been developed to finding a general solution of the modified linear first-order ordinary differential equations in the sense of the truncated M-fractional derivative. By using proposed approach, a general solution of two MoreIn the present article, the Abel's technique has been developed to finding a general solution of the modified linear first-order ordinary differential equations in the sense of the truncated M-fractional derivative. By using proposed approach, a general solution of two well-recognized nonlinear first-order ordinary differential equations, Bernoulli and Riccati, in agreement with truncated M-fractional derivative have been obtained. For each equation, some examples are presented for satisfactory and efficiency of the proposed method. Manuscript profile -
Open Access Article
4 - Control Chart Recognition Patterns using Fuzzy Rule-Based System
Alireza Alinezhad Ali TaherinezhadControl Chart Patterns (CCPs) recognition is one the most important concepts in control chart application. Relating the patterns exhibited on the control chart to assignable causes is an ambiguous and vague task especially when multiple patterns co-exist. In this study, MoreControl Chart Patterns (CCPs) recognition is one the most important concepts in control chart application. Relating the patterns exhibited on the control chart to assignable causes is an ambiguous and vague task especially when multiple patterns co-exist. In this study, a fuzzy rule-based system is developed for X ̅ control charts to prioritize the control chart causes based on the accumulated evidence. To demonstrate the reasonable performance of the proposed fuzzy rule-based system, the case studies are performed and the results are analyzed. Manuscript profile -
Open Access Article
5 - A Branch and Bound for single machine stochastic batch scheduling with delivery costs. A Chance Constraint approach (Case study in Iran)
حمیدرضا حدادThis paper study a single machine stochastic scheduling problem based on an Iranian real case study in Saipa company in which the objective is to minimize total completion times and delivery costs. According to existence data sets of this company the processing times fo MoreThis paper study a single machine stochastic scheduling problem based on an Iranian real case study in Saipa company in which the objective is to minimize total completion times and delivery costs. According to existence data sets of this company the processing times follows a Normal distribution and based on the managerial decisions two objectives have to be achieved simultaneously including total completion times and controlling tardiness values so that their values are lower than an specified penalty. So, a Chance Constraint Programming (CCP) approach is employed and a mathematical model is presented. In order to solve the problem a Branch and Bound (B&B) method is used to solve the problem optimally and a Particle Swarm Optimization (PSO) metaheuristic is used to find near optimal solutions for large scales. The results show that using the proposed mathematical model and solution approach, could increase the effectiveness and efficiency of production line as 16 to 40 percent. Computational experiments validate the accuracy of proposed method. Manuscript profile -
Open Access Article
6 - Resonant solitons solutions to the time M-fractional Schrödinger equation
موسی ایلی علی خوش کنارIn this research the time M-fractional resonant nonlinear Schrödinger differential equation with different forms of nonlinearities, containing Kerr-law and parabolic-law has been studied. For this objective, the modified Kudryashov method and the sine-Gordon expans MoreIn this research the time M-fractional resonant nonlinear Schrödinger differential equation with different forms of nonlinearities, containing Kerr-law and parabolic-law has been studied. For this objective, the modified Kudryashov method and the sine-Gordon expansion approach have been implemented to retrieve a series of resonant solitons solutions for the abovementioned model. The prospective of the schemes in founding soliton solutions of nonlinear time-fractional equations in the truncated M-fractional derivative sense is confirmed. Manuscript profile -
Open Access Article
7 - Lump solutions of Biharmonic equation
Azadeh Badiepour Zainab Ayati Hamideh EbrahimiIn this article, through symbolic computation With Maple, we get the solution of the (1 + 1)-dimensional Biharmonic-equation. These solutions, which we call lump solution, obtained using square functions, are rationally localized in all directions in the space. It shoul MoreIn this article, through symbolic computation With Maple, we get the solution of the (1 + 1)-dimensional Biharmonic-equation. These solutions, which we call lump solution, obtained using square functions, are rationally localized in all directions in the space. It should be noted that not all nonlinear partial differential equations have a lump solution. Finally, by selecting the appropriate parameter, the lump solutions are shown in the figures. Manuscript profile -
Open Access Article
8 - Dynamic GAS Mathematical Based Modeling for Predicting and Assessing the Memory Free Value at Risk of Tehran Stock Exchange Total Index
محمدابراهیم سماوی هاشم نیکومرام مهدی معدنچی زاج احمد یعقوب نژادIn recent decades, especially since 2000, advanced mathematical methods for financial modeling have been widely used so that the basic challenges of financial science can be overcome by using these methods. The first step in risk management in the field of investment is MoreIn recent decades, especially since 2000, advanced mathematical methods for financial modeling have been widely used so that the basic challenges of financial science can be overcome by using these methods. The first step in risk management in the field of investment is to calculate the variable that explains the risk accurately. One of the most widely used criteria for calculating risk is the value at risk, which has been the focus of financial researchers for the past three decades. The aim of the present study is dynamic modeling and variable time using a technique called Generalized Autoregressive Score (GAS) to estimate value at risk in TSE by using daily data since 2010 to 2020 and assuming the distribution of t-student. its results are compared with the results of known AR and GARCH models. For TSE only two models, GAS and GARCH, are suitable for estimating value at risk and GAS model is preferable. Also, the duration of risk of value at risk errors for all three models for gold and TSE lacks long-term memory, indicating its reliance on financial turmoil. Manuscript profile -
Open Access Article
9 - LIE SYMMETRIES, SELF-ADJOINTNESS, AND CONSERVATION LAWS OF THE MONG-AMPERE EQUATION
زهرا مومن نژاد مهدی نجفی خواه‎This paper addresses an extended 2-dimensional Mong-Ampere equation By the Lie method‎. The symmetries of Mong-Ampere equation are found ‎and the method of non-linear self-adjointness is applied to the considered equation‎. ‎By applying Ibragimov&rs More‎This paper addresses an extended 2-dimensional Mong-Ampere equation By the Lie method‎. The symmetries of Mong-Ampere equation are found ‎and the method of non-linear self-adjointness is applied to the considered equation‎. ‎By applying Ibragimov’s method and Noether operators the infinite set of conservation laws associated with the finite algebra of Lie point symmetry of the Mong-Ampere equation is extracted‎. ‎The corresponding conserved quantities are computed from their respective densities‎. Manuscript profile -
Open Access Article
10 - Unweighted p-center problem on extended stars
جعفر فتحعلی نادر جعفری راد صادق رحیمی شعربافAn extended star is a tree which has only one vertex with degree larger than two. The -center problem in a graph asks to find a subset of the vertices of of cardinality such that the maximum weighted distances from to all vertices is minimized. In this paper we consider MoreAn extended star is a tree which has only one vertex with degree larger than two. The -center problem in a graph asks to find a subset of the vertices of of cardinality such that the maximum weighted distances from to all vertices is minimized. In this paper we consider the -center problem on the unweighted extended stars, and present some properties to find solution. Manuscript profile