Difference sets and their generalisations to difference families arise from the study of designs and many other applications. Here we give a brief survey of some of these applications, noting in particular the diverse definitions of difference families and the variations in priorities in constructions. We propose a definition of disjoint difference families that encompasses these variations and...

We present a new family of one-coincidence sequence sets suitable for frequency hopping code division multiple access (FH-CDMA) systems with dispersed (low density) sequence elements. These sets are derived from one-coincidence prime sequence sets, such that for each one-coincidence prime sequence set there is a new one-coincidence set comprised of sequences with dispersed sequence elements, re...

D spread spectrum (DSSS) and frequency-hopping spread spectrum (FHSS) technologies have different physical mechanisms for rejecting narrowband interference. Because of these physical differences, they perform differently in the presence of the same levels of narrowband interference. This is an important case for successful operation in the ISM bands. After presenting the physical mechanisms by ...

We briefly review some common diffusion-limited reactions with emphasis on results for two-species reactions with anisotropic hopping. Our review also covers single-species reactions. The scope is that of providing reference and general discussion rather than details of methods and results. Recent exact results for a two-species model with anisotropic hopping and with ‘sticky’ interaction of li...

Nowadays, the world hop industry is faced with one of the biggest crisis in the history. Permanent decrease of hopping rates in the world beer industry during last 20 years caused many problems to hop producers all around the world. It resulted in the huge surpluses of hop stocks between years 2008 and 2010, the ages known as “years of famine” for hop farmers. Th e hop contains some compounds h...

In this paper, an experimental characterization of a MIMO underground channel is presented. A simple statistical model is proposed at 2.45 GHz. The channel is characterized in terms of path loss, shadowing, RMS delay spread, and capacity. The measurements are carried out in an underground mine, which is a harsh confined environment. The path loss model is extracted from measured data for the li...

This paper examines the predictive power of credit spreads from the corporate bond market. The high-yield bond spread and investment-grade spread can explain 68 per cent and 42 per cent of output variations one year ahead, while the term spread based on government debts can explain only 12 per cent of them. For output forecasts up to one year ahead, the corporate bond spreads also outperform po...