Solving Fuzzy Linear Programming Problems with Piecewise Linear Membership Function

In this paper, we concentrate on linear programming problems in which both the right-hand side and the technological coefficients are fuzzy numbers. We consider here only the case of fuzzy numbers with linear membership functions. The symmetric method of Bellman and Zadeh (1970) is used for a defuzzification of these problems. The crisp problems obtained after the defuzzification are non-linear and even non-convex in general. We propose here the modified subgradient method and method of feasible directions and uses for solving these problems see Bazaraa (1993). We also compare the new proposed methods with well known fuzzy decisive set method . Finally, we give illustrative examples and their numerical solutions

Neural network models for solving the maximum flow problem

In this paper, two new neural network models for solving the maximum flow problem are presented. The maximum flow problem in networks is formulated as a special type of linear programming problem and it is solved by appropriately defined neural networks. The nonlinear neural networks are able to generate optimal solution for maximum flow problem. We solve neural network models by one of the numerical method. Finally, some numerical examples are provided for the sake of illustration

A New Piecewise-Spectral Homotopy Analysis Method for Solving Chaotic Systems of Initial Value Problems

An accurate algorithm for solving initial value problems (IVPs) which are highly oscillatory is proposed. The proposed method is based on a novel technique of extending the standard spectral homotopy analysis method (SHAM) and adapting it to a sequence of multiple intervals. In this new application the method is referred to as the piecewise spectral homotopy analysis method (PSHAM). The applicability of the proposed method is examined on the differential equation system modeling HIV infection of CD4+ T cells and the Genesio-Tesi system which is known to be chaotic and highly oscillatory. Also, for the first time, we present here a convergence proof for SHAM. We treat in detail Legendre collocation and Chebyshev collocation. The method is compared to MATLAB’s ode45 inbuilt solver as a measure of accuracy and efficiency

Serum profiles of calcium, phosphorus, magnesium, vitamin D and parathyroid hormone in Caspian horses during different seasons

Minerals play an essential role in the normal vital process. Calcium, phosphorus and magnesium are the most abundant minerals. Vitamin D and parathyroid hormone play a key role in regulation of their homeostasis as well. The aim of this study was to evaluate calcium, phosphorus, magnesium, vitamin D and parathyroid hormone on 30 Caspian horses of Guilan Province (south of the Caspian Sea) in two different seasons. So that, 15 stallions and 15 mares were sampled at the age groups ≤ 3 years and > 3 years, respectively. Fasting blood samples were collected twice, in August and January 2015 from jugular vein of horses. Serum calcium, phosphorus and magnesium were measured by colorimetric methods, while 25(OH)D3 and parathyroid hormone were measured by ELISA. The calcium (11.50 vs. 14.25 mg dL-1 ), magnesium (2.13 vs. 3.72 mg dL-1 ) and vitamin D (1.66 vs. 2.48 ng mL-1 ) levels were lower in winter than in summer (P < 0.05). The Caspian horses had higher phosphorus (4.52 vs. 3.26 mg dL-1 ) in winter than in summer (P < 0.05). Effect of sex on the measured parameters was not significant. Effects of age on the calcium, magnesium, vitamin D and parathyroid hormone levels were not significant, but ≤ 3 year - old horses had higher phosphorus (4.63 vs. 3.15 mg dL-1 ) than > 3 year - old ones (P < 0.05). The vitamin D level of mares was higher (3.10 vs. 1.43 ng mL-1 ) in summer than in winter (P < 0.05). Effects of sex, season, age and their interactions on parathyroid hormone were not significant. In conclusion, calcium, phosphorus, magnesium and parathyroid hormone levels in Caspian horses were within their physiological range, but vitamin D was low without any signs of deficiency. The Caspian horses had lower calcium, magnesium and vitamin D levels in winter than in summer

Influence of the initial chemical conditions on the rational design of silica particles

The influence of the water content in the initial composition on the size of silica particles produced using the Stöber process is well known. We have shown that there are three morphological regimes defined by compositional boundaries. At low water levels (below stoichiometric ratio of water:tetraethoxysilane), very high surface area and aggregated structures are formed; at high water content (>40 wt%) similar structures are also seen. Between these two boundary conditions, discrete particles are formed whose size are dictated by the water content. Within the compositional regime that enables the classical Stöber silica, the structural evolution shows a more rapid attainment of final particle size than the rate of formation of silica supporting the monomer addition hypothesis. The clearer understanding of the role of the initial composition on the output of this synthesis method will be of considerable use for the establishment of reliable reproducible silica production for future industrial adoption

Strengthening livelihood resilience in upper catchments of dry areas by integrated natural resources management

The Livelihood Resilience project evolved around the hypothesis that better integrated management can improve the livelihoods of poor farming communities and increase the environmental integrity and water productivity of upstream watersheds in dry areas. This hypothesis was tested by researchers from different Iranian research and executive organizations and farming communities in two benchmark research watersheds in upper Karkheh River Basin in Iran, under the guidance of the ICARDA scientists. Participatory technology development, water, soil, erosion, land degradation and vegetation assessments, livelihood, gender and policy analyses, and integrated workshops delivered a set of principles for watershed management in dry areas