Gradient enhanced multi-fidelity regression with neural networks: application to turbulent flow reconstruction

A multi-fidelity regression model is proposed for combining multiple datasets with different fidelities, particularly abundant low-fidelity data and scarce high-fidelity observations. The model builds upon recent multi-fidelity frameworks based on neural networks, which employ two distinct networks for learning low- and high-fidelity data, and extends them by feeding the gradients information of low-fidelity data into the second network, while the gradients are computed using automatic differentiation with minimal computational overhead. The accuracy of the proposed framework is demonstrated through a variety of benchmark examples, and it is shown that the proposed model performs better than conventional multi-fidelity neural network models that do not use gradient information. Additionally, the proposed model is applied to the challenging case of turbulent flow reconstruction. In particular, we study the effectiveness of the model in reconstructing the instantaneous velocity field of the decaying of homogeneous isotropic turbulence given low-resolution/low-fidelity data as well as small amount of high-resolution/high-fidelity data. The results indicate that the proposed model is able to reconstruct turbulent field and capture small scale structures with good accuracy, making it suitable for more practical applications

Investigation into the Thermal Behavior and Loadability Characteristic of a YASA-AFPM Generator via an Improved 3-D Coupled Electromagnetic-Thermal Approach

The objective of this paper is to investigate the thermal behaviour and loadability characteristic of a yokeless and segmented armature axial-flux permanent-magnet (YASA-AFPM) generator, which uses an improved 3-D coupled electromagnetic-thermal approach. Firstly, a 1-kW YASA-AFPM generator is modelled and analysed by using the proposed approach; the transient and steady-state temperatures of different parts of the generator are determined. To improve the modelling accuracy, the information is exchanged between the thermal and electromagnetic models at each step of the co-simulation, considering both the accurate calculation of losses and the impacts of temperature rise on the temperature-dependent characteristics of the materials. Then, by using the proposed approach, the impact of the slot opening width and the turn number of stator segments on the generator loadability are investigated. After that, the experimental tests are performed. The results reveal the effectiveness and accuracy of the approach to predict the machine loadability and thermal behavior

Epidemiological Pattern of Injuries in Iran; a Nationwide Review of Seven Million Emergency Department Admissions

Introduction: Globally, it is estimated that around 5.8 million people die annually as result of injuries, which causes 10% of all deaths and 16% of disability adjusted life years lost worldwide. This study aimed to determine the epidemiology of injuries in emergency departments in Iran.Method: This cross sectional study was carried out using national injury surveillance data registry from 21 March 2009 to 20 March 2014.Results: 7,176,344 patients with the mean age of 27.5 ± 17.8 years were registered to 657 EDs (70.6% male). Road Traffic Crash (RTC) was the most common cause of injury (31.0%) followed by hit (28.2%) and fall (10.1%). While roads were the commonest place of injuries, 34.0% of patients have been injured at home. More than 90% of injuries were unintentional. Assault and suicide attempt were causes of injury in 5.6% and 3.9% of patients, respectively.Conclusion:This paper addresses where prevention measures are most urgently needed and offers insights which could be useful for injury prevention programs in Iran and other developing countries

Scrutinization of overall energy efficiency of machinery in plowing process

This work was dedicated to describe overall energy efficiency of machinery in plowing process as affected by some operational variables of plowing depth (10-30 cm) and forward speed (2-6 km/h). To achieve this aim, field trials in clay loam soil in southern region of Iran were performed by means of disk plow implement and front wheel assist tractor. The effects of the operational variables on the efficiency were examined. General two-variable linear and quadratic equations were fitted to obtained field data in order to model the efficiency with respect to plowing depth and forward speed. The results demonstrated that the individual effect of plowing depth on the efficiency was more dominant (1.2 times) than that of forward speed. Meanwhile, the compounded effect of plowing depth and forward speed on the efficiency was prevailed (4 and 3.2 times) than that of the individual effect of forward speed and plowing depth, respectively. The satisfactory results drawn from fitness of the quadratic equation on data rather than the linear equation manifested nonlinear increasing variations of overall energy efficiency as influenced by augmentation of plowing depth and forward speed. The condensed analytical information in conjunction with modeling results disseminate knowledge in usable and useful form to farmers, associated policy division, and stakeholders

A comparative study between mathematical models and the ANN data mining technique in draft force prediction of disk plow implement in clay loam soil

This paper communicates the prediction of required draft force of disk plow implement during tillage operations. The well-known mathematical model proposed by American Society of Agricultural and Biological Engineers (ASABE), multiple linear regression (MLR) and data mining model, based on artificial neural network (ANN), were employed for this purpose. The input variables of the models were considered as forward speed of 2-6 (km/h) and plowing depth of 10-30 (cm). The development details of the models are documented in the paper. On account of statistical performance criteria, the best ANN model with coefficient of determination of 0.971, root mean square error of 0.762 (kN), mean absolute percentage error of 1.886 (%) and mean value of absolute prediction residual errors of 0.968 (kN) was better performed than ASABE and MLR models for prediction of required draft force. The ANN modeling results also showed that the simultaneous or individual increment of forward speed and plowing depth caused nonlinear increment of draft force. The well-developed ANN model is considered operational to predict draft force as an essential step toward proper selection of combination of tractor and disk plow implement

Acute stroke secondary to internal carotid artery pseudoaneurysm: MRI findingsand treatment with endovascularcoiling

Internal carotid artery pseudoaneurysms are uncommon. We report a young man with history of trivialtrauma who presented with middle cerebral artery stroke.Head CT scan revealed a right parapharyngeal mass. MRI confirmed the diagnosis of internal carotidpseudoaneurysm. Cerebral angiogram showed dissection of internal carotid artery with a large pseudoaneurysm and almost complete occlusion of vessel distal to aneurysm.Vessel was obliterated by fibercoiling and gluing byendovascular technique to diminish risk of furthere mbolization. MRI characteristics of carotid pseudoaneurysms and role of endovascular treatment arediscussed

The ocular hypotensive effect of saffron extract in primary open angle glaucoma: a pilot study

BACKGROUND: The progressive nature of glaucoma and its growing incidence make its therapy an important target for research. The role of oxidative damage in the pathogenesis of glaucoma makes antioxidants such as saffron extract an attractive target for potential clinical use. Herein, we evaluate the effect of aqueous saffron extract on intraocular pressure (IOP) in eyes with primary open-angle glaucoma (POAG). METHODS: Thirty-four eyes of 34 clinically stable POAG patients receiving treatment with timolol and dorzolamide eye drops were enrolled in this prospective, comparative, randomized interventional pilot study. Eligible subjects were randomized to receive 30 mg/day aqueous saffron extract orally (17 subjects, 17 eyes) or placebo (17 subjects, 17 eyes) for one month as an adjunct to timolol and dorzolamide. Following treatment, both study groups entered a one-month wash-out period. The main outcome measure was IOP during treatment and after the wash-out period. RESULTS: Mean baseline IOP was 12.9 ± 3.7 versus 14.0 ± 2.5 mmHg in the saffron and control groups, respectively (p = 0.31). After three weeks of treatment, IOP was significantly decreased to 10.9 ± 3.3 mmHg in the saffron group as compared to 13.5 ± 2.3 mmHg in the control group (p = 0.013). At four weeks, IOP was still significantly lower in the saffron group (10.6 ± 3.0 versus 13.8 ± 2.2 mmHg, p = 0.001). At the end of the wash-out period, IOP was 12.9 ± 3.0 in the saffron group versus 14.2 ± 2.0 mmHg in the control group (p = 0.175). None of the patients experienced side effects during the study and wash-out period. CONCLUSIONS: Oral aqueous saffron extract seems to exert an ocular hypotensive effect in primary open-angle glaucoma. This effect became evident after three weeks of therapy. The current study was registered at the International Clinical Trials Registry Platform (ICTRP) as IRCT201201278832N1

Antifungal Effect of Echinophora Platyloba’ s Extract against Candida albicans

The present study was undertaken to investigate the effectiveness of the ethanolic extract of Echinophora platyloba DC. on Candida albicans. Using the agar dilution method, the growth condition of standard Candida albicans ATCC 10231, cultured on the media containing plant extracts at different concentrations (1, 2, 4, 8, 16, 32, 64, 128 and 256 mg/ml) was studied. The results were recorded twenty one days after the incubation period, maximum time for the growth of fungi. Results showed that the extract of Echinophora platyloba, equal or above the concentration of 2mg/ml, effectively inhibits the growth of Candida albicans. In other words it shows growth on media containing 1mg/ml of the extract. Results of the present study revealed a great promise in the application of Echinophora platyloba extract against Candida albicans. It is concluded that the plant studied could be a good antifungal source