OBJECTIVES To determine the level of oxygen cylinder use at which it becomes more cost effective to provide oxygen by concentrator at home in Northern Ireland, and to examine potential cost savings if cylinder use above this level had been replaced by concentrator in 1996. DESIGN Cost minimisation analysis. SETTING Area health boards in Northern Ireland. MAIN OUTCOME MEASURES Cost effecti...

High efficiency GaAs concentrator cells are useful for numerous applications requiring isolated power and voltage, or transmission of power without electromagnetic interference. This paper concerns the characteristics of GaAs concentrator cells illuminated by high-intensity laser beams. The objectives of this study are to identify and understand the mechanisms which limit the performance of GaA...

This project focuses on the development of a micro-organism concentrator. Pathogen detection, particularly MEMS based detection, is often limited by sample concentration. The proposed concentrator will interface with a pathogen detector. This type of pathogen concentrator can be useful for many kinds of applications including water purification systems, medical applications and biological warfa...

Concentration and superconcentration operations play a central role in the constructions of nonblocking switching networks. This was established in a seminal effort by Bassalygo and Pinsker who showed that an n-input nonblocking switching network can be constructed with O(n log n) crosspoints if concentrators can be constructed with O(n) crosspoints. Starting with the pioneering work of Marguli...

Packet concentrators are used in many highspeed computer communication systems such as fast packet switches. In these systems, the time available for concentration is very short. It is therefore desirable to realize the packet concentrators as hardware chips for fast concentration. The knockout concentrator was proposed for hardware realization. In this paper, we improve this concentrator to re...

The rules for casting maximum en,ergy on a cell placed in a static concentrator of minimum entry aperture are derived. A concentration o( 9.13 for collecting the direct sun~eam throughout the year and of 4.5 for collecting diffuse light are upper bounds when using practical ~! erials. Practical bifacial solar cells required to achieve ~hose figu: res are presented. A prototype of concentrator w...

High-concentration solar-power optics require precise two-axis tracking. The planar micro-optic solar concentrator uses a lenslet array over a planar waveguide with small reflective facets at the focal point of each lenslet to couple incident light into the waveguide. The concentrator can use conventional tracking, tilting the entire assembly, but the system geometry also allows tracking by sma...

In this paper, we propose a concept of application concentrator that realizes the multiple association at an application level. Since network technologies have been quickly advanced in recent years, various social activities have shifted on a network. Thus, a technology for realizing multiple association to many closed networks is crucial. In this paper, we propose a concept of application conc...

Packet concentrators are used in shared-memory and knockout switches to select and route packets into individual outputs. Recently, a switch model was introduced to investigate the intrinsic relationship between the switching complexity and traffic characteristics of packet concentrators. Using this model, it was shown that any bipartite packet concentrator with n inputs, m outputs and peak per...

Due to chip area and pin count constraints, large con-centrator switches sometimes must be partitioned among several chips. This paper presents designs for two mul-tichip partial concentrator switches, both of which follow from a lemma showing that an "-nearsorter is also an (n; m; 1 ? "=m) partial concentrator.