Coded Cooperative Data Exchange for a Secret Key

We consider a coded cooperative data exchange problem with the goal of generating a secret key. Specifically, we investigate the number of public transmissions required for a set of clients to agree on a secret key with probability one, subject to the constraint that it remains private from an eavesdropper. Although the problems are closely related, we prove that secret key generation with fewest number of linear transmissions is NP-hard, while it is known that the analogous problem in traditional cooperative data exchange can be solved in polynomial time. In doing this, we completely characterize the best possible performance of linear coding schemes, and also prove that linear codes can be strictly suboptimal. Finally, we extend the single-key results to characterize the minimum number of public transmissions required to generate a desired integer number of statistically independent secret keys.Comment: Full version of a paper that appeared at ISIT 2014. 19 pages, 2 figure

Method for producing oxygen from lunar materials

This invention is related to producing oxygen from lunar or Martian materials, particularly from lunar ilmenite in situ. The process includes producing a slurry of the minerals and hot sulfuric acid, the acid and minerals reacting to form sulfates of the metal. Water is added to the slurry to dissolve the minerals into an aqueous solution, the first aqueous solution is separated from unreacted minerals from the slurry, and the aqueous solution is electrolyzed to produce the metal and oxygen

Anolis cooki

Number of Pages: 2Integrative BiologyGeological Science

Sticky Exudates on the Inflorescences of \u3ci\u3eCirsium Discolor\u3c/i\u3e (Asteraceae) and \u3ci\u3ePenstemon Digitalis\u3c/i\u3e (Scrophulariaceae) as Possible Defense Against Seed Predators

From 1982 through 1987, I investigated whether sticky exudates released by Cirsium discolor and Penstemon digitalis in their inflorescences provide defense against seed predators. I tested two hypotheses: 1: Exudates directly deter seed predators, and 2: Insects struggling in exudates attract predatory arthropods that remain and defend the inflorescences against seed predators. These hypotheses predict that neutralizing the stickiness will increase seed predation (by allowing access to more seed predators, or by decreasing the number of predatory arthropods attracted), and therefore decrease successful seed production. Results did not support either hypothesis, with no increase in seed predators (nor decrease in predatory arthropods), and no decrease in seed production, when traps were neutralized

An Overview of Meson-Nuclear Physics

This conference covers an extremely broad range of topics and in just a few pages it is impossible to even touch on all the areas which will be discussed. We have chosen to summarise just one area where there has recently been impressive progress, namely our quantitative understanding of strangeness in the nucleon. We also discuss a couple of examples where theoretical progress is of direct importance for future experiments as well as for the interpretation of hitherto anomalous results. Finally we make some remarks on meson and baryon spectroscopy and the exciting array of new facilities that are coming on-line in the near future.Comment: Invited talk at MENU201