In this paper we consider chosen-ciphertext attacks against noncommutative Polly Cracker-type cryptosystems. We present several versions of these attacks, as well as techniques to counter them. First we introduce a chosen-ciphertext attack, which assumes a very simple private key. We then present generalizations of this attack which are valid in more general situations, and propose a simple but...

A study to mea~ure the effect of walnut scale infestation on English walnut qualityand yield has shown no differences in yield and no consistentdifferencein kernel quality between infested and non-infested trees for the four years ~f the study. Yield and quality of English walnut are not overly sensitive to walnut scale infestation and some degree of infestation can be tolerated with no measura...

In order to investigate the shucking technology and design the efficient Sheller, it’s highly significant to study on the mechanical characteristics of walnut. The Pro/E software and finite element method was adopted to build the geometry and finite element model of walnut. Afterwards, the walnut stress distribution with different loads was analyzed to seek the optimum force-applying forms whic...

Using Gröbner bases for the construction of public key cryptosystems has been often attempted, but has always failed. We review the reason for these failures, and show that only ideals generated by binomials may give a successful cryptosystem. As a consequence, we concentrate on binomial ideals that correspond to Euclidean lattices. We show how to build a cryptosystem based on lattice ideals an...

The distribution and survival of trees during the last glacial maximum (LGM) has been of interest to paleoecologists, biogeographers, and geneticists. Ecological niche models that associate species occurrence and abundance with climatic variables are widely used to gain ecological and evolutionary insights and to predict species distributions over space and time. The present study deals with th...

Gases leaking from a polyethene plant and a cracker plant were visualized with the gas-correlation imaging technique. Ethene escaping from flares due to incomplete or erratic combustion was monitored. A leakage at a high-pressure reactor tank could be found and visualized by scanning the camera system over the industrial site. The image processing methods rely on the information from three simu...