Doctor of Philosophy, The Ohio State University, 2015, Computer Science and Engineering

The interactions among fluids and solids create many interesting phenomena that are excessively complex for manual creation in animation. It is popular to model these interactions in physically based simulation but it is challenging especially in real-time applications. Collisions handling is a major bottleneck for solid-solid interaction problems because of high computational cost of neighbor searching in space. Solid-fluid interactions are also difficult to simulate mostly because of the difference in representations of fluids and solids. Typically simulation systems use Eulerian methods for fluids and Lagrangian methods for solids. The most adopted coupling strategy uses solid velocity as boundary condition in fluid solver and integrate fluid pressure along solid boundary to apply force on solid. However, the quality of fluid animation is limited by resolution of Eulerian grid thus it cannot handle interaction with thin features on solids. In this dissertation we focus on specific types of interactions among fluids and solids and develop simulation methods with improved quality and performance toward real-time applications. First we address the problem of cloth, air, and deformable body interactions modeling in a layered structure as commonly seen in real world. We develop an accelerated collision detection method taking advantage of the layer structure to improve efficiency and an accurate anisotropic friction model to achieve fine contact details. The interaction of air and other layers is modeled using a fast air mass field model. Next, we turn to fracture simulation in solid-solid interaction, which is known to be computationally expensive in high resolution. We develop a surface refinement approach that adds fine details to existing low-resolution fracture animation with negligible extra computation cost. Finally, we explore coupling of fluid and solid with thin features. We take a stable and fast approach that couples hybrid Eulerian-Lagrangian fluid and (open full item for complete abstract)

Committee: Huamin Wang (Advisor); Roger Crawfis (Committee Member); Shen Han-wei (Committee Member) Subjects: Computer Science

Doctor of Philosophy, The Ohio State University, 2015, Civil Engineering

The construction of ancient monuments, such as the Colosseum (Coliseum) of Rome, was an enigmatic and complex process that has never been explored. Most sources about the largest ancient amphitheater focus on the historical and archaeological aspects. This dissertation seeks to elaborate on the construction methods of the Colosseum using engineering principles, based on which a digital reconstruction of the most likely of these methods in the form of a virtual-reality simulation – a process that has never been attempted before in the construction study of this ancient monument – was created. This dissertation presents a state-of-the-art and comprehensive exploration of the construction of the Colosseum, deriving and compiling information from both personal observations and a number of different historical and archaeological sources as well as findings from the monument itself. The construction processes of the Colosseum can be divided into five distinct stages: the pre-plan and plan, which details how the site of the construction was selected and drafted; the substructure, involving an analysis the best and safest alternative for constructing the foundation of the building; the hypogea or underground chambers, which provide chambers beneath the arena to house the gladiators and other contestants; the superstructure, the majority of the building which could have been built in several different ways, each of which consists of a number of organized stages; and the velarium, or roof awning, which can be installed in several different ways, resulting in different ranges of protection from the weather. After the different construction methods that may be employed for all of these stages are compared, a number of possible pathways of construction are established, and one of them is selected as the most plausible given the construction practices of the ancient Romans. The findings of the construction methods of such a majestic structure are not complete without simulation (open full item for complete abstract)

Committee: Frank Croft Jr. (Advisor); Tarunjit Butalia (Committee Member); Rachel Kajfez (Committee Member) Subjects: Archaeology; Architecture; Civil Engineering; Classical Studies; Computer Science; Engineering; History

Master of Arts, The Ohio State University, 1985, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2005, Graduate School

Committee: Not Provided (Other) Subjects:

Doctor of Philosophy, The Ohio State University, 1986, Graduate School

Committee: Not Provided (Other) Subjects: Education

Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee: Not Provided (Other) Subjects: Education

Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee: Not Provided (Other) Subjects: Computer Science

Doctor of Philosophy, The Ohio State University, 1984, Graduate School

Committee: Not Provided (Other) Subjects: Computer Science

Doctor of Philosophy (PhD), Wright State University, 2010, Computer Science and Engineering PhD

Wireless Capsule Endoscopy (WCE) is a new technology that allows medical personnel to view the gastrointestinal (GI) mucosa. It is a swallowable miniature capsule device the size of a pill that transmits thousands of screenshots of the digestive tract to a wearable receiver. When the procedure finishes the video is uploaded to a workstation for viewing. Capsule Endoscopy has been established as a tool to identify various gastrointestinal (GI) conditions, such as blood-based abnormalities, polyps, ulcers, Crohn's disease in the small intestine, where the classical endoscopy is not regularly used. As of 2009 the market is dominated by Given Imaging Inc. capsule (PillCam SB). More than 300,000 capsules have been sold since 2001 when it was first introduced. The company provides a software package (RAPID) to view the WCE video, offering a bleeding detector feature based on red color. It provides a position estimator of the capsule inside the digestive tract. Additionally its multi-view feature gives a simultaneous view of two or four consecutive video frames in multiple windows. Finally a library of reference images (RAPID Atlas) is provided so that the user can have easy access to on-screen case images. Although the company's software is a useful tool, the viewing of a WCE video is still a time consuming process (~ 2 hours), even for experienced gastroenterologists. In addition, the company's software has serious limitations (35% bleeding detection) and no capability of detecting polyps or ulcers according to gastroenterologists. Therefore, the need for computer aided model-methodology with robust detection performance on various conditions (blood, polyps, ulcers, etc) is clearly obvious. Thus, our research studies have been successfully carried out on: a) the automatic detection of malignant intestinal features like polyps, bleeding, and abnormal regions (tumors); b) finding the boundaries of the digestive organs; and c) reducing the viewing-examination time with a (open full item for complete abstract)

Committee: Nikolaos Bourbakis PhD (Advisor); Soon Chung PhD (Committee Member); Thomas Hangartner PhD (Committee Member); Yong Pei PhD (Committee Member); Marios Pouagare PhD (Committee Member) Subjects: Computer Science

Doctor of Philosophy, The Ohio State University, 2012, Computer Science and Engineering

Caves are commonly used as environments in computer games. As the popularity of open world games rises, so does the demand for expansive virtual environments. To ease this cost, many tools have been developed to create and edit content for games including terrain, plants, roads, buildings, and cities. The same is not true for caves. We present data structures and algorithms to create, evaluate, edit, and illuminate three dimensional models of caves for use in computer games. Game levels can be classified according to their spatial configuration: linear, maze, or open. Caves formed by the same geological process have similar features. These define parameters that can be used to partially or fully automate the creation of cave models of different spatial configurations. Additional information about the model such as its volume, number of branching paths, and number of connected components can be used by the designer in evaluating and editing the model to meet gameplay requirements. To assist in editing of cave models we propose a new data structure and framework and compare its use to existing modeling approaches. Physically based illumination of a cave typically results in low level lighting which is not suitable for games. We introduce a new illumination model based on radiant flux that can be used to ensure a sufficient amount of light is present throughout the cave. The new illumination model can also be adapted to assist in player navigation. Illuminating a scene according to distance to objects within it creates highlights that captures the player's visual attention. A user study was done to evaluate the new technique.

Committee: Roger Crawfis PhD (Advisor); Han-Wei Shen PhD (Committee Member); Richard Parent PhD (Committee Member) Subjects: Computer Science

Master of Science, The Ohio State University, 2008, Computer Science and Engineering

This work conveys the personality of a virtual character through its posture. A standard personality model from literature is integrated with a customized behavior model to design a system that takes the high-level personality configuration of the character as input. Several works from the field of nonverbal behavior have been surveyed and a set of rules that map psychological states to physiological behavior have been formulated. These rules have been implemented in a system that outputs postures given high level psychological states or personality configurations as inputs.

Committee: Richard Parent Phd (Advisor); Matthew Lewis Phd (Committee Member) Subjects: Computer Science

Doctor of Philosophy, The Ohio State University, 2006, Computer and Information Science

Fluid animation remains one of the most challenging problems in computer graphics. Research on methods using physics-based simulation for animation has recently increased since this method has the capability of producing realistic fluid behavior. However, the primary drawback to using a simulation method is control of the resulting flow field because it is computationally expensive and highly nonlinear. The main goal of this research is to help users produce physically realistic fluid effects along a NURBS curve that can be specified directly or derived from an image or video. A linear-feedback velocity matching method is used to control the fluid flow. A physically realistic smoke flow along a user-specified path is generated by first procedurally producing a target velocity field, and then matching the velocity field obtained from a three-dimensional flow simulation with the target velocity field. The target velocity field can include various effects such as the small scale swirling motion characteristic of turbulent flows. The swirling motion is achieved by incorporating a vortex particle method into the linear feedback loop. The method is flexible in that any procedurally-generated target velocity field may be integrated with the fluid simulation. The efficacy of this approach is demonstrated by generating several three-dimensional flow animations for complex fluid paths, two-dimensional artistic fluid effects, and realistic tornado animations.

Committee: Raghu Machiraju (Advisor) Subjects: Computer Science

Master of Science (MS), Ohio University, 1984, Industrial and Manufacturing Systems Engineering (Engineering)

Design of a graphical package as a teaching device for probability and statistics courses

Committee: Robert Williams (Advisor) Subjects: Engineering, Industrial

Master of Fine Arts, The Ohio State University, 2013, Industrial, Interior Visual Communication Design

The Moon Experience is an interactive and immersive virtual reality system based on the historic events of the Apollo Program (1961-1972). The goal of this thesis project is to demonstrate a solution to the design challenge of framing and creating an effective learning experience in a virtual space that would otherwise be impossible to realize in the real world. I employ technologies and approaches from multiple disciplines in the design and implementation of the system. Through the technology of virtual reality I establish the virtual lunar world, which provides participants with immersive firsthand experiences. Computer game technology reinforces the effectiveness of the learning environment, lending The Moon Experience the qualities of entertainment, deep thought, and knowledge retention. Motion capture and computer animation facilitate real-time interactions between users and the system to sustain the sensation of being on the Moon. I take into account related learning principles and narrative storytelling to give a participant the proper situated learning content. Providing a framework of narrative helps heighten the audience's perception, trigger their imagination, and transcend the virtual reality's current limitations.

Committee: Alan Price (Advisor); Maria Palazzi (Committee Member); Rick Parent (Committee Member) Subjects: Computer Engineering; Computer Science; Design; Information Technology

Master of Science, The Ohio State University, 2012, Civil Engineering

This research focuses on the construction process of the Colosseum, the famous ancient Roman amphitheater, by digitally recreating the step-by-step processes that would have been involved in the construction process, demonstrating that the process of retracing the construction of such a large and complex monument presents a variety of challenges. Computer-generated imagery, or CGI, has long been used to recreate ancient structures based on literature and archaeological evidence. Most of the simulations that are generated, however, focus primarily on the appearance of the structures upon completion and during use. Given enough data, computer graphics can serve as an effective tool in simulating the construction of ancient monuments as well, which is demonstrated via the digital (re)construction of the Colosseum as mentioned previously. Through extensive research and on-site analysis, enough dimensions for the construction process and the architectural features and concepts that such a simulation will likely entail can be obtained to create relatively accurate representations, which will in turn serve as a breeding ground for theories concerning their design, construction, and ability to withstand the test of time. In this case, the background of the study is presented in the form of the history of Roman architecture in general and especially of theaters such as the amphitheater, the category which the Colosseum belongs to. This clarification provides a starting point for the research, and forms the precedent for most of the ideas that will be employed. The background of the simulation includes software, in this case Autodesk Inventor, which provides an ideal balance of user-friendliness and complexity handling. Coupling this is a structural analysis of the monument that provides the key dimensions and features that are present in the actual model. With this in mind, the creation of the model, using the functionality of the user interface, is compared to the actual co (open full item for complete abstract)

Committee: Franklin Croft (Advisor); William Wolfe (Committee Member); Richard Freuler (Committee Member) Subjects: Civil Engineering; Computer Science

Master of Science, The Ohio State University, 2005, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1970, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1969, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1971, Graduate School

Committee: Not Provided (Other) Subjects:

Doctor of Philosophy, The Ohio State University, 2018, Computer Science and Engineering

Recent advancements in the computing power have enabled the application scientists to design their simulation study using very high-resolution computational models. The output data from such simulations provide a plethora of information that need to be explored for enhanced understanding of the underlying phenomena. Large-scale simulations, nowadays, produce multivariate, time-varying data sets in the order of petabytes and beyond. Traditional post-processing based analysis utilizing raw data cannot be readily applicable, since storing all the data is becoming prohibitively expensive. This is because of the bottleneck stemming from output data size and I/O compared to the ever-increasing computing speed. Hence, exploration and visualization of such extreme-scale simulation outputs are posing significant challenges. This dissertation addresses the aforementioned issues and suggests an alternative pathway by enabling in situ analysis, i.e., in-place analysis of data, while it still resides in supercomputer memory. We embrace the in situ technology and adopt simulation time data analysis, triage, and summarization using various data transformation techniques. The proposed methods process data as the simulation generates it and employ different analysis techniques to extract important data properties efficiently. However, the amount of work that can be done in situ is often limited in terms of time and storage since overburdening the simulation with additional computation is undesired. Furthermore, while some application domain driven analyses fit well for an in situ environment, a wide range of visual-analytics tasks require longer time involving iterative exploration during post-processing. Therefore, to this end, we conduct in situ statistical data summarization in the form of compact probability distribution functions, which preserve essential statistical data properties and facilitate flexible and scalable post-hoc exploration. We show that the reduced stati (open full item for complete abstract)

Committee: Han-Wei Shen (Advisor) Subjects: Computer Engineering; Computer Science