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Experimenting with Orange Pavement Markings on Indiana Roadways
Get PDFThis session presents the status of experimental orange pavement markings on Indiana roadways. The presentation includes a summary of the MUTCD experimentation request and an evaluation of orange pavement marking types— including tapes and paints with a focus on color and retroreflectivity retention. The effects of driving behavior on the safety of work zones, vehicle lane positioning, and public opinion are also discussed
Interstate Highway Congestion Policy Request: When and How
Get PDFThis session will highlight current IHCP tables, policy tables, request templates, analysis tools, INDOT queue analysis spreadsheet, INDOT detour route summary spreadsheet, hourly day-of-the-week con- version factors, additional modeling efforts, common and repeated mistakes, IHCP exception checklist, and example projects
From Image Gradients to a Perceptual Metric Space
Get PDFHow do we achieve a sense of spatial dimension from a sense of location? There are three predominant ideas about how we achieve this; spatial isomorphism, in which what we see reflects differences in distance or size in the brain; that spatial extent depends upon motor sensations or intentions related to eye movements; and that distance is computed from the degree of correlation in neural activity between adjacent locations, with distance inversely proportional to the correlation. There are problems with each of these approaches, for example, neural correlation may depend more on image structure than adjacency - consider the case of images containing repeating lines or sine gratings. Here a new computational strategy is outlined and assessed. Human image motion computation naturally relies on a set of linear temporal filters which can be defined in a window of around 100ms. However, gradient motion models can be reformulated to operate on just two frames, with image frame sums and differences taking the place of extended temporal derivative filters. This approach constitutes an image gradient approach to computing retinal disparity. This strategy can itself be re-purposed to compute the separation of points in a single image, rather than computing image displacement in the left and right eye’s images. This new strategy allows us to compute spatial separation, on the basis of a non-spatial measure, the image brightness difference, and a local spatial brightness gradient
Mechanics in Organic Mixed Ionic-Electronic Conductors
No full textThis Dissertation aims at establishing an integrated framework of multimodal experiments and multiphysics theory to extend the understanding of the mechanics in electrochemically active materials using organic mixed ionic-electronic conductors (OMIECs) as a model system. OMIECs allow the transport of both ions and electrons, which is accompanied by the (electronic, micro-) structural reorganization. The electronic structural change in OMIECs induces transforms in the electrical conductivity and optical absorbance. The change in molecular packing invites the size change and evolution of mechanical properties. The multiphysics processes render OMIECs a fascinating platform for understanding the multi-physics coupling and advancing organic electrochemical devices. Despite significant progress, there are urgent needs in the experimental techniques and the subsequent mechanical characterization, theoretical understanding of the multiphysics processes, and mechanics-informed design principles for high-performance devices. Specifically, (i) an accurate and straightforward experimental method is in need to better understand the mechanical behaviors and kinetics such as swelling and softening of OMIECs upon electrochemical redox reactions; (ii) a theoretical framework is missing that describes the rich coupled multiphysics processes such as large deformation, charge and mass transport, electrostatics, and phase evolution in OMIECs; (iii) the rational design of the materials and structures based on mechanics principles are required for mechanically reliable, high-performance organic electrochemical devices. In this Dissertation, the mechanics of OMIECs are studied systematically. The basics of OMIECs, knowledge gaps, and the outline are introduced in Chapter 1. The in-situ environmental nanoindentation apparatus and the associating characterization techniques are presented in Chapter 2. In Chapter 3, a theoretical mechanics model is presented that elucidates the interfacial mechanical degradation of thin-film electrodes and outlines the design principles for mechanically reliable electrodes. In Chapter 4, the electrochemical doping kinetics and its stress dependency on conductive polymers are studied via a designed moving front device. Chapter 5 presents a thermodynamically consistent continuum theory of two-phase OMIECs undergoing large deformation, charge and mass transport, electrostatics, and phase separation, which forms the theoretical foundation for such conductive polymer systems. The conclusion and perspectives on future work are presented in Chapter 6
Exploring the Effect of Hand Appearance and Tactile Feedback on the Virtual Hand Illusion
No full textCurrent virtual reality (VR) technologies allow users to not only observe virtual environments but also interact within them by performing a variety of tasks more efficiently and intuitively. In addition, humans experience VR content not only through their visual and auditory systems but also through the somatosensory system. Therefore, we decided to perform three different studies regarding Virtual Hand Illusion (VHI). We conducted our first 3 x 2 study (abstract, mannequin, and realistic x tactile and no tactile) both in our lab setting and remotely to investigate the effects of virtual hand appearance and tactile feedback on ownership, external appearance, and tactile sensation embodiment dimensions when participants were instructed to perform an assembly task in a virtual environment. As a result, we observed that the mannequin hand had a greater effect size on ownership, and the realistic hand had a greater effect size on tactile sensation and external appearance. We also found that the tactile feedback condition had a greater effect size on external appearance than the no-tactile feedback condition, and the realistic hand appearance in conjunction with the tactile feedback had a significant effect size on the perceived tactile sensation. Participants in the lab setting rated the external appearance of the realistic hand model higher than the remote participants. We conducted a second virtual reality study to explore the virtual hand illusion through three levels of appearance (Appearance dimension: realistic vs. pixelated vs. toon hand appearances) and two levels of tactile feedback (Tactile dimension: no tactile vs. tactile feedback using another virtual assembly task. We asked the participants to provide self-reported ratings on a survey that captured presence and five embodiment dimensions (hand ownership, touch sensation, agency and motor control, external appearance, and response to external stimuli). The results of our study indicated that (1) tactile feedback was associated with [3] a stronger sense of presence, touch sensation, and response to external stimuli; (2) pixelated hand appearance was associated with the least hand ownership and external appearance; and (3) in the presence of the pixelated hand, prior virtual reality experience of participants [4] was associated with their agency and motor control and their response to external stimuli ratings. For our third study, we conducted a VR study to further explore the just noticeable difference (JND) of tactile feedback to understand humans’ perceptions of tactile stimuli. Our VR study examined the JND in terms of the intensity, duration, and frequency of tactile feedback provided through commercially available vibrotactile motion controllers, the Oculus Quest 2 controllers. We instructed participants to report whether they perceived a difference between a reference (variation) and a testing stimulus at each point in the experiment for a different property (intensity, duration, and frequency) of tactile feedback. We report both positive and negative JND values for the three properties of tactile feedback. We discuss our findings and limitations at the end of each chapter and provide future study directions in the final chapter. In the end of the dissertation, we list out our contributions of all three studies in two different directions. One is regarding the design considerations in VR assembly applications. We consider specific hand models, hand and finger animations and assembly task indicators should be applied. The other direction is virtual hand design guideline. We suggest specific rendering style, activation of tactile feedback and JND values for adjustment in VR applications should be developed for stronger sense of embodiment