2,336 research outputs found
Diagnosing faults in autonomous robot plan execution
A major requirement for an autonomous robot is the capability to diagnose faults during plan execution in an uncertain environment. Many diagnostic researches concentrate only on hardware failures within an autonomous robot. Taking a different approach, the implementation of a Telerobot Diagnostic System that addresses, in addition to the hardware failures, failures caused by unexpected event changes in the environment or failures due to plan errors, is described. One feature of the system is the utilization of task-plan knowledge and context information to deduce fault symptoms. This forward deduction provides valuable information on past activities and the current expectations of a robotic event, both of which can guide the plan-execution inference process. The inference process adopts a model-based technique to recreate the plan-execution process and to confirm fault-source hypotheses. This technique allows the system to diagnose multiple faults due to either unexpected plan failures or hardware errors. This research initiates a major effort to investigate relationships between hardware faults and plan errors, relationships which were not addressed in the past. The results of this research will provide a clear understanding of how to generate a better task planner for an autonomous robot and how to recover the robot from faults in a critical environment
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White coat hypertension is associated with increased small vessel disease in the brain
Objective:
Small vessel disease, as measured by white matter hyperintensity (WMH) in the brain, is known to be associated with increased stroke risk and cognitive impairment. This study explored the relationship between WMH on computerised tomography (CT) and white coat hypertension/effect (WCH/E) in patients with recent transient ischaemic attack (TIA) or lacunar stroke (LS).
Design and method:
Ninety-six patients recruited for the ASIST trial (Arterial Stiffness in Lacunar Stroke and TIA) underwent measurement of clinic blood pressure (BP) and ambulatory BP monitoring (APBM) within two weeks of TIA or LS. Twenty-three patients had normotension (clinic BP / = 140/90mmHg and day-time ABPM < 135/85mmHg). Arterial stiffness was measured using carotid-femoral pulse wave velocity (PWV) (CompliorÂź, ALAM Medical) and carotid-ankle vascular index (CAVI) (VaSera VS-1500NÂź, Fukuda Denshi). CT images were scored for WMH using the four-point Fazekas visual rating scale. Patients were grouped into no-mild WMH (scores 0â1) or moderate-severe (scores 2â3) groups. The relationship between BP, vascular stiffness and WMH was explored with t-tests, chi-square and logistic regression accounting for known cardiovascular risk factors.
Results:
Forty-four percent of patients with WCH/E had moderate-severe WMH compared to 17% of normotensives (p = 0.047). The regression model with WMH as the dependent factor, and WCH/E and cardiovascular risk factors as independent factors showed WCH/E and either CAVI or PWV to be the only independent significant factor contributing to WMH (CAVI:p = 0.038, PWV:p = 0.043)
Applicative Bidirectional Programming with Lenses
A bidirectional transformation is a pair of mappings between source and view data objects, one in each direction. When the view is modified, the source is updated accordingly with respect to some laws. One way to reduce the development and maintenance effort of bidirectional transformations is to have specialized languages in which the resulting programs are bidirectional by construction---giving rise to the paradigm of bidirectional programming.
In this paper, we develop a framework for applicative-style and higher-order bidirectional programming, in which we can write bidirectional transformations as unidirectional programs in standard functional languages, opening up access to the bundle of language features previously only available to conventional unidirectional languages. Our framework essentially bridges two very different approaches of bidirectional programming, namely the lens framework and Voigtlanderâs semantic bidirectionalization, creating a new programming style that is able to bag benefits from both
Single-Incision Multi-Port Appendectomy for a Patient with Situs Inversus Totalis : First case report
Situs inversus totalis (SIT) is a rare autosomal recessive condition involving the complete lateral transposition of the organs. When individuals with this condition suffer from appendicitis, associated pain and symptoms are usually present on the left side, resulting in diagnostic difficulties. Moreover, the laparoscopic removal of the left-sided appendix may pose practical problems during surgery. Removal of an inflamed appendix is generally performed using a multiple-port laparoscopy. We report a 22-year-old male who presented to the Lifeline Institute of Minimal Access Surgery in Chennai, India, in April 2015 with pain in the left iliac fossa. Chest X-rays and ultrasonography confirmed SIT with an acutely inflamed appendix on the left side. The patient underwent a single-incision multi-port laparoscopic appendectomy with a successful outcome. To the best of the authorsâ knowledge, this is the first report in the literature of a single-incision multi-port appendectomy in a patient with SIT
Exposure to Household Air Pollution from Biomass-Burning Cookstoves and HbA1c and Diabetic Status Among Honduran Women
Household air pollution from biomass cookstoves is estimated to be responsible for more than two and a half million premature deaths annually, primarily in low and middleâincome countries where cardiometabolic disorders, such as Type II Diabetes, are increasing. Growing evidence supports a link between ambient air pollution and diabetes, but evidence for household air pollution is limited. This crossâsectional study of 142 women (72 with traditional stoves and 70 with cleanerâburning Justa stoves) in rural Honduras evaluated the association of exposure to household air pollution (stove type, 24âhour average kitchen and personal fine particulate matter [PM2.5] mass and black carbon) with glycated hemoglobin (HbA1c) levels and diabetic status based on HbA1c levels. The prevalence ratio (PR) per interquartile range increase in pollution concentration indicated higher prevalence of prediabetes/diabetes (vs normal HbA1c) for all pollutant measures (eg, PR per 84 ÎŒg/m3 increase in personal PM2.5, 1.49; 95% confidence interval [CI], 1.11â2.01). Results for HbA1c as a continuous variable were generally in the hypothesized direction. These results provide some evidence linking household air pollution with the prevalence of prediabetes/diabetes, and, if confirmed, suggest that the global public health impact of household air pollution may be broader than currently estimated
Development and experimental assessment of a numerical modelling code to aid the design of profile extrusion cooling tools
On the extrusion of thermoplastic profiles, upon the forming stage that takes place in the extrusion die, the profile must be cooled in a metallic calibrator. This stage must be done at a high rate, to assure increased productivity, but avoiding the development of high temperature gradients, in order to minimize the level of induced thermal residual stresses. In this work, we present a new coupled numerical solver, developed in the framework of the OpenFOAMÂź computational library, that computes the temperature distribution in both domains simultaneously (metallic calibrator and plastic profile), whose implementation aimed the minimization of the computational time. The new solver was experimentally assessed with an industrial case study.SFRH/BPD/100353/2014info:eu-repo/semantics/publishedVersio
Role of paan chewing and dietary habits in cervical carcinoma in Chennai, India
/=5 paan day(-1)=4.0; 95% CI 1.2-13.3). Among dietary habits, the highest vs lowest intake tertile for vegetables and fruit was associated with an OR of 0.5 (95% CI 0.2-1.0). Low education level and low body weight were also risk factors for ICC, but they did not account for the associations of paan chewing and low vegetable and fruit intake. In the analyses restricted to HPV-positive cases and controls, the inverse association with vegetable and fruit intake was confirmed. Conversely, the adverse influence of paan chewing on ICC risk seemed to be attributable to a higher prevalence of cervical HPV infection in women who chewed
Experimental assessment of a numerical modelling code developed for the profile extrusion cooling stage
One of the critical stages in the extrusion of thermoplastic profiles is the cooling of the profile, which
is usually undertaken in a metallic calibrator. In order to assure the highest possible productivity, the
profile thermal energy must be removed as fast as possible. However, due to the typical low diffusivity
of thermoplastic materials, the cooling stage is relatively long and the temperature gradients along the
profile thickness are high, promoting the development of thermal residual stresses, which should be
minimized. Consequently, designing an optimum calibration system that ensures fast and low level of
thermal residual stresses is always a difficult task, especially when dealing with complex geometry
profiles.
In this work, we firstly report the experimental assessment of a previously developed numerical
modelling code [1], which is able to model the thermal interchanges that take place at the profile
extrusion calibration stage, and was developed in the framework of the OpenFOAMÂź [2]
computational library. This task is undertaken with an industrial case study: a cooling system,
composed by three calibrators in series, used in the production of a swimming pool cover profile. The
experimental data of the temperature evolution along the calibration length was found to be similar to
the numerical predictions, with a maximum relative error of circa 8.6% near the inlet of the second
calibrator unit, which allowed the numerical code validation.
Upon the experimental assessment the numerical code was used to support the redesign of the
calibration system. This study led to an alternative calibration system design, which has a simpler
constructive solution and a better performance than the original one, considered in the validation of the
numerical code.
As main conclusions, the results reported in this work prove the accuracy of the numerical code
developed to compute the temperature distribution in the cooling/calibration extrusion stage, and its
suitability to support the design of these systems.This work is funded by UID/CTM/50025/2013 - LA0025, with the financial support of FCT/MEC
through national funds and when applicable by FEDER co-funded, within the partnership agreement
PT2020
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