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A Model of Positive Sequential Dependencies in Judgments of FrequencyAnnis, Jeffrey Scott 01 January 2013 (has links)
Positive sequential dependencies occur when the response on the current trial n is positively correlated with the response on trial n-1. This was recently observed in a Judgment of Frequency (JOF) task (Malmberg and Annis, 2011). A model of positive sequential dependencies was developed in the REM framework (Shiffrin & Steyvers, 1997) by assuming that features that represent the current test item in a retrieval cue carry over from the previous retrieval cue. To assess the model, we sought a set of data that allows us to distinguish between frequency similarity and item similarity. Therefore, we chose to use a JOF task in which we manipulated the item similarity of the stimuli by presenting either landscape photos (high similarity), or photos of everyday objects such as shoes, cars, etc (low similarity). Similarity was modeled by assuming either that the item representations share a proportion of features or by assuming that the exemplars from different stimulus classes vary in the distinctiveness or diagnosticity. The model fits indicated that the best way to model similarity was to assume that items share a proportions of features.
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Analysis of quasiconformal maps in RnPurcell, Andrew 01 June 2006 (has links)
In this thesis, we examine quasiconformal mappings in Rn. We begin by proving basic properties of the modulus of curve families. We then give the geometric, analytic,and metric space definitions of quasiconformal maps and show their equivalence. We conclude with several computational examples.
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Absolute Measurements of Large MirrorsSu, Peng January 2008 (has links)
The ability to produce mirrors for large astronomical telescopes is limited by the accuracy of the systems used to test the surfaces of such mirrors. Typically the mirror surfaces are measured by comparing their actual shapes to a precision master, which may be created using combinations of mirrors, lenses, and holograms. The work presented here develops several optical testing techniques that do not rely on a large or expensive precision, master reference surface. In a sense these techniques provide absolute optical testing.The Giant Magellan Telescope (GMT) has been designed with a 350 m2 collecting area provided by a 25 m diameter primary mirror made out from seven circular independent mirror segments. These segments create an equivalent f/0.7 paraboloidal primary mirror consisting of a central segment and six outer segments. Each of the outer segments is 8.4 m in diameter and has an off-axis aspheric shape departing 14.5 mm from the best-fitting sphere. Much of the work in this dissertation is motivated by the need to measure the surfaces or such large mirrors accurately, without relying on a large or expensive precision reference surface.One method for absolute testing describing in this dissertation uses multiple measurements relative to a reference surface that is located in different positions with respect to the test surface of interest. The test measurements are performed with an algorithm that is based on the maximum likelihood (ML) method. Some methodologies for measuring large flat surfaces in the 2 m diameter range and for measuring the GMT primary mirror segments were specifically developed. For example, the optical figure of a 1.6-m flat mirror was determined to 2 nm rms accuracy using multiple 1-meter sub-aperture measurements. The optical figure of the reference surface used in the 1-meter sub-aperture measurements was also determined to the 2 nm level. The optical test methodology for a 1.7-m off axis parabola was evaluated by moving several times the mirror under test in relation to the test system. The result was a separation of errors in the optical test system to those errors from the mirror under test. This method proved to be accurate to 12nm rms.Another absolute measurement technique discussed in this dissertation utilizes the property of a paraboloidal surface of reflecting rays parallel to its optical axis, to its focal point. We have developed a scanning pentaprism technique that exploits this geometry to measure off-axis paraboloidal mirrors such as the GMT segments. This technique was demonstrated on a 1.7 m diameter prototype and proved to have a precision of about 50 nm rms.
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MIDAS Predicting Volatility at Different FrequenciesShi, Wensi January 2010 (has links)
I compared various MIDAS (mixed data sampling) regression models to predict volatility from one week to one month with different regressors based on the records of Chinese Shanghai composite index. The main regressors are in 2 types, one is the realized power (involving 5-min absolute returns), the other is the quadratic variation, computed by squared returns. And realized power performs best at all the forecast horizons. I also compare the effect of lag numbers in regression, form 1 to 200, and it doesn’t change much after 50. In 3 week and month predict horizons, the fitness result with different lag numbers has a waving type among all the regressors, that implies there exists a seasonal effect which is the same as predict horizons in the lagged variables. At last,the out-of -sample and in-sample result of RV and RAV are quite similar, but in sometimes, out-of sample performs better.
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Stereochemistry of Challenging Natural Products Studied by NMR-based MethodsSun, Han 23 November 2012 (has links)
No description available.
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Geological and Geochemical Studies of the Roskruge Range, Pima County, ArizonaBikerman, Michael January 1965 (has links)
A combined field and laboratory investigation of the primarily volcanic Roskruge range, Pima County, Arizona, produced the following results: The rocks in the area fall into three major and several minor divisions. The major groups are: (1) The pre-Laramide dark-colored andesites and sediments that floor the range. A K-Ar date on one of the andesites produced a number, 108 m. y. , on a whole rock analysis. (2) The brightly colored and widespread Laramide volcanics and an associated hypabyssal pluton at Cocoraque Butte, which gave K-Ar mineral ages in the 74 m. y. to 66 m. y. spread. (3) The mid-Tertiary potassic basaltic andesites found on an eroded plain that is cut into the Laramide volcanics. These dark-colored extrusives were dated at 23 m. y. by whole rock K-Ar. Amongst the minor units in distribution is the petrographically unusual Recortado ash flow, a small 13 m. ye old unit that preserves a vitrophyre just above its base. Also included in the miscellaneous group of units are the post-orogenic true basalts, which appear as dikes and as a flow(?) at Brawley Wash and which gave whole rock K-Ar dates of about 10 m. y. Initial strontium 87/86 ratios indicate that the Laramide and mid-Tertiary rocks (including the Recortado ash flow) have values ranging from . 7056 to .7092, while the Brawley Wash basalt has a true deep-seated basalt ratio of .7038. The combination of radiochemical assay, petrographic and field study, and isotopic data has established good gross correlation with the already known sequence of formations and plutons in the Tucson Mountains.
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Dissiplinêre verhore : 'n reg op regsverteenwoordiging vir werknemers / deur Lezanne AppelgrynAppelgryn, Lezanne January 2005 (has links)
An employee is usually entitled to representation in a disciplinary hearing.
The question arises whether this representation includes legal representation
or whether it is limited to representation by union representatives or a fellow
employee? An employee's right to legal representation will in most cases be
determined by a collective agreement, the employment contract or a
disciplinary code.
Over the years the Courts have indicated that they are not prepared to grant
an absolute right to legal representation in disciplinary enquiries. Yet in some
cases the courts found legal representation to be a sine qua non for a fair
hearing and an intrinsic part of natural justice. It seems that the conclusion
that can be drawn from this research is that legal representation might soon
become a requirement for a fair disciplinary hearing in serious and complex
matters.
This research looks at numerous decisions both in die public and private
sector before and after 1994. The right to legal representation is also
discussed in the light of a fair hearing. The various advantages and
disadvantages of legal representation are briefly examined. It is argued that
all employees should be granted legal representation in complex and serious
matters where the employee is likely to be dismissed. It is thus said that all
presiding officers should be granted a discretion to allow legal representation
in serious and complex matters. / Thesis (LL.M. (Labour Law))--North-West University, Potchefstroom Campus, 2006.
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Studies of the rotating-disk boundary-layer flowImayama, Shintaro January 2014 (has links)
The rotating-disk boundary layer is not only a simpler model for the study of cross-flow instability than swept-wing boundary layers but also a useful simplification of many industrial-flow applications where rotating configurations are present. For the rotating disk, it has been suggested that a local absolute instability, leading to a global instability, is responsible for the small variation in the observed laminar-turbulent transition Reynolds number however the exact nature of the transition is still not fully understood. This thesis aims to clarify certain aspects of the transition process. Furthermore, the thesis considers the turbulent rotating-disk boundary layer, as an example of a class of three-dimensional turbulent boundary-layer flows. The rotating-disk boundary layer has been investigated in an experimental apparatus designed for low vibration levels and with a polished glass disk that gave a smooth surface. The apparatus provided a low-disturbance environment and velocity measurements of the azimuthal component were made with a single hot-wire probe. A new way to present data in the form of a probability density function (PDF) map of the azimuthal fluctuation velocity, which gives clear insights into the laminar-turbulent transition region, has been proposed. Measurements performed with various disk-edge conditions and edge Reynolds numbers showed that neither of these conditions a↵ect the transition process significantly, and the Reynolds number for the onset of transition was observed to be highly reproducible. Laminar-turbulent transition for a ‘clean’ disk was compared with that for a disk with roughness elements located upstream of the critical Reynolds number for absolute instability. This showed that, even with minute surface roughness elements, strong convectively unstable stationary disturbances were excited. In this case, breakdown of the flow occurred before reaching the absolutely unstable region, i.e. through a convectively unstable route. For the rough disk, the breakdown location was shown to depend on the amplitude of individual stationary vortices. In contrast, for the smooth (clean-disk) condition, the amplitude of the stationary vortices did not fix the breakdown location, which instead was fixed by a well-defined Reynolds number. Furthermore, for the clean-disk case, travelling disturbances have been observed at the onset of nonlinearity, and the associated disturbance profile is in good agreement with the eigenfunction of the critical absolute instability. Finally, the turbulent boundary layer on the rotating disk has been investigated. The azimuthal friction velocity was directly measured from the azimuthal velocity profile in the viscous sublayer and the velocity statistics, normalized by the inner scale, are presented. The characteristics of this three-dimensional turbulent boundary-layer flow have been compared with those for the two-dimensional flow over a flat plate and close to the wall they are found to be quite similar but with rather large differences in the outer region. / <p>QC 20150119</p>
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Agnostic democracy : the decentred "I" of the 1990sKang, Kathryn Muriel January 2005 (has links)
The thesis concerns the dynamics during the 1990s of political action by many groups of people, in what came to be called the movement of movements. The activists, who held that corporations were overstepping some mark, worked on alternative arrangements for self-rule. The thesis views the movement as micropolitics, using concepts devised by Deleuze and Guattari. It sets out particulars of the rhizomic make -up of the movement. A key point is that the movement trains participants in decentred organisation, which entails the forming of subject-groups as opposed to subjugated groups. The thesis records how the movement was shaped by earlier events in political action and thinking, especially from the 1960s on. The movement had previously been read as a push for absolute democracy (Hardt and Negri). The thesis shows that reading to have been incomplete: the movement is, in part, a push for agonistic democracy. More a practice than a form of rule, agonistic democracy is found where state power is bent on not moulding peoples into any unified polity. It is found where state power fosters conflicted-self-rule, so that every citizen may engage in the polity as a decentred "I". The thesis throws light on relations between the movement and the constitutionalist state. Part of the movement, while cynical about the existing form of state rule, wears a mask of obedience to constituted authority. When one upholds the fiction of legitimate rule, one can use the fiction as a restraint on the cynics-in-power. The play creates a shadow social contract, producing detente within the polity and within the �I.� The thesis also reports on a search in mainstream cinema for some expression of the movement's dynamics. The search leads to a cycle of thrillers, set in a nonfiction frame story about a coverup of gross abuse of state power.
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Straffe zweidimensionale Untermannigfaltigkeiten kompakter euklidischer RaumformenOtto, Marc-Oliver, January 2003 (has links) (PDF)
Stuttgart, Univ., Diss., 2003.
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