A modular Decision Support System for optimum investment selection in presence of uncertainty: Combination of fuzzy mathematical programming and fuzzy rule based system

In this paper, we have developed a modular Decision Support System (DSS) in order to select an optimum portfolio of several chances for investments in presence of uncertainty. The investments are considered as the projects so as their initial investment costs, profits, resource requirement, and total available budget are assumed to be uncertain. This uncertainty has been modeled using fuzzy concepts. The proposed DSS has two main modules. The first one is a fuzzy binary programming model which represents the mathematical model of the associated fuzzy capital-budgeting problem. It involves finding optimum combination of investment portfolio considering a multi-objective measurement function and subject to several set of constraints. The results of optimistic and pessimistic analysis of the aforementioned fuzzy binary programming model plus a managerial Confidence Level (CL) value are treated as input of a fuzzy rule based system which is the second module of the proposed DSS. Although some projects are simple to make a decision about at the final step of the first module but the unique output of the second module of the proposed DSS is Risk of Investment (ROI) for all remained project. The logic relations between precedence parts of the rules as well as CL value will work in favor of computational efforts in second module through diminishing some unessential rules. This will help to define a complete set of fuzzy IF-THEN rules more efficiently. The proposed DSS can help the decision makers to select an optimum investment portfolio with minimum risk in a complete ambiguous condition.     

An adaptive switching scheme for uncertain discrete time‐delay systems

In this paper, an adaptive switching control algorithm is proposed for the stabilization of uncertain discrete‐time systems with time‐varying delay. It is assumed that the time delay is unknown and time varying, nonetheless bounded with a known bound. It is supposed that the system is highly uncertain, and that a set of controllers are designed (off‐line) to stabilize the system in the whole uncertain parameter space; subsequently, a switching scheme is developed to stabilize the uncertain time‐delay system. A thorough stability analysis for the uncertain time‐delay system under the mentioned control scheme is provided. Furthermore, an upper bound on the allowable rate of change of the system parameters and delay is obtained. Simulation results are presented to show the efficacy of the proposed switching scheme. Copyright © 2008 John Wiley & Sons, Ltd.     

The effects of the challenges in the transliteration of Persian names into English on the recall of retrieved results in the web of science

Scientometrics - The objective of this study was to examine the effects of the challenges in the transliteration of Persian names into English on the recall of retrieved results in the Web of...     

Reflected shock tube experiments on aeroacoustic signature of hot jets

Journal of Mechanical Science and Technology - We used a reflected shock tube to investigate the acoustic signature of a hot jet at the far-field. Experiments were performed at Mach = 1.4 and a...     

Unit Commitment solution using an optimized genetic system

This paper presents an investigation into the application of an optimized Genetic Algorithm (GA) to solve the Thermal Unit Commitment (UC) problem. A Parallel structure was first developed to handle the infeasibility problem in a structured and improved GA which provides an effective search process and therefore greater economy. The proposed methodology resulted in a better performance with faster operation by using both computational methods and classification of unit characteristics. Typical constraints such as system power balance, minimum up and down times, start-up and shut-down ramps, have also been considered. A number of important parameters (standard and new parameters) of the UC problem have been identified. The proposed method is implemented and tested using a C# program. The tests are carried out using two systems including 10 and 20 units during a scheduling period of 24 h. The results are finally compared with those obtained from genetic schemes in other similar investigations through which the effectiveness of the proposed scheme is affirmed.     

Topological aspects of meshless methods and nodal ordering for meshless discretizations

The meshless element‐free Galerkin method (EFGM) is considered and compared to the finite‐element method (FEM). In particular, topological aspects of meshless methods as the nodal connectivity and invertibility of matrices are studied and compared to those of the FE method. We define four associated graphs for meshless discretizations of EFGM and investigate their connectivity. The ways that the associated graphs for coupled FE‐EFG models might be defined are recommended. The associated graphs are used for nodal ordering of meshless models in order to reduce the bandwidth, profile, maximum frontwidth, and root‐mean‐square wavefront of the corresponding matrices. Finally, the associated graphs are numerically compared. Copyright © 2001 John Wiley & Sons, Ltd.     

Facile microwave‐assisted synthesis of NiO nanoparticles and its effect on soybean (Glycine max)

NiO nanoparticles in high purity, 15 ± 0.5 nm in size, were prepared via solid‐state microwave irradiation. The [Ni(NH₃)₆](NO₃)₂ complex as a novel source was decomposed in the presence of microwave irradiation for a short time (10 min). The present method is facile, safe, and low‐cost. This method exhibits other advantages; there is no need of a solvent, fuel, surfactant, expensive material, or complex instrument. Synthesised NiO nanoparticles were determined by various analyses. Also, for the first time, NiO nanoparticle effects on biochemical factors in soybean were investigated. Seeds of soybean were grown in the Murashige and Skoog agar medium containing different concentrations of NiO nanoparticles (0, 200, and 400 mg/L) for 21 days under growth chamber conditions. Estimates of malondialdehyde, hydrogen peroxide contents, and antioxidant enzymes (catalase and ascorbate peroxidase) under treatment of NiO nanoparticles were assayed. The result showed that by significantly increasing the concentration of NiO nanoparticles, the activity of catalase and ascorbate peroxidase enzymes was enhanced. Malondialdehyde and hydrogen peroxide contents significantly increased in the presence of NiO nanoparticles. In this study, the increasing activity of catalase and ascorbate peroxidase was not enough for radical oxygen species detoxification.Inspec keywords: nickel compounds, molecular biophysics, biotechnology, microorganisms, nanoparticles, biochemistry, microwave materials processing, hydrogen compounds, enzymes, cellular biophysicsOther keywords: solid‐state microwave irradiation, synthesised NiO nanoparticles, soybean, facile microwave‐assisted synthesis, biochemical factors, Murashige, Skoog agar medium, malondialdehyde, hydrogen peroxide contents, antioxidant enzymes, ascorbate peroxidase enzymes, radical oxygen species detoxification, NiO, [Ni(NH₃)₆](NO₃)₂      

Comparing the Sensitivity of Spot Test Method and a Novel Computer Vision System for Iron Detecting in Fortificated Flours

Controlling of added iron to fortified flours is very important, and the common method is spot test inaccurate method. In this study, we invented a new method based on a computer vision system. We also compared the accuracy of this method and the spot test with atomic absorption spectroscopy. In new method, ferrous sulfate particles in the samples were oxidized, and some red spots were formed on the surface of samples. The captured images from samples were changed to binary images and analyzed using the Clemex Vision 3.5 software. After processing of image, the number of colored spots and the area of spots were determined. The calibration curves were drawn, and in order to compare the sensitivity of the new method with spot test, 33 samples were selected randomly, and the amounts of added iron were detected using new method, spot test, and atomic absorption. We used t test and linear regression tests with a confidence interval of 95 % to compare the results. Results showed that there was a higher correlation (R ²?=?0.988, p?<?0.001) between new method and atomic absorption method in comparison with spot test (R ²?=?0.501, p?<?0.001). Therefore, spot test and atomic absorption can be replaced by an accurate but inexpensive method.