Search results for "Computer Science::Systems and Control"
showing 10 items of 54 documents
Elastische Streuung langsamer Elektronen an einem Bi-Atomstrahl
1968
The angular distribution of electrons elastically scattered by bismuth atoms has been investigated in the angular range from 30 to 155° and with electron energies between 5 and 1200 eV. Theoretical data, which are available for energies above 100 eV, are in good agreement with experiment.
Winkelverteilung von elastisch und mit 6,7 eV-Energieverlust an freien Hg-Atomen gestreuten Elektronen
1970
The angular dependence of electrons scattered elastically and inelastically at free mercury atoms have been measured for electron energies between 20 and 300 eV (angular range from 20 to 155°).
Winkelverteilungen elastisch an Edelgas-Atomstrahlen gestreuter Elektronen; Spinpolarisation eines an Argon gestreuten 40 eV-Elektronenstrahls
1967
The angular distribution of electrons scattered elastically by rare-gas atomic beams (He, Ne, Ar, Kr, Xe) has been investigated over the angular range from 20° to 155° and with electron energies between 5 eV and 1000 eV. The results are compared with theory. Only for energies above 300 eV the agreement is good. The angular dependence of polarization P(Θ) of electrons, elastically scattered by a beam of argon atoms, is measured in a double scattering experiment for an electron energy of 40 eV. Maximum degree of polarization measured isP=12.5% ± 2.5%.
Messungen zur Ansprechwahrscheinlichkeit und Impulshöhenverteilung eines Sekundärelektronenvervielfachers
1966
The pulse height distribution of a CuBe-secondary electron multiplier has been investigated under the action of single electrons. For an energy interval from 150 eV to 1000 eV the maximum pulse height increases with increasing electron energy (the energy corresponding to maximum yield being 365±10 eV). This shows the statistics of secondary electron emission as being dependant on primary electron energy.
Spectral Measurement of Photon Emission from Individual Gold Nanoparticles Using Scanning Tunneling Microscopy
2016
The light emission spectra of individual Au nanoparticles induced by a scanning tunneling microscope (STM) have been investigated. Two-dimensional ensembles of tunnel-coupled Au particles were prepared by thermal evaporation onto a native oxide silicon wafer in ultrahigh vacuum (10 – 9 mbar). Our STM measurements show a single peak at photon energy 1.6 eV in the tunneling mode and two peaks at 2.2 eV (connected with the Mie plasmon) and 1.45 eV (a new peak which was not discussed in literature before) in the field emission mode.
On the robust design of unknown inputs Takagi-Sugeno observer
2012
This paper deals with the observer design for Takagi-Sugeno (T-S) fuzzy models subject to unknown inputs and disturbance affecting both states and outputs of the system. Sufficient conditions to design an unknown input T-S observer are given in Linear Matrix Inequalities (LMIs) terms. Relaxations are introduced by using intermediate variables. Numerical example is given to illustrate the effectiveness of the given result.
Hankelet-based dynamical systems modeling for 3D action recognition
2015
This paper proposes to model an action as the output of a sequence of atomic Linear Time Invariant (LTI) systems. The sequence of LTI systems generating the action is modeled as a Markov chain, where a Hidden Markov Model (HMM) is used to model the transition from one atomic LTI system to another. In turn, the LTI systems are represented in terms of their Hankel matrices. For classification purposes, the parameters of a set of HMMs (one for each action class) are learned via a discriminative approach. This work proposes a novel method to learn the atomic LTI systems from training data, and analyzes in detail the action representation in terms of a sequence of Hankel matrices. Extensive eval…
Extended Kalman Filter for sensorless control of induction motors
2010
This paper deals with speed and rotor flux estimation of induction motors via Extended Kalman Filter (EKF). The filter is designed starting from a discrete time model obtained by means of a first order discretization of the original nonlinear model of the induction motor (IM). In order to obtain accurate estimation of the above mentioned variables, the load torque is included into the state variables and then estimated, thus constructing a sixth order EKF. Experimental results are shown with reference to a closed loop sensorless control system, consisting of a 750 W induction motor supplied by a voltage source inverter, a cascade controller consisting of four PI control loops and the design…
Design and prototyping of a magnetic actuator based permanent magnets for microbead navigation in viscous environment
2017
International audience; For actuating the magnetic microrobots, two types of magnetic actuation technologies have been used during the last past years. These magnetic technologies may be either electromagnetic coils or permanent magnets based systems. This second solution is not the most used by researchers, because of the difficulties to control the magnetic force. In this paper we propose a magnetic actuator prototype based on permanent magnets. In addition to the magnets, the actuator is also composed of a mechanical structure. This structure is used for positioning the permanent magnets, which allows to control the magnetic force generated by the actuator. We demonstrated in simulation …
The Upgrade of the ATLAS Level-1 Central Trigger Processor
2013
The ATLAS Level-1 Central Trigger Processor (CTP) combines information from calorimeter and muon trigger processors as well as other sources and makes the final Level-1 Accept (L1A) decision. Due to the increasing luminosity of the LHC and the growing demands of physics and monitoring placed on the ATLAS Level-1 trigger system, the current CTP has reached its design limits. Therefore and in order to provide some margin for future operation, the CTP will be upgraded during the LHC shutdown of 2013/14.