337 research outputs found

    Visually-impaired people studying via ebook: investigating current use and potential for improvement

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    Everyday activities and tasks should be easy to perform for everyone, especially in an educational context, in order to foster inclusivity and assure equal opportunities for all. In this paper, we investigate strategies and issues experienced by visually impaired people when studying via eBook. An online survey was designed to investigate preferences regarding the different formats and understand what types of actions are possible and desirable when using eBooks in an educational context. We collected the views and experiences of 75 visually-impaired people, which revealed the need to develop tools that can provide both full accessibility and high usability when reading for study. Visually impaired people would like to rely on the same widely used strategies that sighted people use when studying a text. In addition, 92% of the visually-impaired people participating in the online survey declared they were interested in a (new) reading app. The results could orient the design of new digital reading tools and functionalities that can improve interaction

    A quantum computational semantics for epistemic logical operators. Part I: epistemic structures

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    Some critical open problems of epistemic logics can be investigated in the framework of a quantum computational approach. The basic idea is to interpret sentences like “Alice knows that Bob does not understand that π is irrational” as pieces of quantum information (generally represented by density operators of convenient Hilbert spaces). Logical epistemic operators (to understand, to know. . .) are dealt with as (generally irreversible) quantum operations, which are, in a sense, similar to measurement-procedures. This approach permits us to model some characteristic epistemic processes, that concern both human and artificial intelligence. For instance, the operation of “memorizing and retrieving information” can be formally represented, in this framework, by using a quantum teleportation phenomenon

    Simple smart homes web interfaces for blind people

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    Last-decade great advances in technology have contributed to make home smarter and more comfortable, especially for people with disabilities. A lot of low cost solutions are available on the market, which can be controlled remotely by a Home Automation System (HAS). Unfortunately, the user interfaces are usually designed to be visually oriented which can exclude some user categories, like those who are blind. This paper focuses on the design of usable Web user interfaces for Home Automation Systems, with a special attention to the functions as well as the interface arrangement in order to enhance the interaction via screen reader. The proposed indications could inspire other designers to make the user experience more satisfying and effective for people who interact via screen reader

    Augmented contents as assistive technology to make more inclusive everyday objects for visually impaired people

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    This study investigates how to exploit technologies for making society more inclusive by increasing the usability of artefacts that may be not accessible to people with disabilities. Accessing everyday objects can be a challenge for blind and visually impaired people. Although digital calendars are available, a tangible paper-based calendar can be more suitable or preferred by users, in specific contexts. Such a calendar should be as inclusive as possible. This paper shares the experience of designing an inclusive paper-based calendar conceived in codesign sessions with blind and visually impaired users

    Designing assistive technology for getting more independence for blind people when performing everyday tasks: an auditory-based tool as a case study

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    Everyday activities and tasks should in theory be easily carried by everyone, including the blind. Information and Communication Technology (ICT) has been widely used for supporting solutions. However, the solutions can be problematic for the visually impaired since familiarity with digital devices is often required. Or, indeed the procedure can be perceived as fiddly or impractical particularly for repetitive tasks due to the number/type of steps required to complete the task. This paper introduces a simple audio-based tool aimed at supporting visually-impaired people in the seemingly simple activity of checking whether the light in a room is on or off. It is an example of potential low tech devices that can be designed without the need for specific skills or knowledge by the user, and that functions in a practical way. In this context, we discuss the main issues and considerations for totally blind users in identifying whether a light is switched on. The proposed prototype is based on a simple circuit and a form of auditory feedback which informs the user whether they are switching on or off the light. Two prototypes have been designed and built for two different kinds of installation. For the subsequent second prototype, three different versions are proposed to provide a blind person with further support in easily identifying the light status at home. The new design includes enhanced auditory feedback and modifications to the dimensions. The evaluation conducted by involving various groups of end-users revealed the usefulness of the proposed tool. In addition, a survey conducted with 100 visually-impaired people reported the limitations and difficulties encountered by the blind in using existing devices. Moreover, the study revealed the interest from 94% of the participants for a potential (new) basic tool integrable with the existing lighting system. This study gives a contribution in the ambient intelligence field by (1) showing how an auditory-based tool can be used to support totally blind people to check the lights in an autonomous and relatively simple way; (2) proposing an idea that can be exploited in other application cases that use light feedback; and (3) proposing seven potential recommendations for designing assistive technology tools and common everyday devices, based on information gathered from the online survey

    Enriquecimiento cognoscitivo: el hombre visto como sistema abierto

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    Texto sobre las aportaciones y los beneficios de la perspectiva psicológica del enriquecimiento cognoscitivo para la intervención educativa y terapéutica con personas que demuestran desempeño retardado y otros tipos de desviación emocional o conductual. Se incluye también texto sobre el Primer Coloquio Internacional de Psicología Comunitaria y la Décima Semana de Psicología en el ITESO

    Competition of the connectivity with the local and the global order in polymer melts and crystals

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    The competition between the connectivity and the local or global order in model fully-flexible chain molecules is investigated by molecular-dynamics simulations. States with both missing (melts) and high (crystal) global order are considered. Local order is characterized within the first coordination shell (FCS) of a tagged monomer and found to be lower than in atomic systems in both melt and crystal. The role played by the bonds linking the tagged monomer to FCS monomers (radial bonds), and the bonds linking two FCS monomers (shell bonds) is investigated. The detailed analysis in terms of Steinhardt's orientation order parameters Q_l (l = 2 - 10) reveals that increasing the number of shell bonds decreases the FCS order in both melt and crystal. Differently, the FCS arrangements organize the radial bonds. Even if the molecular chains are fully flexible, the distribution of the angle formed by adjacent radial bonds exhibits sharp contributions at the characteristic angles {\theta} = 70{\deg}, 122{\deg}, 180{\deg}. The fractions of adjacent radial bonds with {\theta} = 122{\deg}, 180{\deg} are enhanced by the global order of the crystal, whereas the fraction with 70{\deg} < {\theta} < 110{\deg} is nearly unaffected by the crystallization. Kink defects, i.e. large lateral displacements of the chains, are evidenced in the crystalline state.Comment: J. Chem. Phys. in pres

    A first-order epistemic quantum computational semantics with relativistic-like epistemic effects

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    Quantum computation has suggested new forms of quantum logic, called quantum computational logics. In these logics well-formed formulas are supposed to denote pieces of quantum information: possible pure states of quantum systems that can store the information in question. At the same time, the logical connectives are interpreted as quantum logical gates: unitary operators that process quantum information in a reversible way, giving rise to quantum circuits. Quantum computational logics have been mainly studied as sentential logics (whose alphabet consists of atomic sentences and of logical connectives). In this article we propose a semantic characterization for a first-order epistemic quantum computational logic, whose language can express sentences like "Alice knows that everybody knows that she is pretty". One can prove that (unlike the case of logical connectives) both quantifiers and epistemic operators cannot be generally represented as (reversible) quantum logical gates. The "act of knowing" and the use of universal (or existential) assertions seem to involve some irreversible "theoretic jumps", which are similar to quantum measurements. Since all epistemic agents are characterized by specific epistemic domains (which contain all pieces of information accessible to them), the unrealistic phenomenon of logical omniscience is here avoided: knowing a given sentence does not imply knowing all its logical consequences

    Coincident correlation between vibrational dynamics and primary relaxation of polymers with strong or weak johari-goldstein relaxation

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    The correlation between the vibrational dynamics, as sensed by the Debye-Waller factor, and the primary relaxation in the presence of secondary Johari-Goldstein (JG) relaxation, has been investigated through molecular dynamics simulations. Two melts of polymer chains with different bond length, resulting in rather different strength of the JG relaxation are studied. We focus on the bond-orientation correlation function, exhibiting higher JG sensitivity with respect to alternatives provided by torsional autocorrelation function and intermediate scattering function. We find that, even if changing the bond length alters both the strength and the relaxation time of the JG relaxation, it leaves unaffected the correlation between the vibrational dynamics and the primary relaxation. The finding is in harmony with previous studies reporting that numerical models not showing secondary relaxations exhibit striking agreement with experimental data of polymers also where the presence of JG relaxation is known

    On the onset of breathing mode in Hall thrusters and the role of electron mobility fluctuations

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    Breathing mode is an ionization instability which is observed ubiquitously in the operation of Hall thrusters. It is recognized as a relatively low frequency (10-30 kHz) longitudinal oscillation of the discharge current and the plasma parameters. Although breathing instability is widely studied in the literature, the conditions for its origin are not fully understood. In this work we investigate the mechanisms responsible for the origin of the breathing mode in Hall thrusters by using a numerical model, allowing us to highlight the importance of electron mobility fluctuations for the onset and self-sustenance of the instability. Our one-dimensional, fully fluid model of the thruster channel is calibrated against the measured discharge current signal for a 5 kW-class Hall thruster operating in a condition where breathing mode is fully developed. The corresponding steady, unstable configuration (base state) is numerically computed by applying the Selective Frequency Damping (SFD) method. Then, a series of numerical tests is performed to show the existence of a feedback loop involving fluctuations around the base state of the neutral density, electron mobility, and electric field. We show that oscillations of the electron mobility are mainly caused by variations of the neutral density and are in phase with them; this, in turn, induces oscillations of the electric field, which are in phase opposition. The electric field acts simultaneously on the electron temperature and on the ion dynamics, promoting the depletion and replenishment of neutrals in the chamber
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