203 research outputs found
On Model Predictive Path Following and Trajectory Tracking for Industrial Robots
In this article we show how the model predictive path following controller
allows robotic manipulators to stop at obstructions in a way that model
predictive trajectory tracking controllers cannot. We present both controllers
as applied to robotic manipulators, simulations for a two-link manipulator
using an interior point solver, consider discretization of the optimal control
problem using collocation or Runge-Kutta, and discuss the real-time viability
of our implementation of the model predictive path following controller.Comment: Draft of article for CASE 201
A Caged Ret Kinase Inhibitor and its Effect on Motoneuron Development in Zebrafish Embryos
Proto-oncogene tyrosine-protein kinase receptor RET is implicated in the development and maintenance of neurons of the central and peripheral nervous systems. Attaching activity-compromising photocleavable groups (caging) to inhibitors could allow for external spatiotemporally controlled inhibition using light, potentially providing novel information on how these kinase receptors are involved in cellular processes. Here, caged RET inhibitors were obtained from 3-substituted pyrazolopyrimidine-based compounds by attaching photolabile groups to the exocyclic amino function. The most promising compound displayed excellent inhibitory effect in cell-free, as well as live-cell assays upon decaging. Furthermore, inhibition could be efficiently activated with light in vivo in zebrafish embryos and was shown to effect motoneuron development
PSO and Kalman Filter-Based Node Motion Prediction for Data Collection from Ocean Wireless Sensors Network with UAV
Source at https://ctsoc.ieee.org/In this paper, we consider a wireless sensor network
of nodes at the sea surface drifting due to wind and sea currents.
In our scenario an Unmanned Aerial Vehicle (UAV) will be used
to gather data from the sensor nodes. The goal is to find a
flyable path which is optimal in terms of sensor node energy
consumption, total channel throughput between the UAV and
sensor nodes, flight time for the UAV and frequency of the
node visits by the UAV. Finally, the path should also be optimal
concerning node position estimation uncertainty. A Kalman Filter
(KF) is used to estimate the nodes motions and Particle Swarm
Optimization (PSO) is the method used to calculate the UAV
path taking all of these objectives into account. The proposed
node tracking aware path planning solution is compared to two
other scenarios: One where the path planning is based on full
knowledge of the node positions at all times, and one where path
planning is based on the last known positions of the nodes
Real-time temporal adaptation of dynamic movement primitives for moving targets
This work is aimed at extending the standard dynamic movement primitives (DMP) framework to adapt to real-time changes in the task execution time while preserving its style characteristics. We propose an alternative polynomial canonical system and an adaptive law allowing a higher degree of control over the execution time. The extended framework has a potential application in robotic manipulation tasks that involve moving objects demanding real-time control over the task execution time. The existing methods require a computationally expensive forward simulation of DMP at every time step which makes it undesirable for integration in realtime control systems. To address this deficiency, the behaviour of the canonical system has been adapted according to the changes in the desired execution time of the task performed. An alternative polynomial canonical system is proposed to provide increased real-time control on the temporal scaling of DMP system compared to the standard exponential canonical system. The developed method was evaluated on scenarios of tracking a moving target where the desired tracking time is varied in real-time. The results presented show that the extended version of DMP provide better control over the temporal scaling during the execution of the task. We have evaluated our approach on a UR5 robotic manipulator for tracking a moving object.acceptedVersio
Path planning for UAV harvesting information from dynamical wireless sensor nodes at sea
A system of several wireless sensor nodes and one unmanned aerial vehicle (UAV) is considered in this research. The nodes are only floating and drifting with the sea stream. The UAV will be operating as a data mule to gather sensing information from wireless sensor nodes. Unlike prior studies, this paper addressed a realistic ocean model for the nodes movements which will be the references to the Kalman Filter (KF) in estimating for the nodes’ positions. Simulation results are evaluated for an optimal flight-able path for the UAV under several constraints by particle swarm optimization (PSO). Specifically, the deviation between the estimated positions and the referenced positions, total energy consumption by the sensors network, data rates between UAV and the nodes, flight time for the UAV, and frequency of visiting the nodes by the UAV will be considered for optimization. The systems performances will be evaluated based on these scenarios: a) an ideal and unrealistic scenario where the UAV follows the nodes continuously; b) a realistic case where the UAV only flies periodically. Discussions and solutions were also addressed for the situations when the deployed nodes are more significantly separated than the cases simulated in the paper.acceptedVersio
Design, Synthesis and Inhibitory Activity of Photoswitchable RET Kinase Inhibitors.
REarranged during Transfection (RET) is a transmembrane receptor tyrosine kinase required for normal development and maintenance of neurons of the central and peripheral nervous systems. Deregulation of RET and hyperactivity of the RET kinase is intimately connected to several types of human cancers, most notably thyroid cancers, making it an attractive therapeutic target for small-molecule kinase inhibitors. Novel approaches, allowing external control of the activity of RET, would be key additions to the signal transduction toolbox. In this work, photoswitchable RET kinase inhibitors based on azo-functionalized pyrazolopyrimidines were developed, enabling photonic control of RET activity. The most promising compound displays excellent switching properties and stability with good inhibitory effect towards RET in cell-free as well as live-cell assays and a significant difference in inhibitory activity between its two photoisomeric forms. As the first reported photoswitchable small-molecule kinase inhibitor, we consider the herein presented effector to be a significant step forward in the development of tools for kinase signal transduction studies with spatiotemporal control over inhibitor concentration in situ
Design and evaluation of a microfluidic system for inhibition studies of yeast cell signaling
In cell signaling, different perturbations lead to different responses and using traditional biological techniques that result in averaged data may obscure important cell-to-cell variations. The aim of this study was to develop and evaluate a four-inlet microfluidic system that enables single-cell analysis by investigating the effect on Hog1 localization post a selective Hog1 inhibitor treatment during osmotic stress. Optical tweezers was used to position yeast cells in an array of desired size and density inside the microfluidic system. By changing the flow rates through the inlet channels, controlled and rapid introduction of two different perturbations over the cell array was enabled. The placement of the cells was determined by diffusion rates flow simulations. The system was evaluated by monitoring the subcellular localization of a fluorescently tagged kinase of the yeast "High Osmolarity Glycerol" (HOG) pathway, Hog1-GFP. By sequential treatment of the yeast cells with a selective Hog1 kinase inhibitor and sorbitol, the subcellular localization of Hog1-GFP was analysed on a single-cell level. The results showed impaired Hog1-GFP nuclear localization, providing evidence of a congenial design. The setup made it possible to remove and add an agent within 2 seconds, which is valuable for investigating the dynamic signal transduction pathways and cannot be done using traditional methods. We are confident that the features of the four-inlet microfluidic system will be a valuable tool and hence contribute significantly to unravel the mechanisms of the HOG pathway and similar dynamic signal transduction pathways
New eyes, new life
Bacheloroppgave i sykepleie, 2013Problemstilling: Hvordan kan sykepleier bidra til endring av livsstil hos pasienter med diabetes type 2? Avgrensning: Vi har valgt å bruke begrepet ”sykepleier”, ”pasient” og navnet til pasienten i casen. I følge Folkehelseinstituttet (2012) er det om lag 135 000 pasienter med diabetes type 2, men det er trolig store mørketall av pasienter som er udiagnostisert. Diabetes type 2 er en kronisk sykdom, hvor deler av insulinproduksjonen er for liten og har en nedsatt virkning. Diabetes type 2 kan gi alvorlige senkomplikasjoner som kan hindres ved livsstilsendring. Livsstilsendringer som vi har valgt å ha fokus på i denne oppgaven omhandler fysisk aktivitet og kosthold. Hjemmesykepleien kommer i kontakt med Liv i forbindelse med sårstell. Liv ytrer ønske om å endre livsstil for å få fortgang på sårtilhelingen. Sykepleier bidrar til at Liv kan endre livsstil med hjelp av veiledning og motiverende intervju. Sykepleierteoretikeren som oppgaven har fokus på er Joyce Travelbee
Adaptive sampling for UAV sensor network in oil spill management
In this paper we propose a method for adaptive sampling using Unmanned Aerial Vehicles (UAVs) in oil spill management. The goal is to measure and estimate oil spill concentrations at the sea surface, while at the same time identify the leak rates of sources at known positions. First we construct a cost which approximates the benefit of sampling locations at specific times. This cost is based on measures of observability and of persistency of excitation for the oil spill model. A receding horizon Mixed-Integer Linear Programming (MILP) problem is solved in order to find UAV trajectories which are optimal with respect to the cost. For UAV trajectory tracking we use a Lyapunov based controller. The oil spill concentration measurements taken by the UAVs by following these tracks are used in an adaptive observer, which provides state (concentration) and parameter (leak rate) estimates. Under the assumption that the sampling strategy described above lead to uniform complete observability and persistency of excitation, we prove Uniform Global Asymptotic Stability (UGAS) of the state estimation, parameter identification and UAV trajectory tracking errors. Finally, we provide a simulation of the proposed strategy, and compare it with two other strategies.acceptedVersio
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