Narrow-band variable center frequency single-loop and multistage sigma-delta modulators for bandpass signals

Oversampled narrow-band single-loop and multistage resonator-based bandpass sigma-delta (Σ-Δ) modulators that can accommodate different passband center to sampling frequency ratios are reported. These tunable bandpass configurations are designed by analytically determining and subsequently verifying through detailed empirical simulations the required compensation hardware to deliver enhanced noise-shaping. It is demonstrated that comparatively superior in-band signal-to-noise ratios and dynamic ranges are attributed to the inclusion of appropriate digital feedforward and feedback compensators within these structures.

Tunable centre frequency resonator based bandpass Σ-Δ modulators

This paper presents a methodology for the design of oversampled narrow-band single-loop and multi-stage resonator-based bandpass Σ-Δ modulators that can accommodate different passband centre to sampling frequency ratios. These tunable bandpass configurations are designed by analytically determining the required compensation hardware to deliver good resolution. Thorough simulations demonstrate that comparatively superior in-band signal-to-noise ratios (SNRs) and dynamic ranges (DRs) are attributed to the inclusion of appropriate feedforward and feedback compensators within these structures.

CO2 reduction and efficiency in road freight traffic: measures, baseline and potential

The objective of our research was to analyse the relevant logistic factors influencing energy efficiency in road freight transport, while quantifying the potential for CO2 reduction. We carried out a survey and linked fuel consumption to transport performance parameters in 50 German haulage companies during 2003. Efficiency ranges from 0.8 tkm to 26 tkm for 1 kg CO2 emissions. The results show a high potential for improvements, given a low level of efficiency in vehicle usage and load factor, scarce use of lightweight vehicle design, incorrectly selected vehicle class and a high proportion of empty runs. Efficiency measures are poorly applied.

Integrating Social Knowledge and Collaboration Tools into Dispersed Product Development

Employee collaboration and knowledge sharing is vital for manufacturing organisations wishing to be successful in an ever-changing global market place; Product Development (PD) teams, in particular, rely heavily on these activities to generate innovative designs and enhancements to existing product ranges. To this end, the purpose of this paper is to present the results of a validation study carried out during an Engineering Education Scheme project to confirm the benefits of using bespoke Web 2.0-based groupware to improve employee collaboration and knowledge sharing between dispersed PD teams. The results of a cross-sectional survey concluded that employees would welcome greater usage of social computing technologies. The study confirmed that groupware offers the potential to deliver a more effective collaborative and knowledge sharing environment with additional communication channels on offer. Furthermore, a series of recommended guidelines are presented to show how PD teams, operating in globally dispersed organisations, may use Web 2.0 tools to improve employee collaboration and knowledge sharing.