In this work we present a new low-power medium access scheme for sensor-type networks specifically with low traffic intensity. We call the proposed scheme DCW-MAC where ultra-low-power wake-up receivers are combined with optimal duty-cycled listening. First we introduce a framework for the analysis of energy consumption of the studied network type, then we use it to optimize the MAC scheme to achi

Requirements Engineering and Testing are considered inseparable and together enable successful projects. One could make a statement that serious negligence of any of the two will bring catastrophic consequences for the project, delays, failures and unhappy customers. Thus, alignment and cooperation between the two are not only recommended but highly required for contemporary complex software and s

The effect of pre-chamber volume and nozzle diameter on performance of pre-chamber ignition device in a heavy duty natural gas engine has previously been studied by the authors. From the analysis of recorded pre- and main chamber pressure traces, it was observed that a pre-chamber with a larger volume reduced flame development angle and combustion duration while at a given pre-chamber volume, smal

We analyze the channel capacity of multiple-input multiple-output (MIMO) systems in frequcncy selective channels, with channel knowledge at the transmitter side. An optimum transmission scheme uses Shannon's principle of waterfilling jointly in the frequency and the spatial domain. However, we show in this paper that the largest gain by using waterfilling resides in the spatial domain, and that th

The input device for Remote Gaming has matured from a simple pointing device to a wireless console and recently even motion sensors are added. Similar motion sensors have already been integrated in camera’s to provide for image stabilization. In the cellphone, global motion is foremost determined through image processing. The paper extends this concept to support gaming, while aiming for a low-com

cute pain services were introduced more than 20 years ago as an organizational attempt to meet shortcomings in postoperative pain management. The acute pain service concept received immediate and strong support from a large number of medical and health-care organizations around the world. Literature reviews indicate that 30–70% of North-American and European hospitals, depending on size and academ

A method is described for identifying simultaneous signals from different transmit antennas in multi-antenna sounders. Multiple orthogonal signals are produced from one pseudorandom code by using it to modulate RF carriers at pre-calculated offset frequencies. Although their frequency spectra are interleaved, the spectral lines from different transmitters are separable by Fourier transform at the

Various occupational exposures have been monitored by chromosomal aberrations, sister chromatid exchanges and micronuclei in peripheral blood lymphocytes. During the last decade, epidemiological studies have evaluated whether any of these markers foreshadows cancer risk. Results from Nordic, Italian and Czech cohorts support an approximately twofold cancer risk among subjects with high frequencies

In recent years, public, scientific and governmental interest in ecotourism in Scandinavia has grown substantially. This book is the first to comprehensively describe, analyse and evaluate aspects of Scandinavian ecotourism. It will appeal to researchers and students of tourism in general and ecotourism in particular.

1. The European Water Framework Directive requires the determination of ecological status in European fresh and saline waters. This is to be through the establishment of a typology of surface water bodies, the determination of reference (high status) conditions in each element (ecotype) of the typology and of lower grades of status (good, moderate, poor and bad) for each ecotype. It then requires

A teachable-agent arithmetic game is presented and evaluated in terms of student performance, attitude and self-efficacy. An experimental pre-post study design was used, enrolling 153 3rd and 5th grade students in Sweden. The playing group showed significantly larger gains in math performance and self-efficacy beliefs, but not in general attitude towards math, than the control groups. The contribu

Recent three-dimensional, high-resolution simulations of neutron star coalescences are analysed to assess whether short gamma-ray bursts (GRBs) could originate from such encounters. The two most popular modes of energy extraction - namely the annihilation of and magnetohydrodynamic processes - are explored in order to investigate their viability in launching GRBs. We find that annihilation can pro

This paper explores short and long-run changes in the energy to capital relation. The K/E ratio is calculated for Sweden 1870–2000, at the national, industrial and branch levels. A basic result is a substantial long-run increase in the K/E ratio which is positively correlated with the relative price pE/pK. The price response is stronger in energy intensive industries than in labour intensive indus

This paper presents an overview of power system fault classification methods and challenges. It also contains some ideas about structured testing.

It has previously been shown by the authors that the pre-chamber ignition technique operating with fuel-rich pre-chamber combustion strategy is a very effective means of extending the lean limit of combustion with excess air in heavy duty natural gas engines in order to improve indicated efficiency and reduce emissions. This article presents a study of the influence of pre-chamber volume and nozzl