Proposed shunt rounding technique for large-scale security constrained loss minimization

The official published version can be obtained from the link below - Copyright @ 2010 IEEE.Optimal reactive power flow applications often model large numbers of discrete shunt devices as continuous variables, which are rounded to their nearest discrete value at the final iteration. This can degrade optimality. This paper presents novel methods based on probabilistic and adaptive threshold approaches that can extend existing security constrained optimal reactive power flow methods to effectively solve large-scale network problems involving discrete shunt devices. Loss reduction solutions from the proposed techniques were compared to solutions from the mixed integer nonlinear mathematical programming algorithm (MINLP) using modified IEEE standard networks up to 118 buses. The proposed techniques were also applied to practical large-scale network models of Great Britain. The results show that the proposed techniques can achieve improved loss minimization solutions when compared to the standard rounding method.This work was supported in part by the National Grid and in part by the EPSRC. Paper no. TPWRS-00653-2009

Nurse practitioner interactions in acute and long-term care : an exploration of the role of knotworking in supporting interprofessional collaboration

BACKGROUND: Interprofessional care ensures high quality healthcare. Effective interprofessional collaboration is required to enable interprofessional care, although within the acute care hospital setting interprofessional collaboration is considered suboptimal. The integration of nurse practitioner roles into the acute and long-term care settings is influencing enhanced care. What remains unknown is how the nurse practitioner role enacts interprofessional collaboration or enables interprofessional care to promote high quality care. The study aim was to understand how nurse practitioners employed in acute and long-term care settings enable interprofessional collaboration and care. METHOD: Nurse practitioner interactions with other healthcare professionals were observed throughout the work day. These interactions were explored within the context of "knotworking" to create an understanding of their social practices and processes supporting interprofessional collaboration. Healthcare professionals who worked with nurse practitioners were invited to share their perceptions of valued role attributes and impacts. RESULTS: Twenty-four nurse practitioners employed at six hospitals participated. 384 hours of observation provided 1,284 observed interactions for analysis. Two types of observed interactions are comparable to knotworking. Rapid interactions resemble the traditional knotworking described in earlier studies, while brief interactions are a new form of knotworking with enhanced qualities that more consistently result in interprofessional care. Nurse practitioners were the most common initiators of brief interactions. CONCLUSIONS: Brief interactions reveal new qualities of knotworking with more consistent interprofessional care results. A general process used by nurse practitioners, where they practice a combination of both traditional (rapid) knotworking and brief knotworking to enable interprofessional care within acute and long-term care settings, is revealed

Identifying Retweetable Tweets with a Personalized Global Classifier

In this paper we present a method to identify tweets that a user may find interesting enough to retweet. The method is based on a global, but personalized classifier, which is trained on data from several users, represented in terms of user-specific features. Thus, the method is trained on a sufficient volume of data, while also being able to make personalized decisions, i.e., the same post received by two different users may lead to different classification decisions. Experimenting with a collection of approx.\ 130K tweets received by 122 journalists, we train a logistic regression classifier, using a wide variety of features: the content of each tweet, its novelty, its text similarity to tweets previously posted or retweeted by the recipient or sender of the tweet, the network influence of the author and sender, and their past interactions. Our system obtains F1 approx. 0.9 using only 10 features and 5K training instances.Comment: This is a long paper version of the extended abstract titled "A Personalized Global Filter To Predict Retweets", of the same authors, which was published in the 25th ACM UMAP conference in Bratislava, Slovakia, in July 201

Health professionals' and patients' perceptions of patient-centered care : a comparison

Rationale, aims and objectives: This study aimed to compare health professionals’ and patients’ perceptions of patient-centered care (PCC) practice. Methods: PCC was operationalized into three components: (i) holistic, (ii) collaborative and (iii) responsive care. In a cross-sectional design, a sample of 401 health professionals and 500 patients in acute care settings in Ontario, Canada completed a valid and reliable measure of PCC. Results: The results showed that patients had lower ratings of PCC than health professionals, indicating that patients viewed their care as holistic, collaborative and responsive to a low-moderate extent; this contrasted with a more positive view by health professionals, suggesting a high level of PCC enactment (all p’s 0.05; effect sizes range: 0.38 to 0.88). Discussion and Conclusion: Although methodological, clinical and contextual factors have been suggested, additional research is needed to further explore the mechanisms underlying these differences. Collaboration among management, professionals and patients would promote a collective development of guidelines to deliver PCC

PhotoSpec: A new instrument to measure spatially distributed red and far-red Solar-Induced Chlorophyll Fluorescence

Solar-Induced Chlorophyll Fluorescence (SIF) is an emission of light in the 650–850 nm spectral range from the excited state of the chlorophyll-a pigment after absorption of photosynthetically active radiation (PAR). As this is directly linked to the electron transport chain in oxygenic photosynthesis, SIF is a powerful proxy for photosynthetic activity. SIF observations are relatively new and, while global scale measurements from satellites using high-resolution spectroscopy of Fraunhofer bands are becoming more available, observations at the intermediate canopy scale using these techniques are sparse. We present a novel ground-based spectrometer system - PhotoSpec - for measuring SIF in the red (670–732 nm) and far-red (729–784 nm) wavelength range as well as canopy reflectance (400–900 nm) to calculate vegetation indices, such as the normalized difference vegetation index (NDVI), the enhanced vegetation index (EVI), and the photochemical reflectance index (PRI). PhotoSpec includes a 2D scanning telescope unit which can be pointed to any location in a canopy with a narrow field of view (FOV = 0.7°). PhotoSpec has a high signal-to-noise ratio and spectral resolution, which allows high precision solar Fraunhofer line retrievals over the entire fluorescence wavelength range under all atmospheric conditions using a new two-step linearized least-squares retrieval procedure. Initial PhotoSpec observations include the diurnal SIF cycle of single broad leaves, grass, and dark-light transitions. Results from the first tower-based measurements in Costa Rica show that the instrument can continuously monitor SIF of several tropical species throughout the day. The PhotoSpec instrument can be used to explore the relationship between SIF, photosynthetic efficiencies, Gross Primary Productivity (GPP), and the impact of canopy radiative transfer, viewing geometry, and stress conditions at the canopy scale

The Possibility of an Interdisciplinary Poetic Pedagogy: Re-Conceiving Knowing and Being

This paper grew out of the unique and mysterious discovery of the prolific use of Canadian writer, Bronwen Wallaces poetry, by students and teachers in nursing. Before the actualinterpretation of the kinship of poetry and nursing, it is important to first consider a reconceived understanding of the interconnected relationship of epistemology and ontology that can be found within hermeneutic inquiry. This paper then explores characteristics of hermeneutic inquiry and its rich tradition, which may allow for a possible rendering of the meaning and value of the interdisciplinary relationship of nursing and poetry

Stochastic `Beads on a String' in the Accretion Tail of Arp 285

We present Spitzer infrared, GALEX UV, and SDSS and SARA optical images of the peculiar interacting galaxy pair Arp 285 (NGC 2856/4), and compare with a new numerical model of the interaction. We estimate the ages of clumps of star formation in these galaxies using population synthesis models, carefully considering the uncertainties on these ages. This system contains a striking example of `beads on a string': a series of star formation complexes ~1 kpc apart. These `beads' are found in a tail-like feature that is perpendicular to the disk of NGC 2856, which implies that it was formed from material accreted from the companion NGC 2854. The extreme blueness of the optical/UV colors and redness of the mid-infrared colors implies very young stellar ages (~4 - 20 Myrs) for these star forming regions. Spectral decomposition of these `beads' shows excess emission above the modeled stellar continuum in the 3.6 micron and 4.5 micron bands, indicating either contributions from interstellar matter to these fluxes or a second older stellar population. These clumps have -12.0 < M(B) < -10.6, thus they are less luminous than most dwarf galaxies. Our model suggests that bridge material falling into the potential of the companion overshoots the companion. The gas then piles up at apo-galacticon before falling back onto the companion, and star formation occurs in the pile-up. A luminous (M(B) ~ -13.6) extended (FWHM ~ 1.3 kpc) `bright spot' is visible at the northwestern edge of the NGC 2856 disk, with an intermediate stellar population (400 - 1500 Myrs). Our model suggests that this feature is part of a expanding ripple-like `arc' created by an off-center ring-galaxy-like collision between the two disks.Comment: Accepted by the Astronomical Journal. For color figures and appendix material, go tohttp://www.etsu.edu/physics/bsmith/research/sg/arp285/arp285.htm