Improved Throughput for All-or-Nothing Multicommodity Flows with Arbitrary Demands

Integer Multicommodity Flows with Reduced Demands Integer Multicommodity Flows with Reduced Demands

Given a supply graph G = (V; E), a demand graph H = (T; D), edge capacities c : E 7 ! II N and requests r : D 7 ! II N, we consider the problem of nding integer multiiows subject to c; r. Korach and Penn constructed approximate integer multiiows for planar graphs, but no results were known for the general case. Via derandomization we present a polynomial-time approximation algorithm. There are ...

All or Nothing at All

We continue a study of unconditionally secure all-or-nothing transforms (AONT) begun in [12]. An AONT is a bijective mapping that constructs s outputs from s inputs. We consider the security of t inputs, when s − t outputs are known. Previous work concerned the case t = 1; here we consider the problem for general t, focussing on the case t = 2. We investigate constructions of binary matrices fo...

All-or-Nothing Monitoring

A principal can observe both the output and input of an agent who works at a job involving multiple tasks. We provide a simple theory that explains why it may be optimal for the principal to use only output-based incentive contract, even though the principal can monitor the agent’s actions perfectly in all but one task and knows exactly which action is optimal for each task. (JEL: D82, M5, J33)

Take-all or nothing

Take-all disease of Poaceae is caused by Gaeumannomyces graminis (Magnaporthaceae). Four varieties are recognised in G. graminis based on ascospore size, hyphopodial morphology and host preference. The aim of the present study was to clarify boundaries among species and varieties in Gaeumannomyces by combining morphology and multi-locus phylogenetic analyses based on partial gene sequences of I...

Overwriting : All or Nothing ?