By constructing sub-IFS (iterated function system) of IFS with graph-directed structure, it is proved in this paper that the graph-directed arcs of Hausdorff dimension greater than 1 are Whitney sets; the result dones t need the transitivity condition on directed graph.

Applying the Whitney-Riley model to the soil-root complex,calculating formulas,which were related to modulus of elasticity E_(L)in direction of plant roots growth,modulus of elasticity E_(T) to be vertical to direction of plant roots growth and shearing modulus G_(LT)in plane of plant roots growth,were establis.

Dynamic Security Region for AC/DC Parallel System and Its Critical Cutset Representation;

In the paper,a new approach is proposed for classifying machines into critical cluster and remaining cluster by identifying critical cutset(the weakest cutset)with quantitative assessment index,which is built on the basis of investigation in the feature of transient p.

The simulation and analysis of the feature of transient energy in the multi-machine power system network indicate that the transient energy is propagative in the network and the transient energy of lines belonged to the critical cutset sharing the identical distinguishing property.