This research proposes sets of design patterns of learning environments as an innovative approach towards an intelligent architectural design process. These patterns are based on teachers’ spatial and pedagogical use of their learning environments. The study is based in the desired condition that learning environments are expected to host learning technologies efficiently, to adapt to the fact that its life span is much longer than that of any technology within it, and to accommodate a variation of teaching modes and learning styles. In an effort to address these issues; calls for designing flexible learning spaces have emerged, as well as recommendations for alternative layouts. Yet, more challenging questions emerge; how efficiently do these technologies integrate with other systems in the classroom space? What should architects and facility planners consider for a successful systems’ integration which incorporates learning technologies in the design of the classroom space? And how can these spaces support variations in pedagogical practice. This study attempts to answer these questions by developing a pattern language to support the early design phases of a technology-rich learning environment. The study is qualitative in nature, and based on interviews with a sample of teachers at academic year Governor’s science and technology schools in Virginia. The researcher attempts to capture problems and challenges related to occupants’ performance within the physical boundaries of the classroom when learning technologies are in use. The variation of teaching-learning modes is taken into consideration. In this process, the researcher focuses on integration patterns of learning technologies with the envelope and the interior systems. The findings are then translated into the design language in the form of a pattern language at the building systems scale. / Ph. D.

Stereographic virtual environments display data in such a way that a user perceives objects within the displayed environment to be separated in depth from the display itself. The effectiveness of stereographic virtual environments as learning tools has been evaluated relative to factors such as multidimensional cues, user interaction, and learner characteristics. This study has examined the relationship between two evaluative factors: the presence of stereographic depth cues and field dependence, a learner characteristic associated with performance on visual tasks. Adult learners were identified on a field dependence continuum based on scores on the Group Embedded Figures Test. Each student received instruction related to the heart using stereographic materials or nonstereographic materials, depending on assignment to treatment group. All participants were given two tests, identification and terminology, following this instruction. The scores on the combination of these tests, denoted as the Modified Total Criterion Test (MTCT), represented the level of visual recall relative to the instructional materials reviewed. Analyses of variance revealed an interaction effect between the level of field dependence and the presence of stereographic depth cues within a virtual environment such that field independent participants scored higher on tests of visual recall within stereographic conditions versus nonstereographic conditions and field dependent participants scored lower within stereographic conditions versus nonstereographic conditions. / Ph. D.

This study was designed to investigate the need for a communication tool to support child development professionals, design professionals, and parents in the preschool design process. Guided by the theoretical perspectives of Gardner and Bronfenbrenner, this research examined the need for a support tool in the design process, the format and content of such a tool, and the evaluation of a tool developed using the data as an organizing structure. The following research questions guided this study: (a) Is a tool or support document needed to help educate and support communication between child development professionals, parents, and design professionals in the early phases of designing a preschool facility?, (b) What are the format and content issues that need to be addressed and included in developing such a tool?, and (c) How would child development professionals, design professionals, and parents comment on the usefulness of an educational/communication tool? A multi-method data collection procedure was used to gather the data for the study. A focus group was conducted to ascertain general information from child development professionals, design professionals, and parents about their opinions and perceptions of the design process as a result of their personal experiences. Following the focus group, 13 interviews were conducted with different individuals, but representative of the same three populations. Upon completion of the interviews, the data were used as an organizing structure for the writing of a communication tool to aid in the design process of preschool facilities. The tool was then sent to 26 individuals for feedback using a questionnaire requesting responses about the need, content, and format of the document. The results of this study showed that a support tool that fostered greater communication between child development professionals, design professionals, and parents was needed. Responses to the focus group and interviews also indicated that the format of the tool should be paper-based, or in book form, and that the themes identified in the responses should guide the content of the tool. Questionnaire responses confirm that the tool developed was an appropriate document that provided important information for the respondents. / Ph. D.

The positron when formed as a result of nuclear decay process (β+) can interact with an electron resulting in a positronium formation (Ps). In the first part of this thesis the formation of positronium in benzene solutions containing various halogenated compounds was studied in the presence and absence of C₆F₆ additives. The observed I₂ values, which are indicative of the number of thermalized positronium atoms formed, showed a good correlation with the dissociative electron attachment parameters of the solute species. The formation and the reactions of Ps were found to be very sensitive to structural changes and phase transitions. Therefore, the positron annihilation technique was applied for studying systems such as micelles, liposomes and polymers which have found widespread applications in today's chemical industry. The micelle formation process was investigated in inverted micelles. A distinct cooperative effect of the solution resulting in abrupt changes in the number of thermal ortho-positronium atoms was observed and studied as a function of temperature, counter ion, length and structure of the hydrocarbon chain in the cationic and anionic parts of the surfactant molecules. The results are being discussed in terms of existing models. The thermotropic transition, which is an important parameter for all membranes and liposomes, was studied in sonicated dioctadecyldimethylam-monium chloride versicles (DODAC). The results obtained provide important information on fluidities and allow further assessments of cationic surfactant vesicles as membrane mimetic agents. The third application deals with the study of styrene-butadiene-styrene block copolymers obtained by casting in toluene, carbon tetra-chloride, ethyl acetate and methyl ethyl ketone. The temperature studies show the appearance of two distinct changes in the positron annihilation parameter λ₂ at -70°C and +85°C. They were attributed to the onset of motion of butadiene and styrene respectively. In addition two other abrupt changes in λ₂ were observed at -14°C and +10°C. The change at -14°C was observed in all films whereas the second at +10°C occurs only in films casted in poor solvents (ethyl acetate and methyl ethyl ketone). Their presence is discussed in terms of phase separation and morphological changes. / Ph. D.

Museums are rich and complex learning experiences, using a variety of interactive approaches to engage their audiences. However, the largely unstructured nature of free-choice learning calls for alternative approaches that can effectively engage groups of school age students with diverse cultural backgrounds. In these informal learning spaces employing digital content, classroom-size student groups do not get adequate exposure to content and if they do, it is either through individual interactions with digital exhibits or in a passive style instruction offered by a museum docent to the whole group. This research aims to identify which elements of collocated group collaboration, virtual environments, and serious games can be leveraged for an enhanced learning experience for small and large groups of middle school students. We created a conceptual framework based on the Contextual Model of Learning in museums (John H. Falk and Dierking, 2000) and the most effective educational elements of Virtual Environments (VEs) and Serious Games, in order to increase engagement and social presence and facilitate learning. We then developed C-OLiVE (Collaborative Orchestrated Learning in Virtual Environments), an interactive virtual learning environment supporting group collaboration, which we used as a testbed to respond to our research questions. Our overall hypothesis is that synchronous, collocated, group collaboration will afford greater learning and an improved game experience compared to the conventional approaches used in these spaces so far. We ran three experiments and a case study with 790 students in private and public middle schools, summer camps, and museums both in the US and in Greece. Findings partly supported our hypothesis, mainly during our small group interaction experiments, in which simultaneous interaction of students was found to be associated with increased learning. Guidance of a passive experience was effective in facilitating the more cognitively challenged group of students in a Greek museum. Our audience interaction studies revealed increased retention of information two days after the game. Agency was found to significantly predict learning in all our studies. Engagement and social presence were mostly correlated with higher levels of involvement and agency in the game. / Ph. D.

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Research shows residential students have varying perceptions of satisfaction with their residential environments. It has also been shown that levels of satisfaction may differ between students based on variables such as hall size, organization, gender, or class standing. This study examined residence hall satisfaction levels for students living in the halls at Virginia Tech. The research question was: what are the differences in levels of satisfaction as measured by the Student Residence Environment Scales among residential students based upon hall size, hall type, and gender. The SRES was administered to approximately 1050 students, divided equally between six halls chosen to represent the variables of size, gender, and type. There was a 53% return rate with 55% female responses and 45% male responses. The data were analyzed using the SAS system and three-way ANOVAs were run on all 17 subscales. The results supported the research question in that there were significant differences between scores on the 17 subscales based upon hall size, hall type, and gender. Main effects and significant interactions between independent variables were found for all 17 subscales, indicating that hall size, hall type, and gender affect student satisfaction levels in the residence halls. The number of subscales and interactions do not allow for an abbreviated summary to be made; however, in general students were satisfied with the residence halls at Virginia Tech. The results of the study indicate that there are areas in which residence life personnel could make changes in policies and procedures which would increase levels of satisfaction in the residence halls. / Master of Arts

A Distributed Virtual Environment (DVE) system provides a shared virtual environment where physically separated users can interact and collaborate over a computer network. More simultaneous DVE users could result in intolerable system performance degradation. We address the three major challenges to improve DVE scalability: effective DVE system performance measurement, understanding the controlling factors of system performance/quality and determining the consequences of DVE system changes. We propose a DVE Scalability Engineering (DSE) process that addresses these three major challenges for DVE design. DSE allow us to identify, evaluate, and leverage trade-offs among DVE resources, the DVE software, and the virtual environment. DSE has three stages. First, we show how to simulate different numbers and types of users on DVE resources. Collected user study data is used to identify representative user types. Second, we describe a modeling method to discover the major trade-offs between quality of service and DVE resource usage. The method makes use of a new instrumentation tool called ppt. ppt collects atomic blocks of developer-selected instrumentation at high rates and saves it for offline analysis. Finally, we integrate our load simulation and modeling method into a single process to explore the effects of changes in DVE resources. We use the simple Asteroids DVE as a minimal case study to describe the DSE process. The larger and commercial Torque and Quake III DVE systems provide realistic case studies and demonstrate DSE usage. The Torque case study shows the impact of many users on a DVE system. We apply the DSE process to significantly enhance the Quality of Experience given the available DVE resources. The Quake III case study shows how to identify the DVE network needs and evaluate network characteristics when using a mobile phone platform. We analyze the trade-offs between power consumption and quality of service. The case studies demonstrate the applicability of DSE for discovering and leveraging tradeoffs between Quality of Experience and DVE resource usage. Each of the three stages can be used individually to improve DVE performance. The DSE process enables fast and effective DVE performance improvement. / Ph. D.

Before the recent advances in sensing, actuation, computing and communication technologies, the integration between the digital and the physical environment was limited. Humans linked those two worlds by collecting data about the physical environment before feeding it into the digital environment, and by changing the state of the physical environment based on the state of the digital environment. The incorporation of computing, communication, sensing, and actuation technologies into everyday physical objects has empowered the vision of the Internet of Things (IoT). Things can autonomously collect data about the physical environment, exchange information with other things, and take actions on behalf of humans. Application domains that can benefit from IoT include smart buildings, smart cities, smart water, smart agriculture, smart animal farming, smart metering, security and emergencies, retail, logistics, industrial control, and health care. For decades, building automation, intelligent buildings, and more recently smart buildings have received a considerable attention in both academia and industry. We use the term smart built environments (SBE) to describe smart, intelligent, physical, built, architectural spaces ranging from a single room to a whole city. Legacy SBEs were often closed systems operating their own standards and custom protocols. SBEs evolved to Internet-connected systems leveraging the Internet technologies and services (e.g., cloud services) to unleash new capabilities. IoT-enabled SBEs, as one of the various applications of the IoT, can change the way we experience our homes and workplaces significantly and make interacting with technology almost inevitable. This can provide several benefits to modern society and help to make our life easier. Meanwhile, security, privacy, and safety concerns should be addressed appropriately. Unlike traditional computing devices, things usually have no or limited input/output (I/O) capabilities. Leveraging the ubiquity of general-purpose computing devices (e.g., smartphones), thing vendors usually provide interfaces for their products in the form of mobile apps or web-based portals. Interacting with different things using different mobile apps or web-based portals does not scale well. Requiring the user to switch between tens or hundreds of mobile apps and web-based portals to interact with different things in different smart spaces may not be feasible. Moreover, it can be tricky for non-domestic users (e.g., visitors) of a given SBE to figure out, without guidance, what mobile apps or web-based portals they need to use to interact with the surrounding. While there has been a considerable research effort to address a variety of challenges associated with the thing-to-thing interaction, human-to-thing interaction related research is limited. Many of the proposed approaches and industry-adopted techniques rely on more traditional, well understood and widely used Human-Computer Interaction (HCI) methods and techniques to support interaction between humans and things. Such techniques have mostly originated in a world of desktop computers that have a screen, mouse, and keyboard. However, SBEs introduce a radically different interaction context where there are no centralized, easily identifiable input and output devices. A desktop computer of the past is being replaced with the whole SBE. Depending on the task at hand and personal preferences, a user may prefer to use one interaction modality over another. For instance, turning lights on/off using an app may be more cumbersome or time-consuming compared to using a simple physical switch. This research focuses on leveraging the recent advances in IoT and related technologies to support user interactions with SBEs. We explore how to support flexible and adaptive multimodal interfaces and interactions while providing a consistent user experience in an SBE based on the current context and the available user interface and interaction capabilities. / PHD / The recent advances in sensing, actuation, computing, and communication technologies have brought several rewards to modern society. The incorporation of those technologies into everyday physical objects (or things) has empowered the vision of the Internet of Things (IoT). Things can autonomously collect data about the physical environment, exchange information with other things, and take actions on behalf of humans. Several application domains can benefit from the IoT such as smart buildings, smart cities, security and emergencies, retail, logistics, industrial control, and health care. For decades, building automation, intelligent buildings, and more recently smart buildings have received considerable attention in both academia and industry. We use the term smart built environments (SBE) to describe smart, intelligent, physical, built, architectural spaces ranging from a single room to a whole city. SBEs, as one of the various applications of the IoT, can change the way we experience our homes and workplaces significantly and make interacting with technology almost inevitable. While there has been a considerable research effort to address a variety of challenges associated with the thing-to-thing interaction, human-to-thing interaction related research is limited. Many of the proposed approaches and industry-adopted techniques to support human-to-thing interaction rely on traditional methods. However, SBEs introduce a radically different interaction context. Therefore, adapting the current interaction techniques and/or adopting new ones is crucial for the success and wide adoption of SBEs. This research focuses on leveraging the recent advances in the IoT and related technologies to support user interactions with SBEs. We explore how to support a flexible, adaptive, and multimodal interaction experience between users and SBEs using a variety of user interfaces and proposed interaction techniques.

Reliable sensing and monitoring systems based on optical fibers operating at high temperatures and in harsh environments are of high demand. One of the limitations of such systems is the devitrification of the fused silica based core and cladding glass at elevated temperatures. Crystallites can nucleate on the surface of the cladding and grow into the core. The formation of these crystalline flaws in the optical fiber causes stress concentration and extrinsic optical scattering and in addition leads to decreased mechanical properties and reduced optical stability. Commercial optical fibers of different compositions and core-cladding design were characterized in this study with respect to crystallization rate under various conditions. The optical stability was monitored with an optical spectrum analyzer. The crystallites were characterized with SEM and optical microscopy. The activation energies of crystallization for High OH and Low OH multimode fibers were estimated by measuring the crystal growth rate at different temperatures. The residual stress resulting from the formation of the crystals, which can lead to decreased mechanical performance of the fibers, was characterized with polarized light optical microscopy. The influence of water vapor in the atmosphere on the crystallization rate was determined. The features induced in the attenuation spectra were consistent with hydroxyl (OH) absorption peak. Spectral features such as thermal emission and hydroxyl absorption bands are discussed. The results obtained in this study can be used for selecting optical fibers for high temperature applications. / Master of Science