126 research outputs found

    Fermi Observation of Solar System Gamma-Ray sources

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    The Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope (Fermi) is a pair-conversion detector operating at energies from 20 MeV to >300 GeV. Its main operating mode is the all-sky survey. Since the beginning of the mission the Fermi-LAT has observed the high-energy gamma-ray emission from the sources in the solar system: the Sun, the Moon, and the Earth. This emission is induced by Galactic cosmic ray (CR) interactions with their surface. Additionally, an extended emission around the sun is produced by CR electrons via inverse Compton scattering of solar photons. In this paper we report the current status of observations of the solar system sources

    A Methodology for Creating an Adapted Command Language for Driving an Intelligent Wheelchair

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    Intelligent wheelchairs (IW) are technologies that can increase the autonomy and independence of elderly people and patients suffering from some kind of disability. Nowadays the intelligent wheelchairs and the human-machine studies are very active research areas. This paper presents a methodology and a Data Analysis System (DAS) that provides an adapted command language to an user of the IW. This command language is a set of input sequences that can be created using inputs from an input device or a combination of the inputs available in a multimodal interface. The results show that there are statistical evidences to affirm that the mean of the evaluation of the DAS generated command language is higher than the mean of the evaluation of the command language recommended by the health specialist (p value = 0.002) with a sample of 11 cerebral palsy users. This work demonstrates that it is possible to adapt an intelligent wheelchair interface to the user even when the users present heterogeneous and severe physical constraints

    Adapted control methods for cerebral palsy users of an intelligent wheelchair

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    The development of an intelligent wheelchair (IW) platform that may be easily adapted to any commercial electric powered wheelchair and aid any person with special mobility needs is the main objective of this project. To be able to achieve this main objective, three distinct control methods were implemented in the IW: manual, shared and automatic. Several algorithms were developed for each of these control methods. This paper presents three of the most significant of those algorithms with emphasis on the shared control method. Experiments were performed by users suffering from cerebral palsy, using a realistic simulator, in order to validate the approach. The experiments revealed the importance of using shared (aided) controls for users with severe disabilities. The patients still felt having complete control over the wheelchair movement when using a shared control at a 50% level and thus this control type was very well accepted. Thus it may be used in intelligent wheelchairs since it is able to correct the direction in case of involuntary movements of the user but still gives him a sense of complete control over the IW movement

    A clinical support system based on quality of life estimation

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    Quality of life is a concept influenced by social, economic, psychological, spiritual or medical state factors. More specifically, the perceived quality of an individual's daily life is an assessment of their well-being or lack of it. In this context, information technologies may help on the management of services for healthcare of chronic patients such as estimating the patient quality of life and helping the medical staff to take appropriate measures to increase each patient quality of life. This paper describes a Quality of Life estimation system developed using information technologies and the application of data mining algorithms to access the information of clinical data of patients with cancer from Otorhinolaryngology and Head and Neck services of an oncology institution. The system was evaluated with a sample composed of 3013 patients. The results achieved show that there are variables that may be significant predictors for the Quality of Life of the patient: years of smoking (p value 0.049) and size of the tumor (p value < 0.001). In order to assign the variables to the classification of the quality of life the best accuracy was obtained by applying the John Platt's sequential minimal optimization algorithm for training a support vector classifier. In conclusion data mining techniques allow having access to patients additional information helping the physicians to be able to know the quality of life and produce a well-informed clinical decision

    Evaluation of distinct input methods of an intelligent wheelchair in simulated and real environments: a performance and usability study

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    This paper focuses on evaluating the usability of an Intelligent Wheelchair (IW) in both real and simulated environments. The wheelchair is controlled at a high-level by a flexible multimodal interface, using voice commands, facial expressions, head movements and joystick as its main inputs. A Quasi-experimental design was applied including a deterministic sample with a questionnaire that enabled to apply the System Usability Scale. The subjects were divided in two independent samples: 46 individuals performing the experiment with an Intelligent Wheelchair in a simulated environment (28 using different commands in a sequential way and 18 with the liberty to choose the command); 12 individuals performing the experiment with a real IW. The main conclusion achieved by this study is that the usability of the Intelligent Wheelchair in a real environment is higher than in the simulated environment. However there were not statistical evidences to affirm that there are differences between the real and simulated wheelchairs in terms of safety and control. Also, most of users considered the multimodal way of driving the wheelchair very practical and satisfactory. Thus, it may be concluded that the multimodal interfaces enables very easy and safe control of the IW both in simulated and real environments

    Compliance study of hazard analysis and critical control point system

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    Hazard Analysis and Critical Control Point (HACCP) system is based on a preventive methodology to avoid potential hazards that can cause harm and to ensure that unsafe food is not made available to consumers. This system is recognized by the Economic and Food Safety Authority, a criminal police responsible for food safety and economic inspection in Portugal. Every day, Economic and Food Safety Authority generates a large and complex volume of data from inspections and complaints, also in its classification, registration and in monitoring until the end of the process analysis. This study focuses on the reported entities that are related to non-compliance with HACCP, and tries to understand the most common infractions. Results show values between 30% and 37% related to non-compliance to HACCP. As main conclusions, from 2014 to 2018, the number of these infractions maintained the same level and it will be important to understand if the relationship between these problems are related to legislation understanding or application.info:eu-repo/semantics/publishedVersio

    Combination of Cytotoxic Drugs for Patients with HER2-Negative Metastatic Breast Cancer

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    In the last few decades the approach to metastatic breast cancer (MBC) treatment using chemotherapy, either as single or combination agents, has been largely studied and a wide spectrum of therapeutic options is now available. Anthracyclines and taxanes remain the cornerstone of treatment in this setting. The choice of combination chemotherapy versus monochemotherapy is still open to debate since results from clinical trials are, unfortunately, conflicting. Despite improvements in response and disease-free survival rates, there has been no overall survival benefit reported although toxicity is increased. Therefore, based on available data, clinical decision-making for a busy practitioner should consider not only patient/tumor characteristics and the potential benefits of treatments, but also their toxicity profiles and patient preferences. Novel cytotoxic compounds have been approved for clinical use and combination regimens incorporating these agents may bring new treatment opportunities for MBC patients. In this review, we summarize the main achievements and the currently available and future combinations of cytotoxic drugs for patients with HER2-negative MBC

    Ex vivo analysis of root canal cleaning using Endo-PTC associated to NaOCl and different irrigant solutions

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    The aim of this study was to assess qualitatively, by means of SEM images, the cleaning of the dentin walls of root canals after chemical-surgical preparation using Endo-PTC cream with 0.5% and 1% sodium hypochlorite and different final irrigating solutions. Seventy-two single-rooted human teeth were divided into eight groups and prepared using Endo-PTC cream with sodium hypochlorite (NaOCl) at different concentrations, and irrigated with NaOCl at different concentrations. Final irrigation was performed with either EDTA-T or EDTA-C. The best results were obtained with Group 1, followed by Groups 5, 2, 7, 8, 3, 6 and 4. We can conclude that the use of 0.5% NaOCl during instrumentation and final flush of the root canals was more efficient in cleaning than was 1% sodium hypochlorite. EDTA-T was more efficient in removing smear layer than EDTA-C, and the cervical third presented better cleaning of the root canal walls than did the middle third, which showed cleaner dentin walls than the apical third

    Estudo Estatístico sobre Saldos de Caixa de Empresas Portuguesas

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    The cash balances of businesses have recently become one of the main topics of interest in the financial area. As a result of this interest, several studies and theories have been applied to this field, mainly to larger companies, and with a lesser application to the universe of small businesses. Portuguese business context is mainly composed by owner managed companies of the small businesses. The theoretical support that was considered most appropriate to back the analysis was the trade-off theory. The trade-off theory, in general terms, explains the amount of cash reported by companies on their balance sheets. This study is based on a sample of Portuguese manufacturing firms. It uses a methodology of econometric nature, based on models that were constructed to test if the tradeoff theory can explain the amount of cash held by these companies. The modeling considered four key variables (determinants) significant in the explanation of such amounts: the "net working capital", the "debt", the "size" and "cash flow". Moreover, after a closer analysis, the results indicate that there are significant differences when if there is or not an auditor that certifies the accounts of the companies is added as control.info:eu-repo/semantics/publishedVersio

    A METHODOLOGY FOR CREATING INTELLIGENT WHEELCHAIR USERS’ PROFILES

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    Intelligent Wheelchair (IW) is a new concept aiming to allow higher autonomy to people with lower mobility such as disabled or elderly individuals. Some of the more recent IWs have a multimodal interface, enabling multiple command modes such as joystick, voice commands, head movements, or even facial expressions. In these IW it may be very useful to provide the user with the best way of driving it through an adaptive interface. This paper describes the foundations for creating a simple methodology for extracting user profiles, which can be used to adequately select the best IW command mode for each user. The methodology is based on an interactive wizard composed by a flexible set of simple tasks presented to the user, and a method for extracting and analyzing the user’s execution of those tasks. The results achieved showed that it is possible to extract simple user profiles, using the proposed method. Thus, the approach may be further used to extract more complete user profiles, just by extending the set of tasks used, enabling the adaptation of the IW interface to each user’s characteristics.info:eu-repo/semantics/publishedVersio
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