In this paper,we discuss the exact estimation on n-K width and n-G width of periodic convolution classes K_M(Ψ) in L spaces and K_∞(Ψ) in L*_M spaces when kernel function satisfy certain restrictive conditions.

In order to achieve accurate measurement under normal load and lower load,this paper produces a project of three-phase watt-hour meter,with real-time subsection according to load power.

Dynamics of soil infiltrability of sloped lands under rainfall conditions measured with runoff-ponding method and the accuracy estimations;

Accuracy estimation is an important part in linear parameter processing,and cumulative-sum method is a new method for linear parameter processing.

The methods of precision estimation of GPS RTK survey production are given in this paper,and their application is introduced with examples.

The methods of precision estimation of GPS RTK survey produc- tion are given in this paper.

After reading some related research papers and a whole study of the principles and methods of controling network,the writer probes into the technologies of GIS -based automatical place-selecting , automatical network building and tentative precision estimation of the controling network.