3,404 research outputs found

    Globule transitions of a single homopolymer: a Wang-Landau Monte Carlo study

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    The temperature-independent Wang-Landau Monte Carlo approach is implemented for an off-lattice model of flexible homopolymers and applied to the coil-globule and solidification transitions based on chain sizes up to N=300. An intermediate transformation from low-density liquid globule to high-density liquid globule is suggested. A scheme for identifying polymer structures representative of particular temperatures in the course of the simulation is presented and applied to illustrate intermediate states in the coil-globule transition. Transition temperatures are calculated and used to obtain a theta point of at least Θ=1.96, distinctly higher than the solid-liquid transition temperature TM=1.26

    Developing Accessible Collection and Presentation Methods for Observational Data

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    The processes of collecting, cleaning, and presenting data are critical in ensuring the proper analysis of data at a later date. An opportunity exists to enhance the data collection and presentation process for those who are not data scientists – such as healthcare professionals and businesspeople interested in using data to help them make decisions. In this work, creating an observational data collection and presentation tool is investigated, with a focus on developing a tool prioritizing user-friendliness and context preservation of the data collected. This aim is achieved via the integration of three approaches to data collection and presentation.In the first approach, the collection of observational data is structured and carried out via a trichotomous, tailored, sub-branching scoring (TTSS) system. The system allows for deep levels of data collection while enabling data to be summarized quickly by a user via collapsing details. The system is evaluated against the stated requirements of usability and extensibility, proving the latter by providing examples of various evaluations created using the TTSS framework.Next, this approach is integrated with automated data collection via mobile device sensors, to facilitate the efficient completion of the assessment. Results are presented from a system used to combine the capture of complex data from the built environment and compare the results of the data collection, including how the system uses quantitative measures specifically. This approach is evaluated against other solutions for obtaining data about the accessibility of a built environment, and several assessments taken in the field are compared to illustrate the system’s flexibility. The extension of the system for automated data capture is also discussed.Finally, the use of accessibility information for data context preservation is integrated. This approach is evaluated via investigation of how accessible media entries improve the quality of search for an archival website. Human-generated accessibility information is compared to computer-generated accessibility information, as well as simple reliance on titles/metadata. This is followed by a discussion of how improved accessibility can benefit the understanding of gathered observational data’s context

    Designing an Educational and Intelligent Human-Computer Interface for Older Adults

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    As computing devices continue to become more heavily integrated into our lives, proper design of human-computer interfaces becomes a more important topic of discussion. Efficient and useful human-computer interfaces need to take into account the abilities of the humans who will be using such interfaces, and adapt to difficulties that different users may face – such as the particular difficulties older users must face. However, various issues in the design of human-computer interfaces for older users yet exist: a wide variance of ability is displayed by older adults, which can be difficult to design for. Motions and notions found intuitive by younger users can be anything but for the older user. Properly-designed devices must also assist without injuring the pride and independence of the users – thus, it’s understood that devices designed “for the elderly” may encounter a poor reception when introduced to the ageing community. Affective computing gives current researchers in HCI a useful opportunity to develop applications with interfaces that detect mood and attention via nonverbal cues and take appropriate actions accordingly. Current work in affective computing applications with older adult users points to possibilities reducing feelings of loneliness in the older adult population via these affective applications. However, we believe that everyday applications – such as chat programs or operating systems – can also take advantage of affective computing principles to make themselves more accessible for older adults, via communication enhancement. In this thesis, we document a variety of work in the field of developing human-computer interfaces for the older adult user, and the various requirements each of these studies confirm regarding human-computer interaction design for the elderly. We then explain how integration of affective computing can positively affect these designs, and outline a design approach for proper human-computer interfaces for the elderly which take into account affective computing principles. We then develop a case study around a chat application – ChitChat – which takes these principles and guidelines into account from the beginning, and give several examples of real-world applications also built with these guidelines. Finally, we conclude by summarizing the broader impacts of this work

    Considerations in Designing Human-Computer Interfaces for Elderly People

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    As computing devices continue to become more heavily integrated into our lives, proper design of human-computer interfaces becomes a more important topic of discussion. Efficient and useful human-computer interfaces need to take into account the abilities of the humans who will be using such interfaces, and adapt to difficulties that different users may face – such as the difficulties that elderly users must deal with. Interfaces that allow for user-specific customization, while taking into account the multiple difficulties that older users might face, can assist the elderly in properly using these newer computing devices, and in doing so possibly achieving a better quality of life through the advanced technological support that these devices offer. In this paper, we explore common problems the elderly face when using computing devices and solutions developed for these problems. Difficulties ultimately fall into several categories: cognition, auditory, haptic, visual, and motor-based troubles. We also present an idea for a new adaptive operating system with advanced customizations that would simplify computing for older users

    Tissue-specific regulation of sirtuin and nicotinamide adenine dinucleotide biosynthetic pathways identified in C57Bl/6 mice in response to high-fat feeding

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    Funding: The Scottish Government's Rural and Environment Science and Analytical Services Division.Peer reviewedPostprin

    An off-lattice Wang-Landau study of the coil-globule and melting transitions of a flexible homopolymer

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    The Wang-Landau Monte Carlo approach is applied to the coil-globule and melting transitions of off-lattice flexible homopolymers. The solid-liquid melting point and coil-globule transition temperatures are identified by their respective peaks in the heat capacity as a function of temperature. The melting and theta points are well separated, indicating that the coil-globule transition occurs separately from melting even in the thermodynamic limit. We also observe a feature in the heat capacity between the coil-globule and melting transitions which we attribute to a transformation from a low-density liquid globule to a high-density liquid globule.This work was supported by an Australian ARC Discovery Grant

    The Probabilistic Niche Model Reveals the Niche Structure and Role of Body Size in a Complex Food Web

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    The niche model has been widely used to model the structure of complex food webs, and yet the ecological meaning of the single niche dimension has not been explored. In the niche model, each species has three traits, niche position, diet position and feeding range. Here, a new probabilistic niche model, which allows the maximum likelihood set of trait values to be estimated for each species, is applied to the food web of the Benguela fishery. We also developed the allometric niche model, in which body size is used as the niche dimension. About 80% of the links in the empirical data are predicted by the probabilistic niche model, a significant improvement over recent models. As in the niche model, species are uniformly distributed on the niche axis. Feeding ranges are exponentially distributed, but diet positions are not uniformly distributed below the predator. Species traits are strongly correlated with body size, but the allometric niche model performs significantly worse than the probabilistic niche model. The best-fit parameter set provides a significantly better model of the structure of the Benguela food web than was previously available. The methodology allows the identification of a number of taxa that stand out as outliers either in the model's poor performance at predicting their predators or prey or in their parameter values. While important, body size alone does not explain the structure of the one-dimensional niche
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