A Digital Signal Processing Approach for Affective Sensing of a Computer User through Pupil Diameter Monitoring

Recent research has indicated that the pupil diameter (PD) in humans varies with their affective states. However, this signal has not been fully investigated for affective sensing purposes in human-computer interaction systems. This may be due to the dominant separate effect of the pupillary light reflex (PLR), which shrinks the pupil when light intensity increases. In this dissertation, an adaptive interference canceller (AIC) system using the H∞ time-varying (HITV) adaptive algorithm was developed to minimize the impact of the PLR on the measured pupil diameter signal. The modified pupil diameter (MPD) signal, obtained from the AIC was expected to reflect primarily the pupillary affective responses (PAR) of the subject. Additional manipulations of the AIC output resulted in a processed MPD (PMPD) signal, from which a classification feature, PMPDmean, was extracted. This feature was used to train and test a support vector machine (SVM), for the identification of stress states in the subject from whom the pupil diameter signal was recorded, achieving an accuracy rate of 77.78%. The advantages of affective recognition through the PD signal were verified by comparatively investigating the classification of stress and relaxation states through features derived from the simultaneously recorded galvanic skin response (GSR) and blood volume pulse (BVP) signals, with and without the PD feature. The discriminating potential of each individual feature extracted from GSR, BVP and PD was studied by analysis of its receiver operating characteristic (ROC) curve. The ROC curve found for the PMPDmean feature encompassed the largest area (0.8546) of all the single-feature ROCs investigated. The encouraging results seen in affective sensing based on pupil diameter monitoring were obtained in spite of intermittent illumination increases purposely introduced during the experiments. Therefore, these results confirmed the benefits of using the AIC implementation with the HITV adaptive algorithm to isolate the PAR and the potential of using PD monitoring to sense the evolving affective states of a computer user.

A method for enhancing digital information displayed to computer users with visual refractive errors via spatial and spectral processing

This research pursued the conceptualization, implementation, and verification of a system that enhances digital information displayed on an LCD panel to users with visual refractive errors. The target user groups for this system are individuals who have moderate to severe visual aberrations for which conventional means of compensation, such as glasses or contact lenses, does not improve their vision. This research is based on a priori knowledge of the user's visual aberration, as measured by a wavefront analyzer. With this information it is possible to generate images that, when displayed to this user, will counteract his/her visual aberration. The method described in this dissertation advances the development of techniques for providing such compensation by integrating spatial information in the image as a means to eliminate some of the shortcomings inherent in using display devices such as monitors or LCD panels. Additionally, physiological considerations are discussed and integrated into the method for providing said compensation. In order to provide a realistic sense of the performance of the methods described, they were tested by mathematical simulation in software, as well as by using a single-lens high resolution CCD camera that models an aberrated eye, and finally with human subjects having various forms of visual aberrations. Experiments were conducted on these systems and the data collected from these experiments was evaluated using statistical analysis. The experimental results revealed that the pre-compensation method resulted in a statistically significant improvement in vision for all of the systems. Although significant, the improvement was not as large as expected for the human subject tests. Further analysis suggest that even under the controlled conditions employed for testing with human subjects, the characterization of the eye may be changing. This would require real-time monitoring of relevant variables (e.g. pupil diameter) and continuous adjustment in the pre-compensation process to yield maximum viewing enhancement.

On-screen pre-deblurring of digital images using the wavefront aberration function of the human eye to improve computer access for the visually impaired

Traditional Optics has provided ways to compensate some common visual limitations (up to second order visual impairments) through spectacles or contact lenses. Recent developments in wavefront science make it possible to obtain an accurate model of the Point Spread Function (PSF) of the human eye. Through what is known as the "Wavefront Aberration Function" of the human eye, exact knowledge of the optical aberration of the human eye is possible, allowing a mathematical model of the PSF to be obtained. This model could be used to pre-compensate (inverse-filter) the images displayed on computer screens in order to counter the distortion in the user's eye. This project takes advantage of the fact that the wavefront aberration function, commonly expressed as a Zernike polynomial, can be generated from the ophthalmic prescription used to fit spectacles to a person. This allows the pre-compensation, or onscreen deblurring, to be done for various visual impairments, up to second order (commonly known as myopia, hyperopia, or astigmatism). The technique proposed towards that goal and results obtained using a lens, for which the PSF is known, that is introduced into the visual path of subjects without visual impairment will be presented. In addition to substituting the effect of spectacles or contact lenses in correcting the loworder visual limitations of the viewer, the significance of this approach is that it has the potential to address higher-order abnormalities in the eye, currently not correctable by simple means.

Digital Flora of Ucayali, Perú

The primary dataset represents the vouchered botanical collections of James Graham and Jose Schunke Vigo in the Department of Ucayali, Peru, from October 1997 until the present. Over 3500 separate collections are included to date, many of which have associated images. We present here primary collections data. Other data on natural history collections for the Department of Ucayali have been compiled, but are not presented at this time. We hope to make this data available as part of a Ucayali Collections dataset, as time and resources permit. It is hoped that this data will will contribute to the exchange of scientific information, and will enhance our knowledge of, and appreciation for, the complex of species, habitats, communities, ecosystems and ecoregions of Amazonia.

Between the Graduate School and Cataloging: How a Digital Collections Center Contributes Quality to the ETD Process

This presentation was given at the 2015 USETDA (United States Electronic Theses and Dissertations Association) conference in Austin, Texas explores the history of Digital Collections Center at Florida International University and where and how it functions in the process of publishing, archiving, and promoting the university's electronic theses and dissertations. Additionally, the functionality of Digital Commons is discussed along with the use of Adobe Acrobat for creating archival quality PDFs. The final section discusses promotion techniques used via social media for increased discoverability of ETDs.

The Case of the 35 Gigabyte Digital Record: OCR and Digital Workflows

This presentation was given at the Panhandle Library Access Network's (PLAN) Innovation Conference: Digitization- Preserving the Past for the Future Conference on August 14th, 2015. The presentation uses a specific collection of directories as a case study of the complications librarians and archivists face in digitizing older materials that may also be quite large, such as a directory. Prime OCR and Abbyy Fine Reader are discussed and their pros and cons covered. Troubleshooting and editing with Adobe Photoshop is also discussed.

From the Elementary to the Circuitous: Digital Processing Workflows at FIU

This presentation was given at the FLVC regional conference at Broward College on May 7, 2015 and introduced scanning, processing, record creation, dissemination, and preservation in FIU Libraries' Digital Collections Center. The main focus was on processing, specifically employing OCR technology with difficult sources.