345 research outputs found
The people behind the papers - Yonit Maroudas-Sacks and Marko Popovic
No full textDuring Hydra regeneration, supracellular actomyosin fibres are disoriented at two distinct foci of the regenerating tissue. These sites of nematic topological defects eventually form the new head and foot of the regenerated animal. In a new study, Yonit MaroudasSacks, Marko Popovic, Kinneret Keren and colleagues propose a positive-feedback loop that incorporates fibre organisation, tissue strain and morphogen gradients to promote head organiser formation. To find out more about the work, we caught up with first author Yonit Maroudas-Sacks and co-corresponding author Marko Popovic, Group Leader at the Max Planck Institute for the Physics of Complex Systems, Germany
A somatotopic bidirectional hand prosthesis with transcutaneous electrical nerve stimulation based sensory feedback
No full textAccording to amputees, sensory feedback is amongst the most important features lacking from commercial prostheses. Although restoration of touch by means of implantable neural interfaces has been achieved, these approaches require surgical interventions, and their long-term usability still needs to be fully investigated. Here, we developed a non-invasive alternative which maintains some of the advantages of invasive approaches, such as a somatotopic sensory restitution scheme. We used transcutaneous electrical nerve stimulation (TENS) to induce referred sensations to the phantom hand of amputees. These sensations were characterized in four amputees over two weeks. Although the induced sensation was often paresthesia, the location corresponded to parts of the innervation regions of the median and ulnar nerves, and electroencephalographic (EEG) recordings confirmed the presence of appropriate responses in relevant cortical areas. Using these sensations as feedback during bidirectional prosthesis control, the patients were able to perform several functional tasks that would not be possible otherwise, such as applying one of three levels of force on an external sensor. Performance during these tasks was high, suggesting that this approach could be a viable alternative to the more invasive solutions, offering a trade-off between the quality of the sensation, and the invasiveness of the intervention.TN
Correction: Infiltrated porous oxide monoliths as high lithium transference number electrolytes
No full textCorrection for ‘Infiltrated porous oxide monoliths as high lithium transference number electrolytes’ by Jelena Popovic et al., J. Mater. Chem. A, 2016, 4, 7135–7140.</p
Short- and Long-Term Learning of Feedforward Control of a Myoelectric Prosthesis with Sensory Feedback by Amputees
No full textPublisher Copyright: © 2017 IEEE.Human motor control relies on a combination of feedback and feedforward strategies. The aim of this study was to longitudinally investigate artificial somatosensory feedback and feedforward control in the context of grasping with myoelectric prosthesis. Nine amputee subjects performed routine grasping trials, with the aim to produce four levels of force during four blocks of 60 trials across five days. The electrotactile force feedback was provided in the second and third block usingmultipad electrode and spatial coding. The first baseline and last validation block (open-loop control) evaluated the effects of long-(across sessions) and short-term (within session) learning, respectively.The outcomemeasureswere the absolute error between the generated and target force, and the number of force saturations. The results demonstrated that the electrotactile feedback improved the performance both within and across sessions. In the validation block, the performance did not significantly decrease and the quality of openloop control (baseline) improved across days, converging to the performance characterizing closed-loop control. This paper provides important insights into the feedback and feedforwardprocessesin prosthesiscontrol, contributing to the better understanding of the role and design of feedback in prosthetic systems.Manuscript received October 19, 2016; revised April 2, 2017; accepted May 17, 2017. Date of publication June 6, 2017; date of current version November 6, 2017. This work was supported in part by Tec-nalia Research & Innovation, Spain, in part by FIK, Spain, in part by the European Commission under the MYOSENS project (FP7-PEOPLE-2011-IAPP-286208), and in part by the Ministry of Education, Science and Technological Development of Serbia under Project 175016. (Corresponding author: Matija Štrbac.) M. Štrbac and M. Isaković are with Tecnalia Serbia Ltd., 11000 Belgrade, Serbia, and also with the School of Electrical Engineering, University of Belgrade, Belgrade 11000, Serbia (e-mail: [email protected]; [email protected]).Peer reviewe
Impact of online games and M2M applications traffic on performance of HSPA radio access networks
No full textHSPA radio access performance evaluation for online games and M2M applications traffic (TCP vs UDP)
No full textTraffic generation application for simulating online games and M2M applications via wireless networks
No full textGeneral Programs for Least pth and Near Minimax Approximation
No full textTitle: General Programs for Least pth and Near Minimax Approximation, Author: Jadranka K. Rizoniko-Popovic, Location: ThodeUser-oriented computer programs in FORTRAN IV for discrete least pth approximation with a single specified function, and more generalized discrete least pth approximation with various specifications, which may also be used for nonlinear programming, are presented. Values of p up to 10^6 can be used successfully in conjunction with efficient gradient minimization algorithms such as the Fletcher-Powell method and a recent method due to Fletcher. It has already been demonstrated how efficiently extremely near minimax results can be achieved on a discrete set of sample points using this approach and the programs written verify this. The programs may be applied to a wide variety of design problems with a wide range of specifications. They are suitable for electrical network and system design and such problems as filter design.ThesisMaster of Engineering (ME
Stojan Jovanovic - a state cadet and the author of French grammar
No full textStojan Jovanovic, called by the name of Cukic by his contemporaries, is
mainly known as a leader of Katanska buna (The Rebellion of Katanas) in 1844.
The subject of this paper is Jovanovic?s education in Serbia and Vienna. A
thesis statement is that Stojan Jovanovic, Filip Hristic, and Anastas
Jovanovic have enjoyed the favor and support of the Obrenovic family, to whom
they have been loyal in return. Stojan Jovanovic belonged to the first
generation of students who've graduated from all schools existing in Serbia
during Prince Milos?s reign - he has finished the primary school in Belgrade,
the High School, i.e. the Kragujevac Gymnasium in 1836, and has attended the
Military Academy in Pozarevac, Belgrade and Kragujevac between 1837 and 1838.
In 1839. Jovanovic was appointed to the first group of state cadets who were
sent to study in Vienna. This generation of students was in many ways similar
to the one that attended the Belgrade Higher School (1808 - 1813). Jovanovic
stayed in Vienna for three years. For the first two years he has learned
French and German, preparing for the Law school. He has enrolled at the
Vienna University in the winter of 1841, and passed three exams by the end of
the school year. Several times he has asked the Ministry of education in
Belgrade to send him to study in Paris, but he was denied. On the initiative
of the emissary of the Serbian government, Jovan Sterija Popovic, Jovanovic
and other cadets have been withdrawn from the studies in Vienna. Between
1842. and 1844. Jovanovic has taken part in three rebellions against the
regime of Ustavobranitelji (the Defenders of the Constitution). In the summer
of 1844. in Vienna, Jovanovic has printed a manual for learning French,
French Grammar. Although it is a compilation, the manual is significant since
it has brought contemporary methods of learning French language to Serbian
readers. The papers end with a well founded presumption, based on the yet
unknown document, that Stojan Jovanovic has survived the Katanska buna in
1844.</jats:p
La plainte du chien battu, ou la poésie désenchanteresse (1991-2013) de Michel Houellebecq
No full textCe mémoire propose une étude des poésies de Michel Houellebecq menée dans le respect des visées et du cadre théorique de la sociocritique (Duchet, Robin, Popovic). Chacun de ses trois chapitres explore un thème de recherche qui s’est imposé par sa prégnance dans l’œuvre étudiée : la vie urbaine, la vie sociale, les altérités de la ville. L’hypothèse principale est que l’écriture houellebecquienne capte des signes, des actes de langage, des représentations qui circulent dans la société française contemporaine, et qu’elle le fait de manière dynamique, c’est-à-dire en les soumettant à un travail scriptural qui critique leur usage et qui en modifie le sens. La « mise en texte » (Duchet) de la vie urbaine (premier chapitre) met à jour une domination de la ville et de ses habitants par les seules lois économiques. Elle décrit ainsi un monde qui n’est plus que marchand. Celle de la vie sociale et des liens interpersonnels (deuxième chapitre) démontre leur étonnante facticité et atteste que leur organisation restreint de plus en plus les libertés individuelles. Ce qui était un acquis de la modernité sociale : pouvoir bénéficier de « temps libre » pour prendre soin de soi et des proches, devient de plus en plus impossible. Enfin, celle des altérités de la ville (banlieue, province, nature – troisième chapitre), prouve que ces dernières n’offrent aucune alternative à l’hostilité du monde urbain et à la règle du chacun pour soi. Malgré ce diagnostic désolant, la poésie cherche à déceler ici ou là des traces d’espoir et de solidarité.This master’s dissertation is a study of Michel Houellebecq’s poetry according to the theoretical framework of sociocritic (Duchet, Robin, Popovic). Urban life, social life and alterities of the city are the most present themes in the poetical work of the author. The main hypothesis is that the writing mobilizes and take over signs, linguistic acts and representations which float around in the French contemporary society, but in a dynamic way: the scriptural act of writing modifies their meaning and criticizes their common use. In the first chapter, we will discuss the “putting into text” (literal translation of the « mise en texte » concept by Duchet, which is the action of putting something into the form of a literary text) of urban life, which shines a light on how much the economic laws rule the city and its inhabitants. It describes a market world where money reigns. In the second chapter, the “putting into text” of social life and people-to-people ties shows how surprisingly artificial they are and certifies that their organization shrinks individual liberties more and more. Having free time to spend with your loved ones was once a given of social modernity but is now becoming difficult to manage. In the third and last chapter, the putting into text of the othernesses of the city (suburbs, province, nature) reveals that they offer no alternative to the hostility of the urban world and the fact that it is, and it will always be, every man for himself. Despite this distressing diagnosis, poetry tries to detect here and there hints of hope and solidarity
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