40 research outputs found

    Multi-score Learning for Affect Recognition: the Case of Body Postures

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    An important challenge in building automatic affective state recognition systems is establishing the ground truth. When the groundtruth is not available, observers are often used to label training and testing sets. Unfortunately, inter-rater reliability between observers tends to vary from fair to moderate when dealing with naturalistic expressions. Nevertheless, the most common approach used is to label each expression with the most frequent label assigned by the observers to that expression. In this paper, we propose a general pattern recognition framework that takes into account the variability between observers for automatic affect recognition. This leads to what we term a multi-score learning problem in which a single expression is associated with multiple values representing the scores of each available emotion label. We also propose several performance measurements and pattern recognition methods for this framework, and report the experimental results obtained when testing and comparing these methods on two affective posture datasets

    Magnetic field effect on the dielectric constant of glasses: Evidence of disorder within tunneling barriers

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    The magnetic field dependence of the low frequency dielectric constant ere_r(H) of a structural glass a - SiO2 + xCyHz was studied from 400 mK to 50 mK and for H up to 3T. Measurement of both the real and the imaginary parts of ere_r is used to eliminate the difficult question of keeping constant the temperature of the sample while increasing H: a non-zero ere_r(H) dependence is reported in the same range as that one very recently reported on multicomponent glasses. In addition to the recently proposed explanation based on interactions, the reported ere_r(H) is interpreted quantitatively as a consequence of the disorder lying within the nanometric barriers of the elementary tunneling systems of the glass.Comment: latex Bcorrige1.tex, 5 files, 4 figures, 7 pages [SPEC-S02/009

    Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

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    Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

    Stereotactic radiosurgery of brain metastases.

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    Brain metastases are a common problem in solid malignancies and still represent a major cause of morbidity and mortality. With the ongoing improvement in systemic therapies, the expectations on the efficacy of brain metastases directed treatment options are growing. As local therapies against brain metastases continue to evolve, treatment patterns have shifted from a palliative "one-treatment-fits-all" towards an individualized, patient adapted approach. In this article we review the evidence for stereotactic radiation treatment based on the current literature. Stereotactic radiosurgery (SRS) as a local high precision approach for the primary treatment of asymptomatic brain metastases has gained wide acceptance. It leads to lasting tumor control with only minor side effects compared to whole brain radiotherapy, since there is only little dose delivered to the healthy brain. The same holds true for hypofractionated stereotactic radiotherapy (HFSRT) for large metastases or for lesions close to organs at risk (e.g. the brainstem). New treatment indications such as neoadjuvant SRS followed by surgical resection or postoperative local therapy to the resection cavity show promising data and are also highlighted in this manuscript. With the evolution of local treatment options, optimal patient selection becomes more and more crucial. This article aims to aid decision making by outlining prognostic factors, treatment techniques and indications and common dose prescriptions

    Using sensors and augmented reality to train apprentices using recorded expert performance:A systematic literature review

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    Experts are imperative for training apprentices, but learning from experts is difficult. Experts often struggle to explicate and/or verbalize their knowledge or simply overlook important details due to internalization of their skills, which may make it more difficult for apprentices to learn from experts. In addition, the shortage of experts to support apprentices in one-to-one settings during trainings limits the development of apprentices. In this review, we investigate how augmented reality and sensor technology can be used to capture expert performance in such a way that the captured performance can be used to train apprentices without increasing the workload on experts. To this end, we have analysed 78 studies that have implemented augmented reality and sensor technology for training purposes. We explored how sensors have been used to capture expert performance with the intention of supporting apprentice training. Furthermore, we classified the instructional methods used by the studies according to the 4C/ID framework to understand how augmented reality and sensor technology have been used to support training. The results of this review show that augmented reality and sensor technology have the potential to capture expert performance for training purposes. The results also outline a methodological approach to how sensors and augmented reality learning environments can be designed for training using recorded expert performance

    HFSRT of the resection cavity in patients with brain metastases.

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    Purpose: Aim of this single center, retrospective study was to assess the efficacy and safety of linear accelerator-based hypofractionated stereotactic radiotherapy (HFSRT) to the resection cavity of brain metastases after surgical resection. Local control (LC), locoregional control (LRC = new brain metastases outside of the treatment volume), overall survival (OS) as well as acute and late toxicity were evaluated. Patients and methods: 46 patients with large (> 3 cm) or symptomatic brain metastases were treated with HFSRT. Median resection cavity volume was 14.16 cm3 (range 1.44–38.68 cm3) and median planning target volume (PTV) was 26.19 cm3 (range 3.45–63.97 cm3). Patients were treated with 35 Gy in 7 fractions prescribed to the 95–100 % isodose line in a stereotactic treatment setup. LC and LRC were assessed by follow-up magnetic resonance imaging. Results: The 1-year LC rate was 88 % and LRC was 48 %; 57% of all patients showed cranial progression after HFSRT (4% local, 44% locoregional, 9% local and locoregional). The median follow-up was 19 months; median OS for the whole cohort was 25 months. Tumor histology and recursive partitioning analysis score were significant predictors for OS. HFSRT was tolerated well without any severe acute side effects > grade 2 according to CTCAE criteria. Conclusion: HFSRT after surgical resection of brain metastases was tolerated well without any severe acute side effects and led to excellent LC and a favorable OS. Since more than half of the patients showed cranial progression after local irradiation of the resection cavity, close patient follow-up is warranted. A prospective evaluation in clinical trials is currently being performed
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