All current theories of spoken word recognition (e.g., Allopenna et al., 1998; McClelland & Elman, 1986; Norris, 1994) suggest that any part of a target word triggers activation of candidate words. Visual world paradigm studies have relied on the linking hypothesis that the probability of looking at the referent of a word directly tracks the word’s level of activation (e.g., Allopenna et al., 1998). However, how much information is needed to trigger a saccade to a visual representation of the word’s referent? To address this question, the present study manipulated the number and location of shared segments between the target and competitor words. Experimental evidence is provided by two visual world paradigm experiments on Japanese, using natural and synthesized speech. In both experiments, cohort competitor pictures were not fixated more than unrelated distractor pictures unless the cohort competitor shares the initial CVC with the target. Bayesian analyses provide strong support for the null hypothesis that shorter overlap does not affect eye movements. The results suggest that a listener needs to accumulate enough evidence for a word before a saccade is generated. The human data were validated by an interactive computational model (TRACE: McClelland & Elman, 1986). The model was adapted to Japanese language to examine whether the TRACE model predicts competitor effects that fit human data. The model predicted that there should be effects when words share any amount with a target which confirms the current theory. However, the model did not fit the human data unless there is longer overlap between words. This indicates that eye movements are not as closely tied to fixation probabilities of lexical representations as previously believed. The present study suggests that looking at a referent of a word is a decision, made when the word’s activation exceeds a context-specific threshold. Subthreshold activations do not drive saccades. The present study conclude that decision-making processes need to be incorporated in models linking word activation to eye movements.

No description available.

We present a method for extracting contours from digital images, using techniques from computational geometry. Our approach is different from traditional pixel-based methods in image processing. Instead of working directly with pixels, we extract a set of oriented feature points from the input digital images, then apply classical geometric techniques, such as clustering, linking, and simplification, to find contours among these points. Experiments on synthetic and natural images show that our method can effectively extract contours, even from images with considerable noise; moreover, the extracted contours have a very compact representation.

The purpose of this research was to develop observed score and true score equating procedures to be used in conjunction with the Multidimensional Item Response Theory (MIRT) framework. Currently, MIRT scale linking procedures exist to place item parameter estimates and ability estimates on the same scale after separate calibrations are conducted. These procedures account for indeterminacies in (1) translation, (2) dilation, (3) rotation, and (4) correlation. However, no procedures currently exist to equate number correct scores after parameter estimates are placed on the same scale. This research sought to fill this void in the current psychometric literature. Three equating procedures--two observed score procedures and one true score procedure--were created and described in detail. One observed score procedure was presented as a direct extension of unidimensional IRT observed score equating, and is referred to as the "Full MIRT Observed Score Equating Procedure." The true score procedure and the second observed score procedure incorporated the statistical definition of the "direction of best measurement" in an attempt to equate exams using unidimensional IRT (UIRT) equating principles. These procedures are referred to as the "Unidimensional Approximation of MIRT True Score Equating Procedure" and the "Unidimensional Approximation of MIRT Observed Score Equating Procedure," respectively. Three exams within the Iowa Test of Educational Development (ITED) Form A and Form B batteries were used to conduct UIRT observed score and true score equating, MIRT observed score and true score equating, and equipercentile equating. The equipercentile equating procedure was conducted for the purpose of comparison since this procedure does not explicitly violate the IRT assumption of unidimensionality. Results indicated that the MIRT equating procedures performed more similarly to the equipercentile equating procedure than the UIRT equating procedures, presumably due to the violation of the unidimensionality assumption under the UIRT equating procedures. Future studies are expected to address how the MIRT procedures perform under varying levels of multidimensionality (weak, moderate, strong), varying frameworks of dimensionality (simple structure vs. complex structure), and number of dimensions, among other conditions.

Dominant ‘society centred’ interpretations of social capital in Australia are inadequate to explain the economic fortunes and social prosperity of rural Australian communities. Given the continued contention over interpretations and measurement of social capital, this research sought to assess the relationship between different interpretations of social capital and rural communities’ resilience and prosperity. ¶ Utilising both quantitative and qualitative techniques to establish the relative levels of social capital in two communities of divergent growth, the primary objective was to test the association asserted between levels of social capital and prosperity and resilience in the rural Australian context. ¶ The research findings highlight three notable issues. Surveying social capital with current instruments is only effective in establishing the well being of rural communities which appears related to their resilience, not their ability to prosper. Secondly, the operational frameworks and responsibilities for social capital adopted by governments dictate the manner in, and degree to which they deem bridging and linking networks necessary and appropriate. This significantly affects the role social capital is perceived to play in communities. Lastly, while interpretations of social capital regard it as a normative factor in social life, rather than being comprised of different and dynamic elements affecting communities’ ability to prosper, the concept will remain unable to effectively contribute to the policy domain.

<p>The thesis work is conducted in the division of computer engineering at thedepartment of electrical engineering in Linköping University. During the thesiswork, a configurable Direct Memory Access (DMA) controller was designed andimplemented. The DMA controller runs at 200MHz under 65nm digital CMOS technology. The estimated gate count is 26595.</p><p>The DMA controller has two address generators and can provide two clocksources. It can thus handle data read and write simultaneously. There are 16channels built in the DMA controller, the data width can be 16-bit, 32-bit and64-bit. The DMA controller supports 2D data access by configuring its intelligentlinking table. The DMA is designed for advanced DSP applications and it is notdedicated for cache which has a fixed priority.</p>

Primary amine-based plasma polymer films (PPF) attract an increasing interest due to their potential applications as platforms to support cell growth and biomacromolecule immobilization. It has been demonstrated that the biological response of these films is correlated to their primary amine content (%NH2). Control and optimization of the process are thus very important requirements. However, despite the abundant literature related to this attractive technology, plasma polymerization remains very complex so that strong efforts are still needed to understand the relationship between the plasma chemistry and the PPF characteristics. The main part of this work describes the pulsed plasma polymerization of two isomeric precursors, namely allylamine and cyclopropylamine, with the aim to study the influence of the precursor on the plasma and the PPF physico-chemistries. The systems have been compared in similar conditions of mean power injected in the discharge (Pmean). Both experimental and theoretical approaches have been used to shed light on the process. Taking into account the electron energy in the plasma, differences between allylamine and cyclopropylamine plasma chemistries have been rationalized with the help of Density Functional Theory calculations. It is demonstrated that %NH2 can be increased by an appropriate choice of the precursor and the experimental conditions. Indeed, the use of cyclopropylamine can yield to PPF with a larger %NH2 compared to allylamine due to a preferential opening of the ring structure in the plasma. A method is also proposed to discriminate the PPF according to their cross-linking density (÷). While it appears to be independent of the chemical structure of the precursor, ÷ is observed to significantly vary with Pmean. The PPF have further been investigated with the aim to better understand the phenomena taking place when immersed in liquid medium, an essential step for biological applications. The results show that the decrease in the PPF thickness (Äd), conventionally observed upon immersion, directly depends on Pmean; the higher Pmean, the lower Äd. For the first time to our knowledge, the present work allows to unambiguously attribute this phenomenon to an increase of ÷ with Pmean. Furthermore, thanks to the analysis of the resulting solutions, the data give a new insight into the PPF behavior in liquid medium, suggesting that Äd is mostly related to a reorganization of the PPF network and not to material dissolution as usually claimed. Finally, some preliminary experiments indicate that the PPF can be used to support muscle cell culture; the performances of the PPF-coated materials reveal to be at least similar to those of the standard surfaces.

The topological significance of the spectral Atiyah-Patodi-Singer η-invariant is investigated. We show that twice the fractional part of the invariant is computed by the linking pairing in K-theory with the orientation bundle of the manifold. The Pontrjagin duality implies the nondegeneracy of the linking form. An example of a nontrivial fractional part for an even-order operator is presented.

We give a formula for the η-invariant of odd order operators on even-dimensional manifolds, and for even order operators on odd-dimensional manifolds. Geometric second order operators are found with nontrivial η-invariants. This solves a problem posed by P. Gilkey.

The creation of complex polymer structures has been one of the major research topics over the last couple of decades. This work deals with the synthesis of (block co-)polymers, the creation of complex and stimuli-responsive aggregates by self-assembly, and the cross-linking of these structures. Also the higher-order self-assembly of the aggregates is investigated. The formation of poly-2-oxazoline based micelles in aqueous solution and their simultaneous functionalization and cross-linking using thiol-yne chemistry is e.g. presented. By introducing pH responsive thiols in the core of the micelles the influence of charged groups in the core of micelles on the entire structure can be studied. The charging of these groups leads to a swelling of the core and a decrease in the local concentration of the corona forming block (poly(2-ethyl-2-oxazoline)). This decrease in concentration yields a shift in the cloud point temperature to higher temperatures for this Type I thermoresponsive polymer. When the swelling of the core is prohibited, e.g. by the introduction of sufficient amounts of salt, this behavior disappears. Similar structures can be prepared using complex coacervate core micelles (C3Ms) built through the interaction of weakly acidic and basic polymer blocks. The advantage of these structures is that two different stabilizing blocks can be incorporated, which allows for more diverse and complex structures and behavior of the micelles. Using block copolymers with either a polyanionic or a polycationic block C3Ms could be created with a corona which contains two different soluble nonionic polymers, which either have a mixed corona or a Janus type corona, depending on the polymers that were chosen. Using NHS and EDC the micelles could easily be cross-linked by the formation of amide bonds in the core of the micelles. The higher-order self-assembly behavior of these core cross-linked complex coacervate core micelles (C5Ms) was studied. Due to the cross-linking the micelles are stabilized towards changes in pH and ionic strength, but polymer chains are also no longer able to rearrange. For C5Ms with a mixed corona likely network structures were formed upon the collapse of the thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm), whereas for Janus type C5Ms well defined spherical aggregates of micelles could be obtained, depending on the pH of the solution. Furthermore it could be shown that Janus micelles can adsorb onto inorganic nanoparticles such as colloidal silica (through a selective interaction between PEO and the silica surface) or gold nanoparticles (by the binding of thiol end-groups). Asymmetric aggregates were also formed using the streptavidin-biotin binding motive. This is achieved by using three out of the four binding sites of streptavidin for the binding of one three-arm star polymer, end-functionalized with biotin groups. A homopolymer with one biotin end-group can be used to occupy the last position. This binding of two different polymers makes it possible to create asymmetric complexes. This phase separation is theoretically independent of the kind of polymer since the structure of the protein is the driving force, not the intrinsic phase separation between polymers. Besides Janus structures also specific cross-linking can be achieved by using other mixing ratios. / In den letzten Jahrzehnten war die Herstellung von komplizierten Polymerstrukturen ein wichtiges Forschungsthema für Polymerchemiker. Diese Arbeit behandelt die Synthese von (Blockco-)Polymere, die Herstellung von komplexen und stimulus-responsiven Aggregaten (Mizellen) durch Selbstorganisation, sowie die Vernetzung dieser Strukturen. Auch die Anordnung dieser Mizellen zu Aggregaten mit höherer Ordnung wurde untersucht. Zum Beispiel wird die Bildung von Poly(2-oxazolin) basierter Mizellen in wässriger Lösung und die gleichzeitige Funktionalisierung und Vernetzung dieser Mizellen mittels Thiol-In-Chemie beschrieben. Durch die Einführung von pH-responsiven Gruppen in den Kern der Mizellen konnte der Einfluss von geladenen Gruppen im Kern auf das gesamte Aggregat untersucht werden. Das Einführen von Ladung führt zum Quellen des Mizellkerns und damit zu einer niedrigeren lokalen Konzentration von wasserlöslichem Poly(2-ethyl-2-oxazolin) (PEtOx). Diese niedrigere Konzentration ergibt eine Verschiebung des Trübungspunkt dieses Typ I thermoresponsiven Polymers zu höheren Temperaturen. Wenn die Ausdehnung des Kerns nicht erfolgt, z.B. in Anwesenheit einer hohen Salzkonzentration, findet dieser Effekt nicht statt. Ähnliche Strukturen können mithilfe von Mizellen mit komplexen Koazervatkern (English: Complex Coacervate Core Micelles, C3Ms) durch die Interaktion zwischen Polymeren mit negativ und positiv geladenen Blöcken hergestellt werden. Der Vorteil dieser Strukturen ist, dass zwei verschiedene stabilisierende Polymerblöcke in einem Aggregat vereint werden können, was zur Bildung einer Vielzahl noch komplizierterer Strukturen und zu mehr Responsivität führen kann. Mithilfe von Blockcopolymeren, bestehend aus jeweils einen polyionischen Block und einem neutralen Block (z.B. PEtOx, PEO oder poly(N-isopropylacrylamid) (PNIPAAm)), konnten C3Ms hergestellt werden, in denen zwei neutrale Polymere vereint wurden. Es konnte gezeigt werden, dass diese Polymere sowohl gemischt als auch phasensepariert vorliegen können (letzteres ergibt Janus Mizellen), abhängig welche Polymere gewählt werden. Durch Vernetzung im Kern konnten die Mizellen stabilisiert und fixiert werden (C5Ms). Die Selbstanordnung dieser vernetzten Mizellen zu größeren Aggregaten wurde untersucht. Wenn eine Lösung mit vernetzten Mizellen über den Trübungspunkt von PNIPAAm erhitzt wurde, bildeten sich Netzwerke aus Mizellen mit einer gemischten Korona, während Janus Mizellen sich zu wohldefinierten Aggregaten höherer Ordnung anordneten. Weiterhin konnte gezeigt werden, dass Janus Mizellen sich auf der Oberfläche von anorganischen Nanopartikeln anlagern können; z.B. durch die selektive Wechselwirkung zwischen PEO und Silica oder durch die Adsorption von Thiolgruppen auf Gold-Nanopartikeln. Asymmetrische Aggregate konnten auch mithilfe des Streptavidin-Biotin Komplexes erhalten werden. Durch das Binden der Biotin-Endgruppen eines dreiarmigen Sternpolymeren an eine Streptavidin-Einheit und anschließende Belegung der verbliebenen Bindungsstelle mit der Biotin-gruppe eines Homopolymers, können sehr spezifisch zwei verschiedene Polymere in einem Janus Aggregat vereint werden. Auch die Vernetzung des Streptavidins kann erzielt werden, indem andere Mischverhältnisse gewählt werden.