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Description
When looking at drawings of graphs, questions about graph density, community structures, local clustering and other graph properties may be of critical importance for analysis. While graph layout algorithms have focused on minimizing edge crossing, symmetry, and other such layout properties, there is not much known about how these algorithms relate to a user’s ability to perceive graph properties for a given graph layout. This study applies previously established methodologies for perceptual analysis to identify which graph drawing layout will help the user best perceive a particular graph property. A large scale (n = 588) crowdsourced experiment is conducted to investigate whether the perception of two graph properties (graph density and average local clustering coefficient) can be modeled using Weber’s law. Three graph layout algorithms from three representative classes (Force Directed - FD, Circular, and Multi-Dimensional Scaling - MDS) are studied, and the results of this experiment establish the precision of judgment for these graph layouts and properties. The findings demonstrate that the perception of graph density can be modeled with Weber’s law. Furthermore, the perception of the average clustering coefficient can be modeled as an inverse of Weber’s law, and the MDS layout showed a significantly different precision of judgment than the FD layout.
ContributorsSoni, Utkarsh (Author) / Maciejewski, Ross (Thesis advisor) / Kobourov, Stephen (Committee member) / Sefair, Jorge (Committee member) / Arizona State University (Publisher)
Created2018
Description
Cellular metabolism is an essential process required for tissue formation, energy production and systemic homeostasis and becomes dysregulated in many disease states. In the context of human cerebral cortex development, there’s a limited understanding of how metabolic pathways, such as glycolysis, impacts proliferation and differentiation of cortical cells. The technical challenges of studying primary in vivo cortical tissue at a cellular and molecular level led to the development of human pluripotent stem cell (PSC) derived cortical organoids. Cortical organoids are a highly tractable model system that can be used for high-throughput investigation of early stages of development and corresponding glycolytic programs. Through transplantation of cortical organoids into the developing mouse cortex, human cortical cells can also be studied in an in vivo environment that more closely resembles endogenous development where the impact of metabolism in typical developmental programs and disease states can be studied. While current data is preliminary, initial observations suggest that cortical populations increase glucose uptake over time and regulation of glucose uptake rates occur in cell type-specific manner. Additionally, mouse transplantation data suggests that glycolytic activity is downregulated post-transplantation, suggesting that the in vitro environment contributes metabolic state. The more dynamic range of metabolic states in vivo may impact the rate of differentiation and maturation in cellular populations in the transplant model. I hypothesize that the more endogenous-like regulation of glycolysis may impact the proliferative window and expansion of key progenitor cell types in the human brain, particularly the intermediate progenitor cells.
ContributorsMorales, Alexandria (Author) / Andrews, Madeline (Thesis advisor) / Newbern, Jason (Committee member) / Stabenfeldt, Sarah (Committee member) / Arizona State University (Publisher)
Created2023
Description
Mid-air ultrasound haptic technology can enhance user interaction and immersion in extended reality (XR) applications through contactless touch feedback. However, existing design tools for mid-air haptics primarily support the creation of static tactile sensations (tactons), which lack adaptability at runtime. These tactons do not offer the required expressiveness in interactive scenarios where a continuous closed-loop response to user movement or environmental states is desirable. This thesis proposes AdapTics, a toolkit featuring a graphical interface for the rapid prototyping of adaptive tactons—dynamic sensations that can adjust at runtime based on user interactions, environmental changes, or other inputs. A software library and a Unity package accompany the graphical interface to enable integration of adaptive tactons in existing applications. The design space provided by AdapTics for creating adaptive mid-air ultrasound tactons is presented, along with evidence that the design tool enhances Creativity Support Index ratings for Exploration and Expressiveness, as demonstrated in a user study involving 12 XR and haptic designers.
ContributorsJohn, Kevin (Author) / Seifi, Hasti (Thesis advisor) / Bryan, Chris (Committee member) / Schneider, Oliver (Committee member) / Arizona State University (Publisher)
Created2024