Cryptography from tensor problems

We describe a new proposal for a trap-door one-way function. The new proposal belongs to the "multivariate quadratic" family but the trap-door is different from existing methods, and is simpler

More Word Network Spasns in the OSPD

In the February 1989 Word Ways, I examined various word networks based on words from the Official Scrabble Players Dictionary (OSPD). To refresh the reader\u27s memory, a word network consists of a set of words of a given length that can be joined by word ladders (single-letter changes). Each pair of words in a word network can be connected by a minimum-length ladder (one which cannot be reduced by any alternative ladder)

Lewis Carroll\u27s Word Ladders

My knowledge of the history of word ladders comes from two books The Magic of Lewis Carroll by John Fisher (1973), and The Oxford Guide to Word Games by Tony Augarde (1984). It is not necessary to describe word ladders to the readers of Word Ways; in any event the concept should be ovbious from the examples. Carroll started writing about what he called Doublets in 1879; he had originally called them Word Links. The idea, of course, is to find the shortest ladder between a pair of words

Facing the Mirror: Dilemmas and Issues Encountered on a TESOL programme in an International University Environment

Abstract: This paper investigates the experiences of three postgraduate students studying on an MA TESOL and Applied Linguistics course in a British university context. It demonstrates how subtle discourses of „ownership‟ of English (Holliday, 2014; Pennycook, 1994, 2001; Kumaravadevelu, 2003) persist in such training contexts, despite the general shift towards internationalizing higher education environments in the UK. The paper will discuss how the participants negotiated the teaching practice components of the course, and the issues they faced through being „non-native‟ speakers of English. It further examines the impact this had on their professional development and self-perceptions of „legitimacy‟ as teachers of English. The different constructs of a TESOL teacher are discussed and the need for a heightened awareness of training needs for teachers across diverse contexts

The quantifier semigroup for bipartite graphs

In a bipartite graph there are two widely encountered monotone mappings from subsets of one side of the graph to subsets of the other side: one corresponds to the quantifier "there exists a neighbor in the subset" and the other to the quantifier "all neighbors are in the subset." These mappings generate a partially ordered semigroup which we characterize in terms of "run-unimodal" words

Four-Letter Word Network Update

A word network is a set of words of a given length in which any two words differing by only one letter in a single position (such as aunt and runt, or hire and hare) are connected by a line. Using three lines, one can trace out a path leading from any word in a network to any other word in the same network. THe terminal words, together with the intermediate words in the path, form a word ladder, well-known since the days of Lewis Caroll. This article updates a number of recent articles in Word Ways describing the properties of four-letter word networks and ladders

Validation of a model for investigating red cell mass changes during weightlessness

The model, both the conceptual model and simulation model, provided a convenient framework on which to demonstrate the commonality between such diverse stresses as descent from altitude, red cell infusions, bed rest, and weightlessness. The results suggest that all of these stresses induce an increased blood hematocrit leading to tissue hyperoxia and eventual inhibition of the erythyocyte producing circuit until the hyperoxic condition is relieved. The erythropoietic system was acting, in these situations, as if it were an hematocrit sensor and regulator. In these terms the decreases in red cell mass during Skylab may be explained in terms of normal feedback regulation of the erythropoietic system in the face of sustained decreases in plasma colume

The modeling and simulation of feedback control systems

A brief description of the principles of mathematical models and their development is given. It should serve as an introduction to those unfamiliar with the topic