Master of Science (MS), Ohio University, 2013, Industrial and Systems Engineering (Engineering and Technology)

Touch screen surfaces are increasingly used in mobile phones, tablets, notebook and desktop computers, and other industrial applications as a convenient method of interaction between a user and a device. They offer versatile features such as being space saving, easy to clean, less noisy for data input, and adjustable when compared to other data input methods. While research has been conducted in the relationship between hand size and mobile phone use, little research has investigated the relationship between touch screen keyboard size, hand anthropometry, and performance metrics. In this study, the relationship between the user's anthropometric data and the relative size of the touch screen keyboard to typing speed and the typing accuracy was studied. Thirty participants were recruited based on their hand size (Small n = 10, Medium n = 10, and Large n = 10). They were given 15 sentences to type on three different sizes of keyboards (14x14, 18x18, and 22x22 mm). The speed was measured by characters per minute and accuracy was measured by the correct characters per minute and incorrect ratio. Characters per minute and correct characters per minute data were statistically analyzed using a mixed model ANOVA. Keyboard sizes were significantly different for both characters per minute and correct characters per minute at p < .05. However, hand size and the interaction factor were not significantly different. Future research may focus 4 on further developments on touch screen keyboard sizes to improve the speed and accuracy rather than the hand sizes.

Committee: Diana Schwerha Ph.D. (Advisor); David Koonce Ph.D. (Committee Member); Gary Weckman Ph.D. (Committee Member); Andrew Snow Ph.D. (Committee Member) Subjects: Industrial Engineering; Information Technology

Master of Science (MS), Wright State University, 2016, Human Factors and Industrial/Organizational Psychology MS

Effects of tactile and audio feedback are examined in the context of touchscreen and mobile use. Prior experimental research is graphically summarized by task type (handheld text entry, tabletop text entry, non-text input), tactile feedback type (active, passive), and significant findings, revealing a research gap evaluating passive tactile feedback in handheld text entry (a.k.a. “texting”). A passive custom tactile overlay is evaluated in a new experiment wherein 24 participants perform a handheld text entry task on an iPhone under four tactile and audio feedback conditions with measures of text entry speed and accuracy. Results indicate audio feedback produces better performance, while the tactile overlay degrades performance, consistent with reviewed literature. Contrary to previous findings, the combined feedback condition did not produce improved performance. Findings are discussed in light of skill-based behavior and feed-forward control principles described by Gibson (1966) and Rasmussen (1983).

Committee: Kevin Bennett Ph.D. (Advisor); John Flach Ph.D. (Committee Member); Scott Watamaniuk Ph.D. (Committee Member) Subjects: Communication; Computer Engineering; Computer Science; Design; Engineering; Experiments; Industrial Engineering; Information Technology; Physiological Psychology; Psychology; Systems Design; Systems Science; Technology

Master of Science, Miami University, 2023, Mechanical Engineering

Available devices with smaller touchscreen displays (TSDs) offer users adequate haptic feedback, whereas larger TSDs still lack meaningful tactile sensations. This study is focused on rendering vibrotactile feedback on large TSDs. Existing methods for localized vibrotactile rendering on large TSDs use many actuators. Practically, using many actuators is not desirable due to space constraints, power supply limitations, etc., for consumer-centric large TSD devices. Therefore, this study investigates localized vibrotactile feedback on large TSDs using a restricted number of electrostatic resonant actuators (ERAs). Using flexible boundary conditions combined with multi-frequency excitation, a novel method is presented to render localized vibrotactile feedback for two types of large TSDs: a narrow touch bar and a rectangular touch surface. A method for managing/positioning localized haptic feedback on large TSDs is also investigated. In-house finite-element-based simulation models of TSDs are developed along with experimental prototypes for verifying the vibrotactile performance. The modeling and analysis strategy presented here is general and can be extended for haptic rendering methods of different touch surfaces, actuators, and boundary conditions. Finally, model-based parametric studies are presented for better design considerations and improved vibrotactile intensity.

Committee: Kumar Singh (Advisor); Jeong-Hoi Koo (Advisor); James Chagdes (Committee Member) Subjects: Electrical Engineering; Engineering; Mechanical Engineering

Doctor of Philosophy, The Ohio State University, 2016, Computer Science and Engineering

Scientists visualize their data and interact with them on computers in order to thoroughly understand them. Nowadays, data become so large and complex that it is impossible to display the entire data on a single image. Scientific visualization often suffers from visual clutter problem because of high spacial resolution/dimension and temporal resolution. Interacting with the visualizations of large data, on the other hand, allows users to dynamically explore different parts of the data and gradually understand all information in the data. Information congestion and visual clutter exist in visualizations of different kinds of data, such as flow field data, tensor field data, and time-varying data. Occlusion presents a major challenge in visualizing 3D flow and tensor fields using streamlines. Displaying too many streamlines creates a dense visualization filled with occluded structures, but displaying too few streams risks losing important features. Glyph as a powerful multivariate visualization technique is used to visualize data through its visual channels. Placing large number of glyphs over the entire 3D space results in occlusion and visual clutter that make the visualization ineffective. To avoid the occlusion in streamline and glyph visualization, we propose a view-dependent interactive 3D lens that removes the occluding streamlines/glyphs by pulling the them aside through animations. High resolution simulations are capable of generating very large vector fields that are expensive to store and analyze. In addition, the noise and/or uncertainty contained in the data often affects the quality of visualization by producing visual clutter that interferes with both the interpretation and identification of important features. Instead, we can store the distributions of many vector orientations and visualize the distributions with 3D glyphs, which largely reduce visual clutter. Empowered by rapid advance of high performance computer architectures and software, it is (open full item for complete abstract)

Committee: Han-Wei Shen (Advisor); Huamin Wang (Committee Member); Arnab Nandi (Committee Member) Subjects: Computer Engineering; Computer Science

MS, University of Cincinnati, 2007, Medicine : Environmental Health

Data entry is a common practice in many facilities throughout the world. From an ergonomic prospective, these jobs place employees at risk of musculoskeletal disorders due to prolonged sitting, static postures, and highly repetitive motions. The study's objective was to evaluate the differences between data entry tasks performed in both sitting and standing positions with different work heights using a keyboard and a touch screen input device. Twenty subjects performed multiple food order entries where postural analysis, error rate, self-reported regional body discomfort, and usability data were measured. The results indicate that the angled touch screen produced less ergonomic stress and body discomfort as compared to traditional keyboard and was the preferred input device. The proper position of the touch screen depended upon the height of the work surface—angled touch screen for the sitting condition and angled or horizontal touch screen for the standing at high work surface height.

Committee: Dr. Kermit Davis (Advisor) Subjects: