98 research outputs found

    User-Centered Evaluation of Adaptive and Adaptable Systems

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    Adaptive and adaptable systems provide tailored output to various users in various contexts. While adaptive systems base their output on implicit inferences, adaptable systems use explicitly provided information. Since the presentation or output of these systems is adapted, standard user-centered evaluation methods do not produce results that can be easily generalized. This calls for a reflection on the appropriateness of standard evaluation methods for user-centered evaluations of these systems. We have conducted a literature review to create an overview of the methods that have been used. When reviewing the empirical evaluation studies we have, among other things, focused on the variables measured and the implementation of results in the (re)design process. The goal of our review has been to compose a framework for user-centered evaluation. In the next phase of the project, we intend to test some of the most valid and feasible methods with an adaptive or adaptable system

    Evaluation of User Support: Factors That Affect User Satisfaction With Helpdesks and Helplines

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    In addition to technical documentation, face-to-face helpdesks and telephonic helplines are a powerful means for supporting users of technical products and services. This study investigates the factors that determine user satisfaction with helpdesks and helplines. A survey, based on the SERVQUAL framework and questionnaire, shows that the SERVQUAL dimensions of customer satisfaction are not applicable in these contexts. Three quality dimensions were found instead: solution quality, the experience of the consultation, and, in the case of a physical environment, the so-called tangibles. Helpdesk customers base their overall quality perceptions mainly on their experiences during a consultation, while helpline customers focus strongly on the quality of the solution offered.\ud The study also found a connection between the perceived helpline quality and the appreciation of the primary service

    Thermal Ablation for Treating Tumor-induced Osteomalacia in a Patient With IV Phosphate Dependency

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    Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome associated with tumors secreting fibroblast growth factor 23 that can be cured with complete surgical resection of the tumor. However, when these tumors are at difficult locations, less invasive modalities such as thermal ablation (TA) might be a good alternative. A 40-year-old woman was seen for a second opinion because of severe hypophosphatemia with complaints of fatigue, myalgia, and muscle weakness for which she needed IV phosphate for 15 to 18 hours per day in addition to oral alfacalcidol and phosphate. Initial laboratory results revealed hypophosphatemia (0.59 mmol/L [1.83 mg/dL]; reference range, 0.90-1.50 mmol/L [8.40-10.2 mg/dL]), increased fibroblast growth factor 23 levels (137 RU/mL; reference range, &lt;125 RU/mL), and a reduced TmP-GFR (0.47 mmol/L; reference range, 0.8-1.4 mmol/L). Gallium-positron emission tomography/computed tomography (CT) showed moderately increased uptake at thoracic vertebra (Th) 8 and mildly increased uptake at Th7, suggestive of TIO. Complete tumor removal would have required resection of at least 1 vertebral body. Therefore, CT-guided TA was performed at Th8. No complications were observed, and in the months after, treatment with IV phosphate could be discontinued, indicating a satisfying result from the procedure. This extreme TIO case demonstrates that CT-guided TA can be an alternative to extensive or risky classical surgery.</p

    Acceptance and potential impact of the ewall platform for health monitoring and promotion in persons with a chronic disease or age-related impairment

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    Pervasive health technologies can increase the effectiveness of personal health monitoring and training, but more user studies are necessary to understand the interest for these technologies, and how they should be designed and implemented. In the present study, we evaluated eWALL, a user-centered pervasive health technology consisting of a platform that monitors users’ physical and cognitive behavior, providing feedback and motivation via an easy-to-use, touch-based user interface. The eWALL was placed for one month in the home of 48 subjects with a chronic condition (chronic obstructive pulmonary disease—COPD or mild cognitive impairment—MCI) or with an age-related impairment. User acceptance, platform use, and potential clinical effects were evaluated using surveys, data logs, and clinical scales. Although some features of the platform need to be improved before reaching technical maturity and making a difference in patients’ lives, the real-life evaluation of eWALL has shown how some features may influence patients’ intention to use this promising technology. Furthermore, this study made it clear how the free use of different health apps is modulated by the real needs of the patient and by their usefulness in the context of the patient’s clinical status

    Hamiltonian dynamics of the two-dimensional lattice phi^4 model

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    The Hamiltonian dynamics of the classical ϕ4\phi^4 model on a two-dimensional square lattice is investigated by means of numerical simulations. The macroscopic observables are computed as time averages. The results clearly reveal the presence of the continuous phase transition at a finite energy density and are consistent both qualitatively and quantitatively with the predictions of equilibrium statistical mechanics. The Hamiltonian microscopic dynamics also exhibits critical slowing down close to the transition. Moreover, the relationship between chaos and the phase transition is considered, and interpreted in the light of a geometrization of dynamics.Comment: REVTeX, 24 pages with 20 PostScript figure

    Geometry of dynamics, Lyapunov exponents and phase transitions

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    The Hamiltonian dynamics of classical planar Heisenberg model is numerically investigated in two and three dimensions. By considering the dynamics as a geodesic flow on a suitable Riemannian manifold, it is possible to analytically estimate the largest Lyapunov exponent in terms of some curvature fluctuations. The agreement between numerical and analytical values for Lyapunov exponents is very good in a wide range of temperatures. Moreover, in the three dimensional case, in correspondence with the second order phase transition, the curvature fluctuations exibit a singular behaviour which is reproduced in an abstract geometric model suggesting that the phase transition might correspond to a change in the topology of the manifold whose geodesics are the motions of the system.Comment: REVTeX, 10 pages, 5 PostScript figures, published versio

    Effects of decoherence and errors on Bell-inequality violation

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    We study optimal conditions for violation of the Clauser-Horne-Shimony-Holt form of the Bell inequality in the presence of decoherence and measurement errors. We obtain all detector configurations providing the maximal Bell inequality violation for a general (pure or mixed) state. We consider local decoherence which includes energy relaxation at the zero temperature and arbitrary dephasing. Conditions for the maximal Bell-inequality violation in the presence of decoherence are analyzed both analytically and numerically for the general case and for a number of important special cases. Combined effects of measurement errors and decoherence are also discussed.Comment: 18 pages, 5 figure

    Women in post-trafficking services in moldova: diagnostic interviews over two time periods to assess returning women's mental health

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    BACKGROUND: Trafficking in women is a widespread human rights violation commonly associated with poor mental health. Yet, to date, no studies have used psychiatric diagnostic assessment to identify common forms of mental distress among survivors returning to their home country. METHODS: A longitudinal study was conducted of women aged 18 and over who returned to Moldova between December 2007 and December 2008 registered by the International Organisation for Migration as a survivor of human trafficking. Psychiatric diagnoses in women at a mean of 6 months after return (range 2-12 months) were made by a trained Moldavian psychiatrist using the Structured Clinical Interview for DSM-IV, and compared with diagnoses recorded in the same women within 5 days of return. We described the socio-demographic characteristics of the women in the sample including both pre and post-trafficking information. We then described the distribution of mental health diagnoses recorded during the crisis intervention phase (1-5 days after return) and the re-integration phase (2-12 months after return). We compared diagnoses at the patient level between the two time points by tabulating the diagnoses and carrying out a kappa test of agreement and the Stuart-Maxwell test for marginal homogeneity (an extension of the McNemar test to kxk table). RESULTS: 120/176 (68%) eligible women participated. At 2-12 months after their return, 54% met criteria for at least one psychiatric diagnoses comprising post-traumatic stress disorder (PTSD) alone (16%); co-morbid PTSD (20%); other anxiety or mood disorder (18%). 85% of women who had been diagnosed in the crisis phase with co-morbid PTSD or with another anxiety or mood disorder sustained a diagnosis of any psychiatric disorder when followed up during rehabilitation. CONCLUSIONS: Trafficked women returning to their country of origin are likely to suffer serious psychological distress that may endure well beyond the time they return. Women found to have co-morbid PTSD or other forms of anxiety and depression immediately post-return should be offered evidenced-based mental health treatment for at least the standard 12-month period of rehabilitation

    Responsibility Ascriptions in Technology Development and Engineering: Three Perspectives

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    In the last decades increasing attention is paid to the topic of responsibility in technology development and engineering. The discussion of this topic is often guided by questions related to liability and blameworthiness. Recent discussions in engineering ethics call for a reconsideration of the traditional quest for responsibility. Rather than on alleged wrongdoing and blaming, the focus should shift to more socially responsible engineering, some authors argue. The present paper aims at exploring the different approaches to responsibility in order to see which one is most appropriate to apply to engineering and technology development. Using the example of the development of a new sewage water treatment technology, the paper shows how different approaches for ascribing responsibilities have different implications for engineering practice in general, and R&D or technological design in particular. It was found that there was a tension between the demands that follow from these different approaches, most notably between efficacy and fairness. Although the consequentialist approach with its efficacy criterion turned out to be most powerful, it was also shown that the fairness of responsibility ascriptions should somehow be taken into account. It is proposed to look for alternative, more procedural ways to approach the fairness of responsibility ascriptions
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