Repository UNSAP (Universitas Sebelas April)
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Spatially aware mobile interface for 3D visualization and interactive surgery planning
No full textWhile medical images are fundamental in the surgery planning procedure, the process of analysis of such images slice-by-slice is still tedious and inefficient. In this work we introduce a system for exploration of the internal anatomy structures directly on the surface of the real body using a mobile display device as a window to the interior of the patient’s body. The method is based on volume visualization of standard computed tomography datasets and augmented reality for interactive visualization of the generated volume. It supports our liver surgery planner method in the analysis of the segmented liver and in the color classification of the vessels. We present a set of experiments showing the system’s ability to operate on mobile devices. Quantitative performance results are detailed, and applications in teaching anatomy and doctor-patient communication are discussedSCI-IC-R
Analysis Of Pin Removal Experiments Conducted In A Supercritical Light Water Reactor-Like Test Lattice
No full textA comprehensive program of integral experiments, largely based on the measurement of reaction rate distributions, was carried out recently in the PROTEUS zero-power research reactor at the Paul Scherrer Institute in Switzerland, employing a fuel lattice resembling that of a supercritical light water reactor. The present paper reports on the analysis of a complementary set of measurements, in which the reactivity effects of removing individual pins from the unperturbed, heterogeneously moderated reference lattice were investigated. It has been found that the detailed Monte Carlo modeling of the whole reactor using MCNPX is able-as in the case of the reaction rate distributions to reproduce the experimental results for the pin removal worths within the achievable statistical accuracy. A comparison of reduced-geometry calculations between MCNPX and the deterministic light water reactor assembly code CASMO-4E has revealed certain discrepancies. On the basis of a reactivity decomposition analysis of the differences between the codes, it has been suggested that these could be due at least partly to CASMO-4E deficiencies in calculating the effect, upon pin removal, of the extra moderation in the neighboring fuel pins.S
In Vivo Evidence for a Lactate Gradient from Astrocytes to Neurons
No full textInvestigating lactate dynamics in brain tissue is challenging, partly because in vivo data at cellular resolution are not available. We monitored lactate in cortical astrocytes and neurons of mice using the genetically encoded FRET sensor Laconic in combination with two-photon microscopy. An intravenous lactate injection rapidly increased the Laconic signal in both astrocytes and neurons, demonstrating high lactate permeability across tissue. The signal increase was significantly smaller in astrocytes, pointing to higher basal lactate levels in these cells, confirmed by a one-point calibration protocol. Trans-acceleration of the monocarboxylate transporter with pyruvate was able to reduce intracellular lactate in astrocytes but not in neurons. Collectively, these data provide in vivo evidence for a lactate gradient from astrocytes to neurons. This gradient is a prerequisite for a carrier-mediated lactate flux from astrocytes to neurons and thus supports the astrocyte-neuron lactate shuttle model, in which astrocyte-derived lactate acts as an energy substrate for neurons.LENLND
On a Markov modulated chain exhibiting self-similarities over finite timescale
No full textRecent papers have pointed out that data traffic exhibits self-similarity, but self-similarity is observed only on a finite timescale. In order to account for that, we introduce the concept of pseudo long-range dependencies. In this paper, we describe a Modulated Markov process producing self-similarity on a finite timescale; the process is quite easy to manipulate and depends only on three parameters (two real numbers and one integer). An advantage of using it is that it is possible to re-use the well-known analytical queuing theory techniques developed in the past in order to evaluate network performance. A quantitative method based on the decomposability theory of Courtois is given to evaluate the domain of validity where the process exhibits pseudo long-range dependencies. The validation on a queuing problem is also discussed. Finally, we analyze the inputs of a statistical multiplexer in the context of a project called Scalability Enhancements for Connection-Oriented Networks (SCONE).LCALCA
Lowering motional resistance by partially HfO2 gap filling in double-ended tuning fork MEMS resonators.
No full textNANOLA
Byzantine tolerant gradient descent for distributed machine learning with adversaries
No full textThe present application concerns a computer-implemented method for training a machine learning model in a distributed fashion, using Stochastic Gradient Descent, SGD, wherein the method is performed by a first computer in a distributed computing environment and comprises performing a learning round, comprising broadcasting a parameter vector to a plurality of worker computers in the distributed computing environment, receiving an estimate update vector (gradient) from all or a subset of the worker computers, wherein each received estimate vector is either an estimate of a gradient of a cost function, or an erroneous vector, and determining an updated parameter vector for use in a next learning round based only on a subset of the received estimate vectors. The method aggregates the gradients while guaranteeing resilience to up to half workers being compromised (malfunctioning, erroneous or modified by attackers).AVP-R-TTODCLAlternative title(s) : (fr) Descente de gradient tolérant les byzantines pour apprentissage machine distribué avec des adversaire
Accurate Implementation of Rotating Magneto-Hydrodynamics in a Channel Geometry Using an Influence Matrix Method
No full textWe numerically study wall-bounded convectively driven magneto-hydrodynamic (MHD) flows subject to rotation in a Cartesian periodic channel. For the accurate treatment of the rotating MHD equations, we develop a pseudo-spectral simulation code with accurate treatment of boundary conditions for both velocity and magnetic fields. The solenoidal condition on the magnetic field is enforced by the addition of a fictitious magnetic pressure. This allows us to employ an influence matrix method with tau correction for the treatment of velocity and magnetic fields subject to Robin boundary conditions at the confining walls. We validate the developed method for the specific case of no slip velocity and perfectly conducting magnetic boundary conditions. The validation includes the accurate reproduction of linear stability thresholds and of turbulent statistics. The code shows favorable parallel scaling properties.ECP
Iron oxide-mediated semiconductor photocatalysis vs. heterogeneous photo-Fenton treatment of viruses in wastewater. Impact of the oxide particle size
No full textThe photo-Fenton process is recognized as a promising technique towards microorganism disinfection in wastewater, but its efficiency is hampered at near-neutral pH operating values. In this work, we overcome these obstacles by using the heterogeneous photo-Fenton process as the default disinfecting technique, targeting MS2 coliphage in wastewater. The use of low concentrations of iron oxides in wastewater without H2O2 (widstite, maghemite, magnetite) has demonstrated limited semiconductor-mediated MS2 inactivation. Changing the operational pH and the size of the oxide particles indicated that the isoelectric point of the iron oxides and the active surface area are crucial in the success of the process, and the possible underlying mechanisms are investigated. Furthermore, the addition of low amounts of Fe-oxides (1 mg L-1) and H2O2 in the system (1.5 and 10 mg L-1) greatly enhanced the inactivation process, leading to heterogeneous photo-Fenton processes on the surface of the magnetically separable oxides used. Additionally, photo-dissolution of iron in the bulk, lead to homogeneous photo-Fenton, further aided by the complexation by the dissolved organic matter in the solution. Finally, we assess the impact of the presence of the bacterial host and the difference caused by the different iron sources (salts, oxides) and the Fe-oxide size (normal, nano-sized). (C) 2017 Elsevier B.V. All rights reserved.GPA