21,961 research outputs found
#30 - Human-Machine Interactions Using a Flex-Sensor And 3D Printed Robot Arm
Title: Human-Machine Interactions Using a Flex-Sensor And 3D Printed Robot Arm
Abstract
We developed a flex-sensor based glove system that can be used to tele-operate a 3D printed humanoid arm (Langevin, 2014). The glove and arm are interconnected through an Arduino based microcontroller which has been programmed to collect sensor data from the glove and to control individual fingers of the 3D printed arm. We present our initial study in understanding the reliability and feasibility of human interfacing with the electro-mechanical arm. Using this system, we plan to understand and quantify biomimetic finger movement. The flex-sensor data captured by the Arduino is processed in order to replicate human finger movement. We plan to extend our project to create a robot hand with biomimetic movement.
Keywords: Flex-sensor, Humanoid-arm, Arduino, Electro-mechanical, and Biomimetic,
References:
Langevin, G. (2014). InMoov open-source 3D printed life-size robot. pp. URL: http://inmoov. fr, License: http://creativecommons. org/licenses/by–nc/3.0/legalcode
A List of Bright Interferometric Calibrators measured at the ESO VLTI
In a previous publication (Richichi & Percheron 2005) we described a program
of observations of candidate calibrator stars at the ESO Very Large Telescope
Interferometer (VLTI), and presented the main results from a statistical point
of view. In the present paper, we concentrate on establishing a new homogeneous
group of bright interferometric calibrators, based entirely on publicly
available K-band VLTI observations carried out with the VINCI instrument up to
July 2004. For this, we have defined a number of selection criteria for the
quality and volume of the observations, and we have accordingly selected a list
of 17 primary and 47 secondary calibrators. We have developed an approach to a
robust global fit for the angular diameters using the whole volume of
quality-controlled data, largely independent of a priori assumptions. Our
results have been compared with direct measurements, and indirect estimates
based on spectrophotometric methods, and general agreement is found within the
combined uncertainties. The stars in our list cover the range K=-2.9 to +3.0
mag in brightness, and 1.3 to 20.5 milliarcseconds in uniform-disk diameter.
The relative accuracy of the angular diameter values is on average 0.4% and 2%
for the primary and secondary calibrators respectively. Our calibrators are
well suited for interferometric observations in the near-infrared on baselines
between ~20m and ~200m, and their accuracy is superior, at least for the
primary calibrators, to other similar catalogues. Therefore, the present list
of calibrators has the potential to lead to significantly improved
interferometric scientific results
Patch-based Convolutional Neural Network for Whole Slide Tissue Image Classification
Convolutional Neural Networks (CNN) are state-of-the-art models for many
image classification tasks. However, to recognize cancer subtypes
automatically, training a CNN on gigapixel resolution Whole Slide Tissue Images
(WSI) is currently computationally impossible. The differentiation of cancer
subtypes is based on cellular-level visual features observed on image patch
scale. Therefore, we argue that in this situation, training a patch-level
classifier on image patches will perform better than or similar to an
image-level classifier. The challenge becomes how to intelligently combine
patch-level classification results and model the fact that not all patches will
be discriminative. We propose to train a decision fusion model to aggregate
patch-level predictions given by patch-level CNNs, which to the best of our
knowledge has not been shown before. Furthermore, we formulate a novel
Expectation-Maximization (EM) based method that automatically locates
discriminative patches robustly by utilizing the spatial relationships of
patches. We apply our method to the classification of glioma and non-small-cell
lung carcinoma cases into subtypes. The classification accuracy of our method
is similar to the inter-observer agreement between pathologists. Although it is
impossible to train CNNs on WSIs, we experimentally demonstrate using a
comparable non-cancer dataset of smaller images that a patch-based CNN can
outperform an image-based CNN
Recommended from our members
Feasibility Evaluation of Commercially Available Video Conferencing Devices to Technically Direct Untrained Nonmedical Personnel to Perform a Rapid Trauma Ultrasound Examination.
Introduction: Point-of-care ultrasound (POCUS) is a rapidly expanding discipline that has proven to be a valuable modality in the hospital setting. Recent evidence has demonstrated the utility of commercially available video conferencing technologies, namely, FaceTime (Apple Inc, Cupertino, CA, USA) and Google Glass (Google Inc, Mountain View, CA, USA), to allow an expert POCUS examiner to remotely guide a novice medical professional. However, few studies have evaluated the ability to use these teleultrasound technologies to guide a nonmedical novice to perform an acute care POCUS examination for cardiac, pulmonary, and abdominal assessments. Additionally, few studies have shown the ability of a POCUS-trained cardiac anesthesiologist to perform the role of an expert instructor. This study sought to evaluate the ability of a POCUS-trained anesthesiologist to remotely guide a nonmedically trained participant to perform an acute care POCUS examination. Methods: A total of 21 nonmedically trained undergraduate students who had no prior ultrasound experience were recruited to perform a three-part ultrasound examination on a standardized patient with the guidance of a remote expert who was a POCUS-trained cardiac anesthesiologist. The examination included the following acute care POCUS topics: (1) cardiac function via parasternal long/short axis views, (2) pneumothorax assessment via pleural sliding exam via anterior lung views, and (3) abdominal free fluid exam via right upper quadrant abdominal view. Each examiner was given a handout with static images of probe placement and actual ultrasound images for the three views. After a brief 8 min tutorial on the teleultrasound technologies, a connection was established with the expert, and they were guided through the acute care POCUS exam. Each view was deemed to be complete when the expert sonographer was satisfied with the obtained image or if the expert sonographer determined that the image could not be obtained after 5 min. Image quality was scored on a previously validated 0 to 4 grading scale. The entire session was recorded, and the image quality was scored during the exam by the remote expert instructor as well as by a separate POCUS-trained, blinded expert anesthesiologist. Results: A total of 21 subjects completed the study. The average total time for the exam was 8.5 min (standard deviation = 4.6). A comparison between the live expert examiner and the blinded postexam reviewer showed a 100% agreement between image interpretations. A review of the exams rated as three or higher demonstrated that 87% of abdominal, 90% of cardiac, and 95% of pulmonary exams achieved this level of image quality. A satisfaction survey of the novice users demonstrated higher ease of following commands for the cardiac and pulmonary exams compared to the abdominal exam. Conclusions: The results from this pilot study demonstrate that nonmedically trained individuals can be guided to complete a relevant ultrasound examination within a short period. Further evaluation of using telemedicine technologies to promote POCUS should be evaluated
Panchromatic properties of galaxies in wide-field optical spectroscopic and photometric surveys
The past 15 years have seen an explosion in the number of redshifts recovered
via wide area spectroscopic surveys. At the current time there are
approximately 2million spectroscopic galaxy redshifts known (and rising) which
represents an extraordinary growth since the pioneering work of Marc Davis and
John Huchra. Similarly there has been a parallel explosion in wavelength
coverage with imaging surveys progressing from single band, to multi-band, to
truly multiwavelength or pan-chromatic involving the coordination of multiple
facilities. With these empirically motivated studies has come a wealth of new
discoveries impacting almost all areas of astrophysics. Today individual
surveys, as best demonstrated by the Sloan Digital Sky Survey, now rank
shoulder-to-shoulder alongside major facilities. In the coming years this trend
is set to continue as we being the process of designing and conducting the next
generation of spectroscopic surveys supported by multi-facility wavelength
coverage.Comment: Invited review article to be published in Proceedings of IAU
Symposium 284 on "The Spectral Energy Distribution of Galaxies", (Eds:
R.J.Tuffs & C.C.Popescu
The Coarse Geometry of Merger Trees in \Lambda CDM
We introduce the contour process to describe the geometrical properties of
merger trees. The contour process produces a one-dimensional object, the
contour walk, which is a translation of the merger tree. We portray the contour
walk through its length and action. The length is proportional to to the number
of progenitors in the tree, and the action can be interpreted as a proxy of the
mean length of a branch in a merger tree.
We obtain the contour walk for merger trees extracted from the public
database of the Millennium Run and also for merger trees constructed with a
public Monte-Carlo code which implements a Markovian algorithm. The trees
correspond to halos of final masses between 10^{11} h^{-1} M_sol and 10^{14}
h^{-1} M_sol. We study how the length and action of the walks evolve with the
mass of the final halo. In all the cases, except for the action measured from
Markovian trees, we find a transitional scale around 3 \times 10^{12} h^{-1}
M_sol. As a general trend the length and action measured from the Markovian
trees show a large scatter in comparison with the case of the Millennium Run
trees.Comment: 7 pages, 5 figures, submitted to MNRA
Inverting Ray-Knight identity
We provide a short proof of the Ray-Knight second generalized Theorem, using
a martingale which can be seen (on the positive quadrant) as the Radon-Nikodym
derivative of the reversed vertex-reinforced jump process measure with respect
to the Markov jump process with the same conductances. Next we show that a
variant of this process provides an inversion of that Ray-Knight identity. We
give a similar result for the Ray-Knight first generalized Theorem.Comment: 18 page
Zebrafish (Danio rerio) Hoxb6: An Exploration into the Divergence of Genomic DNA Sequence and Gene Expression Across Teleost Fishes Post-Genome Duplication
Hoxb6 is an evolutionarily conserved developmental regulatory gene that functions, in part, to pattern several organs and organ systems within the embryonic trunk during vertebrate embryogenesis. The cis-regulatory circuitry mediating trunk expression in mouse (Mus musculus) may be conserved across gnathostome vertebrates, as several other species show similar trunk expression patterns, including chicken (Gallus gallus), dogfish shark (Scyliorhinus canicula), and several teleost fishes. A whole genome duplication event that occurred in the lineage leading to teleost fishes has generated at least two Hoxb6 genes, hoxb6a and b6b. Two teleost fishes of the superorder Acanthopterygii, Japanese medaka (Oryzias latipes) and Nile tilapia (Oreochromis niloticus), exhibit divergent Hoxb6 expression patterns from those of non-teleost vertebrates. This includes an anterior expansion of expression for both hoxb6a and b6b into pharyngeal arch 7, the posterior-most pharyngeal arch that, along with the other posterior pharyngeal arches, gives rise to the pharyngeal jaw apparatus in teleost fishes. While these patterns of expression are observed for both duplicate Hoxb6 genes in Acanthopterygians, it is uncertain whether this pharyngeal arch expression is shared with other teleost taxa. Here we present the expression patterns of hoxb6a and b6b in zebrafish (Danio rerio), a member of the Ostariophysi superorder. We show that, unlike the strict orthologs from medaka and tilapia, zebrafish hoxb6a is expressed in pharyngeal arches 5-7, whereas hoxb6b is not expressed in any of the pharyngeal arches. Further, we show through comparative genomic DNA sequence analyses that, although all teleost-specific sequences exhibit moderate conservation with the region functionally tested in mouse, zebrafish hoxb6a and b6b exhibit little to no conservation in sequence with their strict orthologs of medaka or tilapia outside of this region. Our data suggest that divergence in the cis-regulatory circuitry post-genome duplication has generated divergent hoxb6a and b6b expression patterns among teleost fishes
An astrobiological study of an alkaline-saline hydrothermal environment, relevant to understanding the habitability of Mars
The on going exploration of planets such as Mars is producing a wealth of data which is being used to shape a better understanding of potentially habitable environments beyond the Earth. On Mars, the relatively recent identification of minerals which indicate the presence of neutral/alkaline aqueous activity has increased the number of potentially habitable environments which require characterisation and exploration. The study of terrestrial analogue environments enables us to develop a better understanding of where life can exist, what types of organisms can exist and what evidence of that life may be preserved. The study of analogue environments is necessary not only in relation to the possibility of identifying extinct/extant indigenous life on Mars, but also for understanding the potential for contamination. As well as gaining an insight into the habitability of an environment, it is also essential to understand how to identify such environments using the instruments available to missions to Mars. It is important to be aware of instrument limitations to ensure that evidence of a particular environment is not overlooked. This work focuses upon studying the bacterial and archaeal diversity of Lake Magadi, a hypersaline and alkaline soda lake, and its associated hydrothermal springs. Culture dependent and culture independent analytical methods have been used and have led to the identification of potentially novel isolates. In addition, the effects of simulated Martian conditions such as desiccation and UVC radiation upon single strains isolated from this environment, and the effects upon a complex soil community have been assessed. Results have also provided an indication of what issues may arise with identifying minerals associated with these environments using the equipment such as the ExoMars PanCam. It is hoped that this work has contributed to our understanding of the possible habitability of Mars
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