# Hend Dawood

## Senior Assistant Lecturer of Computational Mathematics

Department of Mathematics, Faculty of Science, Cairo University, Giza, PO Box: 12613, Egypt. (email)

Department of Mathematics, Faculty of Science, Cairo University, Giza, PO Box: 12613, Egypt. (email)

in

For various scientific and engineering problems, how to deal with variables and parameters of uncertain value is an important issue. Generally, the parameters are taken as constant/crisp for simplifying the problem. However, there is incomplete information about the variables being a result of errors in measurement, observations, experiment, or the application of different operating conditions, or a maintenance induced error, etc. Rather than the particular value, only the vague, imprecise and incomplete information about the parameter is present, which is called the uncertain information. Recently, investigations are being done throughout the globe by taking the material or geometrical properties as uncertain. Rather than the particular value of the material properties or parameters, we may have only the imprecise bounds of the values. These may be handled by taking the parameters in terms of interval and/or fuzzy. The corresponding problem will then become uncertain and the analysis and solution would require then careful application of the methods. Recently, the soft computing and other methods have come as a relief from such problems.