Sonar range nders are commonly used in mobile robotics for map building, navigation, and localisation. All robot sonar systems must, implicitly or explicitly, use a model of the sonar sensor. However, no systematic attempt has been made to experimentally model the behaviour and reliability of sonar range returns. This paper describes an empirical model of sonar time-ofight, derived from a large...

Hand hygiene represents a fundamental nursing care practice and is traditionally considered the most important and effective measure in the prevention and control of healthcare-related infections. However, studies indicate that adherence to the procedure is unsatisfactory throughout the world, and show low adherence rates. In a context in which patient safety stands out as a priority, this text...

The program PDFFIT is designed for the full pro®le structural re®nement of the atomic pair distribution function (PDF). In contrast to conventional structure re®nement based on Bragg intensities, the PDF probes the local structure of the studied material. The program presented here allows the re®nement of atomic positions, anisotropic thermal parameters and site occupancies as well as lattice p...

Migration in nature occurs against a complex, shifting backdrop of kaleidoscopic changes through time due to many distinct forces of variation acting over different time scales, from stochastic daily fl uctuations in the weather, to multi-annual oscillations in the abundance of resources and natural enemy populations, to the stately march of climate change over geological time. Migrants move ac...

A parafoil controlled by parafoil brake de ection offers a lightweight and space-efŽ cient control mechanism for autonomous placement of air-dropped payloads to speciŽ ed ground coordinates. The work reported here investigates control issues for a parafoil and payload system with left and right parafoil brakes used as the control mechanism.It is shown thatparafoilandpayloadsystems can exhibit ...

In order to improve the quality of binaural based virtual reality systems, the use of individual headrelated transfer functions (HRTF) plays a major role. This paper presents a system for individual HRTF measurements developed at the Institute of Technical Acoustics in Aachen. The main characteristic of this system is the close distance between head and sound sources. This allows to make use of...

High-speed digital LSI chips usually consist of many sub-circuits coupled with multi-conductor interconnects embedded in the substrate. They sometimes cause serious problems of the fault switching operations due to the time-delays, crosstalks, re ections, etc. In order to solve these problems, it is very important to develop a user-friendly simulator for the analysis of LSIs coupled with interc...

This paper describes 3-D radio channel measurements at the base which combines an RF switched receiver array and a synthetic aperture technique and allows full 3-D characterization of the channel. Additionally, dual-polarized patch antennas as array elements enable full determination of the polarization properties of the impinging signals. We describe measurements at over 70 di erent transmitte...

is paper investigates how inquiry into normative language can improve substantive normative theorizing. First I examine twodimensions alongwhich normative language differs: “strength” and “subjectivity.” Next I show how greater sensitivity to these features of the meaning and use of normative language can illuminate debates about three issues in ethics: the coherence of moral dilemmas, the pos...