Search

There is strong interest in positioing in wireless networks, partly to support end user service needs, but also to support network management with network-based network information. The focus in this paper is on the latter, while using measurements that are readily available in wireless networks. We show how thesignal direction of departure and inter-distance between the base station and the mobile terminal can be estimated, and how particle filters and smoothers can be used to post-process the measurements. The methods are evaluated in a live 3GPP LTE network with promising results inlcuding position error medians of less than 100 m., Funding Agencies|SSF, Swedish Foundation for Strategic Research

With BitTorrent, efficient peer upload utilization is achieved by splitting contents into many small pieces, each of which may be downloaded from different peers within the same swarm. Unfortunately, piece and bandwidth availability may cause the file-sharing efficiency to degrade in small swarms with few participating peers. Using extensive measurements, we identified hundreds of thousands of torrents with several small swarms for which reallocating peers among swarms and/or modifying the peer behavior could significantly improve the system performance. Motivated by this observation, we propose a centralized and a distributed protocol for dynamic swarm management. The centralized protocol (CSM) manages the swarms of peers at minimal tracker overhead. The distributed protocol (DSM) manages the swarms of peers while ensuring load fairness among the trackers. Both protocols achieve their performance improvements by identifying and merging small swarms and allow load sharing for large torrents. Our evaluations are based on measurement data collected during eight days from over 700 trackers worldwide, which collectively maintain state information about 2.8 million unique torrents. We find that CSM and DSM can achieve most of the performance gains of dynamic swarm management. These gains are estimated to be up to 40% on average for small torrents., QC 20130320

QC 20140915. (Editorial)

Workload characterization is important for understanding how systems and services are used in practice and to help identify design improvements. To better understand the longitudinal workload dynamics of chunk-based content delivery systems, this paper analyzes the BitTorrent usage as observed from two different vantage points. Using two simultaneously collected 48-week long traces, we analyze the differences in download characteristics and popularity dynamics observed locally at a university campus versus at a global scale. We find that campus users typically download larger files and are early adopters of new content, in the sense that they typically download files well before the time at which the global popularity of the files peak. The noticeable exception is music files, which the campus users are late to download. We also find that there typically is high churn in the set of files that are popular each week, both locally and globally, and that the most popular files peak significantly later than their release date. These findings provide insights that may improve the efficiency of content sharing locally, and thus increase the scalability of the global system., QC 20120802

BACKGROUND: Despite knowledge of the adverse health effects of passive smoking, children are still being exposed. Children's nurses play an important role in tobacco preventive work through dialogue with parents aimed at identifying how children can be protected from environmental tobacco smoke (ETS) exposure. The study describes the experiences of Child Health Care (CHC) nurses when using the validated instrument SiCET (Smoking in Children's Environment Test) in dialogue with parents. METHOD: In an intervention in CHC centres in south-eastern Sweden nurses were invited to use the SiCET. Eighteen nurses participated in focus group interviews. Transcripts were reviewed and their contents were coded into categories by three investigators using the method described for focus groups interviews. RESULTS: The SiCET was used in dialogue with parents in tobacco preventive work and resulted in focused discussions on smoking and support for behavioural changes among parents. The instrument had both strengths and limitations. The nurses experienced that the SiCET facilitated dialogue with parents and gave a comprehensive view of the child's ETS exposure. This gave nurses the possibility of taking on a supportive role by offering parents long-term help in protecting their child from ETS exposure and in considering smoking cessation. CONCLUSION: Our findings indicate that the SiCET supports nurses in their dialogue with parents on children's ETS exposure at CHC. There is a need for more clinical use and evaluation of the SiCET to determine its usefulness in clinical practice under varying circumstances.

The purpose of this study was to describe parents' attitudes to smoking and their experience of the tobacco preventive work in antenatal care and in Child Health Care (CHC) in Sweden. A population based survey in which 62 percent of 3000 randomly selected parents with 1- and 3-year-old children answered a questionnaire. Fifty-six percent stated that smoking was registered in the health record of the child yet no further discussion regarding passive smoking took place. The parents' educational level and smoking status was related to the attitudes and experiences of the tobacco preventive work. The results indicated that the dialogue with parents regarding children and environmental tobacco smoke (ETS) exposure has to be redesigned and intensified in order to meet the needs of parents with different backgrounds.

AIM: To investigate and analyse the attitudes to tobacco prevention among child healthcare nurses, to study how tobacco preventive work is carried out at child healthcare centres today. To evaluate how the tobacco preventive work had changed in child health care since the Swedish National Board of Health and Welfare's national evaluation in 1997. BACKGROUND: Exposure to environmental tobacco smoke has adverse health effects. Interventions aiming at minimising environmental tobacco smoke have been developed and implemented at child healthcare centres in Sweden but the long-term effects of the interventions have not been studied. DESIGN: Survey. METHODS: In 2004, a postal questionnaire was sent to all nurses (n = 196) working at 92 child healthcare centres in two counties in south-eastern Sweden. The questionnaire was based on questions used by the National Board of Health and Welfare in their national evaluation in 1997 and individual semi-structured interviews performed for this study. RESULTS: Almost all the nurses considered it very important to ask parents about their smoking habits (median 9.5, range 5.1-10.0). Collaboration with antenatal care had decreased since 1997. Nearly all the nurses mentioned difficulties in reaching fathers (70%), groups such as immigrant families (87%) and socially vulnerable families (94%) with the tobacco preventive programme. No nurses reported having special strategies to reach these groups. CONCLUSIONS: Improvement of methods for tobacco prevention at child healthcare centres is called for, especially for vulnerable groups in society. However, the positive attitude among nurses found in this study forms a promising basis for successful interventions. RELEVANCE TO CLINICAL PRACTICE: This study shows that launching national programmes for tobacco prevention is not sufficient to achieve sustainable work. Nurses working in child healthcare centres have an overall positive attitude to tobacco prevention but need continuous education a

Using a combination of high-performance ion chromatography analysis and kinetic studies, the pathway of dephosphorylation of myo-inositol hexakisphosphate by the phytases purified from faba bean and lupine seeds, respectively, was established. The data demonstrate that the legume seed phytases under investigation dephosphorylate myo-inositol hexakisphosphate in a stereospecific way. The phytase from faba bean seeds and the phytase LP2 from lupine seeds degrade phytate by sequential removal of phosphate groups via D-Ins(1,2,3,5,6)P5, D-Ins(1,2,5,6)P4, D-Ins(1,2,6)P3, and D-Ins(1,2)P2 to finally Ins(2)P, whereas the phytases LP11 and LP12 from lupine seeds generate the final degradation product Ins(2)P via D-Ins(1,2,4,5,6)P5, D-Ins(1,2,5,6)P4, D-Ins(1,2,6)P3, and D-Ins(1,2)P2.

Patent also granted in Australia AU 2001230648 (B2) 2006-07-13, in the U.S. US 7801781 (B2) 2010-09-21 and by division US 8229813 (B2) 2012-07-24, in China CN 101789868 (B) 2012-12-12 and in Japan JP 5301689 (B2) 2013-09-25. International application WO 02/ 28026 (A1) 2002-04-04.

We have studied self-assembled InAs quantum dots embedded in an InP matrix using photocapacitance and photocurrent spectroscopy. These dots are potentially promising for memories due to the large confinement energy for holes. In this work we have realized simple quantum dot memory by placing the dots in the space–charge region of a Schottky junction. Our measurements reveal that a maximum of about one hole can be stored per dot. We also find that illumination for an extended period deletes the stored charge. We show that these limitations do not reflect the intrinsic properties of the dots, but rather the sample structure in combination with deep traps present in the sample.