The best understood 3-manifolds are Haken 3-manifolds; these are manifolds that are irreducible and contain incompressible surfaces. One approach to 3-manifolds is to try to generalize the notion of an incompressible surface. Essential laminations and mapped-in π1-injective surfaces have both been used with some success as substitutes for incompressible surfaces, yielding theorems which apply t...

in semi arid area geomorphological impacts of dams are very major. dams, as man- made structures, have major impacts on river hydrology, primarly through in the timing, magnitude, and frequency of low and high flows, ultimately producing a hydrologic regime differing significantly from the pre-impoundment natural flow regime. despite the profiles of dams on river regulation for water resources ...

A map f : R ! S of continua R and S is called a universal map from R to S if for any map g : R ! S, f(x) = g(x) for some point x 2 R. When R and S are trees, we characterize universal maps by reducing to the case of light minimal universal maps. The characterization uses the notions of combinatorial map and folded subedge of R. MOS Subject Classi cation Primary: 54H25 Secondary: 54F20

In recent years, chaos has been extensively used in cryptographic systems. In this regard, one dimensional chaotic maps gained increased attention because of their intrinsic simplicity and ease in application. Many image encryption algorithms that are based on chaotic substitution boxes (S-boxes) have been studied in the last few years but some of them appear to be vulnerable to robustness. We,...

Homeomorphisms between curves and between surfaces are fundamental to many applications of 3D modeling, graphics, and animation. They define how to map a texture from one object to another, how to morph between two shapes, and how to measure the discrepancy between shapes or the variability in a class of shapes. Previously proposed maps between two surfaces, S and S ′, suffer from two drawbacks...

Owing to the recent development of digital broadcasting technology such as Satellite, CATV, the Internet and the expansion of the network systems, the amount of video data we can obtain is increasing day by day. In this paper, we propose Advanced Database TV (ADTV), an interactive video database system which lets us share video data on the network, as an application for future Interactive TV se...

In this paper we present two new texture segmentation algorithms based on local spectrum analysis with the two dimensional S-Transform. The effectiveness of these algorithms is demonstrated both on simple synthetic images, and complicated, real images of glacial sediment deposits. The S-Transform method is robust and is insensitive to changes in light intensity, and moisture variations. The eff...

If V is a vector space over some field F, then we have the well known exact sequence 0 → Λ2(V ) T2(V S2(V 0, where first map given by x∧y x⊗y−y⊗x and second x⊗y 7→ xy. The obvious generalization, an sequence, Λk(V T