People spend a significant amount of time using computers at work, at home, or school. Given users switch tasks and are frequently interrupted or distracted while working, reconstructing working context is inevitable. For example, users sometimes need to revisit an arbitrary task from the past to retrieve necessary information (e.g., webpages, files). In this scenario, retrieving working context can be time-consuming or even impossible; users may rely on their memory and may not be able to retrieve the relevant documents that they used before. Sometimes application provides a chronological history of recently opened documents (files, websites). However, it can be challenging to find the right information they need as there are many and users may not recognize from the text-based data (e.g. web page titles, document file name). Therefore, helping them reconstruct mental context and retrieving relevant applications and files can enhance overall productivity. To that end, the concept of self-tracking, which is widely used in health and fitness, is applied to the context of computer usage. In particular, the idea of using a history of a computer screen can provide visuals that users can associate with existing meta-data (file location, web page URL, time). A user can reconstruct working context from the screen visual that they recognize. The idea of using a visual history of a computer screen activities is tested through the development of ScreenTrack, a program that captures a computer screen regularly and let a user watch a time-lapse video made of computer screenshots, and retrieve applications, files, and web pages from a snapshot of a screen. I hypothesize that the chronological history of computer screen activities can effectively help users navigate visual working context and retrieve information that is associated with a snapshot. Through a controlled user study, it was found that participants were able to retrieve information that they were asked more quickly with ScreenTrack than the control condition with statistical significance (p<0.005). Besides, participants gave positive feedback on the software that they would like to use such software in their computers in various context, but expressed potential concerns of using such software for privacy and computer storage problems. In this thesis, I motivate the need of such software, review the related work, share the design consideration, and introduce design and implementation process, validate the effects of ScreenTrack with a controlled user study. / Master of Science / Nowadays, people spend a significant amount of time using computers at work, at home, or school. Users switch software frequently and are often interrupted or distracted while working. Hence recalling previous working context is inevitable for computer users. Recalling previous working context can take lots of time or even impossible. Because users may rely on their own memory and may not be able to recall and retrieve the relevant documents that they used before. Sometimes software provides a history of recently opened documents (files, websites). However, it can be challenging to find the right information they need as there are many recorded information. And users may not recognize documents of interest from the textual data (e.g. web page titles, document file name). Therefore, helping people restore previous working context and reopening relevant software and files can enhance overall productivity. I designed and developed a software, called ScreenTrack. This software can take pictures of current computer screen regularly and store them. Later, users can watch a video made of stored screenshots. Based on this video, individuals can recall their previous computer activities and reopen closed software, websites, files, and documents from a snapshot. Through a controlled user study, I found that participants were able to retrieve previous computer activities more quickly under the help of ScreenTrack than without ScreenTrack. With ScreenTrack, participants spend 27.1 seconds on average to reopen a previous closed website, 37% faster than without it. Furthermore, participants gave positive feedback on this software that they would like to use ScreenTrack in the future for various purposes, for doing researches and reading papers.

This thesis deals with the introduction into the topic of time-lapse video creation. It focuses on cases where tripod is not used and therefore it is  necessary to eliminate incurred shortcomings. The main shortcomings are different position of individual frames, different brightness and color adjustment. The next topic describes which principles should be followed during the creation process. Thesis describes and implements methods for elimination of main shortcomings during process long time-lapse videos, which are recorded by hand. Thesis also precisely describes image registration, correction of brightness and colors. Thesis is also considers histograms comparison. Result of this work is application, which eliminates problems described above.

Le cortex cérébral primate a subi des modifications majeures pendant l'évolution qui ont permis le développement de fonctions cognitives supérieures. Un accroissement massif a eu lieu avec l'extension spécifique des couches supragranulaires et une forte expansion tangentielle. Le cortex primate ne possède pas uniquement davantage de neurones, comparé au rongeur, mais aussi des différences qualitatives. Ceci suggère des différences qualitatives pendant le développement du cortex.Une zone proliférative corticale supplémentaire a été identifiée chez le singe macaque: la zone subventriculaire externe (OSVZ) supposée être impliquée dans l'expansion du cortex primate. Mais les propriétés des précurseurs de l'OSVZ restent mal connues. Des techniques de microscopie en temps réel et d'immunofluorescence ont permis de réaliser une description exhaustive des précurseurs de l'OSVZ et de leurs propriétés chez le singe macaque.Nos résultats mettent en évidence des différences primates/rongeurs majeures. Les observations en temps réel révèlent des capacités prolifératives bien plus importantes des précurseurs. Les précurseurs primates de l'OSVZ présentent des taux de prolifération variables pendant la corticogenèse liés à la cinétique du cycle cellulaire. Nos enregistrements ont permis la génération d'une grande base de données de propriétés et lignages de précurseurs et la mise en évidence d’une diversité morphologique inattendue. 5 types ont été identifiés. Impliqués dans des lignages complexes, chaque type a la capacité de s'auto-renouveler et de générer directement des neurones. Parallèlement, nous avons développé une méthode de classification non supervisée des précurseurs corticaux. Cette technique a identifié les mêmes 5 types de précurseurs.Les résultats de cette thèse apportent de nouveaux éléments dans la compréhension des spécificités de la corticogenèse primate qui contribuent à l'expansion corticale et au développement de capacités cognitives supérieures. / The primate cerebral cortex underwent major modifications during evolution that enabled the development of high cognitive functions. A massive enlargement occurred with the specific expansion of the supra granular layers and the apparition of new frontal areas. Not only quantitative differences are found compared to the rodent but also qualitative differences. This points to potential qualitative differences in primate cortical development. An extra proliferating zone had already been identified during macaque corticogenesis: the outer subventricular zone (OSVZ). This zone is assumed to play a key role in the expansion of the primate cortex but the cellular and functional properties of OSVZ precursors remain elusive. We used quantitative long-term time-lapse video-microscopy (TLV) and immunofluorescence in and ex vivo to perform a detailed and exhaustive description of OSVZ precursor types and proliferative abilities at different stages of macaque cortical development. Our results highlight major rodent/primate differences. TLV observations revealed a much higher proliferative potential of OSVZ compared to the rodent SVZ. We report variable rates of proliferation linked to cell-cycle duration in a stage-specific manner. TLV recordings allowed the formation of a large database of primate precursor properties and lineages. This dataset unravelled an unexpectedly high diversity of OSVZ precursor morphologies. Five precursor types were identified. Involved in complex lineages, each precursor type can self-renew and directly generate neurons. In a parallel approach, we developed an unbiased clustering tool to automatically classify cortical precursors. This technique returned the same five precursor types as the morphological categorization. The results of this PhD thesis provide new insights into primate specificities during corticogenesis that contribute to cortical expansion and to the development of higher cognitive abilities.

Despite extensive international acceptance of the critical role of mammalian post-dispersal seed predation in many plant communities, in New Zealand we have limited knowledge of these predators’ influence on plant recruitment in our forests. The principle objective of my thesis was to determine the importance of exotic mammals as post-dispersal seed predators in a New Zealand conifer-broadleaf forest remnant. To address this goal, I used a series of field-based experiments where the actions of different post-dispersal seed predators were separated by wire-mesh exclosures. My study was conducted at Mount Peel Forest Park Scenic Reserve, South Canterbury, New Zealand. Being a human modified conifer forest currently dominated by broadleaf species, it is typical of forest remnants in New Zealand. This presented an opportunity to study a wide range of both potential post-dispersal seed predators and broadleaf tree species. My findings indicate that exotic mammals are not only post-dispersal seed predators at Peel Forest, but are responsible for the majority of post-dispersal predation events observed. Ship rats (Rattus rattus) were the dominant post-dispersal seed predators, while brushtail possums (Trichosurus vulpecula), house mice (Mus musculus) and native invertebrates were also important post-dispersal seed predators for several tree species. Through use of time-lapse video and cafeteria experiments I found that exotic mammalian seed predators, when compared to native invertebrate seed predators, preyed upon larger-seeded plant species and were responsible for considerable seed losses of several tree species. However, exotic mammalian seed predators do share several foraging characteristics with native invertebrate seed predators, as predators foraged in similar habitats and responded in a similar way to changes in seed density. In investigating if post-dispersal seed predation by mammals had a flow-on effect to plant recruitment, I observed natural seedling densities at Peel Forest were significantly higher in the absence of mammalian seed predators, but I found no evidence that the presence of mammals significantly altered the overall species richness. At the community level, I did not find an interaction between habitat and exotic mammals, however I present evidence that for individual plant species a significant mammal : habitat interaction occurred. Consequently, even though my cafeteria experiment implied there was no significant difference in the overall amount of seed preyed upon within different habitats, the less favourable microsite conditions for germination under an intact continuous canopy allows mammals to exacerbate habitat-related patterns of seed mortality and have a noticeable effect on seedling establishment. In an effort to validate the use of manipulative experiments to predict the long-term effect of post-dispersal seed predation on plant dynamics, I attempted to link results of my cafeteria experiment with observed seedling abundance at Peel Forest. Seven tree species were used in this comparison and a strong correlation was observed. This result shows that the level of post-dispersal seed predation determined in the cafeteria experiment provided a good predictor of the effect of mammalian post-dispersal seed predation on seedling establishment. To fully gauge the impact of mammalian post-dispersal seed predators on seedling establishment, the relationship between these seed predators and the type of recruitment limitation experienced by a plant species was also investigated. By using a combination of seed addition, plot manipulations and seed predator exclusion I was able to investigate this relationship. I found evidence that seed limitation at Peel Forest is positively correlated with seed size, and that while mammalian post-dispersal seed predators can further reduce plant recruitment of plant species experiencing seed limitation, the influence of mammals in determining plant recruitment was limited for plant species experiencing microsite limitation. My study has proven that exotic mammals are now the dominant post-dispersal seed predators at Peel Forest, the amount of seed preyed upon varies among plant species, and post-dispersal seed predation by mammalian species can lead to differences in seedling richness and abundance. I proved that the influence of exotic mammals on seedling establishment is also linked to habitat structure and recruitment limitations. When combined these observations suggest that exotic mammalian post-dispersal seed predators may play an important role in determining landscape abundance and distribution of plants at Peel Forest.

The topic of this master's thesis is the time lapse from stationary camera images. Unwanted phenomena, which arise in time lapse, were analyzed and algorithms to overcome these limitations were designed. The algorithms were implemented and compared using the captured dataset. The resulting application creates time lapse from the video input and allows users to choose the processing technique including the setting of appropriate parameters.