Theory of Approximation and Applications
Volume:1 Issue: 2, Summer 2005

DEA is a technique to evaluate the relative efficiency of decision making units. Because weights are too free to measure the relative efficiency in the original DEA models, management always tries to control the weights to enact its decisions. Imposing non-homogeneous weight restrictions in DEA models may incorrectly evaluate the maximum relative efficiency of assessed unit. This paper identifies a kind of non-homogeneous weight restrictions that doesn�t cause the observed error and also investigates a kind of redundant non-homogeneous weight restrictions in the BCC model.Effect of imposing of non-homogeneous weight restrictions on PPS is also considered. In other words, when non-homogeneous weight restrictions are imposed in DEA models, PPS will be changed.

In this paper the function of mathematics in different participant countries in TIMSS are evaluated with help of data covering analysis.The countries introduce themseles by offering indexes including teacher''s age, their self-confidence in teaching, their emphasis on reasoning and problem solving in teaching, their academic papers, etc. The help of these indexes, mathematical teaching of different countries is evaluated and was compared with ranking of countries in TIMSS. Relative efficient evaluation of countries is assessed with the help of non-radius models.

In the study of decision making in complex environment, such term as “multiple objective” is used to describe decision situations. Basically, Multiple Objective Decision Making (MODM) methods are used for an infinite set of alternatives implicitly defined by the constrains. Indeed, MODM methods address design problems. In most methods for solving MODM problems (except one category) we need to determine the weight of each objective. And determination of weights is very important. In this paper using fuzzy theory we estimate the weights.

In this paper order condition p and their equations in runge-kutta methods with ferchet derivatives and root trees are introduced, with concepts of effective order and combining methods.It is demonstrated that the speed of calculations is increased and the number of order condition equations is reduced.

The cauchy''s mean value theorem involving n functions discustion and consideration are dealt in [3] with some examples. It is proved that a given example is not correct, Heureu a correct example is proved.

The aim of this paper is to study a theorem in matrix theory that Herstein has proved in regard to one of the theorems of Putnum and Winter.

The aim of this paper is to compare two methods of finding global optimization of real functions.

In this paper several Riccati equations in general are solved by the use of chain fractions. by replacing variables,the result was a sequence of Riccati equation. The solution of main Riccati equations would be a chain fraction.