Design is a multidimensional activity involving a variety of skills and thought processes, including analytic reasoning, intuition, and creative expression. Learning how to design can be a frustrating and confusing process that some students find difficult to understand. Professors employ a range of strategies when teaching design. These strategies are often based on how their professors taught them with little or no theoretical basis in how students learn. For students, the failure to grasp the process of designing can challenge their willingness to stay motivated and actively engaged in the studio project. The result is less than optimal learning and students that do not achieve their full potential. One important factor that influences design learning is the process of self-regulated learning. Self-regulated learning (SRL) refers to a student's self-generated thoughts, strategies, and goal-directed behaviors. This study examined SRL in landscape architecture design studios in order to find out how students self-regulate their learning and performance on studio projects. Interviews with landscape architecture students were used to answer the research questions. Study findings suggest that landscape architecture students self-regulate their learning on studio projects through a process of engaging in design, then using SRL to address issues that arise during design, then generating more design issues that require additional SRL, and so on. The findings indicate that a student's ability to engage in SRL is based on their understanding of design as a complex set of behaviors and activities. Since students in each year have a different understanding of what designing entails, they use and engage in SRL differently. The findings suggest that high achievement in a design studio is a result of advanced knowledge that comes from the freedom to pursue additional issues beyond the basic requirements of the project. The freedom comes when a student attains the expertise to shift cognitive resources away from learning how to design and redirects them towards risk-taking, personal interests, and learning new information. The study sheds light on how students learn, engage, and self-regulate their learning in design studios and provides design educators with a basis for effective design teaching strategies. / Ph. D.

This dissertation presents a new framework for the development and analysis of blind adaptive algorithms. An adaptive algorithm is said to be 'blind' if it does not require a known training sequence. The main focus is on application of these algorithms to adaptive antenna arrays in mobile radio communications. Adaptive antenna arrays can reduce the effects of cochannel interference, multipath fading, and background noise as compared to more conventional antenna systems. For these reasons, the use of adaptive antennas in wireless communication has received a great deal of attention in the literature. There are several reasons why the study of blind adaptive algorithms is important. First, it is common practice to switch to a blind mode once the training sequence has been processed in order to track a changing environment. Furthermore, the use of a blind algorithm can completely eliminate the need for a training sequence. This is desirable since the use of a training sequence reduces the number of bits available for transmitting information. The analysis framework introduced here is shown to include the well-known Constant Modulus Algorithm (CMA) and decision directed algorithm (DDA). New results on the behavior of the CMA and DDA are presented here, including analytic results on the convergence rate. Previous results have relied on Monte Carlo simulation. This framework is also used to propose a new class of blind adaptive algorithms that offer the potential for improved convergence rate. / Ph. D.

The purpose of the present study was to investigate the role of pitch contours in directing infant attention to adult speech. Several studies have shown that infants from a few days old to 9 months of age prefer infant-directed (ID) over adult-directed (AD) speech. Moreover, 4-month-olds have been shown to prefer pitch contours that simulate ID speech, suggesting that the exaggerated pitch contours are necessary for infant attention. The current study investigated this attentional preference utilizing ID and AD pitch contours in a fixation-based preference procedure. Results from the first experiment failed to show a similar preference for the ID pitch contours. Because a lack of preference could have been due to a failure to discriminate, a habituation study was also conducted. The results from the second experiment showed that 4-month-olds can discriminate the ID and AD pitch contours. From these results, it is argued that the pitch contour may be but one of many possible prosodic characteristics that attract infant attention and this attention may occur only within a language context. It is suggested that future studies investigate ID speech using a more context-dependent procedure, where natural or more complete speech samples are utilized. / Master of Science

In this thesis, we focus on the steady state properties of two systems which are genuinely out of equilibrium. The first project is an application of dynamic field theory to a specific non equilibrium critical phenomenon, while the second project involves both simulations and analytical calculations. The methods of field theory are used on both these projects. In the first part of this thesis, we investigate a generalization of the well-known field theory for directed percolation (DP). The DP theory is known to describe an evolving population, near extinction. We have coupled this evolving population to an environment with its own nontrivial spatio-temporal dynamics. Here, we consider the special case where the environment follows a simple relaxational (model A) dynamics. We find two marginal couplings with upper critical dimension of four, which couple the two theories in a nontrivial way. While the Wilson-Fisher fixed point remains completely unaffected, a mismatch of time scales destabilizes the usual DP fixed point. Some open questions and future work remain. In the second project, we focus on a simple particle transport model far from equilibrium, namely, the totally asymmetric simple exclusion process (TASEP). While its stationary properties are well studied, many of its dynamic features remain unexplored. Here, we focus on the power spectrum of the total particle occupancy in the system. This quantity exhibits unexpected oscillations in the low density phase. Using standard Monte Carlo simulations and analytic calculations, we probe the dependence of these oscillations on boundary effects, the system size, and the overall particle density. Our simulations are fitted to the predictions of a linearized theory for the fluctuation of the particle density. Two of the fit parameters, namely the diffusion constant and the noise strength, deviate from their naive bare values [6]. In particular, the former increases significantly with the system size. Since this behavior can only be caused by nonlinear effects, we calculate the lowest order corrections in perturbation theory. Several open questions and future work are discussed. / Ph. D.

As directed energy technology continues to evolve and become a viable weapon alternative, a need exists to investigate the impacts of these applications without a "plug-and-check" method, but rather with an analysis governed by fundamental principles. This thesis examines the transient thermal loads that a high-energy weapon system introduces into a high performance aircraft using fundamental thermodynamic and heat transfer analyses. The high-energy weapon system employed in this research contains power storage, power conditioning equipment, optics, and a solid-state laser. The high-energy weapon system is integrated into the aircraft by a dedicated thermal management system connected to the onboard air and fuel fluid networks. The dedicated thermal management system includes heat exchangers, thermal storage, microchannel coolers, valves, and pumps. Governing equations for the electric directed energy weapon subsystem and thermal management system are formulated for each system component and modeled in Mathwork's Simulink™. System models are integrated into a generic, high-performance aircraft model created as part of the Air Force Research Laboratory's Integrated Vehicle Energy Technology Demonstration (INVENT) program. The aircraft model performs a defined mission profile, firing the directed energy weapon during the high-altitude, transonic cruise segment. When firing a 100-kilowatt directed energy weapon system operating at 16.9% efficiency, large thermal transients quickly heat downstream onboard systems. Real-time heat rejection causes temperature spikes in avionic and environment systems that exceed allowable operation constraints. The addition of thermal storage to the thermal management system mitigates thermal impacts downstream of the directed energy weapon by delaying the time thermal loads are rejected to aircraft, thereby reducing peak and average loads. Although thermal storage is shown to mitigate peak loads in downstream onboard systems, thermal closure is yet to be achieved. This research presents a general and fundamental approach to investigating the thermal impacts of a directed energy weapon system on a high-performance aircraft. Although specific cases are analyzed, this general approach to model development and simulation is conducive to component and system customization for many other cases. Additionally, the supplementation of models with analytical, semi-empirical, and empirical data further tailors model development to each user's need while increasing the potential to enhance accuracy and efficacy. Without the material expenses of a "plug-and-check" method, component and system level modeling of the directed energy weapon system and high-performance aircraft provides valuable insight into the thermal responses of highly-coupled systems. / Master of Science

Infant speech perception develops within the context of specific language experience. While there is a corpus of empirical evidence concerning infants' perception of linguistic and prosodic information in speech, few studies have explored the interaction of the two. The present investigation was designed to combine what is known about infants' perception of nonnative phonemes (linguistic information) with what is known about infant preferences for ID speech (prosodic information). In particular, the purpose of this series of studies was to examine infant preferences for ID speech within the timeline of the phonemic perceptual reorganization that occurs at the end of the first postnatal year. In Experiment 1, 20 Native-English 10- to 11-month-old infants were tested in an infant-controlled preference procedure for attention to ID speech in their native language versus ID speech in a foreign language. The results showed that infants significantly preferred the ID-native speech. In Experiment 2, the preferred prosodic information (ID speech) was separated from the preferred linguistic information (native speech), as a means of discerning the relative perceptual draw of these types of speech characteristics. Specifically, a second group of 20 10- to 11-month-old infants was tested for a preference between ID speech in a foreign language and AD speech in their native language. In this case the infants exhibited a significant preference for ID-foreign speech, suggesting that prosodic information in speech has more perceptual weight than linguistic information. This pattern of results suggests that infants attend to linguistic-level information by 10- to 11-months of age, and that ID speech may play a role in the native-language tuning process by directing infants' attention to linguistic specifics in speech. / Master of Science

As a prerequisite for all adult learners in life-long learning, self-directed learning has been constantly discussed since the early 1960s. However, in what manner research operationalizes the concepts and what similarities occur across the empirical studies and theoretical studies are still ambiguous. The purpose of this study is to employ an integrative literature review to investigate and disentangle various interpretations of self-directed learning by identifying how the topic is defined and what competencies and strategies are needed for a highly self-directed learner. This is a six-phase study, including: 1) problem formulation; 2) data collection; 3) problem re-formulation; 4) data evaluation; 5) data collection; and 6) presentation of the findings. This study provided a comprehensive perspective of self-directed learning in a dynamically expanding process to include multifaceted interpretations of the topic and advanced research in self-directed learning in an updated, enriched learning environment. Specifically, the researcher updated the evidence for self-directed learning to date, identified all of the potential dimensions of self-directed learning that distinguish a highly-directed self-directed learner and the related instructional strategies, and made suggestions for the future direction of research on the topic. / Ph. D.

Much research has examined how rate affects visual preferences in human infants and auditory preferences in avian infants. In the visual domain, it seems that human infants prefer stimuli (e.g., flashing displays) presented at faster relative rates. Research using avian species has shown that ducklings, for example, prefer their species- specific maternal call only when it is presented at values close to the species-typical mean. These studies have shown that experience affects ducklings'­ preferences for rate in auditory events. Researchers in the areas of human infant preferences for visual rate and avian infant preferences for auditory rate have suggested that an effective window of frequencies exists for which infants show maximal attention. Unlike these two areas, little research has addressed how rate affects human infants' preferences for auditory events. A study by Cooper and Cooper (1997) was the first to find that infants attend to rates of speaking infant directed (ID) speech. Specifically, infants preferred ID speech at its normal rate to ID speech at a faster rate. The present study was intended to further investigate how rate of speaking affected infants' preferences for ID speech. More specifically, this study sought to determine whether a window of effective rates also exists for infant preferences for rate in ID speech. Using an infant-controlled preference procedure, 20 six- to eight-week old infants were presented with ID-normal speech (ID speech as its normal rate) and ID- slow speech (ID speech slowed to half the normal rate). It was found that infants looked longer to a visual display when it was paired with ID-slow speech than when it was paired with ID-normal speech. How these results relate to research and theory on visual rate preferences in human infants and auditory rate in avian species is discussed, as well as future directions for this line of research. / Master of Science

A recent study by Polka, Rvachew, and Molnar (2008) found that 6- to 8-month-old infants do not discriminate a simple native consonant-vowel contrast when familiarized to it in the presence of distraction noise (i.e., recordings of crickets and birds chirping), even when testing was conducted in quiet. Because the distraction noise did not overlap with the phonemes' frequencies, failure to encode the familiarization phoneme could be due more to a disruption in infant attention than to direct masking effects. Given that infants learn speech under natural conditions involving noise and distraction, it is important to identify factors that may 'protect' their speech perception under non-ideal listening conditions. The current study investigated three possible factors: speech register, face information, and speaker gender. Six-month-old infants watched a video of a female speaker producing a native phoneme in either an adult-directed or infant-directed manner accompanied by the same background noise as in Polka et al. (2008). After habituation, infants were tested with alternating trials of the familiar phoneme and a novel phoneme in quiet. Phoneme discrimination was measured by recording infants' heart rate and looking times during familiar and novel trials. Discrimination was poor in infants who viewed a female speaker using adult-directed speech but was significantly improved (as seen in both dependent measures of attention) when the female speaker used infant-directed speech. Results indicate that common factors in the typical environment of infants can promote speech perception abilities in noise. / Master of Science

Continuous advances in VLSI technology have led to more complex digital designs and shrinking transistor sizes. Due to these developments, design verification and manufacturing test have gained more importance and 70 % of the design expenditure in on validation processes. Electronic Design Automation (EDA) tools play a huge role in the validation process with various verification and test tools. Their efficiency have a high impact in saving time and money in this competitive market. Direct Acyclic Graphs (DAGs) are the backbone for most of the EDA tools. DAG is the most efficient data structure to store circuit information and also have efficient backt traversing structure which help in developing reasoning/ debugging tools. In this thesis, we focus on two such EDA tools using graphs as their underlying structure for circuit information storage • Scan pattern Debugger for Partial Scan Designs • Circuit SAT Bounded Model Checkers We developed a complete Interactive Scan Pattern Debugger Suite currently being used in the industry for next generation microprocessor design. The back end is an implication graph based sequential logic simulator which creates a Debug Implication Graph during the logic simulation of the failing patterns. An efficient node traversal mechanism across time frames, in the DIG, is used to perform the root-cause analysis for the failing scan-cells. In addition, the debugger provides visibility into the circuit internals to understand and fix the root-cause. We integrated the proposed technique into the scan ATPG flow for industrial microprocessor designs. We were able to resolve the First Silicon logical pattern failures within hours, which would have otherwise taken a few days of manual effort for root-causing the failure, understanding the root-cause and fixing it. For our circuit SAT implementation, we replace the internal implication graph used by the SAT solver with our debug implication graph (DIG). There is a high amount of circuit unrolling in circuit SAT/ BMC (Bounded Model Checking) problems which creates copies of the same combinational blocks in multiple time frames. This allows us to use the repetitive circuit structure and club it with the CNF database in the SAT solver. We propose a new data structure to store data in a circuit SAT solver which results up to 90% reduction in number of nodes. / Master of Science