964 resultados para Two-point
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A mosaic of two WorldView-2 high resolution multispectral images (Acquisition dates: October 2010 and April 2012), in conjunction with field survey data, was used to create a habitat map of the Danajon Bank, Philippines (10°15'0'' N, 124°08'0'' E) using an object-based approach. To create the habitat map, we conducted benthic cover (seafloor) field surveys using two methods. Firstly, we undertook georeferenced point intercept transects (English et al., 1997). For ten sites we recorded habitat cover types at 1 m intervals on 10 m long transects (n= 2,070 points). Second, we conducted geo-referenced spot check surveys, by placing a viewing bucket in the water to estimate the percent cover benthic cover types (n = 2,357 points). Survey locations were chosen to cover a diverse and representative subset of habitats found in the Danajon Bank. The combination of methods was a compromise between the higher accuracy of point intercept transects and the larger sample area achievable through spot check surveys (Roelfsema and Phinn, 2008, doi:10.1117/12.804806). Object-based image analysis, using the field data as calibration data, was used to classify the image mosaic at each of the reef, geomorphic and benthic community levels. The benthic community level segregated the image into a total of 17 pure and mixed benthic classes.
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Objectives: Hospital discharge is a transition of care, where medication discrepancies are likely to occur and potentially cause patient harm. The purpose of our study was to assess the prescribing accuracy of hospital discharge medication orders at a London, UK teaching hospital. The timeliness of the discharge summary reaching the general practitioner (GP, family physician) was also assessed based on the 72 h target referenced in the Care Quality Commission report.1 Method: 501 consecutive discharge medication orders from 142 patients were examined and the following records were compared (1) the final inpatient drug chart at the point of discharge, (2) printed signed copy of the initial to take away (TTA) discharge summary produced electronically by the physician, (3) the pharmacist's amendments on the initial TTA that were hand written, (4) the final electronic patient discharge summary record, (5) the patients final take home medication from the hospital. Discrepancies between the physician's order (6) and pharmacist's change(s) (7) were compared with two types of failures – ‘failure to make a required change’ and ‘change where none was required’. Once the patient was discharged, the patient's GP, was contacted 72 h after discharge to see if the patient discharge summary, sent by post or via email, was received. Results: Over half the patients seen (73 out of 142) patients had at least one discrepancy that was made on the initial TTA by the doctor and amended by the pharmacist. Out of the 501 drugs, there were 140 discrepancies, 108 were ‘failures to make a required change’ (77%) and 32 were ‘changes where none were required’ (23%). The types of ‘failures to make required changes’ discrepancies that were found between the initial TTA and pharmacist's amendments were paracetamol and ibuprofen changes (dose banding) 38 (27%), directions of use 34 (24%), incorrect formulation of medication 28 (20%) and incorrect strength 8 (6%). The types of ‘changes where none were required discrepancies’ were omitted medication 15 (11%), unnecessary drug 14 (10%) and incorrect medicine including spelling mistakes 3 (2%). After contacting the GPs of the discharged patients 72 h postdischarge; 49% had received the discharge summary and 45% had not, the remaining 6% were patients who were discharged without a GP. Conclusion: This study shows that doctor prescribing at discharge is often not accurate, and interventions made by pharmacist to reconcile are important at this point of care. It was also found that half the discharge summaries had not reached the patient's family physician (according to the GP) within 72 h.
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Aims The pubococcygeal line (PCL) is an important reference line for determining measures of pelvic organ support on sagittal-plane magnetic resonance imaging (MRI); however, there is no consensus on where to place the posterior point of the PCL. As coccyx movement produced during pelvic floor muscle (PFM) contractions may affect other measures, optimal placement of the posterior point is important. This study compared two methods for measuring the PCL, with different posterior points, on T2-weighted sagittal MRI to determine the effect of coccygeal movement on measures of pelvic organ support in older women. Methods MRI of the pelvis was performed in the midsagittal plane, at rest and during PFM contractions, on 47 community-dwelling women 60 and over. The first PCL was measured to the tip of the coccyx (PCLtip) and the second to the sacrococcygeal joint (PCLjnt). Four measures of pelvic organ support were made using each PCL as the reference line: urethrovesical junction height, uterovaginal junction height, M-line and levator plate angle. Results During the PFM contraction the PCLtip shortened and lifted (P < 0.001); the PCLjnt did not change (P > 0.05). The changes in the four measures of pelvic organ support were smaller when measured relative to the PCLtip as compared to those to the PCLjnt (P < 0.001). Conclusions Coccyx movement affected the length and position of the PCLtip, which resulted in underestimates of the pelvic-organ lift produced by the PFM contraction. Therefore, we recommend that the PCL be measured to the sacrococcygeal joint and not to the tip of the coccyx
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In a sediment core from the Pacific sector of the Antarctic Zone (AZ) of the Southern Ocean, we report diatom-bound N isotope (d15Ndb) records for total recoverable diatoms and two distinct diatom assemblages (pennate and centric rich). These data indicate tight coupling between the degree of nitrate consumption and Antarctic climate across the last two glacial cycles, with d15Ndb (and thus the degree of nitrate consumption) increasing at each major Antarctic cooling event. Coupled with evidence from opal- and barium-based proxies for reduced export production during ice ages, the d15Ndb increases point to ice age reductions in the supply of deep ocean-sourced nitrate to the AZ surface. The two diatom assemblages and species abundance data indicate that the d15Ndb changes are not the result of changing species composition. The pennate and centric assemblage d15Ndb records indicate similar changes but with a significant decline in their difference during peak ice ages. A tentative seasonality-based interpretation of the centric-to-pennate d15Ndb difference suggests that late summer surface waters became nitrate free during the peak glacials.
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Electron microprobe (EMP) dating on monazite in granulite- facies rocks from Forefinger Point, East Antarctica, yielded dominant ages of 500 Ma on matrix monazites.They are associated with secondary cordierite, biotite and sapphirine, formed during nearly isothermal decompression after the high P-T assemblages involving garnet, orthopyroxene and sillimanite. Older ages around 750-1000 Ma are detected in monazite cores and in monazite inclusions in garnet porphyroblast. Combining the available age data and the reaction textures, it becomes evident that the Forefinger Point granulites have been overprinted by a granulite-facies decompressional event of Pan-African age. Moreover, EMP monazite dating imply that the Forefinger Point granulites have experienced at least two stages of metamorphic evolution.
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Copyright history has long been a subject of intense and contested enquiry. Historical narratives about the early development of copyright were first prominently mobilised in eighteenth century British legal discourse, during the so-called Battle of the Booksellers between Scottish and London publishers. The two landmark copyright decisions of that time – Millar v. Taylor (1769) and Donaldson v. Becket (1774) – continue to provoke debate today. The orthodox reading of Millar and Donaldson presents copyright as a natural proprietary right at common law inherent in authors. Revisionist accounts dispute that traditional analysis. These conflicting perspectives have, once again, become the subject of critical scrutiny with the publication of Copyright at Common Law in 1774 by Prof Tomas Gomez-Arostegui in 2014, in the Connecticut Law Review ((2014) 47 Conn. L. Rev. 1) and as a CREATe Working Paper (No. 2014/16, 3 November 2014).
Taking Prof Gomez-Arostegui’s extraordinary work in this area as a point of departure, Dr Elena Cooper and Professor Ronan Deazley (then both academics at CREATe) organised an event, held at the University of Glasgow on 26th and 27th March 2015, to consider the interplay between copyright history and contemporary copyright policy. Is Donaldson still relevant, and, if so, why? What justificatory goals are served by historical investigation, and what might be learned from the history of the history of copyright? Does the study of copyright history still have any currency within an evidence-based policy context that is increasingly preoccupied with economic impact analysis?
This paper provides a lasting record of these discussions, including an editorial introduction, written comments by each of the panelists and Prof. Gomez-Arostegui and an edited transcript of the Symposium debate.
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Copyright history has long been a subject of intense and contested enquiry, and has once again become the subject of critical scrutiny with the publication of "Copyright at Common Law in 1774" by Prof Tomas Gomez-Arostegui in the Connecticut Law Review ((2014) 47 Conn. L. Rev. 1).
This online resource documents two events organised to explore the impact of "Copyright at Common Law in 1774". It incorporates a public lecture by Prof Gomez-Arostegui, and the full record of a one-day symposium of international experts debating the implications of Gomez-Arostegui's scholarship in this domain.
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Analysis of seed exchange networks at a single point in time may reify sporadic relations into apparently fixed and long-lasting ones. In northern Cameroon, where environment is not only strongly seasonal but also shows unpredictable interannual variation, farmers’ social networks are flexible from year to year. When adjusting their strategies, Tupuri farmers do not systematically solicit the same partners to acquire the desired propagules. Seed acquisitions documented during a single cropping season may thus not accurately reflect the underlying larger social network that can be mobilized at the local level. To test this hypothesis, we documented, at the outset of two cropping seasons (2010 and 2011), the relationships through which seeds were acquired by the members of 16 households in a Tupuri community. In 2011, farmers faced sudden failure of the rains and had to solicit distant relatives, highlighting their ability to quickly trigger specific social relations to acquire necessary seeding material. Observing the same set of individuals during two successive years and the seed sources they solicited in each year enabled us to discriminate repeated relations from sporadic ones. Although farmers did not acquire seeds from the same individuals from one year to the next, they relied on quite similar relational categories of people. However, the worse weather conditions during the second year led to (1) a shift from red sorghum seeds to pearl millet seeds, (2) a geographical extension of the network, and (3) an increased participation of women in seed acquisitions. In critical situations, women mobilized their own kin almost exclusively. We suggest that studying the seed acquisition network over a single year provides a misrepresentation of the underlying social network. Depending on the difficulties farmers face, they may occasionally call on relationships that transcend the local relationships used each year.
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In recent papers, Wied and his coauthors have introduced change-point procedures to detect and estimate structural breaks in the correlation between time series. To prove the asymptotic distribution of the test statistic and stopping time as well as the change-point estimation rate, they use an extended functional Delta method and assume nearly constant expectations and variances of the time series. In this thesis, we allow asymptotically infinitely many structural breaks in the means and variances of the time series. For this setting, we present test statistics and stopping times which are used to determine whether or not the correlation between two time series is and stays constant, respectively. Additionally, we consider estimates for change-points in the correlations. The employed nonparametric statistics depend on the means and variances. These (nuisance) parameters are replaced by estimates in the course of this thesis. We avoid assuming a fixed form of these estimates but rather we use "blackbox" estimates, i.e. we derive results under assumptions that these estimates fulfill. These results are supplement with examples. This thesis is organized in seven sections. In Section 1, we motivate the issue and present the mathematical model. In Section 2, we consider a posteriori and sequential testing procedures, and investigate convergence rates for change-point estimation, always assuming that the means and the variances of the time series are known. In the following sections, the assumptions of known means and variances are relaxed. In Section 3, we present the assumptions for the mean and variance estimates that we will use for the mean in Section 4, for the variance in Section 5, and for both parameters in Section 6. Finally, in Section 7, a simulation study illustrates the finite sample behaviors of some testing procedures and estimates.
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Avec l’avènement des objets connectés, la bande passante nécessaire dépasse la capacité des interconnections électriques et interface sans fils dans les réseaux d’accès mais aussi dans les réseaux coeurs. Des systèmes photoniques haute capacité situés dans les réseaux d’accès utilisant la technologie radio sur fibre systèmes ont été proposés comme solution dans les réseaux sans fil de 5e générations. Afin de maximiser l’utilisation des ressources des serveurs et des ressources réseau, le cloud computing et des services de stockage sont en cours de déploiement. De cette manière, les ressources centralisées pourraient être diffusées de façon dynamique comme l’utilisateur final le souhaite. Chaque échange nécessitant une synchronisation entre le serveur et son infrastructure, une couche physique optique permet au cloud de supporter la virtualisation des réseaux et de les définir de façon logicielle. Les amplificateurs à semi-conducteurs réflectifs (RSOA) sont une technologie clé au niveau des ONU(unité de communications optiques) dans les réseaux d’accès passif (PON) à fibres. Nous examinons ici la possibilité d’utiliser un RSOA et la technologie radio sur fibre pour transporter des signaux sans fil ainsi qu’un signal numérique sur un PON. La radio sur fibres peut être facilement réalisée grâce à l’insensibilité a la longueur d’onde du RSOA. Le choix de la longueur d’onde pour la couche physique est cependant choisi dans les couches 2/3 du modèle OSI. Les interactions entre la couche physique et la commutation de réseaux peuvent être faites par l’ajout d’un contrôleur SDN pour inclure des gestionnaires de couches optiques. La virtualisation réseau pourrait ainsi bénéficier d’une couche optique flexible grâce des ressources réseau dynamique et adaptée. Dans ce mémoire, nous étudions un système disposant d’une couche physique optique basé sur un RSOA. Celle-ci nous permet de façon simultanée un envoi de signaux sans fil et le transport de signaux numérique au format modulation tout ou rien (OOK) dans un système WDM(multiplexage en longueur d’onde)-PON. Le RSOA a été caractérisé pour montrer sa capacité à gérer une plage dynamique élevée du signal sans fil analogique. Ensuite, les signaux RF et IF du système de fibres sont comparés avec ses avantages et ses inconvénients. Finalement, nous réalisons de façon expérimentale une liaison point à point WDM utilisant la transmission en duplex intégral d’un signal wifi analogique ainsi qu’un signal descendant au format OOK. En introduisant deux mélangeurs RF dans la liaison montante, nous avons résolu le problème d’incompatibilité avec le système sans fil basé sur le TDD (multiplexage en temps duplexé).
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Discovering ‘photo-excess’: what difference does digital photography bring to the archaeological process, and does this difference constitute a paradigm shift from the traditional film model? Using reflexive practice, the contribution that digital photography has made to the archaeological process is explored. The themes presented in the photographs and exegesis combine visual exploration and original research to examine the role and place of archaeological photography in both a contemporary and an historical context. In contrasting the development of film-based photography of archaeology undertaken in the Eastern Mediterranean during the early 1900s with contemporary digital photography, this exegesis and creative work explores both the synergies and differences of the two photographic methods in archaeology. I introduce the term ‘photo-excess’ to describe the new role that digital photography plays in archaeological practice as compared to film, and demonstrate this difference through my creative work. At the turn of the 20th century, photography was affirmed as the major instrument for visual recording of an archaeological excavation. The combination of archaeological methods and photographic techniques from that era formed an approach to archaeological documentation and recording that was formalised by William Matthews Flinders Petrie in 1904. In this thesis I propose that Petrie became the father of modern archaeological photography through his work, and in recognition of his contribution I refer to his method as the ‘Petrie Paradigm’. Digital photography has made possible a quantum leap in the volume, quality and immediacy of visual data available to the user. Further, through the creative process, digital archaeological photography may provide visual information that exceeds the archaeologist’s original research questions, so that the digital image may sometimes exceed its primary role as a recording device. In such cases it may become the starting point for new research due to its potential photo-excess. I propose this as an emerging paradigm for archaeological photography.
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This dissertation examines the principles of education imbued in a three year correspondence between an eighteenth century woman and her teenage son from the French speaking region of Vaud, current day Switzerland. Despite her great respect for the literature and ideas of the new pedagogues of the Enlightenment, especially J.J. Rousseau and Mme de Genlis, Catherine de Charrière de Sévery maintained the traditional perspective of education of the Ancien Régime. To explore the concepts of education and instruction through the epistolary practice, this research is based on the corpus of 107 letters that Mme de Sévery wrote to her son Vilhelm between 1780 and 1783. Additional documents - among them Mme de Sévery’s diaries - from the particularly rich archival holdings of this aristocratic family have been used to complement her correspondence. Most previous studies on family correspondence have dealt with mothers to daughters, or fathers to sons, whereas this research is centered on letters between a mother and her son. The location of this family – Lausanne and the Pays de Vaud – provides a particular regional perspective due to two factors: immersion into a region uniformly Protestant, and the dual-influence of Germanic and French cultures. The study analyzes the educational principles that appear throughout Mme de Sévery’s letters by comparison with three literary works of the 18th century: a familiar correspondence, the Lettres du Lord Chesterfield à son fils (1776); the fundamental education treatise by J.J. Rousseau, Émile, ou de l’Éducation (1762); and a pedagogical treatise written by Mme de Genlis as an epistolary novel, Adèle et Théodore, ou lettres sur l’éducation. Using letters as the main tool to guide her son’s upbringing, Mme de Sévery highlights the moral and family values that are most important to her and leads him to find his place in society.
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In this paper we consider instabilities of localised solutions in planar neural field firing rate models of Wilson-Cowan or Amari type. Importantly we show that angular perturbations can destabilise spatially localised solutions. For a scalar model with Heaviside firing rate function we calculate symmetric one-bump and ring solutions explicitly and use an Evans function approach to predict the point of instability and the shapes of the dominant growing modes. Our predictions are shown to be in excellent agreement with direct numerical simulations. Moreover, beyond the instability our simulations demonstrate the emergence of multi-bump and labyrinthine patterns. With the addition of spike-frequency adaptation, numerical simulations of the resulting vector model show that it is possible for structures without rotational symmetry, and in particular multi-bumps, to undergo an instability to a rotating wave. We use a general argument, valid for smooth firing rate functions, to establish the conditions necessary to generate such a rotational instability. Numerical continuation of the rotating wave is used to quantify the emergent angular velocity as a bifurcation parameter is varied. Wave stability is found via the numerical evaluation of an associated eigenvalue problem.
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The Stagecoach Ride at Cedar Point featured simulated attacks by desperadoes. The ride existed for only two season, closing in 1968. The Cedar Point and Lake Erie Railroad, which opened in 1963, is the most popular ride in the history of Cedar Point. It features authentic steam-powered, coal-driven burning locomotives. It celebrated its 50th anniversary in 2013.
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We investigate numerically the nonlinear interactions between hetons. Hetons are baroclinic structures consisting of two vortices of opposite sign lying at different depths. Hetons are long-lived. They most often translate (they can sometimes rotate) and therefore they can noticeably contribute to the transport of scalar properties in the oceans. Heton interactions can interrupt this translation and thus this transport, by inducing a reconfiguration of interacting hetons into more complex baroclinic multipoles. More specifically, we study here the general case of two hetons, which collide with an offset between their translation axes. For this purpose, we use the point vortex theory, the ellipsoidal vortex model and direct simulations in the three-dimensional quasi-geostrophic contour surgery model. More specifically, this paper shows that there are in general three regimes for the interaction. For small horizontal offsets between the hetons, their vortices recombine as same-depth dipoles which escape at an angle. The angle depends in particular on the horizontal offset. It is a right angle for no offset, and the angle is shallower for small but finite offsets. The second limiting regime is for large horizontal offsets where the two hetons remain the same hetonic structures but are deflected by the weaker mutual interaction. Finally, the intermediate regime is for moderate offsets. This is the regime where the formation of a metastable quadrupole is possible. The formation of this quadrupole greatly restrains transport. Indeed, it constrains the vortices to reside in a closed area. It is shown that the formation of such structures is enhanced by the quasi-periodic deformation of the vortices. Indeed, these structures are nearly unobtainable for singular vortices (point vortices) but may be obtained using deformable, finite-core vortices.