3,717 research outputs found
Linear Programming Relaxations for Goldreich's Generators over Non-Binary Alphabets
Goldreich suggested candidates of one-way functions and pseudorandom
generators included in . It is known that randomly generated
Goldreich's generator using -wise independent predicates with input
variables and output variables is not pseudorandom generator with
high probability for sufficiently large constant . Most of the previous
works assume that the alphabet is binary and use techniques available only for
the binary alphabet. In this paper, we deal with non-binary generalization of
Goldreich's generator and derives the tight threshold for linear programming
relaxation attack using local marginal polytope for randomly generated
Goldreich's generators. We assume that input
variables are known. In that case, we show that when , there is an
exact threshold
such
that for , the LP relaxation can determine
linearly many input variables of Goldreich's generator if
, and that the LP relaxation cannot determine
input variables of Goldreich's generator if
. This paper uses characterization of LP solutions by
combinatorial structures called stopping sets on a bipartite graph, which is
related to a simple algorithm called peeling algorithm.Comment: 14 pages, 1 figur
Synthesis of artificial lymphoid tissue with immunological function.
The ability to generate functional artificial lymphoid tissue to induce specific immunity at ectopic sites could offer a potential breakthrough for treatment of diseases such as cancer and severe infection using immunotherapy. Artificial lymphoid tissue could also offer an informative tool to study further lymphoid tissue development and function in vivo. Here, we review the process of secondary and tertiary lymphoid organization, of which an understanding is essential for artificial lymphoid tissue synthesis. Using this knowledge, we consider the combination of cell types, soluble factors and scaffold properties that will enable proper accumulation and organization of lymphocytes into tissue grafts. Recent success in in vivo induction of artificial lymphoid tissue are also considered
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