Browsing by Author "Polys, Nicholas F."

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    3D Deep Learning for Object-Centric Geometric Perception
    Li, Xiaolong (Virginia Tech, 2022-06-30)
    Object-centric geometric perception aims at extracting the geometric attributes of 3D objects. These attributes include shape, pose, and motion of the target objects, which enable fine-grained object-level understanding for various tasks in graphics, computer vision, and robotics. With the growth of 3D geometry data and 3D deep learning methods, it becomes more and more likely to achieve such tasks directly using 3D input data. Among different 3D representations, a 3D point cloud is a simple, common, and memory-efficient representation that could be directly retrieved from multi-view images, depth scans, or LiDAR range images. Different challenges exist in achieving object-centric geometric perception, such as achieving a fine-grained geometric understanding of common articulated objects with multiple rigid parts, learning disentangled shape and pose representations with fewer labels, or tackling dynamic and sequential geometric input in an end-to-end fashion. Here we identify and solve these challenges from a 3D deep learning perspective by designing effective and generalizable 3D representations, architectures, and pipelines. We propose the first deep pose estimation for common articulated objects by designing a novel hierarchical invariant representation. To push the boundary of 6D pose estimation for common rigid objects, a simple yet effective self-supervised framework is designed to handle unlabeled partial segmented scans. We further contribute a novel 4D convolutional neural network called PointMotionNet to learn spatio-temporal features for 3D point cloud sequences. All these works advance the domain of object-centric geometric perception from a unique 3D deep learning perspective.
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    Advancing the Global Land Grant Institution: Creating a Virtual Environment to Re-envision Extension and Advance GSS-related Research, Education, and Collaboration
    Hall, Ralph P.; Polys, Nicholas F.; Sforza, Peter M.; Eubank, Stephen D.; Lewis, Bryan L.; Krometis, Leigh-Anne H.; Pollyea, Ryan M.; Schoenholtz, Stephen H.; Sridhar, Venkataramana; Crowder, Van; Lipsey, John; Christie, Maria Elisa; Glasson, George E.; Scherer, Hannah H.; Davis, A. Jack; Dunay, Robert J.; King, Nathan T.; Muelenaer, Andre A.; Muelenaer, Penelope; Rist, Cassidy; Wenzel, Sophie (Virginia Tech, 2017-05-15)
    The vision for this project has emerged from several years of research, teaching, and service in Africa and holds the potential to internationalize education at Virginia Tech and in our partner institutions in Malawi. The vision is simple, to develop a state-of-the-art, data rich, virtual decision-support and learning environment that enables local-, regional-, and national-level actors in developed and developing regions to make decisions that improve resilience and sustainability. Achieving these objectives will require a system that can combine biogeophysical and sociocultural data in a way that enables actors to understand and leverage these data to enhance decision-making at various levels. The project will begin by focusing on water, agricultural, and health systems in Malawi, and can be expanded over time to include any sector or system in any country. The core ideas are inherently scalable...
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    Be the Data: Embodied Visual Analytics
    Chen, Xin (Virginia Tech, 2016-08-22)
    With the rise of big data, it is becoming increasingly important to educate students about data analytics. In particular, students without a strong mathematical background usually have an unenthusiastic attitude towards high-dimensional data and find it challenging to understand relevant complex analytical methods, such as dimension reduction. In this thesis, we present an embodied approach for visual analytics designed to teach students exploring alternative 2D projections of high dimensional data points using weighted multidimensional scaling. We proposed a novel application, Be the Data, to explore the possibilities of using human's embodied resources to learn from high dimensional data. In our system, each student embodies a data point and the position of students in a physical space represents a 2D projection of the high-dimensional data. Students physically moves in a room with respect to others to interact with alternative projections and receive visual feedback. We conducted educational workshops with students inexperienced in relevant data analytical methods. Our findings indicate that the students were able to learn about high-dimensional data and data analysis process despite their low level of knowledge about the complex analytical methods. We also applied the same techniques into social meetings to explain social gatherings and facilitate interactions.
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    Beyond the stony veil: Reconstructing the Earth’s earliest large animal traces via computed tomography X-ray imaging
    Meyer, Mike; Polys, Nicholas F.; Yaqoob, Humza; Hinnov, Linda; Xiao, Shuhai (2017-09)
    Trace fossils are superb lines of evidence for examining the ancient biologic world because they offer an opportunity to infer behavioral ecology of organisms. However, traces can be difficult to parse from their matrix, which leads to the loss of important morphological and behavioral data. This is especially true for the earliest marine animal traces from the Ediacaran Period (635–541 Ma), which are usually small (<5 mm in diameter) and simple (mostly small horizontal trails and burrows), and are sometimes difficult to be distinguished from co-existing tubular body fossils. There is also evidence that the prevalence of microbial substrates in Ediacaran oceans may have influenced emerging trace makers in nonactualistic ways from a late Phanerozoic perspective (e.g., microbial mats may have facilitated a strong geochemical gradient across the sediment-water interface). Therefore, the discovery of the relatively large traces of Lamonte trevallis from the Ediacaran Shibantan Member of the Denying Formation (~551–541 Ma) in the Yangtze Gorges area of South China provides a unique opportunity to study early bioturbators. These trace fossils are large enough and have sufficient compositional contrast (relative to the matrix) for in situ analysis via X-ray computed tomography (CT) and microcomputed tomography (microCT). Each analytical method has its own advantages and disadvantages. CT scans can image larger specimens, but cannot adequately resolve small features of interest. MicroC scans can achieve higher resolution, but can only be used with small samples and may involve more post-processing than CT scans. As demonstrated in this study, X-ray CT and microCT in combination with other 3D imaging techniques and resources have the potential to resolve the 3D morphology of Ediacaran trace fossils. A new Volumetric Bioturbation Intensity (VBI) is also proposed, which quantifies whole rock bioturbation using 3D analysis of subsurface traces. Combined with the ability to examine trace fossils in situ, the VBI can enhance our view of ancient ecologies and life’s enduring relationship with sediments.
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    A Bidirectional Pipeline for Semantic Interaction in Visual Analytics
    Binford, Adam Quarles (Virginia Tech, 2016-09-21)
    Semantic interaction in visual data analytics allows users to indirectly adjust model parameters by directly manipulating the output of the models. This is accomplished using an underlying bidirectional pipeline that first uses statistical models to visualize the raw data. When a user interacts with the visualization, the interaction is interpreted into updates in the model parameters automatically, giving the users immediate feedback on each interaction. These interpreted interactions eliminate the need for a deep understanding of the underlying statistical models. However, the development of such tools is necessarily complex due to their interactive nature. Furthermore, each tool defines its own unique pipeline to suit its needs, which leads to difficulty experimenting with different types of data, models, interaction techniques, and visual encodings. To address this issue, we present a flexible multi-model bidirectional pipeline for prototyping visual analytics tools that rely on semantic interaction. The pipeline has plug-and-play functionality, enabling quick alterations to the type of data being visualized, how models transform the data, and interaction methods. In so doing, the pipeline enforces a separation between the data pipeline and the visualization, preventing the two from becoming codependent. To show the flexibility of the pipeline, we demonstrate a new visual analytics tool and several distinct variations, each of which were quickly and easily implemented with slight changes to the pipeline or client.
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    Brain-wide cellular resolution imaging of Cre transgenic zebrafish lines for functional circuit-mapping
    Tabor, Kathryn M.; Marquart, Gregory D.; Hurt, Christopher; Smith, Trevor S.; Geoca, Alexandra K.; Bhandiwad, Ashwin A.; Subedi, Abhignya; Sinclair, Jennifer L.; Rose, Hannah M.; Polys, Nicholas F.; Burgess, Harold A. (2019-02-08)
    Decoding the functional connectivity of the nervous system is facilitated by transgenic methods that express a genetically encoded reporter or effector in specific neurons; however, most transgenic lines show broad spatiotemporal and cell-type expression. Increased specificity can be achieved using intersectional genetic methods which restrict reporter expression to cells that co-express multiple drivers, such as Gal4 and Cre. To facilitate intersectional targeting in zebrafish, we have generated more than 50 new Cre lines, and co-registered brain expression images with the Zebrafish Brain Browser, a cellular resolution atlas of 264 transgenic lines. Lines labeling neurons of interest can be identified using a web-browser to perform a 3D spatial search (zbbrowser.com). This resource facilitates the design of intersectional genetic experiments and will advance a wide range of precision circuit-mapping studies.
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    Bridging Cognitive Gaps Between User and Model in Interactive Dimension Reduction
    Wang, Ming (Virginia Tech, 2020-05-05)
    High-dimensional data is prevalent in all domains but is challenging to explore. Analysis and exploration of high-dimensional data are important for people in numerous fields. To help people explore and understand high-dimensional data, Andromeda, an interactive visual analytics tool, has been developed. However, our analysis uncovered several cognitive gaps relating to the Andromeda system: users do not realize the necessity of explicitly highlighting all the relevant data points; users are not clear about the dimensional information in the Andromeda visualization; and the Andromeda model cannot capture user intentions when constructing and deconstructing clusters. In this study, we designed and implemented solutions to address these gaps. Specifically, for the gap in highlighting all the relevant data points, we introduced a foreground and background view and distance lines. Our user study with a group of undergraduate students revealed that the foreground and background views and distance lines could significantly alleviate the highlighting issue. For the gap in understanding visualization dimensions, we implemented a dimension-assist feature. The results of a second user study with students with various backgrounds suggested that the dimension-assist feature could make it easier for users to find the extremum in one dimension and to describe correlations among multiple dimensions; however, the dimension-assist feature had only a small impact on characterizing the data distribution and assisting users in understanding the meanings of the weighted multidimensional scaling (WMDS) plot axes. Regarding the gap in creating and deconstructing clusters, we implemented a solution utilizing random sampling. A quantitative analysis of the random sampling strategy was performed, and the results demonstrated that the strategy improved Andromeda's capabilities in constructing and deconstructing clusters. We also applied the random sampling to two-point manipulations, making the Andromeda system more flexible and adaptable to differing data exploration tasks. Limitations are discussed, and potential future research directions are identified.
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    Bridging cognitive gaps between user and model in interactive dimension reduction
    Wang, Ming; Wenskovitch, John; House, Leanna L.; Polys, Nicholas F.; North, Christopher L. (2021-06)
    Interactive machine learning (ML) systems are difficult to design because of the "Two Black Boxes" problem that exists at the interface between human and machine. Many algorithms that are used in interactive ML systems are black boxes that are presented to users, while the human cognition represents a second black box that can be difficult for the algorithm to interpret. These black boxes create cognitive gaps between the user and the interactive ML model. In this paper, we identify several cognitive gaps that exist in a previously-developed interactive visual analytics (VA) system, Andromeda, but are also representative of common problems in other VA systems. Our goal with this work is to open both black boxes and bridge these cognitive gaps by making usability improvements to the original Andromeda system. These include designing new visual features to help people better understand how Andromeda processes and interacts with data, as well as improving the underlying algorithm so that the system can better implement the intent of the user during the data exploration process. We evaluate our designs through both qualitative and quantitative analysis, and the results confirm that the improved Andromeda system outperforms the original version in a series of high-dimensional data analysis tasks. (C) 2021 The Author(s). Published by Elsevier B.V. on behalf of Zhejiang University and Zhejiang University Press Co. Ltd.
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    Building 3D Web Interoperability for the Metaverse
    Havele, Anita; Polys, Nicholas F.; Behr, Johannes (ACM, 2023-10-09)
    This workshop brings together participants from around the world with the goal of building a strong foundation for an open, interoperable Metaverse using the Web and the Web Standards ecosystem. The workshop will focus on four main topics: 1) The variety of relevant Standards and technology roles in the Metaverse stack, 2) the role of the 3D Web Interoperability Working Group, which has recently been chartered in the Metaverse Standards Forum, 3) scoping what the Metaverse IS NOT, and 4) how Use Cases and Scenarios can help clarify what the Metaverse IS. In this emerging space, perspectives and tradeoffs abound; we hope this workshop will push our understanding and terminology forward and also provide the community with an actionable set of common (yet extensible) referents and goals.
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    Cinemacraft: Exploring Fidelity Cues in Collaborative Virtual World Interactions
    Narayanan, Siddharth (Virginia Tech, 2018-02-15)
    The research presented in this thesis concerns the contribution of virtual human (or avatar) fidelity to social interaction in virtual environments (VEs) and how sensory fusion can improve these interactions. VEs present new possibilities for mediated communication by placing people in a shared 3D context. However, there are technical constraints in creating photo realistic and behaviorally realistic avatars capable of mimicking a person's actions or intentions in real time. At the same time, previous research findings indicate that virtual humans can elicit social responses even with minimal cues, suggesting that full realism may not be essential for effective social interaction. This research explores the impact of avatar behavioral realism on people's experience of interacting with virtual humans by varying the interaction fidelity. This is accomplished through the creation of Cinemacraft, a technology-mediated immersive platform for collaborative human-computer interaction in a virtual 3D world and the incorporation of sensory fusion to improve the fidelity of interactions and realtime collaboration. It investigates interaction techniques within the context of a multiplayer sandbox voxel game engine and proposes how interaction qualities of the shared virtual 3D space can be used to further involve a user as well as simultaneously offer a stimulating experience. The primary hypothesis of the study is that embodied interactions result in a higher degree of presence and co-presence, and that sensory fusion can improve the quality of presence and co-presence. The argument is developed through research justification, followed by a user-study to demonstrate the qualitative results and quantitative metrics.This research comprises of an experiment involving 24 participants. Experiment tasks focus on distinct but interrelated questions as higher levels of interaction fidelity are introduced.The outcome of this research is the generation of an interactive and accessible sensory fusion platform capable of delivering compelling live collaborative performances and empathetic musical storytelling that uses low fidelity avatars to successfully sidestep the 'uncanny valley'. This research contributes to the field of immersive collaborative interaction by making transparent the methodology, instruments and code. Further, it is presented in non-technical terminology making it accessible for developers aspiring to use interactive 3D media to pro-mote further experimentation and conceptual discussions, as well as team members with less technological expertise.
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    Composing Holochoric Visual Music: Interdisciplinary Matrices
    Rhoades, Michael Jewell (Virginia Tech, 2021-02-01)
    With a lineage originating in the days of silent films, visual music, in its current incarnation, is a relatively recent phenomenon when compared to an historically broad field of creative expression. Today it is a time-based audio/visual territory explored and mined by a handful of visual and musical artists. However, an extensive examination of the literature indicates that few of these composers have delved into the associable areas of merging virtual holography and holophony toward visual music composition. It is posited here that such an approach is extremely rich with novel expressive potential and simultaneously with numerous novel challenges. The goal of this study is, through praxis, to instantiate and document an initial exploration into the implementation of holochory toward the creation of visual music compositions. Obviously, engaging holochoric visual music as a means of artistic expression requires an interdisciplinary pipeline. Certainly, this is demonstrated in merging music and visual art into a cohesive form, which is the basis of visual music composition. However, in this study is revealed another form of interdisciplinarity. A major challenge resides with the development of the means to efficiently render the high-resolution stereoscopic images intrinsic to the animation of virtual holograms. Though rendering is a challenge consistent with creating digital animations in general, here the challenge is further exacerbated by the extensive use of multiple reflections and refractions to create complexity from relatively simple geometric objects. This reveals that, with the level of computational technology currently available, the implementation of high-performance computing is the optimal approach. Unifying such diverse areas as music, visual art, and computer science toward a common artistic medium necessitates a methodological approach in which the interdependency between each facet is recognized and engaged. Ultimately, a quadrilateral reciprocative feedback loop, involving the composer's sensibilities in addition to each of the other facets of the compositional process, must be realized in order to facilitate a cohesive methodology leading toward viability. This dissertation provides documentation of methodologies and ideologies undertaken in an initial foray into creating holochoric visual music compositions. Interlaced matrices of contextualization are intended to disseminate the processes involved in deference to composers who will inevitably follow in the wake of this research. Accomplishing such a goal is a quintessential aspect of practice-based research, through which new knowledge is gained during the act of creating. Rather than formulating theoretical perspectives, it is through the praxis of composing holochoric visual music that the constantly arising challenges are recognized, analyzed, and subsequently addressed and resolved in order to ensure progression in the compositional process. Though measuring the success of the resultant compositions is indeed a subjective endeavor, as is the case with all art, the means by which they are achieved is not. The development of such pipelines and processes, and their implementation in practice, are the basic building blocks of further exploration, discovery, and artistic expression. This is the impetus for this document and for my constantly evolving and progressing trajectory as a scholar, artist, composer, and computer scientist.
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    Compressed Sensing based Micro-CT Methods and Applications
    Sen Sharma, Kriti (Virginia Tech, 2013-06-12)
    High-resolution micro computed tomography (micro-CT) offers 3D image resolution of 1 um for non-destructive evaluation of various samples. However, the micro-CT performance is limited by several factors. Primarily, scan time is extremely long, and sample dimension is restricted by the x-ray beam and the detector size. The latter is the cause for the well-known interior problem. Recent advancement in image reconstruction, spurred by the advent of compressed sensing (CS) theory in 2006 and interior tomography theory since 2007, offers great reduction in the number of views and an increment in the volume of samples, while maintaining reconstruction accuracy. Yet, for a number of reasons, traditional filtered back-projection based reconstruction methods remain the de facto standard on all manufactured scanners. This work demonstrates that CS based global and interior reconstruction methods can enhance the imaging capability of micro-CT scanners. First, CS based few-view reconstruction methods have been developed for use with data from a real micro-CT scanner. By achieving high quality few-view reconstruction, the new approach is able to reduce micro-CT scan time to up to 1/8th of the time required by the conventional protocol. Next, two new reconstruction techniques have been developed that allow accurate interior reconstruction using just a limited number of global scout views as additional information. The techniques represent a significant progress relative to the previous methods that assume a fully sampled global scan. Of the two methods, the second method uses CS techniques and does not place any restrictions on scanning geometry. Finally, analytic and iterative reconstruction methods have been developed for enlargement of the field of view for the interior scan with a small detector. The idea is that truncated projections are acquired in an offset detector geometry, and the reconstruction procedure is performed through the use of a weighting function / weighted iteration updates, and projection completion. The CS based reconstruction yields the highest image quality in the numerical simulation. Yet, some limitations of the CS based techniques are observed in case of real data with various imperfect properties. In all the studies, physical micro-CT phantoms have been designed and utilized for performance analysis. Also, important guidelines are suggested for future improvements.
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    Cross-Platform Presentation of Interactive Volumetric Imagery
    Polys, Nicholas F.; Wood, Andrew; Shinpaugh, Patrick (Department of Computer Science, Virginia Polytechnic Institute & State University, 2012)
    Volume data is useful across many disciplines, not just medicine. Thus, it is very important that researchers have a simple and lightweight method of sharing and reproducing such volumetric data. In this paper, we explore some of the challenges associated with volume rendering, both from a classical sense and from the context of Web3D technologies. We describe and evaluate the pro- posed X3D Volume Rendering Component and its associated styles for their suitability in the visualization of several types of image data. Additionally, we examine the ability for a minimal X3D node set to capture provenance and semantic information from outside ontologies in metadata and integrate it with the scene graph.
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    Design and Display of Enhancing Information in Desktop Information-Rich Virtual Environments: Challenges and Techniques
    Polys, Nicholas F.; Bowman, Douglas A. (Department of Computer Science, Virginia Polytechnic Institute & State University, 2003)
    Information-Rich Virtual Environments (IRVEs) have been described as environments in which perceptual information is enhanced with abstract (or symbolic) information such as text, numbers, images, audio, video, or hyperlinked resources. Desktop VE applications present the same information design and layout challenges as immersive VEs, but in addition, they may also be integrated with external windows or frames commonly used in desktop interfaces. This paper enumerates design approaches for the display of enhancing information both internal and external to the virtual world?s render volume. Using standard web-based software frameworks, we explore a number of implicit and explicit spatial layout methods for the display and linking of abstract information, especially text. Within the virtual environment view, we demonstrate both Heads-Up-Displays and encapsulated scenegraph behaviors we call Semantic Objects. For desktop displays, which support information display venues external to the scene, we demonstrate the linking and integration of the scene with web browsers and the Snap-Together visualization a system. Finally, we describe the application of these techniques in the PathSim Visualizer, an IRVE interface for the biomedical domain. These design techniques are relevant for instructional and informative interfaces for a wide variety of desktop VE applications.
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    Designing Coherent Interactions for Virtual Reality
    Yu, Run (Virginia Tech, 2019-08-26)
    Coherence describes the validity of the internal rules that drive the behaviors of a virtual environment (VE) in presenting a credible scenario. A VR system with a high level of coherence could lead to strong plausibility illusion, which is a key component of the sense of presence. There are few existing studies centered around coherence, and they tend to put the user in a passive role when experiencing the VE without emphasizing on their active participation in the interaction. This dissertation makes up this gap by connecting the concept of coherence with fundamental 3D user interface design that focuses on the algorithms that map the user's actions to the VE's behaviors. Specifically, we inspect the design of coherent interactions for two complicated tasks, namely travel and object manipulation. For travel, we propose a family of redirected walking techniques called "narrative driven cell-based redirection", which lets the user traverse a VE that's much larger than the physical space without breaking the coherence of the scenario. For object manipulation, we propose the novel concept of physics coherence to capture whether an interface conforms to the rules of physics and design several novel techniques that try to balance between physics coherence and usability. Together, we provide some useful tools for designing coherent interactions and discuss how coherence affects user experience in VR interaction.
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    Designing for Social Interactions in a Virtual Art Gallery
    Polys, Nicholas F.; Roshan, Samridhi; Newton, Emily; Narula, Muskaan; Thai, Bao-Tran (ACM, 2022-11-02)
    The dawn of a new digital world has emerged with new ways to communicate and collaborate with other people across the globe. Metaverses and Mirror Worlds have broadened our perspectives on the ways we can utilize 3D virtual environments. A Mirror World is a 3D virtual space that depicts a real-life place or environment that people may want to see physically or would like to manipulate to create something new. A perfect example of this would be an art gallery which provides people an outlet to express themselves through various art forms and be able to socialize and have that human interaction that is needed during times when physical presence may be difficult. This project strives to improve user social interactions and make spatial control easier and more fluid in a virtual art gallery, while also incorporating the existing metaphor of permission and user privileges used in synchronous collaborative environments. We worked to create ways for people to be invited into group chats based on proximity, allowing users to give their consent as to who they want to talk to and who they will allow to share control within the space. We also implemented a way to view the space as a 3D map that highlights pieces of artwork around the space for people to teleport to and view at ease. To demonstrate this shared viewing and navigation experience we also focused on incorporating audio and spatial interaction features within the art gallery prototype of X3D and glTF models, images and audio, and HTML user interface.
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    Development of a Responsible Policy Index to Improve Statutory and Self-Regulatory Policies that Protect Children’s Diet and Health in the America’s Region
    Rincón-Gallardo Patiño, Sofía; Rajamohan, Srijith; Meaney, Kathleen; Coupey, Eloise; Serrano, Elena L.; Hedrick, Valisa E.; da Silva Gomes, Fabio; Polys, Nicholas F.; Kraak, Vivica (MDPI, 2020-01-13)
    In 2010, 193 Member States of the World Health Organization (WHO) endorsed World Health Assembly Resolution WHA63.14 to restrict the marketing of food and beverage products high in fat, sugar and salt (HFSS) to children to prevent obesity and non-communicable diseases (NCDs). No study has examined HFSS marketing policies across the WHO regional office countries in the Americas. Between 2018 and 2019, a transdisciplinary team examined policies to restrict HFSS food and beverage product marketing to children to develop a responsible policy index (RESPI) that provides a quality score based on policy characteristics and marketing techniques. After designing the RESPI, we conducted a comprehensive literature review through October 2019 to examine policies in 14 countries in the WHO Americans Region. We categorized policies (n = 38) as either self-regulatory or statutory and calculated the RESPI scores, ranked from 0 (lowest) to 10 (highest). Results showed Brazil, Canada, Chile, and Uruguay had the highest RESPI scores associated with statutory policies that restricted point of sale, cartoon, licensed media characters and celebrities; and HFSS products in schools and child care settings, and broadcast and print media. Policymakers can use the RESPI tool to evaluate marketing policies within and across geopolitical boundaries to protect children’s diet and health.
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    Dimension Reduction and Clustering for Interactive Visual Analytics
    Wenskovitch Jr, John Edward (Virginia Tech, 2019-09-06)
    When exploring large, high-dimensional datasets, analysts often utilize two techniques for reducing the data to make exploration more tractable. The first technique, dimension reduction, reduces the high-dimensional dataset into a low-dimensional space while preserving high-dimensional structures. The second, clustering, groups similar observations while simultaneously separating dissimilar observations. Existing work presents a number of systems and approaches that utilize these techniques; however, these techniques can cooperate or conflict in unexpected ways. The core contribution of this work is the systematic examination of the design space at the intersection of dimension reduction and clustering when building intelligent, interactive tools in visual analytics. I survey existing techniques for dimension reduction and clustering algorithms in visual analytics tools, and I explore the design space for creating projections and interactions that include dimension reduction and clustering algorithms in the same visual interface. Further, I implement and evaluate three prototype tools that implement specific points within this design space. Finally, I run a cognitive study to understand how analysts perform dimension reduction (spatialization) and clustering (grouping) operations. Contributions of this work include surveys of existing techniques, three interactive tools and usage cases demonstrating their utility, design decisions for implementing future tools, and a presentation of complex human organizational behaviors.
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    Display Techniques in Information-Rich Virtual Environments
    Polys, Nicholas F. (Virginia Tech, 2006-06-02)
    Across domains, researchers, engineers, and designers are faced with large volumes of data that are heterogeneous in nature - including spatial, abstract, and temporal information. There are numerous design and technical challenges when considering the unification, management, and presentation of these information types. Most research and applications have focused on display techniques for each of the information types individually, but much less in known about how to represent the relationships between information types. This research explores the perceptual and usability impacts of data representations and layout algorithms for the next-generation of integrated information spaces. We propose Information-Rich Virtual Environments (IRVEs) as a solution to challenges of integrated information spaces. In this presentation, we will demonstrate the application requirements and foundational technology of IRVEs and articulate crucial tradeoffs in IRVE information design. We will present a design space and evaluation methodology to explore the usability effects of these tradeoffs. Experimental results will be presented for a series of empirical usability evaluations that increase our understanding of how these tradeoffs can be resolved to improve user performance. Finally, we interpret the results though the models of Information Theory and Human Information Processing to derive new conclusions regarding the role of perceptual cues in determining user performance in IRVEs. These lessons are posed as a set of design guidelines to aid developers of new IRVE interfaces and specifications.
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    The Effect of Interaction Fidelity on User Experience in Virtual Reality Locomotion
    Warren, Lawrence Elliot (Virginia Tech, 2018-05-25)
    In virtual worlds, designers often consider "real walking" to be the gold standard when it comes to locomotion, as shown by attempts to incorporate walking techniques within tasks. When real walking is not conceivable due to several different limitations of virtual interactions (space, hardware, tracking, etc.) a walking simulation technique is sometimes used. We call these moderate interaction fidelity techniques and based upon literature, we can speculate that they will often provide an inferior experience if compared to a technique of high or low fidelity. We believe that there is an uncanny valley which is formed if a diagram is created using interaction fidelity and user effectiveness. Finding more points on this graph would help to support claims we have made with our hypothesis. There are several studies done previously in the field of virtual reality, however a vast majority of them considered interaction fidelity as a single construct. We argue that interaction fidelity is more complex involving independent components, with each of those components having an effect of the actual effectiveness of an interface. In addition, the intention of the designer can also have influence on how effective an interface can be. In this study we are going to be doing a deeper look into devices which attempt to overcome the limitations of physical space which we will call semi-natural interfaces. Semi-natural interfaces are sometimes difficult to use at first due to mismatch of cues or possibly due to a lack of fidelity, but training has been shown to be beneficial to overcome this difficulty. As of today, designers have not yet found a fully general solution to walking in large virtual environments.