300 research outputs found
Self-Supervised Relative Depth Learning for Urban Scene Understanding
As an agent moves through the world, the apparent motion of scene elements is
(usually) inversely proportional to their depth. It is natural for a learning
agent to associate image patterns with the magnitude of their displacement over
time: as the agent moves, faraway mountains don't move much; nearby trees move
a lot. This natural relationship between the appearance of objects and their
motion is a rich source of information about the world. In this work, we start
by training a deep network, using fully automatic supervision, to predict
relative scene depth from single images. The relative depth training images are
automatically derived from simple videos of cars moving through a scene, using
recent motion segmentation techniques, and no human-provided labels. This proxy
task of predicting relative depth from a single image induces features in the
network that result in large improvements in a set of downstream tasks
including semantic segmentation, joint road segmentation and car detection, and
monocular (absolute) depth estimation, over a network trained from scratch. The
improvement on the semantic segmentation task is greater than those produced by
any other automatically supervised methods. Moreover, for monocular depth
estimation, our unsupervised pre-training method even outperforms supervised
pre-training with ImageNet. In addition, we demonstrate benefits from learning
to predict (unsupervised) relative depth in the specific videos associated with
various downstream tasks. We adapt to the specific scenes in those tasks in an
unsupervised manner to improve performance. In summary, for semantic
segmentation, we present state-of-the-art results among methods that do not use
supervised pre-training, and we even exceed the performance of supervised
ImageNet pre-trained models for monocular depth estimation, achieving results
that are comparable with state-of-the-art methods
Relationship between the severity of endometriosis symptoms (dyspareunia, dysmenorrhea and chronic pelvic pain) and the spread of the disease on ultrasound
Objectives: About 10�15 of women of childbearing age have endometriosis. The present study aimed to investigate the relationship between the severity of symptoms of endometriosis and the spread as well as the stage of the disease on ultrasonography. The present cross-sectional study evaluates the relationship between the severity of endometriosis symptoms and the spread of disease on ultrasonography in patients with endometriosis. Results: Considering different analyses, the cumulative size of posterior deep infiltrative endometriosis (DIE) (less than 1 cm) is significantly correlated with minimal severity of dyspareunia and chronic pelvic pain. The incidence of dyspareunia was more prevalent in patients with complete stenosis of Douglas pouch than those with incomplete stenosis. Furthermore, the incidence of severe and very severe pain in patients with Douglas pouch stenosis is relatively higher than that in patients without stenosis. Only dyspareunia is related to the stage of endometriosis, and patients with dyspareunia are five times more at risk of a higher stage of the disease. The severity of dyspareunia is related to the stage of endometriosis and the severity of Douglas pouch stenosis. The results showed a correlation between chronic pelvic pain and r-ASRM score (revised American Society for Reproductive Medicine score). © 2020, The Author(s)
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Questionnaire study to gain an insight into the manufacturing and fitting process of artificial eyes in children: an ocularist perspective
Purpose
To gain an insight into the manufacturing and fitting of artificial eyes in children and potential improvements to the process.
Method
An online qualitative survey was distributed to 39 ocularists/prosthetists in Europe and Canada. Participants were recruited through purposive sampling, specifically maximum variation sampling from the researcher’s contacts and an online search.
Results
The findings highlighted the current impression technique as being the most difficult yet most important part of the current process for both the ocularist and child patient. Negatively affecting obtaining a good impression, the child patients distress can be reduced by their parents by providing encouragement, reassurance, practicing the insertion and removal of the artificial eye and being matter of fact. Whilst improvements to the current process provided mixed views, the incorporation of current technology was perceived as not being able to meet the requirements to produce aesthetically pleasing artificial eyes.
Conclusion
The current artificial eye process can be seen as an interaction with its success being dependent on the child patient’s acceptance and adjustment which is dependent on the factors associated to the process. Investigation into the needs of the patient and whether technology can improve the process are the next steps in its advancement
Failure Analysis of Flow-induced Vibration Problem of in-serviced Duplex Stainless Steel Piping System in Oil and Gas Industry
Failure of the duplex stainless steel piping system in oil and gas industry can have disastrous effects. In this study, a novel method of failure analysis of flow-induced vibration problem of in-serviced duplex stainless steel piping system is proposed. The proposed non-destructive technique is able to determine a suitable operating condition for continuous operation without failure. The technique relies on the combined operation of operational modal analysis, operating deflection shape analysis and linear elastic finite element analysis. The effect of different operating conditions for two distinct valve opening cases (i.e. fully opened and partially opened) on the dynamic stress is examined, and they are utilised for forecasting purpose in failure analysis. The result shows that maximum operating conditions are 360 and 400 mmscfd for fully opened and partially opened flow control valves, respectively. Beyond this limit, the piping system most likely will fail
Overview of hydatid disease in Iranian children
Background: Hydatid disease (HD) is still an important health hazard in the world. This disease is a parasitic infestation endemic in many sheep- and cattle-raising areas such as Iran. Objectives: This study aimed to review the clinical manifestations, laboratory aspects, imaging findings, and management of HD. Patients and Methods: Data were collected from the medical records of patients diagnosed with HD in eight referral hospitals in different provinces of Iran from 2001 to 2014. Results: Overall, 161 children at a mean age of 9.25 ± 3.37 years (age range = 1 - 15 years old) hospitalized with a definite diagnosis of the hydatid cyst between 2001 and 2014 were studied. The male-to-female ratio was 1.6:1. The most commonly involved organ was the lung (67.1), followed by the liver (44.1) and a combined liver and lung involvement was found in 15.5 of the patients. The cysts were found more frequently in the right lobe of the liver and lung than in the left lobe. The most frequent complaints were fever (35.4) and abdominal pain (31.7), and the most frequent sign was an abdominal mass in the liver involvement and cough in the lung involvement. There was a high eosinophil count (> 500/micL) in 41 of our cases. A high erythrocyte sedimentation rate (> 30) or positive C-reactive protein (based on the qualitative method) was found in 18.6 of the patients and leukocytosis > 15000/micL in 29.2 of the children. Ultrasonography was the main imaging test, with an accuracy rate of 96, and chest X-ray was helpful in 88.6 of the cases. Surgery was performed in 89 of the patients, and selective patients underwent percutaneous aspiration-injection-reaspiration drainage or medical treatment. Conclusions: The lung was the most commonly involved organ in the children recruited in the present study. Given the high probability of multiple organ involvement, we recommend that patients with HD be assessed via ultrasonography and chest X-ray. In endemic regions, unexplained eosinophilia should be considered as a parasitic disease like HD and its complications. © 2015 Pediartric Infections Research Center
Multimodal database of emotional speech, video and gestures
People express emotions through different modalities. Integration of verbal and non-verbal communication channels creates a system in which the message is easier to understand. Expanding the focus
to several expression forms can facilitate research on emotion recognition as well as human-machine interaction. In this article, the authors
present a Polish emotional database composed of three modalities: facial expressions, body movement and gestures, and speech. The corpora
contains recordings registered in studio conditions, acted out by 16 professional actors (8 male and 8 female). The data is labeled with six basic
emotions categories, according to Ekman’s emotion categories. To check
the quality of performance, all recordings are evaluated by experts and
volunteers. The database is available to academic community and might
be useful in the study on audio-visual emotion recognition
Simulation of gait asymmetry and energy transfer efficiency between unilateral and bilateral amputees
Efficient walking or running requires symmetrical
gait. Gait symmetry is one of the key factors in efficient
human dynamics, kinematics and kinetics. The desire of individuals with a lower-limb amputation to participate
in sports has resulted in the development of energy-storing and-returning (ESR) feet. This paper analyses a case study
to show the effect of symmetry and asymmetry as well as
energy transfer efficiency during periodic jumping between
simulated bilateral and unilateral runners. A custom gait
analysis system is developed as part of this project to track the motion of the body of a physically active subject during a set of predefined motions. Stance and aerial times are accurately measured using a high speed camera. Gait frequency, the level of symmetry and the non-uniform displacement between left and right foot and their effects on the position of the Centre of Mass (CM) were used as
criteria to calculate both peak energies and transformation
efficiency. Gait asymmetry and discrepancy of energy
transfer efficiency between the intact foot and the ESR are
observed. It is concluded that unilateral runners require
excessive effort to compensate for lack of symmetry as well as asymmetry in energy transfer, causing fatigue which could be a reason why bilateral amputee runners using ESR feet have a superior advantage over unilateral amputees
A novel investigation into the application of non-destructive evaluation for vibration assessment and analysis of in-service pipes
Flow induced vibrations that are close to resonance frequencies are a major
problem in all oil and gas processing industries, so all piping systems require
regular condition monitoring and inspection to assess changes in their dynamic
characteristics and structural integrity in order to prevent catastrophic failures.
One of the main causes of pipe failure is weak support causing low frequency
high amplitude flow-induced vibration. This causes wear and tear, especially
near joints due to their dissimilar stiffness resulting in fatigue failure of joints
caused by vibration-induced high cyclic stress. Other contributing factors in pipe
failure are poor or inadequate design, poor workmanship during installation or
maintenance and inadequate or weak and flexible support. These pipes are
usually required to work non-stop for 24 hours a day 7 days a week for weeks,
months or years at a time. Regular monitoring and in-service dynamic analysis
should ensure continuous and safe operation. A novel method of non-destructive
testing and evaluation of these pipes, while in service, is proposed in this paper.
This technique will enable early detection and identification of the root causes of
any impending failure due to excess vibration as a result of cyclic force induced
by the flow. The method pinpoints the location of the impending failure prior to
condition-based maintenance procedures. The technique relies on the combined
application of Operating Deflection Shapes (ODS) analysis and computational
mechanics utilizing Finite Element Analysis (FEA), i.e. linear elastic stress
analysis. Any structural modification to the pipes and their supports can then be
applied virtually and their effects on the system can be analysed. The effect on
vibration levels is assessed and verified. The effect of any change in the forces
corresponding to changes in the Differential Pressure (DP) at constant flow rate
through the pipes can then be estimated. It was concluded that maintaining the
differential pressure above some “critical” threshold ensures the pipe operates
under the allowable dynamic stress for a theoretically “indefinite” life cycle
Developing argumentation skills in mathematics through computer-supported collaborative learning: the role of transactivity
Collaboration scripts and heuristic worked examples are effective means to scaffold university freshmen’s mathematical argumentation skills. Yet, which collaborative learning processes are responsible for these effects has remained unclear. Learners presumably will gain the most out of collaboration if the collaborators refer to each other’s contributions in a dialectic way (dialectic transactivity). Learners also may refer to each other’s contributions in a dialogic way (dialogic transactivity). Alternatively, learners may not refer to each other’s contributions at all, but still construct knowledge (constructive activities). This article investigates the extent to which constructive activities, dialogic transactivity, and dialectic transactivity generated by either the learner or the learning partner can explain the positive effects of collaboration scripts and heuristic worked examples on the learners’ disposition to use argumentation skills. We conducted a 2 × 2 experiment with the factors collaboration script and heuristic worked examples with N = 101 math teacher students. Results showed that the learners’ engagement in self-generated dialectic transactivity (i.e., responding to the learning partner’s contribution in an argumentative way by critiquing and/or integrating their learning partner’s contributions) mediated the effects of both scaffolds on their disposition to use argumentation skills, whereas partner-generated dialectic transactivity or any other measured collaborative learning activity did not. To support the disposition to use argumentation skills in mathematics, learning environments should thus be designed in a way to help learners display dialectic transactivity. Future research should investigate how learners might better benefit from the dialectic transactivity generated by their learning partners
Asynchronous Testing of Synchronous Components in GALS Systems
International audienceGALS (Globally Asynchronous Locally Synchronous) systems, such as the Internet of Things or autonomous cars, integrate reactive synchronous components that interact asynchronously. The complexity induced by combining synchronous and asynchronous aspects makes GALS systems difficult to develop and debug. Ensuring their functional correctness and reliability requires rigorous design methodologies, based on formal methods and assisted by validation tools. In this paper we propose a testing methodology for GALS systems integrating: (1) synchronous and asynchronous concurrent models; (2) functional unit testing and behavioral conformance testing; and (3) various formal methods and their tool equipments. We leverage the conformance test generation for asynchronous systems to automatically derive realistic scenarios (input constraints and oracle), which are necessary ingredients for the unit testing of individual synchronous components, and are difficult and error-prone to design manually. We illustrate our approach on a simple, but relevant example inspired by autonomous cars
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