A capacidade de adaptação das respostas posturais automáticas de acordo com informações do contexto indica uma interação entre dois níveis de controle, em que o processamento cognitivo de alta ordem das características de uma perturbação iminente seria capaz de modular o controle postural em níveis inferiores do sistema sensoriomotor. Os estudos aqui propostos procuram responder quais informações sobre as características da perturbação são utilizadas pelo central set para modular as respostas posturais automáticas. A tarefa estudada consistiu na recuperação do equilíbrio da postura ereta em resposta à translação da base de suporte. No Experimento 1, foi avaliada a influência de dicas visuais sobre a amplitude de deslocamento da base de suporte em sequências repetitivas ou aleatórias de perturbação. No Experimento 2, a dica de amplitude de deslocamento foi dada por meio da sequência de perturbações, comparando-se tentativas repetidas em bloco, em sequência conhecida e em sequência aleatória. No Experimento 3, foi avaliado o efeito de incerteza tanto da amplitude da perturbação quanto do tempo de aplicação da perturbação. O Experimento 4 teve como propósito avaliar a interação entre dica temporal e tarefa cognitiva concomitante à recuperação do equilíbrio. Os resultados mostram que (a) informações prévias sobre a magnitude da perturbação postural parecem ser incapazes de modular respostas posturais automáticas; (b) modulação de respostas posturais automáticas a partir de uma sequência repetitiva de perturbações aparentemente está associada à adaptação do sistema sensoriomotor e não à participação de processamento cognitivo das características físicas da perturbação iminente; (c) previsibilidade temporal da perturbação postural induz uma otimização das respostas posturais automáticas; e (d) a execução de tarefa cognitiva no momento da perturbação inibe o ganho de estabilidade de respostas posturais automáticas conferido pela dica temporal. Como conclusão, parece haver uma limitação do processamento cognitivo em modular respostas posturais automáticas. Considerando-se que o conceito de central set expressa a noção de que processamento cognitivo de dicas contextuais é capaz de otimizar respostas posturais automáticas, nossos resultados sugerem a necessidade da revisão deste conceito amplamente empregado na literatura de controle postural / Adaptability of automatic postural responses according to context information indicates an interaction between two levels of control, in which the high-order cognitive processing of the perturbation characteristics would be able to modulate postural control in lower levels of the sensorimotor system. The studies proposed here intended to scrutinize what cues about the perturbation characteristics are used by the central set to modulate the automatic postural responses. The task studied consisted in the recovery of postural equilibrium in response to a posterior translation of the support base. In Experiment 1, it was evaluated the effect of precueing the displacement amplitude of the supporting base in repetitive or random perturbation sequences. In Experiment 2, precueing of the support base displacement was provided by the sequence of perturbations, comparing repetitive trials, known sequence and random sequence. In Experiment 3, we evaluated the effect of uncertainty about amplitude and time of perturbation. Experiment 4 aimed to evaluate the interaction of temporal precueing and a concurrent cognitive task on body equilibrium recovery. Results show that (a) previous information about perturbation magnitude seems to be unable to modulate automatic postural responses; (b) modulation of automatic postural responses from a repetitive sequence of perturbations is apparently associated with an adaptation of the sensorimotor system rather than to the participation of cognitive processing of the perturbation characteristics; (c) temporal predictability of the postural perturbation induces optimization of automatic postural responses; and (d) cognitive task execution at the time of the perturbation inhibits the gain of automatic postural responses stability provided by temporal precueing. As a conclusion, there seems to be a limitation of cognitive processing to modulate automatic postural responses. Considering that the concept of central set expresses the notion that cognitive processing of a contextual precue is able to optimize automatic postural responses, our results suggest the need for revision of this conceptualization widely used in the postural control literature

Seventy years ago Erikson proposed successful identity formation in adolescence was the foundation for successful intimacy formation in young adulthood. With the extended period of identity exploration in emerging adulthood, it is unclear if intimacy formation continues to be connected to identity. The purpose of this study was to determine the relationship between identity in three domains of love, work, and worldview with long term views of intimacy using Marital Horizons Theory. Results from a sample of 777 college students in the Project READY dataset indicated that identity formation in love is positively associated with views of marriage, identity formation in work has no significant association with views of marriage, and identity formation in worldview is negatively associated with views of marriage. Implications for the transition into marriage and further identity research are discussed.

Traffic signal systems serve as one of the most powerful control tools in improving the efficiency of surface transportation travel. Traffic operations on arterial roads are particularly complex because of traffic interruptions caused by signalized intersections along the corridor. This dissertation research presents a systematic framework of integrated traffic control in an attempt to break down the complexities into several simpler sub-problems such as pattern recognition, environment-mobility relationships and multi-objective optimization for multi-criterial signal timing design. The overall goal of this dissertation is to develop signal timing plans, including a day plan schedule, cycle length parameters, splits and offsets, which are suitable for real traffic conditions with consideration of multi-criterial performance of the surface transportation system. To this end, the specific objectives are to: (1) identify appropriate time-of-day breakpoints and intervals to accommodate traffic pattern variations for day plan schedule of signal timing; (2) explore the relationship between environmental outcomes (e.g., emissions) from emission estimators and mobility measures (e.g., delay and stops) for different types of intersections; (3) optimize signal timing parameters for multi-criteria objectives (e.g., minimizing vehicular delay, number of stops, marginal costs of emissions and total costs), with the comparison of performance metrics for different objectives, at the intersection level; (4) optimize arterial offsets for different objectives at the arterial level and compare the performance metrics of different objectives to recommend suitable objectives for integrated multi-criteria signal timing design in arterial traffic operations. An extensive review of the literature, which covers existing tools, traffic patterns, traffic control with environmental concerns, and related optimization methods, shows that both opportunities and challenges have emerged for multi-criteria traffic signal timing design. These opportunities include large quantities of traffic condition data collected by system detectors or non-intrusive data collection platforms as well as powerful tools for microscopic traffic modeling and instantaneous emission estimation. The challenge is how to effectively deal with these big data, either from field collection or detailed simulation, and provide useful information for decision makers in practice. Methodologically, there's a tradeoff between the accuracy of objective function values and the computational efficiency of simulation and optimization. To address this need, in this dissertation, traffic signal timing design that systematically enables the use of integrated data and models are investigated and analyzed in the four steps/studies. The technology of identifying time-of-day breakpoints in the first study shows a mathematical way to classify dynamic traffic patterns by understanding dynamic traffic features and instabilities at a macroscopic level on arterials. Given the limitations of using built-in emissions modules within current traffic simulation and signal optimization tools, the metamodeling-based approach presented in the second study makes a methodological contribution. The findings of the second study on environment-mobility relationships set up the base for extensive application of two-stage optimization in the third and fourth studies for sustainable traffic operations and management. The comparison of outputs from an advanced estimator with those from the current tool also addresses improving the emissions module for more accurate analysis (e.g., benefit-cost analysis) in practical signal retiming projects. The third study shows that there are tradeoffs between minimizing delay and minimizing marginal costs of emissions. When total cost (including cost of delay, fuel consumption and emissions) is set as a single objective function, that objective clears the way for relatively reliable results for all the aspects. In the fourth study, the improvements in marginal cost of emissions and total cost by dynamic programming procedure are obvious, which indicates the effectiveness of using total link cost as an objective at the corridor level. In summary, this dissertation advocates a sustainable traffic control system by simultaneously considering travel time, fuel consumption and emissions. The outcomes of this integrated multi-criteria signal timing design can be easily implemented by traffic operators in their daily life of retiming signal timing.

Whole document restricted, see Access Instructions file below for details of how to access the print copy. / Generations X and Y have been described as constituting a ‘black hole’ in congregational life. The literature emphasises that generations X and Y are interested in spirituality but not institutional religion. There is now a substantial body of literature arguing that generations X and Y find churches ‘irrelevant’, ‘absent of God’, ‘too rigid’, and ‘laughably out of touch’ with their lives. This thesis argues that generational accounts of religion often fail to make an important distinction between the churched and unchurched in relation to generational distinctiveness. This is a distinction often drawn by sociologists of religion, pointing to two quite different cultures, one communally orientated towards faith communities and the other orientated towards personal freedom and a privatised spiritual quest. Generations X and Y in this thesis refer to a generational unit who share a particular type of faith: owned and embedded within a church community. Employing a methodological approach of in-depth religious life story interviews this thesis is a sociological investigation into the way Christian faith journeys of GenX and GenY are embedded within New Zealand church communities. It is argued that their faith does not make sense outside of this embeddedness. Embedded faith provides a framework for making sense of the participants’ religious biographies. Embedded faith is contrasted to a more privatised understanding of faith and religion popular within sociology of religion. The active dimension of embedded faith is demonstrated through an exploration of modes of engagement with worship and preaching. This thesis builds upon qualitative studies that continue to demonstrate the salience of the collective act of religious involvement and social belonging. One of the challenges of embedded faith however, is finding a church to embed it within. This thesis provides understanding and insight into the relationship between embedded faith and church switching. It explores the way that church switching is an intentional act of disembedding and re-embedding faith and the reasons for this practice.

Whole document restricted, see Access Instructions file below for details of how to access the print copy. / Generations X and Y have been described as constituting a ‘black hole’ in congregational life. The literature emphasises that generations X and Y are interested in spirituality but not institutional religion. There is now a substantial body of literature arguing that generations X and Y find churches ‘irrelevant’, ‘absent of God’, ‘too rigid’, and ‘laughably out of touch’ with their lives. This thesis argues that generational accounts of religion often fail to make an important distinction between the churched and unchurched in relation to generational distinctiveness. This is a distinction often drawn by sociologists of religion, pointing to two quite different cultures, one communally orientated towards faith communities and the other orientated towards personal freedom and a privatised spiritual quest. Generations X and Y in this thesis refer to a generational unit who share a particular type of faith: owned and embedded within a church community. Employing a methodological approach of in-depth religious life story interviews this thesis is a sociological investigation into the way Christian faith journeys of GenX and GenY are embedded within New Zealand church communities. It is argued that their faith does not make sense outside of this embeddedness. Embedded faith provides a framework for making sense of the participants’ religious biographies. Embedded faith is contrasted to a more privatised understanding of faith and religion popular within sociology of religion. The active dimension of embedded faith is demonstrated through an exploration of modes of engagement with worship and preaching. This thesis builds upon qualitative studies that continue to demonstrate the salience of the collective act of religious involvement and social belonging. One of the challenges of embedded faith however, is finding a church to embed it within. This thesis provides understanding and insight into the relationship between embedded faith and church switching. It explores the way that church switching is an intentional act of disembedding and re-embedding faith and the reasons for this practice.

<p>For every operating condition of an internal combustion engine there exists an optimal spark timing, called maximum brake torque (MBT), which maximises the output torque and the efficiency of the engine. Traditionally MBT timing is implemented as an open-loop control where the ignition timing is found by using a combination of static lookup tables and sensor information. With a direct closed-loop control from the combustion process the performance of internal combustion engines could be improved. The thesis investigates if it is possible to estimate the MBT timing from the ionization current for every operating condition of a spark ignited engine where the operating conditions are defined by the engine parameters lambda, internal exhaust gas recirculation, engine load, engine speed and spark advance.</p><p>First an investigation of how much loss of torque an error from the MBT position corresponds to is made. Then the influence of the engine parameters on the shape of the ionization current was studied. Last different peak pressure position (PPP) estimating algorithms are presented and a new technique is developed where an engine operating point dependant part of the ionization current is used depending on the current operating condition of the engine. Two of the presented PPP estimating algorithms are then complemented with this technique and the results look promising.</p>

This thesis deals with the synchronization of digital communication systems. Synchronization (from the Greek syn (together) and chronos (time)) denotes the task of making two systems running at the same time. In communication systems, the synchronization of the transmitter and the receiver requires to accurately estimate a number of parameters such as the carrier frequency and phase offsets, the timing epoch... In the early days of digital communications, synchronizers used to operate in either data-aided (DA) or non-data-aided (NDA) modes. However, with the recent advent of powerful coding techniques, these conventional synchronization modes have been shown to be unable to properly synchronize state-of-the-art receivers. In this context, we investigate in this thesis a new family of synchronizers referred to as code-aided (CA) synchronizers. The idea behind CA synchronization is to take benefit from the structure of the code used to protect the data to improve the estimation quality achieved by the synchronizers. In a first part of the thesis, we address the issue of turbo synchronization, i.e., the iterative synchronization of continuous parameters. In particular, we derive several mathematical frameworks enabling a systematic derivation of turbo synchronizers and a deeper understanding of their behavior. In a second part, we focus on the so-called CA hypothesis testing problem. More particularly, we derive optimal solutions to deal with this problem and propose efficient implementations of the proposed algorithms. Finally, in a last part of this thesis, we derive theoretical lower bounds on the performance of turbo synchronizers.

Synchronization is a very important part of every digital communication receiver. While in bandpass coherent transmission, frequency and phase synchronization play a very important role in reliable transmission, symbol timing recovery is a necessary part of every baseband and bandpass coherent receiver. This dissertation deals with the problem of synchronization in the presence of fading and interference. First, the performance of an automatic frequency control loop is investigated using two parameters of average switching rate and mean time to loss of lock. These parameters are derived in closed-form or as integral-form formulas for different scenarios of modulated and unmodulated signals in different fading channels when there is one interference signal present at the input of the AFC. Then, the results are generalized to the noisy fading scenario and it is shown that in Rayleigh fading case, the performance of AFC becomes better when the desired signal is noisier. In the second part, the problem of symbol timing recovery is investigated in systems that are subject to intersymbol interference and non-data-aided maximum likelihood synchronizer is derived in these channels. Then, a new simple bound on the performance of synchronizers is derived and compared to the previously known lower bounds. It is shown that while this lower bound solves the shortcomings of the well known modified Cramer-Rao bound at small values of signal-to-noise-ratio, it is much easier to compute compared to another well known bound, the detection theory bound. / Communications

Tax planning is a core service provided by tax practices of public accounting firms. Performing this service well is important to the firms, their clients and the tax professionals involved. This study experimentally examines the effects of supervisory advice on the judgment of tax professionals performing tax planning tasks of different complexity, in the presence of the tax contextual features of accountability and time pressure, and finds that such advice is not necessarily helpful to performance. The advice, task complexity and accountability literatures are used in framing arguments and developing hypotheses, which propose that the timing of advice and the complexity of the task interact, so that advice is not necessarily beneficial. The study also draws on the behavioral tax, audit and accounting literatures. Discussions with senior tax practitioners indicate that supervisory advice is usually given to tax professionals before they commence tax planning tasks. The results of this study support the hypotheses and demonstrate that this practice of giving advice may not improve performance in a tax planning task and may even be detrimental. First, the results indicate that the giving of advice by a supervisor should be conditional on task complexity. Supervisory advice is beneficial for a higher-complexity task but detrimental to a lower-complexity task. Second, the timing of when any advice is provided is important. Although advice is beneficial for the higher-complexity task, the results indicate that when advice is given before the tax professional commences the task it interferes with the processing of information and insightful judgments. The giving of advice after the tax professional has thought through the task and prepared a tentative solution results in better performance for this more complex task. / Accounting

Denna avhandling presenterar en undersökning av orsakerna och effekterna av timingosäkerhet i Sigma-Delta Analog-Digital-Omvandlare, med speciellt fokus på Sigma-Delta av den switchade kapacitanstypen. Det undersökta området för orsakerna till timingosäkerhet är digital klockgenerering och området för effekterna är sampling. Upplösningsnivån på analysen i detta arbete börjar på beteendenivå och slutar på transistornivå. Samplingskretsen är den intuitiva komponenten att söka i efter orsakerna till effekterna av timing-osäkerhet i en Analog-Digital-Omvandlare eftersom transformationen från reell tid till digital tid sker i samplingskretsen. Därför har prestandaeffekterna av timingosäkerhet i den typiska samplingskretsen för switchad kapacitans Sigma-Delta Analog-Digital-Omvandlare analyserats utförligt, modellerats och beskrivits i denna avhandling. Under analysprocessen har idéer om förbättrade samplingskretsar med naturlig tolerans mot timing-osäkerhet utvecklats och analyserats, och presenteras även. Två typer av förbättrade samplingstopologier presenteras: parallelsamplern och Sigma-Delta-samplern. Den första erhåller tolerans mot timing-osäkerhet genom att utnyttja ett teorem inom statistiken medan den andra är tolerant mot timing-osäkerhet p.g.a. spektral formning som trycker ut brus ur signalens frekvensband. Digital klockgenerering är ett fundamentalt steg i genereringen av multipla klocksignaler som behövs t.ex. i switchade kapacitansversioner av Sigma-Delta Analog-Digital-Omvandlare. Klockgeneratorkretsarna konverterar en tidsreferens, d.v.s. en klocksignal, som vanligen kommer från en faslåst loop till multipla tidsreferenser. De två typerna av klockgenereringskretsar som behandlas i denna avhandling används för att skapa två icke-överlappande klockor från en klocksignal. Processen som undersökts och beskrivits är hur matningsspänningsbrus och substratbrus omvandlas till timing-osäkerhet då en referenssignal passerar genom en av ovannämnda klockgenereringskretsar. Resultaten i denna avhandling har erhållits genom olika analystekniker. Modelleringarna och beskrivningarna har utförts från ett matematiskt och fysikaliskt perspektiv. Detta har fördelen av att kunna förutsäga prestandainfluenser som olika kretsparametrar har utan att behöva utföra datorsimuleringar. Svårigheterna med den matematiska och fysikaliska modelleringen är balansgången mellan olöslighet och överförenkling som måste hittas. Den andra infallsvinkeln är användandet av datorbaserade simuleringsverktyg både för beskrivnings- och verifieringsändamål. Simuleringsverktygen som använts är MATLAB och Spectre/Cadence. Som nämnts har deras syfte varit både som modell- och beskrivningsverifiering och även som ett sätt att erhålla kvantitativa resultat. Generellt talat bryter simuleringsverktyg den mentala kopplingen mellan resultat och diverse kretsparametrar och det kan vara svårt att uppnå en solid prestandaförståelse. Dock är det ibland bättre att erhålla ett prestandamått utan full förståelse än inget mått alls. / This dissertation presents an investigation of the causes and effects of timing uncertainty in Sigma-Delta Analog-to-Digital Converters, with special focus on the switched-capacitor Sigma-Delta type. The investigated field for cause of timing uncertainty is digital clock generation and the field for effect is sampling. The granularity level of the analysis in this work begins at behavioral level and finishes at transistor level. The sampling circuit is the intuitive component to look for the causes to the effects of timing uncertainty in an Analog-to-Digital Converter since the transformation from real time to digital time takes place in the sampling circuit. Hence, the performance impact of timing uncertainties in a typical sampling circuit of a switched-capacitor Sigma-Delta Analog-to-Digital Converter has been thoroughly analysed, modelled, and described in this dissertation. During the analysis process, ideas of improved sampling circuits with inherent tolerance to timing uncertainties were conceived and analysed, and are also presented. Two cases of improved sampling topologies are presented: the Parallel Sampler and the Sigma- Delta sampler. The first obtains its timing uncertainty tolerance from taking advantage of a theorem in statistics whereas the second is tolerant against timing uncertainties because of spectral shaping that effectively pushes the in-band timing noise out of the signal band. Digital clock generation is a fundamental step of generating multiple clock signals that are needed for example in switched-capacitor versions of Sigma-Delta Analog-to-Digital Converters. The clock generation circuitry converts a single time reference, i.e. a clock signal, usually coming from a phase-locked loop into multiple time references. The two types of clock-generation circuits that are treated in this dissertation are used to create two nonoverlapping clocks from a single clock signal. The process that has been investigated and described is how power-supply noise and substrate noise transforms into timing uncertainty when a reference signal is passed through one of the aforementioned clock generation circuits. The results presented in this dissertation have been obtained using different analysis techniques. The modelling and descriptions have been done from a mathematical and physical perspective. This has the benefit of predicting the performance impact by different circuit parameters without the need for computer based simulations. The difficulty with the mathematical and physical modelling is the balance that has to be found between intractability and oversimplification. The other angle of approach has been the use of computer based simulations for both description and verification purposes. The simulation tools that have been used in this work are MATLAB and Spectre/Cadence. As mentioned, their purpose has been both for model and description verification and also as a means of obtaining result metrics. Generally speaking, simulation tools mentally decouple the result from the various circuit parameters and reaching a solid performance understanding can be difficult. However, obtaining a performance metric without full comprehension can at times be better than having no metric at all. / QC 20100921