published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

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published_or_final_version / abstract / toc / Mechanical Engineering / Master / Master of Philosophy

To a person with an upper limb amputation or congenital defect, a well-functioning prosthesis can open the door to many work and life opportunities. A fundamental component of many modern prostheses is the myoelectric control system, which uses the myoelectric signals from an individual's muscles to control prosthetic movements. Though much research has been done involving the myoelectric control of arm and gross hand movements, more dexterous finger control has not received the same attention. Consequently, the goal of this study was to determine an optimal approach to the myoelectric signal classification of a set of typing motions. Two different movement sets involving the fingers of the right hand were tested: one involving digits two through five (4F - "four finger"), and the other involving digits one and two (FT - "finger/thumb"). Myoelectric data were collected from the forearm muscles of twelve normally-limbed subjects as they performed a set of typing tasks. These data were then used to test a series of classification systems, each comprising a different combination of system element choices. The best classification system over all subjects and the best classification system for each subject were determined for both movement sets. The optimal subject-specific classification systems yielded classification accuracies of 92.8 ± 2.7% for the 4F movement set and 93.6 ± 6.1% for the FT movement set, whereas the optimal overall classification systems yielded significantly lower performance (p<0.05): 89.6 ± 3.4% for the 4F movement set and 89.8 ± 8.5% for the FT movement set. No significant difference in classification accuracy was found between movement sets (p=0.802). A two-way repeated measures ANOVA (α=0.05) was used to determine both significance results. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-10-31 14:59:43.151

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Interactive tabletop systems are becoming popular platforms for group activities. However, current common tabletops do not provide capabilities to differentiate interactions among simultaneous users, i.e. to associate a touch point with its proper owner. My thesis proposes and explores the use of an important biometric property of users as the basis for touch discrimination on multi-user tabletops: Finger Orientation (FO). In this thesis, I first collect the FO ranges of users standing in different positions around a tabletop. Second, I implement a system that uses FO to determine where the users are standing, and based on that extrapolate the owner of the touch. Next, I evaluate the system with two separate experiments, present the results, and discuss all findings. Furthermore, I explore some enhancements with a simple quantitative study. My results indicate that finger orientation is a good natural biometric trait enhances multi-user recognition on tabletops.

Despite the growing popularity and expansion of video game interaction techniques and research in the area of hand gesture recognition, the application of hand gesture video game interaction using arm, hand, and finger motion has not been extensively explored. Most current gesture-based approaches to video game interaction neglect the use of the fingers for interaction, but inclusion of the fingers will allow for more natural and unique interaction and merits further research. To implement arm, hand and finger-based interaction for the video game domain, several problems must be solved including gesture recognition, segmentation, hand visualization, and video game interaction that responds to arm, hand, and finger input. Solutions to each of these problems have been implemented. The potential of this interaction style is illustrated through the introduction of an arm, hand, and finger controlled video game system that responds to players' hand gestures. It includes a finger-gesture recognizer as well as a video game system employing various interaction styles. This consists of a first person shooter game, a driving game, and a menu interaction system. Several users interacted with and played these games, and this form of interaction is especially suitable for real time interaction in first-person games. This is perhaps the first implementation of its kind for video game interaction. Based on test results, arm, hand, and finger interaction a viable form of interaction that deserves further research. This implementation bridges the gap between existing gesture interaction methods and more advanced virtual reality techniques. It successfully combines the solutions to each problem mentioned above into a single, working video game system. This type of interaction has proved to be more intuitive than existing gesture controls in many situations and also less complex to implement than a full virtual reality setup. It allows more control by using the hands' natural motion and allows each hand to interact independently. It can also be reliably implemented using today's technology. This implementation is a base system that can be greatly expanded on. Many possibilities for future work can be applied to this form of interaction.

Pollination and fruit set of four species of native New Zealand flowering plant species were examined through two field seasons. Bird exclusion, pollinator exclusion, natural and supplemental pollination treatments were initiated on individuals of Cordyline australis (Cabbage tree), Phormium tenax (Flax), Kunzea ericoides (Kanuka), and Pseudopanax arboreus (Five-finger). The species differed in the self-compatibility as well as in their floral syndrome. No species showed any evidence of pollen limitation, and two species. K. ericoides and P. arboreus set fruit from more than 70% of their flowers. The response of fruit set to treatment in C. australis varied from season to season, with birds appearing important to pollination in the first but not the second field season, while birds were important in pollination across both seasons for P. tenax. K. ericoides was resilient to treatment, setting high fruit set in every treatment, compared to P. arboreus which set high fruit set when pollinators had access, but low when all pollinators were excluded. No trends relating to fruit set or PLI and self-compatibility or floral syndrome were found. That there was no evidence of pollen limitation for any species, despite variation in fruit set from some treatments, indicates that these species are performing well and not at risk of decreased population size due to pollen limitation.

The Drosophila hindsight (hnt) gene encodes a C2H2-type zinc-finger (ZNF) protein crucial for epithelial morphogenesis. The human HNT homologue, RREB1, functions as a transcriptional modulator and regulates several tumor suppressor genes. HNT’s functional motifs, target genes and its regulatory abilities have not been elucidated. Here I showed that the C-terminal region of HNT containing the last five of 14 ZNFs (ZNF 10-14) binds in vitro to DNA-elements similar to those identified for RREB-1. I then mapped HNT’s endogenous binding sites on polytene chromosomes and focus on two, at 4C and 60C, which are associated with the hnt and nervy (nvy) loci, respectively. Sequence analysis of the bound fragments shows conservation of motifs similar to those bound by HNT in vitro. Data from both hnt loss- and gain-of-function experiments show that HNT attenuates the transcription of the hnt and nvy genes in several tissues and developmental stages. I show that the identified HNT C-terminal DNA binding domain ZNF 10-14 is not required for these regulatory functions. I further delineate the minimal functional motifs of HNT in transcriptional regulation and show that its ninth ZNF in isolation has a repressive activity and is sufficient to confer many regulatory functions of HNT. On the other hand, mutation of ZNF 9 in the context of the full-length protein indicates that it is not necessary for HNT functions. Interestingly, ZNF 9 has been lost from HNT vertebrate homologues. I propose two redundant mechanisms of transcriptional regulation by HNT: one is mediated by the potential protein-interaction abilities of ZNF 9; another is through cooperation of other ZNF motifs of HNT; the DNA binding abilities conferred by the C-terminal five fingers may be essential for the latter mechanism.

The Drosophila hindsight (hnt) gene encodes a C2H2-type zinc-finger (ZNF) protein crucial for epithelial morphogenesis. The human HNT homologue, RREB1, functions as a transcriptional modulator and regulates several tumor suppressor genes. HNT’s functional motifs, target genes and its regulatory abilities have not been elucidated. Here I showed that the C-terminal region of HNT containing the last five of 14 ZNFs (ZNF 10-14) binds in vitro to DNA-elements similar to those identified for RREB-1. I then mapped HNT’s endogenous binding sites on polytene chromosomes and focus on two, at 4C and 60C, which are associated with the hnt and nervy (nvy) loci, respectively. Sequence analysis of the bound fragments shows conservation of motifs similar to those bound by HNT in vitro. Data from both hnt loss- and gain-of-function experiments show that HNT attenuates the transcription of the hnt and nvy genes in several tissues and developmental stages. I show that the identified HNT C-terminal DNA binding domain ZNF 10-14 is not required for these regulatory functions. I further delineate the minimal functional motifs of HNT in transcriptional regulation and show that its ninth ZNF in isolation has a repressive activity and is sufficient to confer many regulatory functions of HNT. On the other hand, mutation of ZNF 9 in the context of the full-length protein indicates that it is not necessary for HNT functions. Interestingly, ZNF 9 has been lost from HNT vertebrate homologues. I propose two redundant mechanisms of transcriptional regulation by HNT: one is mediated by the potential protein-interaction abilities of ZNF 9; another is through cooperation of other ZNF motifs of HNT; the DNA binding abilities conferred by the C-terminal five fingers may be essential for the latter mechanism.