David McCracken

Learn More
The tremendous growth in wireless LANs has generated interest in technologies that provide higher data rates and greater system capacities. The IEEE 802.11a [1] standard, based on coded OFDM modulation [2,3], provides nearly five times the data rate and as much as ten times the overall system capacity as current 802.11b wireless LAN systems. This paper(More)
Two new algorithms for Golomb ruler derivation were developed and are presented together with the previously published standard algorithm. One of the new algorithms was used to prove computationally the optimality of three rulers. Two of these were previously proven but yet unpublished, and the authors' independent derivation connrmed these results. The(More)
1. Understanding the pattern and magnitude of spatial variation in demography and population growth rate (lambda) is key to understanding the structure and dynamics of natural populations. However, such spatial variation is challenging to quantify. We use>20 years of individual life-history data to quantify small- and large-scale spatial variation in(More)
Agriculture constitutes a dominant land cover worldwide, and rural landscapes under extensive farming practices acknowledged due to high biodiversity levels. The High Nature Value farmland (HNVf) concept has been highlighted in the EU environmental and rural policies due to their inherent potential to help characterize and direct financial support to(More)
The intensity of management of lowland grassland fields in the United Kingdom, coupled with the fact that such grasslands dominate much of the lowland landscape, means that there are now few opportunities for many plants, invertebrates, birds, or mammals to survive. The Scottish Agricultural College (SAC) has investigated whether fencing off the margins of(More)
1. Quantifying the pattern of temporal and spatial variation in demography, and identifying the factors that cause this variation, are essential steps towards understanding the structure and dynamics of any population. 2. One critical but understudied demographic rate is pre-breeding survival. We used long-term colour-ringing data to quantify temporal(More)
Graphical interfaces and windowing systems are now the norm for computer-human interaction. Also, advances in computer networking have given computer users access to immense distributed resources accessible from anywhere on the network. In this setting, the desktop, or personal, computer plays the role of a user-interface engine that mediates access to the(More)
Graphical interfaces and windowing systems are now the norm for computer-human interaction. Also, advances in computer networking have given computer users access to immense distributed resources accessible from anywhere on the network. In this setting, the desktop, or personal, computer plays the role of a user-interface engine that mediates access to the(More)
  • Joe W. Kotrlik, Md. Shafiqul Azam, +19 authors George H. Copa
  • 2003
The Journal of Vocational Education Research (JVER) is published three times a year and is an official publication of the American Vocational Education Research Association (AVERA). AVERA was organized in 1966 and strives to: (a) stimulate research and development activities related to vocational education, (b) stimulate the development of training programs(More)
  • 1