A Multi-signal Variant for the GPU-based Parallelization of Growing Self-Organizing Networks

Among the many possible approaches for the parallelization of self-organizing networks, and in particular of growing self-organizing networks, perhaps the most common one is producing an optimized, parallel implementation of the standard sequential algorithms reported in the literature. In this paper we explore an alternative approach, based on a new algorithm variant specifically designed to match the features of the large-scale, fine-grained parallelism of GPUs, in which multiple input signals are processed at once. Comparative tests have been performed, using both parallel and sequential implementations of the new algorithm variant, in particular for a growing self-organizing network that reconstructs surfaces from point clouds. The experimental results show that this approach allows harnessing in a more effective way the intrinsic parallelism that the self-organizing networks algorithms seem intuitively to suggest, obtaining better performances even with networks of smaller size.Comment: 17 page

Influence of water temperature on the efficacy of diquat and endothall versus curlyleaf pondweed

determine the impact of water temperature on the efficacy of the contact herbicides diquat (6,7-dihydrodipyrido [1,2- α:2’,1’-c] pyrazinediium ion) and endothall (7-oxabicyclo [2.2.1] heptane-2,3-dicarboxylic acid) for control of the exotic nuisance species curlyleaf pondweed (Potamogeton crispus L.) across a range of water temperatures

Decadal trends in the diurnal variation of galactic cosmic rays observed using neutron monitor data

The diurnal variation (DV) in galactic cosmic ray (GCR) flux is a widely observed phenomenon in neutron monitor data. The background variation considered primarily in this study is due to the balance between the convection of energetic particles away from the Sun and the inward diffusion of energetic particles along magnetic field lines. However, there are also times of enhanced DV following geomagnetic disturbances caused by coronal mass ejections or corotating interaction regions. In this study we investigate changes in the DV over four solar cycles using ground-based neutron monitors at different magnetic latitudes and longitudes at Earth. We divide all of the hourly neutron monitor data into magnetic polarity cycles to investigate cycle-to-cycle variations in the phase and amplitude of the DV. The results show, in general, a similarity between each of the A  0 cycles, but with a phase change between the two. To investigate this further, we split the neutron monitor data by solar magnetic polarity between times when the dominant polarity was either directed outward (positive) or inward (negative) at the northern solar pole. We find that the maxima and minima of the DV changes by, typically, 1–2 h between the two polarity states for all non-polar neutron monitors. This difference between cycles becomes even larger in amplitude and phase with the removal of periods with enhanced DV caused by solar wind transients. The time difference between polarity cycles is found to vary in a 22-year cycle for both the maximum and minimum times of the DV. The times of the maximum and minimum in the DV do not always vary in the same manner between A > 0 and A  0 cycles. In most cases the change in timing of the maximum /minimum is greatest with the stations' geomagnetic cut-off rigidity shows little variation in the DV phase with latitude. We conclude that the change in the DV with the dominant solar polar polarity is not as simple as a phase change, but rather an asymmetric variation which is sensitive to the neutron monitor's asymptotic viewing direction

The floor in the interplanetary magnetic field: Estimation on the basis of relative duration of ICME observations in solar wind during 1976-2000

To measure the floor in interplanetary magnetic field and estimate the time- invariant open magnetic flux of Sun, it is necessary to know a part of magnetic field of Sun carried away by CMEs. In contrast with previous papers, we did not use global solar parameters: we identified different large-scale types of solar wind for 1976-2000 interval, obtained a fraction of interplanetary CMEs (ICMEs) and calculated magnitude of interplanetary magnetic field B averaged over 2 Carrington rotations. The floor of magnetic field is estimated as B value at solar cycle minimum when the ICMEs were not observed and it was calculated to be 4,65 \pm 6,0 nT. Obtained value is in a good agreement with previous results.Comment: 10 pages, 2 figures, submitted in GR

Key benefits of enterprise resource planning adoption within small family businesses : a conceptual framework

This research mainly focused on the perceived benefits of ERP adoption for Small Family Businesses (SFB). In doing so, it explores some of the key benefits of an ERP system for SMEs. Through the exploration of the literature, a framework is constructed classifying the ERP benefits to SFBs, in that they are different to other businesses where ERP systems have historically been implemented. The literature also helps establish that there are some differences in how ERP benefits SFBs owed to the family ownership and management of business that brings about unique characteristics. Finally, this research concludes that adopting an ERP system within a SFB environment could assist in them achieving their main goals by improving business performance and better managerial control. It could also aid the achievement of SFB’s succession goals. It is, however, unclear how the ERP system can manage the tacit family and business knowledge relied upon by SFBs for their survival

Precision Timing of Two Anomalous X-Ray Pulsars

We report on long-term X-ray timing of two anomalous X-ray pulsars, 1RXS J170849.0-400910 and 1E 2259+586, using the Rossi X-ray Timing Explorer. In monthly observations made over 1.4 yr and 2.6 yr for the two pulsars, respectively, we have obtained phase-coherent timing solutions which imply that these objects have been rotating with great stability throughout the course of our observations. For 1RXS J170849.0-400910, we find a rotation frequency of 0.0909169331(5) Hz and frequency derivative -15.687(4) x 10^(-14) Hz/s, for epoch MJD 51215.931. For 1E 2259+586, we find a rotation frequency of 0.1432880613(2)Hz, and frequency derivative -1.0026(7) x 10^(-14) Hz/s, for epoch MJD 51195.583. RMS phase residuals from these simple models are only about 0.01 cycles for both sources. We show that the frequency derivative for 1E 2259+586 is inconsistent with that inferred from incoherent frequency observations made over the last 20 yr. Our observations are consistent with the magnetar hypothesis and make binary accretion scenarios appear unlikely.Comment: 12 pages including 3 figures. To appear in ApJ Letter

General practitioner experience and perception of Child and Adolescent Mental Health Services (CAMHS) care pathways: a multimethod research study

This is the final version of the article. Available from BMJ Publishing via the DOI in this recordOBJECTIVES: This is a pilot study with the objective of investigating general practitioner (GP) perceptions and experiences in the referral of mentally ill and behaviourally disturbed children and adolescents. DESIGN: Quantitative analyses on patient databases were used to ascertain the source of referrals into Child and Adolescent Mental Health Services (CAMHS) and identify the relative contribution from GP practices. Qualitative semistructured interviews were then used to explore challenges faced by GPs in referring to CAMHS. SETTING: GPs were chosen from the five localities that deliver CAMHS within the local Trust (Peterborough City, Fenland, Huntingdon, Cambridge City and South Cambridgeshire). PARTICIPANTS: For the quantitative portion, data involving 19 466 separate referrals were used. Seven GPs took part in the qualitative interviews. RESULTS: The likelihood of a referral from GPs being rejected by CAMHS was over three times higher compared to all other referral sources combined within the Cambridge and Peterborough NHS Foundation Trust. Interviews showed that detecting the signs and symptoms of mental illness in young people is a challenge for GPs. Communication with referral agencies varies and depends on individual relationships. GPs determine whether to refer on a mixture of the presenting conditions and their perceived likelihood of acceptance by CAMHS; the criteria for the latter were poorly understood by the interviewed GPs. CONCLUSIONS: There are longstanding structural weaknesses in the services for children and young people in general, reflected in poor multiagency cooperation at the primary care level. GP-friendly guidelines and standards are required that will aid in decision-making and help with understanding the referrals process. We look to managers of both commissioning and providing organisations, as well as future research, to drive forward the development of tools, protocols, and health service structures to help aid the recognition and treatment of mental illness in young people.This work was supported by the National Institute for Health Research Collaborations for Leadership in Applied Health Research and Care (CLAHRC), grant number RNAG-186

Suffix Trees Considered Harmful

The implications of adaptive theory have been far-reaching and pervasive. In this paper, au- thors demonstrate the evaluation of journaling file systems, which embodies the intuitive principles of programming languages. We prove that despite the fact that Scheme and Markov models are often incompatible, 802.11 mesh networks and Web services can agree to answer this grand challenge