The notion of weakly quasi continuous functions introduced by Popa and Stan ]. In this paper, the authors obtain the further properties of such functions and introduce weak* quasi continuity which is weaker than semi continuity [2] but independent ofweak quasi continuity.

The objective of this paper is to introduce the fundamental algebro-geometric constructions over the extended tropical semi-ring. The study of tropical varieties, co-varieties and ideals over this extension eventually yields the theorem of the weak tropical Nullstellensatz and gives an algebraic interpretation of the tropical Nullstellensatz.

Abstract In this paper, for a nonsmooth semi-infinite multiobjective programming with locally Lipschitz data, some weak and strong Karush-KuhnTucker type optimality conditions are derived. The necessary conditions are proposed under a constraint qualification, and the sufficient conditions are explored under assumption of generalized invexity. All results are expressed in terms of Clarke subdif...

We first consider subsmoothness for a function family and provide formulas of the subdifferential of the pointwsie supremum of a family of subsmooth functions. Next, we consider subsmooth infinite and semi-infinite optimization problems. In particular, we provide several dual and primal characterizations for a point to be a sharp minimum or a weak sharp minimum for such optimization problems.

This thesis deals with approximation algorithms for the Maximum Independent Set and the Minimum Hitting Set problems on hypergraphs. As a hypergraph is a generalization of a graph, the question is whether the best known approximations on graphs can be extended to hypergraphs. We consider greedy, local search and partitioning algorithms. We introduce a general technique, called shrinkage reducti...

For small involutive and integral quantaloids Q it is shown that covariant presheaves on symmetric Q-categories are equivalent to certain subalgebras of a speci c monad on the category of symmetric Q-categories. This construction is related to a weakening of the subobject classi er axiom which does not require the classi cation of all subalgebras, but only guarantees that classi able subalgebra...

Many cryptographic primitives—such as pseudorandom generators, encryption schemes, and zero-knowledge proofs—center around the notion of approximability. For instance, a pseudorandom generator is an expanding function which on a random seed, approximates the uniform distribution. In this paper, we classify different notions of computational approximability in the literature, and provide several...