965 resultados para Scale of evaluation


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We analyse the global structure of the phase space of the planar planetary 2/1 mean-motion resonance in cases where the outer planet is more massive than its inner companion. Inside the resonant domain, we show the existence of two families of periodic orbits, one associated to the librational motion of resonant angle (sigma-family) and the other related to the circulatory motion of the difference in longitudes of pericentre (Delta pi-family). The well-known apsidal corotation resonances (ACR) appear as intersections between both families. A complex web of secondary resonances is also detected for low eccentricities, whose strengths and positions are dependent on the individual masses and spatial scale of the system. The construction of dynamical maps for various values of the total angular momentum shows the evolution of the families of stable motion with the eccentricities, identifying possible configurations suitable for exoplanetary systems. For low-moderate eccentricities, several different stable modes exist outside the ACR. For larger eccentricities, however, all stable solutions are associated to oscillations around the stationary solutions. Finally, we present a possible link between these stable families and the process of resonance capture, identifying the most probable routes from the secular region to the resonant domain, and discussing how the final resonant configuration may be affected by the extension of the chaotic layer around the resonance region.

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We investigate the depositional time scale of lithological couplets (fine sandstone/siltstone-siltstone/mudstone) from two distinctive outcrops of Permo-Carboniferous glacial rhythmites in the Itarare Group (Parana Basin, Brazil). Resolving the fundamental issue of time scale for these rhythmites is important in light of recent evidence for paleosecular variation measured in these sequences. Spectral analysis and tuning of high-resolution gray scale scans of sediment core microstratigraphy, which comprises pervasive laminations, reveal a comparable spectral content at both localities, with a frequency suite interpreted as that of short-term climate variability of Recent and modern times. This evidence for decadal- to centennial-scale deposition of these lithological couplets is discussed in light of the `varvic` character, i.e., annual time scale that was previously assumed for the rhythmites.

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Colour-magnitude diagrams (CMDs) of the Small Magellanic Cloud (SMC) star cluster NGC 419, derived from Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) data, reveal a well-delineated secondary clump located below the classical compact red clump typical of intermediate-age populations. We demonstrate that this feature belongs to the cluster itself, rather than to the underlying SMC field. Then, we use synthetic CMDs to show that it corresponds very well to the secondary clump predicted to appear as a result of He-ignition in stars just massive enough to avoid e(-)-degeneracy settling in their H-exhausted cores. The main red clump instead is made of the slightly less massive stars which passed through e(-) degeneracy and ignited He at the tip of the red giant branch. In other words, NGC 419 is the rare snapshot of a cluster while undergoing the fast transition from classical to degenerate H-exhausted cores. At this particular moment of a cluster`s life, the colour distance between the main-sequence turn-off and the red clump(s) depends sensitively on the amount of convective core overshooting, Lambda(c). By coupling measurements of this colour separation with fits to the red clump morphology, we are able to estimate simultaneously the cluster mean age (1.35(-0.04)(+0.11) Gyr) and overshooting efficiency (Lambda(c) = 0.47(-0.04)(+0.14)). Therefore, clusters like NGC 419 may constitute important marks in the age scale of intermediate-age populations. After eye inspection of other CMDs derived from HST/ACS data, we suggest that the same secondary clump may also be present in the Large Magellanic Cloud clusters NGC 1751, 1783, 1806, 1846, 1852 and 1917.

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Social organization is an important component of the population biology of a species that influences gene flow, the spatial pattern and scale of movements, and the effects of predation or exploitation by humans. An important element of social structure in mammals is group fidelity, which can be quantified through association indices. To describe the social organization of marine tucuxi dolphins (Sotalia guianensis) found in the Cananeia estuary, southeastern Brazil, association indices were applied to photo-identification data to characterize the temporal stability of relationships among members of this population. Eighty-seven days of fieldwork were conducted from May 2000 to July 2003, resulting in direct observations of 374 distinct groups. A total of 138 dolphins were identified on 1-38 distinct field days. Lone dolphins were rarely seen, whereas groups were composed of up to 60 individuals (mean +/- 1 SD = 12.4 +/- 11.4 individuals per group). A total of 29,327 photographs were analyzed, of which 6,312 (21.5%) were considered useful for identifying individuals. Half-weight and simple ratio indices were used to investigate associations among S. guianensis as revealed by the entire data set, data from the core study site, and data from groups composed of <= 10 individuals. Monte Carlo methods indicated that only 3 (9.3%) of 32 association matrices differed significantly from expectations based on random association. Thus, our study suggests that stable associations are not characteristic of S. guianensis in the Cananeia estuary.

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Data collected by the Pierre Auger Observatory provide evidence for anisotropy in the arrival directions of the cosmic rays with the highest-energies, which are correlated with the positions of relatively nearby active galactic nuclei (AGN) [Pierre Auger Collaboration, Science 318 (2007) 938]. The correlation has maximum significance for cosmic rays with energy greater than similar to 6 x 10(19) eV and AGN at a distance less than similar to 75 Mpc. We have confirmed the anisotropy at a confidence level of more than 99% through a test with parameters specified a priori, using an independent data set. The observed correlation is compatible with the hypothesis that cosmic rays with the highest-energies originate from extra-galactic sources close enough so that their flux is not significantly attenuated by interaction with the cosmic background radiation (the Greisen-Zatsepin-Kuz`min effect). The angular scale of the correlation observed is a few degrees, which suggests a predominantly light composition unless the magnetic fields are very weak outside the thin disk of our galaxy. Our present data do not identify AGN as the sources of cosmic rays unambiguously, and other candidate sources which are distributed as nearby AGN are not ruled out. We discuss the prospect of unequivocal identification of individual sources of the highest-energy cosmic rays within a few years of continued operation of the Pierre Auger Observatory. (C) 2008 Elsevier B.V. All rights reserved.

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Estimating the sizes of hard-to-count populations is a challenging and important problem that occurs frequently in social science, public health, and public policy. This problem is particularly pressing in HIV/AIDS research because estimates of the sizes of the most at-risk populations-illicit drug users, men who have sex with men, and sex workers-are needed for designing, evaluating, and funding programs to curb the spread of the disease. A promising new approach in this area is the network scale-up method, which uses information about the personal networks of respondents to make population size estimates. However, if the target population has low social visibility, as is likely to be the case in HIV/AIDS research, scale-up estimates will be too low. In this paper we develop a game-like activity that we call the game of contacts in order to estimate the social visibility of groups, and report results from a study of heavy drug users in Curitiba, Brazil (n = 294). The game produced estimates of social visibility that were consistent with qualitative expectations but of surprising magnitude. Further, a number of checks suggest that the data are high-quality. While motivated by the specific problem of population size estimation, our method could be used by researchers more broadly and adds to long-standing efforts to combine the richness of social network analysis with the power and scale of sample surveys. (C) 2010 Elsevier B.V. All rights reserved.

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Surface roughness is an important geomorphological variable which has been used in the Earth and planetary sciences to infer material properties, current/past processes, and the time elapsed since formation. No single definition exists; however, within the context of geomorphometry, we use surface roughness as an expression of the variability of a topographic surface at a given scale, where the scale of analysis is determined by the size of the landforms or geomorphic features of interest. Six techniques for the calculation of surface roughness were selected for an assessment of the parameter`s behavior at different spatial scales and data-set resolutions. Area ratio operated independently of scale, providing consistent results across spatial resolutions. Vector dispersion produced results with increasing roughness and homogenization of terrain at coarser resolutions and larger window sizes. Standard deviation of residual topography highlighted local features and did not detect regional relief. Standard deviation of elevation correctly identified breaks of slope and was good at detecting regional relief. Standard deviation of slope (SD(slope)) also correctly identified smooth sloping areas and breaks of slope, providing the best results for geomorphological analysis. Standard deviation of profile curvature identified the breaks of slope, although not as strongly as SD(slope), and it is sensitive to noise and spurious data. In general, SD(slope) offered good performance at a variety of scales, while the simplicity of calculation is perhaps its single greatest benefit.

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We have employed UV-vis spectroscopy in order to investigate details of the solvation of six solvatochromic indicators, hereafter designated as ""probes"", namely, 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl) phenolate (RB); 4-[(E)-2-(1-methylpyridinium-4-yl)ethenyl] phenolate, MePM; 1-methylquinolinium-8-olate, QB; 2-bromo-4-[(E)-2-(1-methylpyridinium-4-yl)ethenyl] phenolate, MePMBr, 2,6-dichloro-4-(2,4,6-triphenylpyridinium-1-yl) phenolate (WB); and 2,6-dibromo-4-[(E)-2-(1-methylpyridinium-4-yl)ethenyl] phenolate, MePMBr,, respectively. These can be divided into three pairs, each includes two probes of similar pK(a) in water and different lipophilicity. Solvation has been studied in binary mixtures, BMs, of water, W, with 12 protic organic solvents, S, including mono- and bifunctional alcohols (2-alkoxyethanoles, unsaturated and chlorinated alcohols). Each medium was treated as a mixture of S, W, and a complex solvent, S-W, formed by hydrogen bonding. Values of lambda(max) (of the probe intramolecular charge transfer) were converted into empirical polarity scales, E(T)(probe) in kcal/mol, whose values were correlated with the effective mole fraction of water in the medium, chi w(effective). This correlation furnished three equilibrium constants for the exchange of solvents in the probe solvation shell; phi(W/S) (W substitutes S): phi(S-W/W) (S-W substitutes W), and phi(S-W/S) (S-W substitutes S), respectively. The values of these constants depend on the physicochemical properties of the probe and the medium. We tested, for the first time, the applicability of a new solvation free energy relationship: phi = constant + a alpha(BM) + b beta(BM) + s(pi*(BM) + d delta) + p log P(BM), where a, b, s, and p are regression coefficients alpha(BM), beta(BM), and pi*(BM) are solvatochromic parameters of the BM, delta is a correction term for pi*, and log P is an empirical scale of lipophilicity. Correlations were carried out with two-, three-, and four-medium descriptors. In all cases, three descriptors gave satisfactory correlations; use of four parameters gave only a marginal increase of the goodness of fit. For phi(W/S), the most important descriptor was found to be the lipophilicity of the medium; for phi(S-W/W) and phi(S-W/S), solvent basicity is either statistically relevant or is the most important descriptor. These responses are different from those of E(T)(probe) of many solvatochromic indicators in pure solvents, where the importance of solvent basicity is usually marginal, and can be neglected.

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The presence of paramagnetic species in the aqueous ring opening metathesis polymerizations of the exo,exo-7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid monomer with RuCl(3) and K(2)[RuCl(5)H(2)O] compounds was studied using ESR techniques. It was observed that the intensities of the Ru(III) signals in the ESR spectra decrease on the time scale of the induction period so that the ROMP can take place. The intensity of the Ru(III) signal almost disappeared 50 min after reacting with K(2)[RuCl(5)H(2)O] and after 100 mm in the case of RuCl(3). Reactions of the cis-[Ru(NH(3))(4)(H(2)O)(2)](tfms)(3) and [Ru(NH(3))(5)H(2)O](tfms)(3) complexes with the monomer and different organic compounds representing the organic functions in the monomer (furan, norbornene, but-2-ene-1,4-diol and formic, acetic, oxalic and maleic acids) were also monitored by ESR and UV/vis spectra. It was deduced that the organic acids provide the disappearance of the Ru(III) signal. The proton NMR relaxation times of the residual water in D(2)O for reactions with oxalic acid suggested that the presence of paramagnetic ions in the solution decreases along with

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This thesis presents an adaptive tuning system that can be described as a dynamic Just Intonation tuning system, being compatible with equally tempered instruments. The tuning system is called Hermode Tuning (HMT) and the tuning used as comparison for evaluation is the standardized western tuning, the equal tempered tuning. This study investigates preferences for these two musical tuning systems, depending on whether the tunings are presented on a piano or with woodwind instruments. A listening test was done with students at the Falun Conservatory of Music, including both a vertical listening (intervalls) and a horizontal listening (cadenses and musical compositions) of Hermode tuned musical material. Overall the results showed no significant preferences for either tuning system irrespectively of what instrument it was presented with. The clearest results was that of a misjudged just intonated perfect third on the piano and a preference for an adaptively tuned piano presented in a simple harmonic structure, with a parameter setting of HMT 70%. Materials for comparison was partly taken from Hermode´s own website, but overall the attitude towards these sequenses (using a likert scale of one to five) showed a low expected value. This shows the complexity of the topic and no general conclusions regarding the choice of intonation or tuning system could be done for the presented material.

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Parkinson’s disease (PD) is an increasing neurological disorder in an aging society. The motor and non-motor symptoms of PD advance with the disease progression and occur in varying frequency and duration. In order to affirm the full extent of a patient’s condition, repeated assessments are necessary to adjust medical prescription. In clinical studies, symptoms are assessed using the unified Parkinson’s disease rating scale (UPDRS). On one hand, the subjective rating using UPDRS relies on clinical expertise. On the other hand, it requires the physical presence of patients in clinics which implies high logistical costs. Another limitation of clinical assessment is that the observation in hospital may not accurately represent a patient’s situation at home. For such reasons, the practical frequency of tracking PD symptoms may under-represent the true time scale of PD fluctuations and may result in an overall inaccurate assessment. Current technologies for at-home PD treatment are based on data-driven approaches for which the interpretation and reproduction of results are problematic.  The overall objective of this thesis is to develop and evaluate unobtrusive computer methods for enabling remote monitoring of patients with PD. It investigates first-principle data-driven model based novel signal and image processing techniques for extraction of clinically useful information from audio recordings of speech (in texts read aloud) and video recordings of gait and finger-tapping motor examinations. The aim is to map between PD symptoms severities estimated using novel computer methods and the clinical ratings based on UPDRS part-III (motor examination). A web-based test battery system consisting of self-assessment of symptoms and motor function tests was previously constructed for a touch screen mobile device. A comprehensive speech framework has been developed for this device to analyze text-dependent running speech by: (1) extracting novel signal features that are able to represent PD deficits in each individual component of the speech system, (2) mapping between clinical ratings and feature estimates of speech symptom severity, and (3) classifying between UPDRS part-III severity levels using speech features and statistical machine learning tools. A novel speech processing method called cepstral separation difference showed stronger ability to classify between speech symptom severities as compared to existing features of PD speech. In the case of finger tapping, the recorded videos of rapid finger tapping examination were processed using a novel computer-vision (CV) algorithm that extracts symptom information from video-based tapping signals using motion analysis of the index-finger which incorporates a face detection module for signal calibration. This algorithm was able to discriminate between UPDRS part III severity levels of finger tapping with high classification rates. Further analysis was performed on novel CV based gait features constructed using a standard human model to discriminate between a healthy gait and a Parkinsonian gait. The findings of this study suggest that the symptom severity levels in PD can be discriminated with high accuracies by involving a combination of first-principle (features) and data-driven (classification) approaches. The processing of audio and video recordings on one hand allows remote monitoring of speech, gait and finger-tapping examinations by the clinical staff. On the other hand, the first-principles approach eases the understanding of symptom estimates for clinicians. We have demonstrated that the selected features of speech, gait and finger tapping were able to discriminate between symptom severity levels, as well as, between healthy controls and PD patients with high classification rates. The findings support suitability of these methods to be used as decision support tools in the context of PD assessment.

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This thesis contributes to the heuristic optimization of the p-median problem and Swedish population redistribution.   The p-median model is the most representative model in the location analysis. When facilities are located to a population geographically distributed in Q demand points, the p-median model systematically considers all the demand points such that each demand point will have an effect on the decision of the location. However, a series of questions arise. How do we measure the distances? Does the number of facilities to be located have a strong impact on the result? What scale of the network is suitable? How good is our solution? We have scrutinized a lot of issues like those. The reason why we are interested in those questions is that there are a lot of uncertainties in the solutions. We cannot guarantee our solution is good enough for making decisions. The technique of heuristic optimization is formulated in the thesis.   Swedish population redistribution is examined by a spatio-temporal covariance model. A descriptive analysis is not always enough to describe the moving effects from the neighbouring population. A correlation or a covariance analysis is more explicit to show the tendencies. Similarly, the optimization technique of the parameter estimation is required and is executed in the frame of statistical modeling. 

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The impact of deregulation on dispersion of earnings in Victoria has been
acknowledged in the findings of the recent task force enquiry into industrial relations in Victoria. This paper argues that the link between hours worked and rates of pay has played a significant role in this increased dispersion. Drawing upon detailed analysis of hours and wages in Victorian agreements, data is presented on declining take-home pay flowing from the loss of penalty rates. This, we argue, is attributable to
the lack of substantive and procedural protections available to Victorian workers under schedule 1A of the Workplace Relations Act, and formerly under the Victorian Employee Relations Act, 1992. We contrast these findings with collective agreements trading off penalty rates certified by the Australian Industrial Relations Commission, and Australian Workplace Agreements approved by the Office of the Employment
Advocate. We conclude by suggesting there is a scale of fair outcomes attached to the wages/hours trade-off, directly attributable to the various institutional mechanisms now influencing Australian wage determination.

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A major issue confronting educators is the extent to which they wish to conform to so-called paradigm shifts in teaching and learning. In the contemporary world of tertiary education these shifts embrace both pedagogy (from instructivist to constructivist) and technology (from classroom to online). As teachers and learners are faced with the potential of these new learning environments, the extent to which learning outcomes are achieved remains a high priority and subject to a wide range of evaluation strategies. Conventionally, evaluation has been positioned at the end of the instructional development cycle, to assess first whether or not the creative effort achieved the original product goals and second whether or not the desired learning outcomes were realized. In the context of online teaching and learning environments, however, the level of understanding teachers, learners and developers have of the medium can impact the ultimate effectiveness of the product. This paper articulates an additional dimension to post-development evaluation processes in proposing proactive evaluation, a framework that identifies critical online learning factors and influences that will better inform the planning, design and development of learning resources. This notion of proactive evaluation advocates resource development being undertaken where all planning activities are assessed against the evaluation criteria that would normally be applied during formative assessment. By performing these evaluation checks proactively, online learning resources will, in principle, work first time as all relevant factors and issues will have been considered and resolved. More importantly, for those participants who are new to online environments, proactive evaluation will perform a scaffolding and professional development role by enhancing online teaching or learning competencies.

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Postnatal depression is a major health issue for childbearing women world-wide, as it is not always identified early. This study aimed to evaluate the clinical application of three screening instruments for the early recognition of post-partum depression, the Postpartum Depression Prediction Inventory, the Postpartum Depression Screening Scale and the Edinburgh Postnatal Depression Scale, and to examine nurse interventions following use of the instruments. Data were collected at two points, at 28 weeks prenatal (107 women) and eight weeks postnatal (84 women). Results showed that 17% of the women scored significant symptoms of post-partum depression and 10–15% had a positive screen for major postnatal depression. There was a statistically significant correlation between the total score on the Postpartum Depression Screening Scale and the Edinburgh Postnatal Depression Scale. Of those eight women identified as being at risk, seven had received anticipatory guidance and five had received counselling by the nurses. The Postpartum Depression Prediction Inventory enabled nurses to identify women at risk of post-partum depression and offer interventions.