WorldWideScience

Sample records for single-mirror beam steering

  1. Holographic memory using beam steering

    Science.gov (United States)

    Chao, Tien-Hsin (Inventor); Hanan, Jay C. (Inventor); Reyes, George F. (Inventor); Zhou, Hanying (Inventor)

    2006-01-01

    A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) or Micro-Electro-Mechanical Systems (MEMS) mirrors steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

  2. Automated beam steering using optimal control

    Energy Technology Data Exchange (ETDEWEB)

    Allen, C. K. (Christopher K.)

    2004-01-01

    We present a steering algorithm which, with the aid of a model, allows the user to specify beam behavior throughout a beamline, rather than just at specified beam position monitor (BPM) locations. The model is used primarily to compute the values of the beam phase vectors from BPM measurements, and to define cost functions that describe the steering objectives. The steering problem is formulated as constrained optimization problem; however, by applying optimal control theory we can reduce it to an unconstrained optimization whose dimension is the number of control signals.

  3. Beam Steering Devices Reduce Payload Weight

    Science.gov (United States)

    2012-01-01

    Scientists have long been able to shift the direction of a laser beam, steering it toward a target, but often the strength and focus of the light is altered. For precision applications, where the quality of the beam cannot be compromised, scientists have typically turned to mechanical steering methods, redirecting the source of the beam by swinging the entire laser apparatus toward the target. Just as the mechanical methods used for turning cars has evolved into simpler, lighter, power steering methods, so has the means by which researchers can direct lasers. Some of the typical contraptions used to redirect lasers are large and bulky, relying on steering gimbals pivoted, rotating supports to shift the device toward its intended target. These devices, some as large and awkward as a piece of heavy luggage, are subject to the same issues confronted by mechanical parts: Components rub, wear out, and get stuck. The poor reliability and bulk not to mention the power requirements to run one of the machines have made mechanical beam steering components less than ideal for use in applications where weight, bulk, and maneuverability are prime concerns, such as on an unmanned aerial vehicle (UAV) or a microscope. The solution to developing reliable, lighter weight, nonmechanical steering methods to replace the hefty steering boxes was to think outside the box, and a NASA research partner did just that by developing a new beam steering method that bends and redirects the beam, as opposed to shifting the entire apparatus. The benefits include lower power requirements, a smaller footprint, reduced weight, and better control and flexibility in steering capabilities. Such benefits are realized without sacrificing aperture size, efficiency, or scanning range, and can be applied to myriad uses: propulsion systems, structures, radiation protection systems, and landing systems.

  4. SPS Beam Steering for LHC Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Gianfelice-Wendt, Eliana [Fermilab; Bartosik, Hannes [CERN; Cornelis, Karel [CERN; Norderhaug Drøsdal, Lene [CERN; Goddard, Brennan [CERN; Kain, Verena [CERN; Meddahi, Malika [CERN; Papaphilippou, Yannis [CERN; Wenninger, Jorg [CERN

    2014-07-01

    The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extracted beam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.

  5. Phase shifter for antenna beam steering

    Energy Technology Data Exchange (ETDEWEB)

    Jindal, Ravi, E-mail: rjindal21@gmail.com [Master’s(MS) in System Electronics and General Electrical, Ecole Polytechnique of university of Nantes France, IETR, Nantes (France); Razban, Tchanguiz, E-mail: tchanguiz.razban-haghighi@univ-nantes.fr [Electronics and Telecommunication Institute of Rennes (IETR-UMR 6164), Ecole Polytechnique of university of Nantes France, IETR, Nantes (France)

    2016-03-09

    Wide band Array Antenna operates in Ku-band (10.7-12.7 GHz) frequency composed of N×N radiating elements. This antenna aims at the reception of television satellite signals. The goal of this research is to provide better possibility of electronic beam control instead of manual or mechanical control, and design compact and low cost phase shifters to be inserted in the feeding network of this antenna. The electronic control of the phase shifter will allow the control of beam steering. The emphasis of this project will be done at the beginning on the design of a good phase shifter in Ku band. The aim of this research is to define, simulate, release and measure a continuous phase shifter. Better reflection loss, low transmission loss, low Cost of array antennas, large range of phase-shifter, phase flatness and bandwidth will be achieved by providing better gain.

  6. Phase shifter for antenna beam steering

    International Nuclear Information System (INIS)

    Jindal, Ravi; Razban, Tchanguiz

    2016-01-01

    Wide band Array Antenna operates in Ku-band (10.7-12.7 GHz) frequency composed of N×N radiating elements. This antenna aims at the reception of television satellite signals. The goal of this research is to provide better possibility of electronic beam control instead of manual or mechanical control, and design compact and low cost phase shifters to be inserted in the feeding network of this antenna. The electronic control of the phase shifter will allow the control of beam steering. The emphasis of this project will be done at the beginning on the design of a good phase shifter in Ku band. The aim of this research is to define, simulate, release and measure a continuous phase shifter. Better reflection loss, low transmission loss, low Cost of array antennas, large range of phase-shifter, phase flatness and bandwidth will be achieved by providing better gain.

  7. Multiquantum well beam-steering device for laser satellite communication

    Science.gov (United States)

    Lahat, Roee; Levy, Itamar; Shlomi, Arnon

    2002-01-01

    With the increasing interest in laser satellite communications, new methods are sought to solve the existing problems of accurate and rapid laser beam deflection. Current solutions in the form of galvanometers or piezo fast steering mirrors with one or two degrees of freedom are bulky, power-consuming and slow. The Multi-Quantum Well (MQW) is a semiconductor device with unique potential to steer laser beams without any moving parts. We have conducted a preliminary evaluation of the potential application of the MQW as a laser beam-steering device for laser satellite communication, examining the performance of critical parameters for this type of communications.

  8. "Intelligent" Automatic Beam Steering and Shaping

    CERN Document Server

    Jansson, A

    2000-01-01

    The strategy for Automated Beam Steering and Shaping (ABS) in the PS complex is to use theoretical response matrices calculated from an optics database. The main reason for this is that it enforces a certain understanding of the machine optics. A drawback is that the validation of such a matrix can be a lengthy process. However, every time a correction is made using an ABS program, a partial measurement of the response matrix is effectively performed. Since the ABS programs are very frequently used, the full matrices could thus be measured on an almost daily basis, provided this information is retained. The information can be used in two ways. Either the program passively logs the data to be analysed off­line, or the information is directly fed back to the matrix, which makes the program 'learn' as it executes. The data logging provides a powerful machine debugging tool, since deviations between the measured and theoretical matrices can be traced back to incorrect optical parameters. The 'learning' mode ensu...

  9. Calculation of the beam injector steering system using Helmholtz coils

    International Nuclear Information System (INIS)

    Passaro, A.; Sircilli Neto, F.; Migliano, A.C.C.

    1991-03-01

    In this work, a preliminary evaluation of the beam injector steering system of the IEAv electron linac is presented. From the existing injector configuration and with the assumptions of monoenergetic beam (100 keV) and uniform magnetic field, two pairs of Helmholtz coils were calculated for the steering system. Excitations of 105 A.turn and 37 A.turn were determined for the first and second coils, respectively. (author)

  10. A hybrid system for beam steering and wavefront control

    Science.gov (United States)

    Nikulin, Vladimir V.

    2004-06-01

    Performance of long-range mobile laser systems operating within Earth's atmosphere is generally limited by several factors. Movement of the communicating platforms, such as aircraft, terrain vehicles, etc., complemented by mechanical vibrations, is the main cause of pointing errors. In addition, atmospheric turbulence causes changes of the refractive index along the propagation path that lead to phase distortions (aberrations), thus creating random redistribution of optical energy in the spatial domain. The combined effect of these factors leads to an increased bit-error probability under adverse operation conditions. While traditional approaches provide separate treatment of these problems, suggesting the development of high-bandwidth beam steering systems to perform tracking and jitter rejection, and wavefront control for the mitigation of atmospheric effects, the two tasks could be integrated. In this paper we present a hybrid laser beam steering/wavefront control system comprising an electrically addressed spatial light modulator (SLM) installed on the Omni-Wrist sensor mount platform. The function of the Omni-Wrist is to provide coarse steering over a wide range of pointing angles, while the purpose of the SLM is twofold: it performs wavefront correction and fine steering. The control law for the Omni-Wrist is synthesized using the decentralized approach that provides independent access to the azimuth and declination channels, while the algorithm for calculating the required phase profile for the SLM is optimization-based. This paper presents the control algorithms, the approach to coordinating the operation of the both systems and the simulation results.

  11. Workshop on automated beam steering and shaping (ABS). Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Lindroos, M [ed.

    1999-09-10

    A workshop on Automated Beam Steering and Shaping (ABS) was held at CERN in December 1998. This was the first workshop dedicated to this subject. The workshop had two major goals: to review the present status of ABS algorithms and systems around the world and to create a worldwide ABS community. These proceedings contain summary reports from all sessions, contributions from several presentations held at the workshop, and a complete set of abstracts for all presentations. (orig.)

  12. Optimum steering of photon beam lines in SPEAR

    International Nuclear Information System (INIS)

    Corbett, W.J.; Fong, B.; Lee, M.; Ziemann, V.

    1993-04-01

    A common operational requirement for many synchrotron light sources is to maintain steered photon beamlines with minimum corrector strength values. To solve this problem for SPEAR, we employed the Singular Value Decomposition (SVD) matrix-inversion technique to minimize corrector strengths while constraining the photon beamlines to remain on target. The result was a reduction in corrector strengths, yielding increased overhead for the photon-beam position feedback systems

  13. Workshop on automated beam steering and shaping (ABS). Proceedings

    International Nuclear Information System (INIS)

    Lindroos, M.

    1999-01-01

    A workshop on Automated Beam Steering and Shaping (ABS) was held at CERN in December 1998. This was the first workshop dedicated to this subject. The workshop had two major goals: to review the present status of ABS algorithms and systems around the world and to create a worldwide ABS community. These proceedings contain summary reports from all sessions, contributions from several presentations held at the workshop, and a complete set of abstracts for all presentations. (orig.)

  14. Packaging consideration of two-dimensional polymer-based photonic crystals for laser beam steering

    Science.gov (United States)

    Dou, Xinyuan; Chen, Xiaonan; Chen, Maggie Yihong; Wang, Alan Xiaolong; Jiang, Wei; Chen, Ray T.

    2009-02-01

    In this paper, we report the theoretical study of polymer-based photonic crystals for laser beam steering which is based on the superprism effect as well as the experiment fabrication of the two dimensional photonic crystals for the laser beam steering. Superprism effect, the principle for beam steering, was separately studied in details through EFC (Equifrequency Contour) analysis. Polymer based photonic crystals were fabricated through double exposure holographic interference method using SU8-2007. The experiment results were also reported.

  15. Ultra-compact laser beam steering device using holographically formed two dimensional photonic crystal.

    Science.gov (United States)

    Dou, Xinyuan; Chen, Xiaonan; Chen, Maggie Yihong; Wang, Alan Xiaolong; Jiang, Wei; Chen, Ray T

    2010-03-01

    In this paper, we report the theoretical study of polymer-based photonic crystals for laser beam steering which is based on the superprism effect as well as the experiment fabrication of the two dimensional photonic crystals for the laser beam steering. Superprism effect, the principle for beam steering, was separately studied in details through EFC (Equifrequency Contour) analysis. Polymer based photonic crystals were fabricated through double exposure holographic interference method using SU8-2007. The experiment results showed a beam steering angle of 10 degree for 30 nm wavelength variation.

  16. Dynamic steering beams for efficient force measurement in optical manipulation

    Institute of Scientific and Technical Information of China (English)

    Xiaocong Yuan; Yuquan Zhang; Rui Cao; Xing Zhao; Jing Bu; Siwei Zhu

    2011-01-01

    @@ An efficient and inexpensive method that uses a glass plate mounted onto a motorized rotating stage as a beam-steering device for the generation of dynamic optical traps is reported.Force analysis reveals that there are drag and trapping forces imposed on the bead in the opposite directions, respectively, in a viscous medium.The trapped bead will be rotated following the beam's motion before it reaches the critical escape velocity when the drag force is equal to the optical trapping force.The equilibrium condition facilitates the experimental measurement of the drag force with potential extensions to the determination of the viscosity of the medium or the refractive index of the bead.The proposed technique can easily be integrated into conventional optical microscopic systems with minimum modifications.%An efficient and inexpensive method that uses a glass plate mounted onto a motorized rotating stage as a beam-steering device for the generation of dynamic optical traps is reported. Force analysis reveals that there are drag and trapping forces imposed on the bead in the opposite directions, respectively, in a viscous medium. The trapped bead will be rotated following the beam's motion before it reaches the critical escape velocity when the drag force is equal to the optical trapping force. The equilibrium condition facilitates the experimental measurement of the drag force with potential extensions to the determination of the viscosity of the medium or the refractive index of the bead. The proposed technique can easily be integrated into conventional optical microscopic systems with minimum modifications.

  17. Beam steering for circular switched parasitic arrays using a combinational approach

    CSIR Research Space (South Africa)

    Mofolo, ROM

    2011-09-01

    Full Text Available In this paper, the authors present a method of electronic beam steering for circular switched parasitic array (SPA) antennas. In circular SPA antennas, one achieves azimuth beam steering by open-circuiting and short-circuiting different parasitic...

  18. Beam steered millimeter-wave fiber-wireless system for 5G indoor coverage

    NARCIS (Netherlands)

    Cao, Z.; Wang, Q.; Tessema, N.M.; Leijtens, X.J.M.; Soares, F.M.; Koonen, A.M.J.

    2016-01-01

    A 38GHz beam steered fiber-wireless system, enabled by a novel integrated optical tunable delay line, is demonstrated for 5G indoor coverage. The beam steering gains 14dBm spatial power focusing and 6 times EVM improvement.

  19. Refractive waveguide non-mechanical beam steering (NMBS) in the MWIR

    Science.gov (United States)

    Myers, Jason D.; Frantz, Jesse A.; Spillmann, Christopher M.; Bekele, Robel Y.; Kolacz, Jakub; Gotjen, Henry; Naciri, Jawad; Shaw, Brandon; Sanghera, Jas S.

    2018-02-01

    Beam steering is a crucial technology for a number of applications, including chemical sensing/mapping and light detection and ranging (LIDAR). Traditional beam steering approaches rely on mechanical movement, such as the realignment of mirrors in gimbal mounts. The mechanical approach to steering has several drawbacks, including large size, weight and power usage (SWAP), and frequent mechanical failures. Recently, alternative non-mechanical approaches have been proposed and developed, but these technologies do not meet the demanding requirements for many beam steering applications. Here, we highlight the development efforts into a particular non-mechanical beam steering (NMBS) approach, refractive waveguides, for application in the MWIR. These waveguides are based on an Ulrich-coupled slab waveguide with a liquid crystal (LC) top cladding; by selectively applying an electric field across the liquid crystal through a prismatic electrode, steering is achieved by creating refraction at prismatic interfaces as light propagates through the device. For applications in the MWIR, we describe a versatile waveguide architecture based on chalcogenide glasses that have a wide range of refractive indices, transmission windows, and dispersion properties. We have further developed robust shadow-masking methods to taper the subcladding layers in the coupling region. We have demonstrated devices with >10° of steering in the MWIR and a number of advantageous properties for beam steering applications, including low-power operation, compact size, and fast point-to-point steering.

  20. An automatic beam steering system for the NSLS X-17T beam line using closed orbit feedback

    International Nuclear Information System (INIS)

    Nawrocky, R.J.; Ma, Li; Rarback, H.M.; Singh, O.V.; Yu, L.H.

    1987-01-01

    Initial observations of motion of the undulator radiation in the NSLS X-17T beam line clearly indicated that the beam had to be stabilized in both directions to be usable for the planned soft x-ray imaging experiments. The low frequency spectra of beam motion contained peaks in the range from dc to 60 Hz and at higher frequencies. A beam steering system employing closed orbit feedback has been designed and installed to stabilize the beam in both planes. In each plane of motion, beam position is measured with a beam position detector and a correction signal is fed back to a local four magnet orbit bump to dynamically control the angle of the radiation at the source. This paper describes the design and performance of the beam steering system

  1. 5G antenna array with wide-angle beam steering and dual linear polarizations

    KAUST Repository

    Klionovski, Kirill; Shamim, Atif; Sharawi, Mohammad Said

    2017-01-01

    In this paper, we present the design of a switched-beam antenna array at millimeter-wave frequencies for future 5G applications. The proposed antenna array is based on wideband patch antenna elements and a Butler matrix feed network. The patch antenna has a broad radiation pattern for wide-angle beam steering and allows the simultaneous operation with two orthogonal linear polarizations. A combination of two separated Butler matrices provides independent beam steering for both polarizations in the wide operating band. The antenna array has a simple multilayer construction, and it is made on a low-cost Rogers laminate.

  2. 5G antenna array with wide-angle beam steering and dual linear polarizations

    KAUST Repository

    Klionovski, Kirill

    2017-10-25

    In this paper, we present the design of a switched-beam antenna array at millimeter-wave frequencies for future 5G applications. The proposed antenna array is based on wideband patch antenna elements and a Butler matrix feed network. The patch antenna has a broad radiation pattern for wide-angle beam steering and allows the simultaneous operation with two orthogonal linear polarizations. A combination of two separated Butler matrices provides independent beam steering for both polarizations in the wide operating band. The antenna array has a simple multilayer construction, and it is made on a low-cost Rogers laminate.

  3. Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

    Science.gov (United States)

    Heck, Martijn J. R.

    2017-01-01

    Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D) imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC) technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by high-bandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs.

  4. Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

    Directory of Open Access Journals (Sweden)

    Heck Martijn J.R.

    2016-06-01

    Full Text Available Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by high-bandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs.

  5. Millimeter wave beam steered fiber wireless systems for 5G indoor coverage : Integrated circuits and systems

    NARCIS (Netherlands)

    Cao, Zizheng; Zhang, Xuebing; Zhao, Xinran; Shen, Longfei; Deng, Xiong; Yin, Xin; Koonen, Ton

    2017-01-01

    In this talk, we review our recent progress and on-going research on millimeter wave beam steered fiber wireless systems for 5G indoor coverage enabled by the advanced photonic integrated circuit and well-designed fiber-wireless networks.

  6. A Waveguide Antenna with an Extended Angular Range for Remote Steering of Wave-Beam Direction

    Science.gov (United States)

    Sobolev, D. I.; Denisov, G. G.

    2018-03-01

    A new method for increasing the angular range of a waveguide antenna for remote steering of the wave-beam direction in thermonuclear-fusion experimental setups with plasma magnetic confinement is proposed. Characteristics for large beam inclination angles can be improved using the synthesized nonuniform waveguide profile. For small angles, the characteristics remain invariable, the waveguide profile differs only slightly from the regular shape, and can be fit to limited waveguide-channel sizes.

  7. Beam steering effects in turbulent high pressure flames

    Energy Technology Data Exchange (ETDEWEB)

    Hemmerling, B; Kaeppeli, B [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    The propagation of a laser beam through a flame is influenced by variations of the optical density. Especially in turbulent high pressure flames this may seriously limit the use of laser diagnostic methods. (author) 1 fig., 2 refs.

  8. Verification and application of beam steering Phased Array UT technique for complex structures

    International Nuclear Information System (INIS)

    Yamamoto, Setsu; Miura, Takahiro; Semboshi, Jun; Ochiai, Makoto; Mitsuhashi, Tadahiro; Adachi, Hiroyuki; Yamamoto, Satoshi

    2013-01-01

    Phased Array Ultrasonic Testing (PAUT) techniques for complex geometries are greatly progressing. We developed an immersion PAUT which is suitable for complex surface profiles such as nozzles and deformed welded areas. Furthermore, we have developed a shape adaptive beam steering technique for 3D complex surface structures with conventional array probe and flexible coupling gel which makes the immersion beam forming technique usable under dry conditions. This system consists of 3 steps. Step1 is surface profile measurement which based on 3D Synthesis Aperture Focusing Technique (SAFT), Step2 is delay law calculation which could take into account the measured 3D surface profiles and steer a shape adjusted ultrasonic beam, Step3 is shape adjusted B-scope construction. In this paper, verification results of property of this PAUT system using R60 curved specimen and nozzle shaped specimen which simulated actual BWR structure. (author)

  9. Non-Mechanical Beam Steering in Free-Space Optical Communication Transceivers

    Science.gov (United States)

    Shortt, Kevin

    Free-space optical communications systems are a rapidly growing field as they carry many of the advantages of traditional fibre-based communications systems without the added investment of installing complex infrastructure. Moreover, these systems are finding key niches in mobile platforms in order to take advantage of the increased bandwidth over traditional RF systems. Of course, the inevitable problem of tracking arises when dealing with mobile stations. To compound the problem in the case of communications to low Earth or geosynchronous orbits, FSOC systems typically operate with tightly confined beams over great distances often requiring pointing accuracies on the order of micro-radians or smaller. Mechanisms such as gimbal mounts and fine-steering mirrors are the usual candidates for platform stabilization, however, these clearly have substantial power requirements and inflate the mass of the system. Spatial light modulators (also known as optical phased arrays), on the other hand, offer a suitable alternative for beam-pointing stabilization. Some of the advantages of spatial light modulators over fine-steering mirrors include programmable multiple simultaneous beams, dynamic focus/defocus and moderate to excellent optical power handling capability. This thesis serves as an investigation into the implementation of spatial light modulators as a replacement for traditional fine-steering mirrors in the fine-pointing subsystem. In particular, pointing accuracy and scanning ability will be highlighted as performance metrics in the context of a variety of communication scenarios. Keywords: Free-space optical communications, beam steering, fine-steering mirror, spatial light modulator, optical phased array.

  10. Optical resonators for true-time-delay beam steering

    Science.gov (United States)

    Gesell, Leslie H.; Evanko, Stephen M.

    1996-06-01

    Conventional true time delay beamforming and steering devices rely on switching between various lengths of delay line. Therefore only discrete delays are possible. Proposed is a new photonics concept for true time delay beamforming which provides a finely controlled continuum of delays with switching speeds on the order of 10's of nanoseconds or faster. The architecture uses an array of waveguide cavities with different resonate frequencies to channelize the signal. Each spectral component of the signal is phase shifted by an amount proportional to the frequency of that component and the desired time delay. These phase shifted spectral components are then summed to obtain the delayed signal. This paper provides an overview of the results of a Phase I SBIR contract where this concept has been refined and analyzed. The parameters for an operational system are determined and indication of the feasibility of this approach is given. Among the issues addressed are the requirements of the resonators and the methods necessary to implement fiber optic Bragg gratings as these resonators.

  11. GMTIFS: the adaptive optics beam steering mirror for the GMT integral-field spectrograph

    Science.gov (United States)

    Davies, J.; Bloxham, G.; Boz, R.; Bundy, D.; Espeland, B.; Fordham, B.; Hart, J.; Herrald, N.; Nielsen, J.; Sharp, R.; Vaccarella, A.; Vest, C.; Young, P. J.

    2016-07-01

    To achieve the high adaptive optics sky coverage necessary to allow the GMT Integral-Field Spectrograph (GMTIFS) to access key scientific targets, the on-instrument adaptive-optics wavefront-sensing (OIWFS) system must patrol the full 180 arcsecond diameter guide field passed to the instrument. The OIWFS uses a diffraction limited guide star as the fundamental pointing reference for the instrument. During an observation the offset between the science target and the guide star will change due to sources such as flexure, differential refraction and non-sidereal tracking rates. GMTIFS uses a beam steering mirror to set the initial offset between science target and guide star and also to correct for changes in offset. In order to reduce image motion from beam steering errors to those comparable to the AO system in the most stringent case, the beam steering mirror is set a requirement of less than 1 milliarcsecond RMS. This corresponds to a dynamic range for both actuators and sensors of better than 1/180,000. The GMTIFS beam steering mirror uses piezo-walk actuators and a combination of eddy current sensors and interferometric sensors to achieve this dynamic range and control. While the sensors are rated for cryogenic operation, the actuators are not. We report on the results of prototype testing of single actuators, with the sensors, on the bench and in a cryogenic environment. Specific failures of the system are explained and suspected reasons for them. A modified test jig is used to investigate the option of heating the actuator and we report the improved results. In addition to individual component testing, we built and tested a complete beam steering mirror assembly. Testing was conducted with a point source microscope, however controlling environmental conditions to less than 1 micron was challenging. The assembly testing investigated acquisition accuracy and if there was any un-sensed hysteresis in the system. Finally we present the revised beam steering mirror

  12. Fusion of adaptive beam steering and optimization-based wavefront control for laser communications in atmosphere

    Science.gov (United States)

    Nikulin, Vladimir V.

    2005-10-01

    The performance of mobile laser communication systems operating within Earth's atmosphere is generally limited by the pointing errors due to movement of the platforms and mechanical vibrations. In addition, atmospheric turbulence causes changes of the refractive index along the propagation path, creating random redistribution of the optical energy in the spatial domain. Under adverse conditions these effects lead to increased bit error rate. While traditional approaches provide separate treatment of these problems, suggesting high-bandwidth beam steering systems for tracking and wavefront control for the mitigation of atmospheric effects, the two tasks can be integrated. This paper presents a hybrid laser beam-steering-wavefront-control system comprising an electrically addressed spatial light modulator (SLM) installed on the Omni-Wrist sensor mount. The function of the Omni-Wrist is to provide coarse steering over a wide range of pointing angles, while that of the SLM is twofold: wavefront correction and fine steering. The control law for the Omni-Wrist is synthesized using a decentralized approach that provides independent access to the azimuth and declination channels; calculation of the required phase profile for the SLM is optimization-based. This paper presents the control algorithms, the approach to coordinating the operation of the two systems, and the results.

  13. Frequency Invariant Beam Steering for Short-Pulse Systems with a Rotman Lens

    Directory of Open Access Journals (Sweden)

    Andreas Lambrecht

    2010-01-01

    Full Text Available A promising approach for beam steering of high-voltage transient signals for HPEM-systems (High Power Electro Magnetic is presented. The inherent capability of the Rotman lens to provide true time delays is used to develop a prototype beam steering device for an antielectronics HPEM system in the frequency range from 350 MHz to 5 GHz. Results of analytical calculations, simulations, and measurements from a hardware prototype are presented. The detailed mechanical setup of the Rotman lens is presented. Additionally the output pulses are investigated when inputting a Gaussian-like transient signal. Then time domain measures of quality (full width at half maximum, ringing, delay spread, maximum of transfer function are investigated for these output transients, and the simulation and measurement results are compared. A concluding analysis of the realizable time domain array pattern shows the radiated pulse form.

  14. 2D Traveling Wave Array Employing a Trapezoidal Dielectric Wedge for Beam Steering

    Science.gov (United States)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranada, Felix A.

    2014-01-01

    This presentation addresses the progress made so far in the development of an antenna array with reconfigurable transmission line feeds connecting each element in series. In particular, 2D traveling wave array employing trapezoidal Dielectric Wedge for Beam Steering will be discussed. The presentation includes current status of the effort and suggested future work. The work is being done as part of the NASA Office of the Chief Technologist's Space Technology Research Fellowship (NSTRF).

  15. A Time Modulated Printed Dipole Antenna Array for Beam Steering Application

    Directory of Open Access Journals (Sweden)

    Ruchi Gahley

    2017-01-01

    Full Text Available This paper presents time modulated beam steered antenna array without phase shifters. The beam steering is analyzed considering a two-element time modulated antenna array (TMAA of printed dipoles with microstrip via-hole balun. The proposed array resonates at the Industrial, Scientific, and Medical (ISM radio bands, 2.45 GHz and 5.8 GHz, and offers wide bandwidth inherited due to modified structure of ground plane. Array elements are excited by complex exponential excitation signal through broadband power divider and radio frequency (RF switches to achieve amplitude and phase variation without phase shifters. Differential Evolution algorithm is used to modify the time sequences of the RF switches connected to the antennas to generate radiation pattern with optimum dynamic efficiency by suppressing sideband radiations. Also switch-on time instant of RF switch connected to the subsequent element is modulated to steer the beam towards different directions. The proposed prototype is fabricated followed by parametric optimization. The fabrication results agree significantly well with simulated results.

  16. Modeling and simulations of new electrostatically driven, bimorph actuator for high beam steering micromirror deflection angles

    Science.gov (United States)

    Walton, John P.; Coutu, Ronald A.; Starman, LaVern

    2015-02-01

    There are numerous applications for micromirror arrays seen in our everyday lives. From flat screen televisions and computer monitors, found in nearly every home and office, to advanced military weapon systems and space vehicles, each application bringing with it a unique set of requirements. The microelectromechanical systems (MEMS) industry has researched many ways micromirror actuation can be accomplished and the different constraints on performance each design brings with it. This paper investigates a new "zipper" approach to electrostatically driven micromirrors with the intent of improving duel plane beam steering by coupling large deflection angles, over 30°, and a fast switching speed. To accomplish this, an extreme initial deflection is needed which can be reached using high stress bimorph beams. Currently this requires long beams and high voltage for the electrostatic pull in or slower electrothermal switching. The idea for this "zipper" approach is to stack multiple beams of a much shorter length and allow for the deflection of each beam to be added together in order to reach the required initial deflection height. This design requires much less pull-in voltage because the pull-in of one short beam will in turn reduce the height of the all subsequent beams, making it much easier to actuate. Using modeling and simulation software to characterize operations characteristics, different bimorph cantilever beam configurations are explored in order to optimize the design. These simulations show that this new "zipper" approach increases initial deflection as additional beams are added to the assembly without increasing the actuation voltage.

  17. MAcro-Electro-Mechanical Systems (MÆMS) based concept for microwave beam steering in reflectarray antennas

    Energy Technology Data Exchange (ETDEWEB)

    Momeni Hasan Abadi, Seyed Mohamad Amin, E-mail: momenihasana@wisc.edu; Booske, John H., E-mail: jhbooske@wisc.edu; Behdad, Nader, E-mail: behdad@wisc.edu [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706 (United States)

    2016-08-07

    We present a new approach to perform beam steering in reflecting type apertures such as reflectarray antennas. The proposed technique exploits macro-scale mechanical movements of parts of the structure to achieve two-dimensional microwave beam steering without using any solid-state devices or phase shifters integrated within the aperture of the antenna. The principles of operation of this microwave beam steering technique are demonstrated in an aperture occupied by ground-plane-backed, sub-wavelength capacitive patches with identical dimensions. We demonstrate that by tilting the ground plane underneath the entire patch array layer, a phase shift gradient can be created over the aperture of the reflectarray that determines the direction of the radiated beam. Changing the direction and slope of this phase shift gradient on the aperture allows for performing beam steering in two dimensions using only one control parameter (i.e., tilt vector of the ground plane). A proof-of-concept prototype of the structure operating at X-band is designed, fabricated, and experimentally characterized. Experiments demonstrate that small mechanical movements of the ground plane (in the order of 0.05λ{sub 0}) can be used to steer the beam direction in the ±10° in two dimensions. It is also demonstrated that this beam scanning range can be greatly enhanced to ±30° by applying this concept to the same structure when its ground plane is segmented.

  18. The steering and manipulation of ion beams for low-energy heavy ion accelerators

    International Nuclear Information System (INIS)

    Beanland, D.G.; Freeman, J.H.

    1976-01-01

    Both electrostatic and magnetic fields are used in low-energy accelerators. Electrostatic fields are essential in the acceleration stages and they are commonly used for ion beam scanning and focussing. Magnetic fields are only infrequently used as lenses, but they are essential for mass analysis and are sometimes employed for beam steering. The electrostatic mirror is a versatile and compact lens which has hitherto received little attention for the controlled manipulation of heavy ions. In addition to energy analysis it can be used to steer, focus and scan such beams and its flexibility and usefulness can be further increased by shaping the electrostatic field in the mirror space. The use of a computer programme to model the focussing behaviour of a variety of lens shapes is described and it is shown that the focal properties of the mirror can be controlled to produce a parallel, convergent or divergent output beam. The use of mirrors for two-dimensional beam focusing is also outlined. To permit the use of the mirror system with heavy ions an apertured front plate, without field-defining gauzes, was utilized. In consequence an additional electrode was incorporated in the lens structure to prevent penetration of the positive electric field along the beam axes outside the mirror space. This factor and the compact design of the mirror, contributed to the minimisation of space-charge defocussing effects which normally militate against the use of such electrostatic lenses with high intensity ion beams. The results of experiments confirming the computer predictions are briefly described and, in conclusion some possible applications of electrostatic mirrors in electromagnetic isotope separators and low energy accelerators are outlined. (Auth.)

  19. Beam steering in superconducting quarter-wave resonators: An analytical approach

    Directory of Open Access Journals (Sweden)

    Alberto Facco

    2011-07-01

    Full Text Available Beam steering in superconducting quarter-wave resonators (QWRs, which is mainly caused by magnetic fields, has been pointed out in 2001 in an early work [A. Facco and V. Zviagintsev, in Proceedings of the Particle Accelerator Conference, Chicago, IL, 2001 (IEEE, New York, 2001, p. 1095], where an analytical formula describing it was proposed and the influence of cavity geometry was discussed. Since then, the importance of this effect was recognized and effective correction techniques have been found [P. N. Ostroumov and K. W. Shepard, Phys. Rev. ST Accel. Beams 4, 110101 (2001PRABFM1098-440210.1103/PhysRevSTAB.4.110101]. This phenomenon was further studied in the following years, mainly with numerical methods. In this paper we intend to go back to the original approach and, using well established approximations, derive a simple analytical expression for QWR steering which includes correction methods and reproduces the data starting from a few calculable geometrical constants which characterize every cavity. This expression, of the type of the Panofski equation, can be a useful tool in the design of superconducting quarter-wave resonators and in the definition of their limits of application with different beams.

  20. Beam steering performance of compressed Luneburg lens based on transformation optics

    Science.gov (United States)

    Gao, Ju; Wang, Cong; Zhang, Kuang; Hao, Yang; Wu, Qun

    2018-06-01

    In this paper, two types of compressed Luneburg lenses based on transformation optics are investigated and simulated using two different sources, namely, waveguides and dipoles, which represent plane and spherical wave sources, respectively. We determined that the largest beam steering angle and the related feed point are intrinsic characteristics of a certain type of compressed Luneburg lens, and that the optimized distance between the feed and lens, gain enhancement, and side-lobe suppression are related to the type of source. Based on our results, we anticipate that these lenses will prove useful in various future antenna applications.

  1. Synthesis of Steered Flat-top Beam Pattern Using Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    D. Mandal

    2016-12-01

    Full Text Available In this paper a pattern synthesis method based on Evolutionary Algorithm is presented. A Flat-top beam pattern has been generated from a concentric ring array of isotropic elements by finding out the optimum set of elements amplitudes and phases using Differential Evolution algorithm. The said pattern is generated in three predefined azimuth planes instate of a single phi plane and also verified for a range of azimuth plane for the same optimum excitations. The main beam is steered to an elevation angle of 30 degree with lower peak SLL and ripple. Dynamic range ratio (DRR is also being improved by eliminating the weakly excited array elements, which simplify the design complexity of feed networks.

  2. Monolithic beam steering in a mid-infrared, surface-emitting, photonic integrated circuit.

    Science.gov (United States)

    Slivken, Steven; Wu, Donghai; Razeghi, Manijeh

    2017-08-16

    The mid-infrared (2.5 < λ < 25 μm) spectral region is utilized for many purposes, such as chemical/biological sensing, free space communications, and illuminators/countermeasures. Compared to near-infrared optical systems, however, mid-infrared component technology is still rather crude, with isolated components exhibiting limited functionality. In this manuscript, we make a significant leap forward in mid-infrared technology by developing a platform which can combine functions of multiple mid-infrared optical elements, including an integrated light source. In a single device, we demonstrate wide wavelength tuning (240 nm) and beam steering (17.9 degrees) in the mid-infrared with a significantly reduced beam divergence (down to 0.5 degrees). The architecture is also set up to be manufacturable and testable on a wafer scale, requiring no cleaved facets or special mirror coating to function.

  3. Automatic local beam steering systems for NSLS x-ray storage ring: Design and implementation

    International Nuclear Information System (INIS)

    Singh, O.V.; Nawrocky, R.; Flannigan, J.

    1991-01-01

    Recently, two local automatic steering systems, controlled by microprocessors, have been installed and commissioned in the NSLS X- Ray storage ring. In each system, the position of the electron beam is stabilized at two locations by four independent servo systems. This paper describes three aspects of the local feedback program: design; commissioning; and limitation. The system design is explained by identifying major elements such as beam position detectors, signal processors, compensation amplifiers, ratio amplifiers, trim equalizers and microprocessor feedback controllers. System commissioning involves steps such as matching trim compensation, determination of local orbit bumps, measurement of open loop responses and design of servo circuits. Several limitations of performance are also discussed. 7 refs., 2 figs

  4. High-performance beam steering using electrowetting-driven liquid prism fabricated by a simple dip-coating method

    Energy Technology Data Exchange (ETDEWEB)

    Enrico Clement, Carlos; Park, Sung-Yong, E-mail: mpeps@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore, Block EA, #07-08, 9 Engineering Drive 1, 117576 (Singapore)

    2016-05-09

    A high degree of beam steering is demonstrated using an electrowetting-driven liquid prism. While prism devices have typically relied on complex and expensive laboratory setups, such as high-vacuum facilities for fabrication of dielectric layers, this work utilizes a simple dip-coating method to provide an ion gel layer as a dielectric, offering 2 or 3 orders higher specific capacitance (c ≈ 10 μF/cm{sup 2}) than that of conventional dielectrics. Analytical studies present the effects of liquid selection and arrangement on overall prism performance. For experimental demonstrations of high-performance beam steering, we not only selected two immiscible liquids of water and 1-bromonaphthalene (1-BN) oil which provide the large refractive index difference (n{sub water} = 1.33 and n{sub 1-BN} = 1.65 at λ = 532 nm) between them, but also utilized a double-stacked prism configuration which increases the number of interfaces for incoming light to be steered. At a prism apex angle of φ = 27°, we were able to achieve significantly large beam steering of up to β = 19.06°, which is the highest beam steering performance ever demonstrated using electrowetting technology.

  5. Simulation and experimental study of a remote steering system for ECRH/ECCD antenna beams

    International Nuclear Information System (INIS)

    Chirkov, A.V.; Denisov, G.G.; Kasparek, W.; Wagner, D.; Gantenbein, G.; Haug, M.; Hollmann, F.

    2001-01-01

    The present design for the ITER electron cyclotron wave launcher is based on individual circular corrugated waveguides running up to the vacuum vessel. At each waveguide end near to the plasma, a pair of movable mitre bends provides steering of the beam between 0 deg. and 40 deg. An alternative to this concept could be corrugated square or rectangular waveguides. These waveguides show imaging characteristics, which can be used for remote scanning of the beam, thus avoiding movable parts near to the plasma. To obtain a safe data base for the realisation of this concept, theoretical and experimental studies were carried out. The calculations show that a scanning range of more than ±10 deg. is possible with negligible loss into side lobes. Furthermore, concepts to improve the scanning range can be derived from the calculations. Measurements of amplitude and phase distribution in the output plane of the waveguide and in the far-field show very good agreement with theory for a beam polarisation perpendicular to the scanning direction. For beams polarised parallel to the scanning direction, where the propagation in the waveguide is determined mainly by the grooved walls, a reduced beam quality is measured, which can be attributed to imperfect machining of the grooves. The results show also, that the imaging characteristics are in principle maintained after the introduction of a pair of mitre bends with the bending plane perpendicular to the scanning plane. Finally, the application to ITER is discussed and concepts to improve the scanning range are given

  6. Novel Microstrip Patch Antennas with Frequency Agility, Polarization Reconfigurability, Dual Null Steering Capability and Phased Array Antenna with Beam Steering Performance

    Science.gov (United States)

    Babakhani, Behrouz

    Nowadays the wireless communication technology is playing an important role in our daily life. People use wireless devices not only as a conventional communication device but also as tracking and navigation tool, web browsing tool, data storage and transfer tool and so for many other reasons. Based on the user demand, wireless communication engineers try to accommodate as many as possible wireless systems and applications in a single device and therefore, creates a multifunctional device. Antenna, as an integral part of any wireless communication systems, should also be evolved and adjusted with development of wireless transceiver systems. Therefore multifunctional antennas have been introduced to support and enhance the functionality on modern wireless systems. The main focus and contribution of this thesis is design of novel multifunctional microstrip antennas with frequency agility, polarization reconfigurablity, dual null steering capability and phased array antenna with beam steering performance. In this thesis, first, a wide bandwidth(1.10 GHz to 1.60 GHz) right-handed circularly polarized (RHCP) directional antenna for global positioning system (GPS) satellite receive application has been introduced which covers all the GPS bands starting from L1 to L5. This design consists of two crossed bow-tie dipole antennas fed with sequentially phase rotated feed network backed with an artificial high impedance surface (HIS) structure to generate high gain directional radiation patterns. This design shows good CP gain and axial ratio (AR) and wide beamwidth performance. Although this design has good radiation quality, the size and the weight can be reduced as future study. In the second design, a frequency agile antenna was developed which also covers the L-band (L1 to L5) satellite communication frequencies. This frequency agile antenna was designed and realized by new implementation of varactor diodes in the geometry of a circular patch antenna. Beside wide frequency

  7. Tongue-driven sonar beam steering by a lingual-echolocating fruit bat.

    Directory of Open Access Journals (Sweden)

    Wu-Jung Lee

    2017-12-01

    Full Text Available Animals enhance sensory acquisition from a specific direction by movements of head, ears, or eyes. As active sensing animals, echolocating bats also aim their directional sonar beam to selectively "illuminate" a confined volume of space, facilitating efficient information processing by reducing echo interference and clutter. Such sonar beam control is generally achieved by head movements or shape changes of the sound-emitting mouth or nose. However, lingual-echolocating Egyptian fruit bats, Rousettus aegyptiacus, which produce sound by clicking their tongue, can dramatically change beam direction at very short temporal intervals without visible morphological changes. The mechanism supporting this capability has remained a mystery. Here, we measured signals from free-flying Egyptian fruit bats and discovered a systematic angular sweep of beam focus across increasing frequency. This unusual signal structure has not been observed in other animals and cannot be explained by the conventional and widely-used "piston model" that describes the emission pattern of other bat species. Through modeling, we show that the observed beam features can be captured by an array of tongue-driven sound sources located along the side of the mouth, and that the sonar beam direction can be steered parsimoniously by inducing changes to the pattern of phase differences through moving tongue location. The effects are broadly similar to those found in a phased array-an engineering design widely found in human-made sonar systems that enables beam direction changes without changes in the physical transducer assembly. Our study reveals an intriguing parallel between biology and human engineering in solving problems in fundamentally similar ways.

  8. A Novel Approach to Beam Steering Using Arrays Composed of Multiple Unique Radiating Modes

    Science.gov (United States)

    Labadie, Nathan Richard

    Phased array antennas have found wide application in both radar and wireless communications systems particularly as implementation costs continue to decrease. The primary advantages of electronically scanned arrays are speed of beam scan and versatility of beamforming compared to mechanically scanned fixed beam antennas. These benefits come at the cost of a few well known design issues including element pattern rolloff and mutual coupling between elements. Our primary contribution to the field of research is the demonstration of significant improvement in phased array scan performance using multiple unique radiating modes. In short, orthogonal radiating modes have minimal coupling by definition and can also be generated with reduced rolloff at wide scan angles. In this dissertation, we present a combination of analysis, full-wave electromagnetic simulation and measured data to support our claims. The novel folded ring resonator (FRR) antenna is introduced as a wideband and multi-band element embedded in a grounded dielectric substrate. Multiple radiating modes of a small ground plane excited by a four element FRR array were also investigated. A novel hemispherical null steering antenna composed of two collocated radiating elements, each supporting a unique radiating mode, is presented in the context of an anti-jam GPS receiver application. Both the antenna aperture and active feed network were fabricated and measured showing excellent agreement with analytical and simulated data. The concept of using an antenna supporting multiple radiating modes for beam steering is also explored. A 16 element hybrid linear phased array was fabricated and measured demonstrating significantly improved scan range and scanned gain compared to a conventional phased array. This idea is expanded to 2 dimensional scanning arrays by analysis and simulation of a hybrid phased array composed of novel multiple mode monopole on patch antenna sub-arrays. Finally, we fabricated and

  9. Beam steering for virtual/augmented reality displays with a cycloidal diffractive waveplate.

    Science.gov (United States)

    Chen, Haiwei; Weng, Yishi; Xu, Daming; Tabiryan, Nelson V; Wu, Shin-Tson

    2016-04-04

    We proposed a switchable beam steering device with cycloidal diffractive waveplate (CDW) for eye tracking in a virtual reality (VR) or augmented reality (AR) display system. Such a CDW diffracts the incident circularly polarized light to the first order with over 95% efficiency. To convert the input linearly polarized light to right-handed or left-handed circular polarization, we developed a broadband polarization switch consisting of a twisted nematic liquid crystal cell and an achromatic quarter-wave retardation film. By cascading 2-3 CDWs together, multiple diffraction angles can be achieved. To suppress the color dispersion, we proposed two approaches to obtain the same diffraction angle for red, green, and blue LEDs-based full color displays. Our device exhibits several advantages, such as high diffraction efficiency, fast response time, low power consumption, and low cost. It holds promise for the emerging VR/AR displays.

  10. 38-GHz millimeter wave beam steered fiber wireless systems for 5G indoor coverage: architectures, devices, and links

    NARCIS (Netherlands)

    Cao, Z.; Zhao, X.; Soares, F.M.; Tessema, N.M.; Koonen, A.M.J.

    2017-01-01

    Millimeter wave (mm-wave) beam steering is a key technique for the next generation (5G) wireless communication. The 28 and 38-GHz bands are widely considered as the candidates for 5G. In the context of indoor coverage, fiber-wireless systems with multiple simplified remote antenna sites are

  11. Advanced Integration Techniques on Broadband Millimeter-Wave Beam Steering for 5G Wireless Networks and Beyond

    NARCIS (Netherlands)

    Cao, Zizheng; Ma, Qian; Smolders, Bart; Jiao, Yuqing; Wale, Mike; Oh, Joanne; wu, hequan; Koonen, Ton

    2015-01-01

    Recently, the desired very high throughput of 5G wireless networks drives millimeter-wave (mm-wave) communication into practical applications. A phased array technique is required to increase the effective antenna aperture at mm-wave frequency. Integrated solutions of beamforming/beam steering are

  12. Diode laser lidar wind velocity sensor using a liquid-crystal retarder for non-mechanical beam-steering

    DEFF Research Database (Denmark)

    Rodrigo, Peter John; Iversen, Theis Faber Quist; Hu, Qi

    2014-01-01

    it either transmits throughor reflects off a polarization splitter. The room-temperature switching timebetween the two LOS is measured to be in the order of 100μs in one switchdirection but 16 ms in the opposite transition. Radial wind speedmeasurement (at 33 Hz rate) while the lidar beam is repeatedly...... the lidar probe beam in two different lines-of-sight (LOS) with a 60° angular separation. Dual-LOS beam-steering isimplemented optically with no moving parts by means of a controllableliquid-crystal retarder (LCR). The LCR switches the polarization betweentwo orthogonal linear states of the lidar beam so...

  13. Beam-Steering Performance of Flat Luneburg Lens at 60 GHz for Future Wireless Communications

    Directory of Open Access Journals (Sweden)

    Robert Foster

    2017-01-01

    Full Text Available The beam-steering capabilities of a simplified flat Luneburg lens are reported at 60 GHz. The design of the lens is first described, using transformation electromagnetics, before discussion of the fabrication of the lens using casting of ceramic composites. The simulated beam-steering performance is shown, demonstrating that the lens, with only six layers and a highest permittivity of 12, achieves scan angles of ±30° with gains of at least 18 dBi over a bandwidth from 57 to 66 GHz. To verify the simulations and further demonstrate the broadband nature of the lens, raw high definition video was transmitted over a wireless link at scan angles up to 36°.

  14. Compact, semi-passive beam steering prism array for solar concentrators.

    Science.gov (United States)

    Zheng, Cheng; Li, Qiyuan; Rosengarten, Gary; Hawkes, Evatt; Taylor, Robert A

    2017-05-10

    In order to maximize solar energy utilization in a limited space (e.g., rooftops), solar collectors should track the sun. As an alternative to rotational tracking systems, this paper presents a compact, semi-passive beam steering prism array which has been designed, analyzed, and tested for solar applications. The proposed prism array enables a linear concentrator system to remain stationary so that it can integrate with a variety of different solar concentrators, and which should be particularly useful for systems which require a low profile (namely rooftop-mounted systems). A case study of this prism array working within a specific rooftop solar collector demonstrates that it can boost the average daily optical efficiency of the collector by 32.7% and expand its effective working time from 6 h to 7.33 h. Overall, the proposed design provides an alternative way to "follow" the sun for a wide range of solar thermal and photovoltaic concentrator systems.

  15. Ultra-Wideband, Dual-Polarized, Beam-Steering P-Band Array Antenna

    Science.gov (United States)

    duToit, Cornelis

    2014-01-01

    A dual-polarized, wide-bandwidth (200 MHz for one polarization, 100 MHz for the orthogonal polarization) antenna array at P-band was designed to be driven by NASA's EcoSAR digital beam former. EcoSAR requires two wide P-band antenna arrays mounted on the wings of an aircraft, each capable of steering its main beam up to 35deg off-boresight, allowing the twin radar beams to be steered at angles to the flight path. The science requirements are mainly for dual-polarization capability and a wide bandwidth of operation of up to 200 MHz if possible, but at least 100 MHz with high polarization port isolation and low cross-polarization. The novel design geometry can be scaled with minor modifications up to about four times higher or down to about half the current design frequencies for any application requiring a dual-polarized, wide-bandwidth steerable antenna array. EcoSAR is an airborne interferometric P-band synthetic aperture radar (SAR) research application for studying two- and three-dimensional fine-scale measurements of terrestrial ecosystem structure and biomass, which will ultimately aid in the broader study of the carbon cycle and climate change. The two 2×8 element Pband antenna arrays required by the system will be separated by a baseline of about 25 m, allowing for interferometry measurements. The wide 100-to- 200-MHz bandwidth dual-polarized beams employed will allow the determination of the amount of biomass and even tree height on the ground. To reduce the size of the patches along the boresight dimension in order to fit them into the available space, two techniques were employed. One technique is to add slots along the edges of each patch where the main electric currents are expected to flow, and the other technique is to bend the central part of the patch away from the ground plane. The latter also facilitates higher mechanical rigidity. The high port isolation of more than 40 dB was achieved by employing a highly symmetrical feed mechanism for each

  16. Optical true-time-delay microwave beam-steering with 1 Gb/s wireless transmission for in-building networks

    NARCIS (Netherlands)

    Cao, Z.; Li, F.; Boom, van den H.P.A.; Tangdiongga, E.; Koonen, A.M.J.

    2013-01-01

    An optical true time delay based microwave beam-steering (OTTD-MBS) scheme integrated with a radio-over-fibre system is demonstrated. Properties of 1Gb/s data wireless transmission with OTTD-MBS are studied.

  17. Mass-stiffness substructuring of an elastic metasurface for full transmission beam steering

    Science.gov (United States)

    Lee, Hyuk; Lee, Jun Kyu; Seung, Hong Min; Kim, Yoon Young

    2018-03-01

    The metasurface concept has a significant potential due to its novel wavefront-shaping functionalities that can be critically useful for ultrasonic and solid wave-based applications. To achieve the desired functionalities, elastic metasurfaces should cover full 2π phase shift and also acquire full transmission within subwavelength scale. However, they have not been explored much with respect to the elastic regime, because the intrinsic proportionality of mass-stiffness within the continuum elastic media causes an inevitable trade-off between abrupt phase shift and sufficient transmission. Our goal is to engineer an elastic metasurface that can realize an inverse relation between (amplified) effective mass and (weakened) stiffness in order to satisfy full 2π phase shift as well as full transmission. To achieve this goal, we propose a continuum elastic metasurface unit cell that is decomposed into two substructures, namely a mass-tuning substructure with a local dipolar resonator and a stiffness-tuning substructure composed of non-resonant multiply-perforated slits. We demonstrate analytically, numerically, and experimentally that this unique substructured unit cell can satisfy the required phase shift with high transmission. The substructuring enables independent tuning of the elastic properties over a wide range of values. We use a mass-spring model of the proposed continuum unit cell to investigate the working mechanism of the proposed metasurface. With the designed metasurface consisting of substructured unit cells embedded in an aluminum plate, we demonstrate that our metasurface can successfully realize anomalous steering and focusing of in-plane longitudinal ultrasonic beams. The proposed substructuring concept is expected to provide a new principle for the design of general elastic metasurfaces that can be used to efficiently engineer arbitrary wave profiles.

  18. Design of Vivaldi antenna array with end-fire beam steering function for 5G mobile terminals

    DEFF Research Database (Denmark)

    Ojaroudiparchin, Naser; Shen, Ming; Pedersen, Gert F.

    2015-01-01

    to form a linear phased array in the edge region (top-side) on a mobile phone PCB. The simulated results show that the antenna has the reflection coefficient (S11) less than -10 dB in the frequency range of 27.4 to 28.6 GHz. The proposed phased array antenna has good gain, efficiency, and 3D beam steering...... characteristics in the entire operation band, which makes it suitable for millimeter-wave 5G communications. In addition, the performance of the antenna in the vicinity of user’s hand has been investigated in this study....

  19. Individual addressing of trapped {sup 171}Yb{sup +} ion qubits using a microelectromechanical systems-based beam steering system

    Energy Technology Data Exchange (ETDEWEB)

    Crain, S.; Mount, E.; Baek, S.; Kim, J., E-mail: jungsang@duke.edu [Electrical and Computer Engineering Department, Fitzpatrick Institute for Photonics, Duke University, Durham, North Carolina 27708 (United States)

    2014-11-03

    The ability to individually manipulate the increasing number of qubits is one of the many challenges towards scalable quantum information processing with trapped ions. Using micro-mirrors fabricated with micro-electromechanical systems technology, we focus laser beams on individual ions in a linear chain and steer the focal point in two dimensions. We demonstrate sequential single qubit gates on multiple {sup 171}Yb{sup +} qubits and characterize the gate performance using quantum state tomography. Our system features negligible crosstalk to neighboring ions (<3×10{sup −4}), and switching speed comparable to typical single qubit gate times (<2 μs)

  20. Performance analysis for W-band antenna alignment using accurate mechanical beam steering

    DEFF Research Database (Denmark)

    Morales Vicente, Alvaro; Rodríguez Páez, Juan Sebastián; Gallardo, Omar

    2017-01-01

    This article presents a study of antenna alignment impact on bit error rate for a wireless link between two directive W-band horn antennas where one of them is mechanically steered by a Stewart platform. Such a technique is applied to find the optimal alignment between transmitter and receiver...... with an accuracy of 18 both in azimuth and elevation angles. The maximum degree of misalignment which can be tolerated is also reported for different values of optical power in the generation of W-band signals by photonic up-conversion. (C) 2017 Wiley Periodicals, Inc....

  1. Method of achieving ultra-wideband true-time-delay beam steering for active electronically scanned arrays

    Energy Technology Data Exchange (ETDEWEB)

    Loui, Hung; Brock, Billy C.

    2016-10-25

    The various embodiments presented herein relate to beam steering an array antenna by modifying intermediate frequency (IF) waveforms prior to conversion to RF signals. For each channel, a direct digital synthesis (DDS) component can be utilized to generate a waveform or modify amplitude, timing and phase of a waveform relative to another waveform, whereby the generation/modification can be performed prior to the IF input port of a mixer on each channel. A local oscillator (LO) signal can be utilized to commonly drive each of the mixers. After conversion at the RF output port of each of the mixers, each RF signal can be transmitted by a respective antenna element in the antenna array. Initiation of transmission of each RF signal can be performed simultaneously at each antenna. The process can be reversed during receive whereby timing, amplitude, and phase of the received can be modified digitally post ADC conversion.

  2. Beam steering application for W-band data links with moving targets in 5G wireless networks

    DEFF Research Database (Denmark)

    Morales Vicente, Alvaro; Rodríguez Páez, Juan Sebastián; Gallardo, Omar

    2017-01-01

    to this problem, RoF (Radio-over-Fiber) architectures have been proposed as low-latency, cost-effective candidates. Two elements are introduced to extend the RoF approach. First, the carrier frequency is raised into the W-band (75–110 GHz) to increase the available capacity. Second, a mechanical beam......-steering solution based on a Stewart platform is adopted for the transmitter antenna to allow it to follow a moving receiver along a known path, thereby enhancing the coverage area. The performance of a system transmitting a 2.5 Gbit/s non-return-to-zero signal generated by photonic up-conversion over a wireless...

  3. A broadband beam-steered fiber mm-wave link with high energy-spectral-spatial efficiency for 5G coverage

    NARCIS (Netherlands)

    Cao, Z.; Zhao, X.; Jiao, Y.; Deng, X.; Tessema, N.; Raz, O.; Koonen, A.M.J.

    2017-01-01

    Utilizing an integrated optical-tunable-delay-line, reversely-modulated single sideband modulation, and Nyquist subcarrier modulation, we demonstrate an 8 Gbps mm-wave beam steered link with a spatial-spectral efficiency of 16 bits/s/Hz.

  4. Near-Infrared and Optical Beam Steering and Frequency Splitting in Air-Holes-in-Silicon Inverse Photonic Crystals

    Science.gov (United States)

    2017-01-01

    We present the design of a dielectric inverse photonic crystal structure that couples line-defect waveguide propagating modes into highly directional beams of controllable directionality. The structure utilizes a triangular lattice made of air holes drilled in an infinitely thick Si slab, and it is designed for operation in the near-infrared and optical regime. The structure operation is based on the excitation and manipulation of dark dielectric surface states, in particular on the tailoring of the dark states’ coupling to outgoing radiation. This coupling is achieved with the use of properly designed external corrugations. The structure adapts and matches modes that travel through the photonic crystal and the free space. Moreover it facilitates the steering of the outgoing waves, is found to generate well-defined, spatially and spectrally isolated beams, and may serve as a frequency splitting component designed for operation in the near-infrared regime and in particular the telecom optical wavelength band. The design complies with the state-of-the-art Si nanofabrication technology and can be directly scaled for operation in the optical regime. PMID:29541653

  5. Acoustic beam steering by light refraction: illustration with directivity patterns of a tilted volume photoacoustic source.

    Science.gov (United States)

    Raetz, Samuel; Dehoux, Thomas; Perton, Mathieu; Audoin, Bertrand

    2013-12-01

    The symmetry of a thermoelastic source resulting from laser absorption can be broken when the direction of light propagation in an elastic half-space is inclined relatively to the surface. This leads to an asymmetry of the directivity patterns of both compressional and shear acoustic waves. In contrast to classical surface acoustic sources, the tunable volume source allows one to take advantage of the mode conversion at the surface to control the directivity of specific modes. Physical interpretations of the evolution of the directivity patterns with the increasing light angle of incidence and of the relations between the preferential directions of compressional- and shear-wave emission are proposed. In order to compare calculated directivity patterns with measurements of normal displacement amplitudes performed on plates, a procedure is proposed to transform the directivity patterns into pseudo-directivity patterns representative of the experimental conditions. The comparison of the theoretical with measured pseudo-directivity patterns demonstrates the ability to enhance bulk-wave amplitudes and to steer specific bulk acoustic modes by adequately tuning light refraction.

  6. Generation of Graphene Surface Plasmons and Their Applications in Beam Steering

    KAUST Repository

    Farhat, Mohamed; Chen, Pai Yen; Guenneau, Sebastien; Bagci, Hakan

    2015-01-01

    We propose a novel concept that uses mechanical and electronic properties of graphene to efficiently couple light to surface plasmon polaritons. A graphene-based infrared beam-former based on the concept of surface leaky-wave is also discussed

  7. Generation of Graphene Surface Plasmons and Their Applications in Beam Steering

    KAUST Repository

    Farhat, Mohamed

    2015-01-01

    We propose a novel concept that uses mechanical and electronic properties of graphene to efficiently couple light to surface plasmon polaritons. A graphene-based infrared beam-former based on the concept of surface leaky-wave is also discussed. © OSA 2015.

  8. Two-dimensional analytic modeling of acoustic diffraction for ultrasonic beam steering by phased array transducers.

    Science.gov (United States)

    Wang, Tiansi; Zhang, Chong; Aleksov, Aleksandar; Salama, Islam; Kar, Aravinda

    2017-04-01

    Phased array ultrasonic transducers enable modulating the focal position of the acoustic waves, and this capability is utilized in many applications, such as medical imaging and non-destructive testing. This type of transducers also provides a mechanism to generate tilted wavefronts in acousto-optic deflectors to deflect laser beams for high precision advanced laser material processing. In this paper, a theoretical model is presented for the diffraction of ultrasonic waves emitted by several phased array transducers into an acousto-optic medium such as TeO 2 crystal. A simple analytic expression is obtained for the distribution of the ultrasonic displacement field in the crystal. The model prediction is found to be in good agreement with the results of a numerical model that is based on a non-paraxial multi-Gaussian beam (NMGB) model. Published by Elsevier B.V.

  9. Infrared beam-steering using acoustically modulated surface plasmons over a graphene monolayer

    KAUST Repository

    Chen, Paiyen

    2014-09-01

    We model and design a graphene-based infrared beamformer based on the concept of leaky-wave (fast traveling wave) antennas. The excitation of infrared surface plasmon polaritons (SPPs) over a \\'one-atom-thick\\' graphene monolayer is typically associated with intrinsically \\'slow light\\'. By modulating the graphene with elastic vibrations based on flexural waves, a dynamic diffraction grating can be formed on the graphene surface, converting propagating SPPs into fast surface waves, able to radiate directive infrared beams into the background medium. This scheme allows fast on-off switching of infrared emission and dynamic tuning of its radiation pattern, beam angle and frequency of operation, by simply varying the acoustic frequency that controls the effective grating period. We envision that this graphene beamformer may be integrated into reconfigurable transmitter/receiver modules, switches and detectors for THz and infrared wireless communication, sensing, imaging and actuation systems.

  10. Quantum steering in cascaded four-wave mixing processes.

    Science.gov (United States)

    Wang, Li; Lv, Shuchao; Jing, Jietai

    2017-07-24

    Quantum steering is used to describe the "spooky action-at-a-distance" nonlocality raised in the Einstein-Podolsky-Rosen (EPR) paradox, which is important for understanding entanglement distribution and constructing quantum networks. Here, in this paper, we study an experimentally feasible scheme for generating quantum steering based on cascaded four-wave-mixing (FWM) processes in hot rubidium (Rb) vapor. Quantum steering, including bipartite steering and genuine tripartite steering among the output light fields, is theoretically analyzed. We find the corresponding gain regions in which the bipartite and tripartite steering exist. The results of bipartite steering can be used to establish a hierarchical steering model in which one beam can steer the other two beams in the whole gain region; however, the other two beams cannot steer the first beam simultaneously. Moreover, the other two beams cannot steer with each other in the whole gain region. More importantly, we investigate the gain dependence of the existence of the genuine tripartite steering and we find that the genuine tripartite steering exists in most of the whole gain region in the ideal case. Also we discuss the effect of losses on the genuine tripartite steering. Our results pave the way to experimental demonstration of quantum steering in cascaded FWM process.

  11. Steering handbook

    CERN Document Server

    Pfeffer, Peter

    2017-01-01

    This edited volume presents basic principles as well as advanced concepts of the computational modeling of steering systems. Moreover, the book includes the components and functionalities of modern steering system, which are presented comprehensively and in a practical way. The book is written by more than 15 leading experts from the automotive industry and its components suppliers. The target audience primarily comprises practicing engineers, developers, researchers as well as graduate students who want to specialize in this field.

  12. Overnight non-contact continuous vital signs monitoring using an intelligent automatic beam-steering Doppler sensor at 2.4 GHz.

    Science.gov (United States)

    Batchu, S; Narasimhachar, H; Mayeda, J C; Hall, T; Lopez, J; Nguyen, T; Banister, R E; Lie, D Y C

    2017-07-01

    Doppler-based non-contact vital signs (NCVS) sensors can monitor heart rates, respiration rates, and motions of patients without physically touching them. We have developed a novel single-board Doppler-based phased-array antenna NCVS biosensor system that can perform robust overnight continuous NCVS monitoring with intelligent automatic subject tracking and optimal beam steering algorithms. Our NCVS sensor achieved overnight continuous vital signs monitoring with an impressive heart-rate monitoring accuracy of over 94% (i.e., within ±5 Beats-Per-Minute vs. a reference sensor), analyzed from over 400,000 data points collected during each overnight monitoring period of ~ 6 hours at a distance of 1.75 meters. The data suggests our intelligent phased-array NCVS sensor can be very attractive for continuous monitoring of low-acuity patients.

  13. Bi-directional 35-Gbit/s 2D beam steered optical wireless downlink and 5-Gbit/s localized 60-GHz communication uplink for hybrid indoor wireless systems

    NARCIS (Netherlands)

    Khalid, A.M.; Baltus, P.G.M.; Dommele, A.R.; Mekonnen, K.A.; Cao, Z.; Oh, C.W.; Matters, M.K.; Koonen, A.M.J.

    2017-01-01

    We present a full-duplex dynamic indoor optical wireless system using 2D passive optical beam steering for downlink and 60-GHz communication for upstream transmission. We demonstrate 35-Gb/s NRZ-OOK downstream multicasting and 5-Gb/s NRZ-ASK upstream communication.

  14. Implementation of a Novel Low-Cost Low-Profile Ku-Band Antenna Array for Single Beam Steering from Space

    Science.gov (United States)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranda, Felix A.

    2013-01-01

    Phased array antennas afford many advantages over traditional reflector antennas due to their conformality, high aperture efficiency, and unfettered beam steering capability at the price of increased cost and complexity. This paper eliminates the complex and costly array backend via the implementation of a series fed array employing a propagation constant reconfigurable transmission line connecting each element in series. Scanning can then be accomplished through one small (less than or equal to 100mil) linear motion that controls propagation constant. Specifically, each element is fed via a reconfigurable coplanar stripline transmission line with a tapered dielectric insert positioned between the transmission line traces. The dielectric insert is allowed to move up and down to control propagation constant and therefore induce scanning. We present a 20 element patch array design, scanning from -25 deg. less than or equal to theta less than or equal to 21 deg. at 13GHz. Measurements achieve only10.5 deg. less than or equal to theta less than or equal to 22 deg. scanning due to a faulty, yet correctable, manufacturing process. Beam squint is measured to be plus or minus 3 deg. for a 600MHz bandwidth. This prototype was improved to give scanning of 3.5 deg. less than or equal to theta less than or equal to 22 deg. Cross-pol patterns were shown to be -15dB below the main beam. Simulations accounting for fabrication errors match measured patterns, thus validating the designs.

  15. The beam steering system of the cyclotron U-120K; Sistema razvodki puchkov tsiklotrona U-120K

    Energy Technology Data Exchange (ETDEWEB)

    Borkova, A; Ivan, J; Trejbal, Z; Dmitrievskij, V P; Pavlov, D V; Chesnov, A F; Chesnova, S I

    1991-12-31

    The calculation of the beam transport system of the isochronous cyclotron U-120K is presented. This system realizes the beam transport with given parameters to six distant targets specializing in the production of radioactive isotopes, the biomedicine investigation, the experimental nuclear physics. At chosen parameters of lenses and bending magnets the beam size is {<=} 1x1 cm and the energy resolution in the monoenergetic line is less than 0.1%. 4 refs.; 6 figs.; 1 tab.

  16. Mechanical 144 GHz beam steering with all-metallic epsilon-near-zero lens antenna

    International Nuclear Information System (INIS)

    Pacheco-Peña, V.; Torres, V.; Orazbayev, B.; Beruete, M.; Sorolla, M.; Navarro-Cía, M.; Engheta, N.

    2014-01-01

    An all-metallic steerable beam antenna composed of an ε-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144 GHz (λ 0  = 2.083 mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides working just near and above the cut-off of the TE 10 mode. The lens focal arc on the xz-plane is initially estimated analytically as well as numerically and compared with experimental results demonstrating good agreement. Next, a flange-ended WR-6.5 waveguide is placed along the lens focal arc to evaluate the ENZ-lens antenna steerability. A gain scan loss below 3 dB is achieved for angles up to ±15°

  17. Steering straight

    Energy Technology Data Exchange (ETDEWEB)

    Louie, Jacqueline

    2011-12-15

    Baker Hughes Inc. has developed a deep azimuthal resistivity measurement tool for subsurface navigation when drilling oil and gas wells. This tool, named AziTrak, has measurement-while-drilling and logging-while-drilling capabilities and data are sent in real time to the surface via mud pulse or wired pipe telemetry. This technology helps the operator detect and visualize bed boundaries in real time, thanks to 3D imagery and a 360 degree view of the subsurface. The AziTrak system makes it possible to steer proactively and to stay within the pay zone at all times to maximize production; the tool had excellent results in field applications. Although this tool is 5 times more expensive than conventional technologies, its use results in a more economic wellbore thanks to its great utility. If the operator puts a high degree of involvement into it, the AziTrak deep azimuthal resistivity measurement tool will allow him to stay in the pay zone at all times.

  18. Multipass Steering: A Reference Implementation

    Science.gov (United States)

    Hennessey, Michael; Tiefenback, Michael

    2015-10-01

    We introduce a reference implementation of a protocol to compute corrections that bring all beams in one of the CEBAF linear accelerators (linac) to axis, including, with a larger tolerance, the lowest energy pass using measured beam trajectory data. This method relies on linear optics as representation of the system; we treat beamline perturbations as magnetic field errors localized to regions between cryomodules, providing the same transverse momentum kick to each beam. We produce a vector of measured beam position data with which we left-multiply the pseudo-inverse of a coefficient array, A, that describes the transport of the beam through the linac using parameters that include the magnetic offsets of the quadrupole magnets, the instrumental offsets of the BPMs, and the beam initial conditions. This process is repeated using a reduced array to produce values that can be applied to the available correcting magnets and beam initial conditions. We show that this method is effective in steering the beam to a straight axis along the linac by using our values in elegant, the accelerator simulation program, on a model of the linac in question. The algorithms in this reference implementation provide a tool for systematic diagnosis and cataloging of perturbations in the beam line. Supported by Jefferson Lab, Old Dominion University, NSF, DOE.

  19. Steering smog prediction

    NARCIS (Netherlands)

    R. van Liere (Robert); J.J. van Wijk (Jack)

    1997-01-01

    textabstractThe use of computational steering for smog prediction is described. This application is representative for many underlying issues found in steering high performance applications: high computing times, large data sets, and many different input parameters. After a short description of the

  20. Steering and evasion assist

    NARCIS (Netherlands)

    Dang, T.; Desens, J.; Franke, U.; Gavrila, D.; Schäfers, L.; Ziegler, W.; Eskandarian, A.

    2012-01-01

    Steering and evasion assistance defines a new and future class of driver assistance systems to avoid an impending collision with other traffic participants. Dynamic and kinematic considerations reveal that an evasive steering maneuver has high potential for collision avoidance in many driving

  1. Experimental temporal quantum steering

    Czech Academy of Sciences Publication Activity Database

    Bartkiewicz, K.; Černoch, Antonín; Lemr, K.; Miranowicz, A.; Nori, F.

    2016-01-01

    Roč. 6, Nov (2016), 1-8, č. článku 38076. ISSN 2045-2322 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : temporal quantum steering * EPR steering Subject RIV: BH - Optics, Masers, Lasers Impact factor: 4.259, year: 2016

  2. A Frictionless Steering Mechanism for the Front Steering ECCD ITER Upper Port Launcher

    International Nuclear Information System (INIS)

    Chavan, R; Henderson, M A; Sanchez, F

    2005-01-01

    A FS launcher is being designed for the ITER upper port, which offers enhanced physics performance over the RS launcher. A two mirror system is used to decouple the focusing and steering aspects of the launcher and provide a relatively small beam waist ( 1.6 m from the steering mirror). The resulting NTM stabilization efficiency (maximum CD density divided by the local bootstrap current >1.6) is above marginal for the q = 2 and 3/2 rational flux surfaces of the relevant ITER equilibria (scenarios 2, 3a and 5) and a factor of ∼3 relative to an equivalent RS launcher. The performance of the FS launcher strongly depends on the reliability of the steering mechanism, which is used to rotate the plasma facing steering mirror. CRPP has designed a frictionless steering mechanism assembled in a compact cartridge capable of up to ±10 deg. rotation (corresponding to a poloidal steering range of up to ±20 deg. for the microwave beam around a fixed axis of rotation) that offers a high operation reliability despite the close proximity to the thermal and neutron flux coming from the ITER plasma

  3. Vehicle steering by side stick: optimising steering characteristics

    NARCIS (Netherlands)

    Zuurbier, J.; Hogema, J.H.; Brekelmans, J.A.W.J.

    2000-01-01

    This paper describes a study that was conducted to investigate the possibilities for optimizing task performance when driving a side stick-steered vehicle. Using steer-by-wire technology, a conventional steering system was mimicked, thus yielding the possibility to modify the steering

  4. Fermilab Steering Group Report

    Energy Technology Data Exchange (ETDEWEB)

    Beier, Eugene; /Pennsylvania U.; Butler, Joel; /Fermilab; Dawson, Sally; /Brookhaven; Edwards, Helen; /Fermilab; Himel, Thomas; /SLAC; Holmes, Stephen; /Fermilab; Kim, Young-Kee; /Fermilab /Chicago U.; Lankford, Andrew; /UC, Irvine; McGinnis, David; /Fermilab; Nagaitsev, Sergei; /Fermilab; Raubenheimer, Tor; /SLAC /Fermilab

    2007-01-01

    The Fermilab Steering Group has developed a plan to keep U.S. accelerator-based particle physics on the pathway to discovery, both at the Terascale with the LHC and the ILC and in the domain of neutrinos and precision physics with a high-intensity accelerator. The plan puts discovering Terascale physics with the LHC and the ILC as Fermilab's highest priority. While supporting ILC development, the plan creates opportunities for exciting science at the intensity frontier. If the ILC remains near the Global Design Effort's technically driven timeline, Fermilab would continue neutrino science with the NOVA experiment, using the NuMI (Neutrinos at the Main Injector) proton plan, scheduled to begin operating in 2011. If ILC construction must wait somewhat longer, Fermilab's plan proposes SNuMI, an upgrade of NuMI to create a more powerful neutrino beam. If the ILC start is postponed significantly, a central feature of the proposed Fermilab plan calls for building an intense proton facility, Project X, consisting of a linear accelerator with the currently planned characteristics of the ILC combined with Fermilab's existing Recycler Ring and the Main Injector accelerator. The major component of Project X is the linac. Cryomodules, radio-frequency distribution, cryogenics and instrumentation for the linac are the same as or similar to those used in the ILC at a scale of about one percent of a full ILC linac. Project X's intense proton beams would open a path to discovery in neutrino science and in precision physics with charged leptons and quarks. World-leading experiments would allow physicists to address key questions of the Quantum Universe: How did the universe come to be? Are there undiscovered principles of nature: new symmetries, new physical laws? Do all the particles and forces become one? What happened to the antimatter? Building Project X's ILC-like linac would offer substantial support for ILC development by accelerating the

  5. Operational experience with model-based steering in the SLC linac

    International Nuclear Information System (INIS)

    Thompson, K.A.; Himel, T.; Moore, S.; Sanchez-Chopitea, L.; Shoaee, H.

    1989-03-01

    Operational experience with model-driven steering in the linac of the Stanford Linear Collider is discussed. Important issues include two-beam steering, sensitivity of algorithms to faulty components, sources of disagreement with the model, and the effects of the finite resolution of beam position monitors. Methods developed to make the steering algorithms more robust in the presence of such complications are also presented. 5 refs., 1 fig

  6. Charge steering of laser plasma accelerated fast ions in a liquid spray — creation of MeV negative ion and neutral atom beams

    International Nuclear Information System (INIS)

    Schnürer, M.; Abicht, F.; Priebe, G.; Braenzel, J.; Prasad, R.; Borghesi, M.; Andreev, A.; Nickles, P. V.; Jequier, S.; Tikhonchuk, V.; Ter-Avetisyan, S.

    2013-01-01

    The scenario of “electron capture and loss” has been recently proposed for the formation of negative ion and neutral atom beams with up to MeV kinetic energy [S. Ter-Avetisyan, et al., Appl. Phys. Lett. 99, 051501 (2011)]. Validation of these processes and of their generic nature is here provided in experiments where the ion source and the interaction medium have been spatially separated. Fast positive ions accelerated from a laser plasma source are sent through a cold spray where their charge is changed. Such formed neutral atom or negative ion has nearly the same momentum as the original positive ion. Experiments are released for protons, carbon, and oxygen ions and corresponding beams of negative ions and neutral atoms have been obtained. The electron capture and loss phenomenon is confirmed to be the origin of the negative ion and neutral atom beams. The equilibrium ratios of different charge components and cross sections have been measured. Our method is general and allows the creation of beams of neutral atoms and negative ions for different species which inherit the characteristics of the positive ion source

  7. One-way EPR steering and genuine multipartite EPR steering

    Science.gov (United States)

    He, Qiongyi; Reid, Margaret D.

    2012-11-01

    We propose criteria and experimental strategies to realise the Einstein-Podolsky-Rosen (EPR) steering nonlocality. One-way steering can be obtained where there is asymmetry of thermal noise on each system. We also present EPR steering inequalities that act as signatures and suggest how to optimise EPR correlations in specific schemes so that the genuine multipartite EPR steering nonlocality (EPR paradox) can also possibly be realised. The results presented here also apply to the spatially separated macroscopic atomic ensembles.

  8. Fundamental X-mode electron cyclotron current drive using remote-steering symmetric direction antenna at larger steering angles

    International Nuclear Information System (INIS)

    Idei, H.; Hanada, K.; Zushi, H.; Sato, K.N.; Sakamoto, M.; Iyomasa, A.; Kawasaki, S.; Nakashima, H.; Higashijima, A.; Ohkubo, K.; Kubo, S.; Shimozuma, T.; Ito, S.; Hasegawa, M.; Nakamura, K.; Notake, T.; Hoshika, H.; Maezono, N.; Nishi, S.; Nakashima, K.

    2005-01-01

    A remote steering antenna has been newly developed for Electron Cyclotron Heating and Current Drive (ECH/ECCD) experiments on the TRIAM-1M tokamak. It is a first application of the remote steering antenna to the ECH/ECCD experiments under the conditions relevant to International Thermonuclear Experimental Reactor. Our launcher is a symmetric direction antenna with extended steering capability. The larger steering angles of 8-19 degrees are available, in addition to that near 0 degree. The output beam from the antenna is the well-defined Gaussian beam with a correct steering angle. The Gaussian content and the steering angle accuracy are 0.85 and -0.3 degrees, respectively. Antenna transmission efficiency in the high power test is evaluated as 0.95. The efficiencies at the low and high power tests are consistent with those in the calculation with higher-order modes. The difference between plasma currents increased at co- and counter-steering injections [+/-19 degrees] is clearly observed in the superposition to the Lower Hybrid Current Driven (LHCD) plasma of the fundamental X-mode injection. (author)

  9. Methodologies for steering clocks

    Science.gov (United States)

    Chadsey, Harold

    1995-01-01

    One of the concerns of the PTTI community is the coordination of one time scale with another. This is accomplished through steering one clock system to another, with a goal of a zero or constant offset in time and frequency. In order to attain this goal, rate differences are calculated and allowed for by the steering algorithm. This paper will present several of these different methods of determining rate differences. Ideally, any change in rate should not cause the offset to change sign (overshoot) by any amount, but certainly not by as much as its previous absolute value. The advantages and disadvantages of each depend on the user's situation.

  10. Steering Your Mysterious Mind

    DEFF Research Database (Denmark)

    Prasad, Ramjee

    Steering the Mysterious Mind, describes a unique, novel concept for a way to gain control of your mind. The five basic elements of human life, that is; Creativity, Content­ment, Confidence, Calmness, and Concentration (C5) have been introduced in my previous book Unlock Your Personalization. Posi....... Compare it with going to the gym where you work on the physical body. In the same way as with arms and legs, the mind is a mus­cle which you exercise through C5 practice. Steering the mind on your personal goal will help you to be creative....

  11. 49 CFR 570.7 - Steering systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Steering systems. 570.7 Section 570.7... Pounds or Less § 570.7 Steering systems. (a) System play. Lash or free play in the steering system shall... in the steering system. Table 1—Steering System Free Play Values Steering wheel diameter (inches...

  12. Progress on the ITER H&CD EC upper launcher steering-mirror control system

    NARCIS (Netherlands)

    Collazos, A.; Bertizzolo, R.; Chavan, R.; Dolizy, F.; Felici, F.; Goodman, T.P.; Henderson, M.A.; Landis, J.-D.; Sanchez, F.

    2010-01-01

    The ITER Heating and Current Drive Upper Launcher (H&CD EC UL) uses a pneumomechanical steering-mirror assembly (SMA) to steer the RF beams for their deposition in the appropriate location in the plasma to control magnetohydrodynamic activity (neoclassical tearing modes (NTMs) and sawtooth

  13. Optimization of steering elements in the RIA driver linac

    International Nuclear Information System (INIS)

    Lessner, E. S.; Aseev, V. S.; Ostroumov, P. N.; Physics

    2005-01-01

    The driver linac of the projected RIA facility is a versatile accelerator, a 1.4-GV, CW superconducting (SC) linac designed to simultaneously accelerate several heavy-ion charge states, providing beams from proton to uranium at 400 MeV/u at power levels at a minimum of 100 kW and up to 400 kW for most beams. Acceleration of multiple-charge-state uranium beams places stringent requirements on the linac design. A steering algorithm was derived that fulfilled the driver's real estate requirements, such as placement of steering dipole coils on SC solenoids and of beam position monitors outside cryostats, and beam-dynamics requirements, such as coupling effects induced by the focusing solenoids. The algorithm has been fully integrated into the tracking code TRACK and it is used to study and optimize the number and position of steering elements that minimize the multiple-beam centroid oscillations and preserve the beam emittance under misalignments of accelerating and transverse focusing elements in the driver linac

  14. Acousto-Optic Beam Steering Study

    Science.gov (United States)

    1994-08-01

    S25 2.500000 PRIVATE CATALOG PWL 830.00 ’THIN’ 1.010000 PWL 830.00 ’ TEO2 ’ 2.200000 REFRACTIVE INDICES GLASS CODE 830.00 SF57 SCHOTT 1.821707 SF11...10.000000 PRIVATE CATALOG PWL 830.00 ’ TEO2 ’ 2.200000 REFRACT IVE :NDICES GLASS CODE 830.00 BK7 SCHCTT 1.510206 ’ TEO2 ’ 2.200000 39 Table 4.2.2-3. Mid...4.1-2 Acoustic Material Figure-of-Merit Trade 11 4.1-3 Degenerate Response in On-Axis TeO 2 12 4. 1-4 Rotated AO Interaction in TeO2 : High-Band Mode 13

  15. Steering Maps and Their Application to Dimension-Bounded Steering

    Science.gov (United States)

    Moroder, Tobias; Gittsovich, Oleg; Huber, Marcus; Uola, Roope; Gühne, Otfried

    2016-03-01

    The existence of quantum correlations that allow one party to steer the quantum state of another party is a counterintuitive quantum effect that was described at the beginning of the past century. Steering occurs if entanglement can be proven even though the description of the measurements on one party is not known, while the other side is characterized. We introduce the concept of steering maps, which allow us to unlock sophisticated techniques that were developed in regular entanglement detection and to use them for certifying steerability. As an application, we show that this allows us to go beyond even the canonical steering scenario; it enables a generalized dimension-bounded steering where one only assumes the Hilbert space dimension on the characterized side, with no description of the measurements. Surprisingly, this does not weaken the detection strength of very symmetric scenarios that have recently been carried out in experiments.

  16. Design of X-Y steering magnet for extraction beamline of K-500 superconducting cyclotron

    International Nuclear Information System (INIS)

    Naser, Md. Zamal A.; Paul, S.; Bhunia, U.; Pradhan, J.; Dey, M.K.; Nandi, C.; Mallik, C.; Bhandari, R.K.

    2005-01-01

    The K-500 Superconducting Cyclotron is in the advanced stage of commissioning at VEC Centre, Kolkata. This accelerator is designed to accelerate up to maximum 80 MeV/nucleon energy. A X-Y steering magnet is essential to guide this high energy beam into the external high energy beam line. This paper describes the designing and the other related necessary aspects of such a steering magnet. (author)

  17. STEER Coastal Use Mapping Project

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Coastal Use Mapping Project is designed to collect critical information on human activities in and near the St. Thomas East End Reserves (STEER). The project...

  18. Advanced Optics for the Remote Steering ITER ECRH Upper Launcher

    International Nuclear Information System (INIS)

    Bruschi, A; Cirant, S; Moro, A; Platania, P; Sozzi, C

    2005-01-01

    The optics of the ECRH Upper Launcher in ITER based on the Remote Steering concept needs special attention, since any focussing element in front of the waveguide has combined effects on the range of steering angles achievable and the beam width in the plasma region. The effects are studied in detail for a setup composed by 8 beams per port (three ports), for a spherical and a hyperbolic mirror surface. Gaussian beam analysis is compared to beam pattern calculations with the optical physics code GRASP, in order to verify the validity of gaussian optics approximation. The standard description with simply astigmatic beams, not adequate in more complex systems as the proposed two-mirror set-up, requires approximations, which are compared with the generalized astigmatic beam description. The ohmic losses at the end mirrors and the related localized heating due to the very large power density cause deformations that depends on the design of the cooling circuit. The distortion of the beam shape has been evaluated in a realistic case of mirror cooling with a small-channel system. The quantification of the effect depends on the precise evaluation ohmic losses and their enhancement in the long term due to the surface deterioration

  19. Use beam steering dipoles to minimize aberrations associated with off-centered transit through the induction bunching module. Design an improved NDCX-I drift compression section to make best use of the new bunching module to optimize planned initial NDCX-I target experiments

    International Nuclear Information System (INIS)

    HIFS-VNL; Seidl, Peter; Seidl, P.; Barnard, J.; Bieniosek, F.; Coleman, J.; Grote, D.; Leitner, M.; Gilson, E.; Logan, B.G.; Lund, S.; Lidia, S.; Ni, P.; Ogata, D.; Roy, P.; Waldron, W.; Welch, D.; Wooton, C.

    2008-01-01

    This milestone has been met by: (1) calculating steering solutions and implementing them in the experiment using the three pairs of crossed magnetic dipoles installed in between the matching solenoids, S1-S4. We have demonstrated the ability to center the beam position and angle to < 1 mm and < 1 mrad upstream of the induction bunching module (IBM) gap, compared to uncorrected beam offsets of several millimeters and milli-radians. (2) Based on LSP and analytic study, the new IBM, which has twice the volt-seconds of our first IBM, should be accompanied by a longer drift compression section in order to achieve a predicted doubling of the energy deposition on future warm-dense matter targets. This will be accomplished by constructing a longer ferro-electric plasma source. (3) Because the bunched current is a function of the longitudinal phase space and emittance of the beam entering the IBM we have characterized the longitudinal phase space with a high-resolution energy analyzer

  20. Bulling among yearling feedlot steers.

    Science.gov (United States)

    Pierson, R E; Jensen, R; Braddy, P M; Horton, D P; Christie, R M

    1976-09-01

    In a survey to determine the cause of illness and deaths among yearling feedlot cattle, bulling was found to be one of the major problems. During the years 1971-1974, 54,913 (2.88%) steers became bullers and represented an annual loss of around +325,000. Some of the causes of bulling were found to be hormones, either as implants or in the feed. In 1974, from 1,988 necropsies, it was determined that 83 steers died from riding injuries.

  1. Driver steering model for closed-loop steering function analysis

    Science.gov (United States)

    Bolia, Pratiksh; Weiskircher, Thomas; Müller, Steffen

    2014-05-01

    In this paper, a two level preview driver steering control model for the use in numerical vehicle dynamics simulation is introduced. The proposed model is composed of cascaded control loops: The outer loop is the path following layer based on potential field framework. The inner loop tries to capture the driver's physical behaviour. The proposed driver model allows easy implementation of different driving situations to simulate a wide range of different driver types, moods and vehicle types. The expediency of the proposed driver model is shown with the help of developed driver steering assist (DSA) function integrated with a conventional series production (Electric Power steering System with rack assist servo unit) system. With the help of the DSA assist function, the driver is prevented from over saturating the front tyre forces and loss of stability and controllability during cornering. The simulation results show different driver reactions caused by the change in the parameters or properties of the proposed driver model if the DSA assist function is activated. Thus, the proposed driver model is useful for the advanced driver steering and vehicle stability assist function evaluation in the early stage of vehicle dynamics handling and stability evaluation.

  2. 46 CFR 176.814 - Steering systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering systems. 176.814 Section 176.814 Shipping COAST...) INSPECTION AND CERTIFICATION Material Inspections § 176.814 Steering systems. At each initial and subsequent inspection for certification the owner or managing operator shall be prepared to test the steering systems of...

  3. Demand side management using profile steering

    NARCIS (Netherlands)

    Gerards, Marco Egbertus Theodorus; Toersche, Hermen; Hoogsteen, Gerwin; van der Klauw, Thijs; Hurink, Johann L.; Smit, Gerardus Johannes Maria

    2015-01-01

    Many Demand Side Management (DSM) approaches use energy prices as steering signals. This paper shows that such steering signals may result in power quality problems and high losses. As an alternative, this paper proposes to use desired (e.g., flat) power profiles as steering signals and presents an

  4. Experimental verification of multidimensional quantum steering

    Science.gov (United States)

    Li, Che-Ming; Lo, Hsin-Pin; Chen, Liang-Yu; Yabushita, Atsushi

    2018-03-01

    Quantum steering enables one party to communicate with another remote party even if the sender is untrusted. Such characteristics of quantum systems not only provide direct applications to quantum information science, but are also conceptually important for distinguishing between quantum and classical resources. While concrete illustrations of steering have been shown in several experiments, quantum steering has not been certified for higher dimensional systems. Here, we introduce a simple method to experimentally certify two different kinds of quantum steering: Einstein-Podolsky-Rosen (EPR) steering and single-system (SS) steering (i.e., temporal steering), for dimensionality (d) up to d = 16. The former reveals the steerability among bipartite systems, whereas the latter manifests itself in single quantum objects. We use multidimensional steering witnesses to verify EPR steering of polarization-entangled pairs and SS steering of single photons. The ratios between the measured witnesses and the maximum values achieved by classical mimicries are observed to increase with d for both EPR and SS steering. The designed scenario offers a new method to study further the genuine multipartite steering of large dimensionality and potential uses in quantum information processing.

  5. Method to evaluate steering and alignment algorithms for controlling emittance growth

    International Nuclear Information System (INIS)

    Adolphsen, C.; Raubenheimer, T.

    1993-04-01

    Future linear colliders will likely use sophisticated beam-based alignment and/or steering algorithms to control the growth of the beam emittance in the linac. In this paper, a mathematical framework is presented which simplifies the evaluation of the effectiveness of these algorithms. As an application, a quad alignment that uses beam data taken with the nominal linac optics, and with a scaled optics, is evaluated in terms of the dispersive emittance growth remaining after alignment

  6. Beam director design report

    International Nuclear Information System (INIS)

    Younger, F.C.

    1986-08-01

    A design and fabrication effort for a beam director is documented. The conceptual design provides for the beam to pass first through a bending and focusing system (or ''achromat''), through a second achromat, through an air-to-vacuum interface (the ''beam window''), and finally through the vernier steering system. Following an initial concept study for a beam director, a prototype permanent magnet 30 0 beam-bending achromat and prototype vernier steering magnet were designed and built. In volume II, copies are included of the funding instruments, requests for quotations, purchase orders, a complete set of as-built drawings, magnetic measurement reports, the concept design report, and the final report on the design and fabrication project

  7. Multiobjective optimization of a steering linkage

    Energy Technology Data Exchange (ETDEWEB)

    Sleesonsom, S.; Bureerat, S. [Sustainable and Infrastructure Research and Development Center, Dept. of Mechanical Engineering, Faculty of Engineering, Khon Kaen University, Khon Kaen (Thailand)

    2016-08-15

    In this paper, multi-objective optimization of a rack-and-pinion steering linkage is proposed. This steering linkage is a common mechanism used in small cars with three advantages as it is simple to construct, economical to manufacture, and compact and easy to operate. In the previous works, many researchers tried to minimize a steering error but minimization of a turning radius is somewhat ignored. As a result, a multi-objective optimization problem is assigned to simultaneously minimize a steering error and a turning radius. The design variables are linkage dimensions. The design problem is solved by the hybrid of multi-objective population-based incremental learning and differential evolution with various constraint handling schemes. The new design strategy leads to effective design of rack-and-pinion steering linkages satisfying both steering error and turning radius criteria.

  8. Multiobjective optimization of a steering linkage

    International Nuclear Information System (INIS)

    Sleesonsom, S.; Bureerat, S.

    2016-01-01

    In this paper, multi-objective optimization of a rack-and-pinion steering linkage is proposed. This steering linkage is a common mechanism used in small cars with three advantages as it is simple to construct, economical to manufacture, and compact and easy to operate. In the previous works, many researchers tried to minimize a steering error but minimization of a turning radius is somewhat ignored. As a result, a multi-objective optimization problem is assigned to simultaneously minimize a steering error and a turning radius. The design variables are linkage dimensions. The design problem is solved by the hybrid of multi-objective population-based incremental learning and differential evolution with various constraint handling schemes. The new design strategy leads to effective design of rack-and-pinion steering linkages satisfying both steering error and turning radius criteria

  9. 46 CFR 108.641 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary steering...

  10. 46 CFR 182.610 - Main steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Main steering gear. 182.610 Section 182.610 Shipping...) MACHINERY INSTALLATION Steering Systems § 182.610 Main steering gear. (a) A vessel must be provided with a main steering gear that is: (1) Of adequate strength and capable of steering the vessel at all service...

  11. Driver behavior following an automatic steering intervention.

    Science.gov (United States)

    Fricke, Nicola; Griesche, Stefan; Schieben, Anna; Hesse, Tobias; Baumann, Martin

    2015-10-01

    The study investigated driver behavior toward an automatic steering intervention of a collision mitigation system. Forty participants were tested in a driving simulator and confronted with an inevitable collision. They performed a naïve drive and afterwards a repeated exposure in which they were told to hold the steering wheel loosely. In a third drive they experienced a false alarm situation. Data on driving behavior, i.e. steering and braking behavior as well as subjective data was assessed in the scenarios. Results showed that most participants held on to the steering wheel strongly or counter-steered during the system intervention during the first encounter. Moreover, subjective data collected after the first drive showed that the majority of drivers was not aware of the system intervention. Data from the repeated drive in which participants were instructed to hold the steering wheel loosely, led to significantly more participants holding the steering wheel loosely and thus complying with the instruction. This study seems to imply that without knowledge and information of the system about an upcoming intervention, the most prevalent driving behavior is a strong reaction with the steering wheel similar to an automatic steering reflex which decreases the system's effectiveness. Results of the second drive show some potential for countermeasures, such as informing drivers shortly before a system intervention in order to prevent inhibiting reactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. On Electrohydraulic Pressure Control for Power Steering Applications : Active Steering for Road Vehicles

    OpenAIRE

    Dell'Amico, Alessandro

    2016-01-01

    This thesis deals with the Electrohydraulic Power Steering system for road vehicles, using electronic pressure control valves. With an ever increasing demand for safer vehicles and fewer traffic accidents, steering-related active safety functions are becoming more common in modern vehicles. Future road vehicles will also evolve towards autonomous vehicles, with several safety, environmental and financial benefits. A key component in realising such solutions is active steering. The power steer...

  13. Beam Techniques - Beam Control and Manipulation

    International Nuclear Information System (INIS)

    Minty, Michiko G

    2003-01-01

    We describe commonly used strategies for the control of charged particle beams and the manipulation of their properties. Emphasis is placed on relativistic beams in linear accelerators and storage rings. After a brief review of linear optics, we discuss basic and advanced beam control techniques, such as transverse and longitudinal lattice diagnostics, matching, orbit correction and steering, beam-based alignment, and linac emittance preservation. A variety of methods for the manipulation of particle beam properties are also presented, for instance, bunch length and energy compression, bunch rotation, changes to the damping partition number, and beam collimation. The different procedures are illustrated by examples from various accelerators. Special topics include injection and extraction methods, beam cooling, spin transport and polarization

  14. Beam Techniques - Beam Control and Manipulation

    Energy Technology Data Exchange (ETDEWEB)

    Minty, Michiko G

    2003-04-24

    We describe commonly used strategies for the control of charged particle beams and the manipulation of their properties. Emphasis is placed on relativistic beams in linear accelerators and storage rings. After a brief review of linear optics, we discuss basic and advanced beam control techniques, such as transverse and longitudinal lattice diagnostics, matching, orbit correction and steering, beam-based alignment, and linac emittance preservation. A variety of methods for the manipulation of particle beam properties are also presented, for instance, bunch length and energy compression, bunch rotation, changes to the damping partition number, and beam collimation. The different procedures are illustrated by examples from various accelerators. Special topics include injection and extraction methods, beam cooling, spin transport and polarization.

  15. Multi-Layer Traffic Steering

    DEFF Research Database (Denmark)

    Fotiadis, Panagiotis; Polignano, Michele; Gimenez, Lucas Chavarria

    2013-01-01

    This paper investigates the potentials of traffic steering in the Radio Resource Control (RRC) Idle state by evaluating the Absolute Priorities (AP) framework in a multilayer Long Term Evolution (LTE) macrocell scenario. Frequency priorities are broadcast on the system information and RRC Idle...... periods are not significantly long. Finally, better alignment between the RRC Connected and Idle mobility procedures is observed, guarantying significant decrease of handovers/reselections and potential battery life savings by minimizing the Inter-Frequency (IF) measurement rate in the RRC Idle....

  16. Experimental validation of a Monte Carlo proton therapy nozzle model incorporating magnetically steered protons

    International Nuclear Information System (INIS)

    Peterson, S W; Polf, J; Archambault, L; Beddar, S; Bues, M; Ciangaru, G; Smith, A

    2009-01-01

    The purpose of this study is to validate the accuracy of a Monte Carlo calculation model of a proton magnetic beam scanning delivery nozzle developed using the Geant4 toolkit. The Monte Carlo model was used to produce depth dose and lateral profiles, which were compared to data measured in the clinical scanning treatment nozzle at several energies. Comparisons were also made between measured and simulated off-axis profiles to test the accuracy of the model's magnetic steering. Comparison of the 80% distal dose fall-off values for the measured and simulated depth dose profiles agreed to within 1 mm for the beam energies evaluated. Agreement of the full width at half maximum values for the measured and simulated lateral fluence profiles was within 1.3 mm for all energies. The position of measured and simulated spot positions for the magnetically steered beams agreed to within 0.7 mm of each other. Based on these results, we found that the Geant4 Monte Carlo model of the beam scanning nozzle has the ability to accurately predict depth dose profiles, lateral profiles perpendicular to the beam axis and magnetic steering of a proton beam during beam scanning proton therapy.

  17. The Front Steering Launcher Design for the ITER ECRH Upper Port

    International Nuclear Information System (INIS)

    Henderson, M A; Chavan, R; Heidinger, R; Nikkola, P; Ramponi, G; Saibene, G; Sanchez, F; Sauter, O; Serikov, A; Zohm, H

    2005-01-01

    The ECRH ITER upper port antenna's role is to stabilize the neoclassical tearing mode (NTM) on either the q = 2 or 3/2 rational flux surfaces, which requires a narrow current deposition profile (j CD ) over a wide range along the resonance surfaces. The width of j CD should be equivalent to the marginal island width to fully stabilise the NTM. Two antenna concepts are under consideration for the upper port launcher: front steering (FS) and remote steering (RS). The FS launcher decouples the steering and focusing aspects using a two mirror system (one focusing and one steering), achieving a wider steering range and higher current density for NTM stabilisation than required by ITER, offering a threefold increase in NTM stabilization efficiency over the RS launcher. The improved physics performance has motivated the further design study of the FS launcher aiming toward a build to print launcher. The present design is compatible with ≥2.0 MW CW operation and 8 beams per port plug. A frictionless backlashfree system is envisioned for the steering mechanism. An overview of the launcher design, the calculated physics performance and the possibility of using the upper port launcher for extended physics applications (beyond NTM stabilisation) are discussed

  18. Three-bead steering microswimmers

    Science.gov (United States)

    Rizvi, Mohd Suhail; Farutin, Alexander; Misbah, Chaouqi

    2018-02-01

    The self-propelled microswimmers have recently attracted considerable attention as model systems for biological cell migration as well as artificial micromachines. A simple and well-studied microswimmer model consists of three identical spherical beads joined by two springs in a linear fashion with active oscillatory forces being applied on the beads to generate self-propulsion. We have extended this linear microswimmer configuration to a triangular geometry where the three beads are connected by three identical springs in an equilateral triangular manner. The active forces acting on each spring can lead to autonomous steering motion; i.e., allowing the swimmer to move along arbitrary paths. We explore the microswimmer dynamics analytically and pinpoint its rich character depending on the nature of the active forces. The microswimmers can translate along a straight trajectory, rotate at a fixed location, as well as perform a simultaneous translation and rotation resulting in complex curved trajectories. The sinusoidal active forces on the three springs of the microswimmer contain naturally four operating parameters which are more than required for the steering motion. We identify the minimal operating parameters which are essential for the motion of the microswimmer along any given arbitrary trajectory. Therefore, along with providing insights into the mechanics of the complex motion of the natural and artificial microswimmers, the triangular three-bead microswimmer can be utilized as a model for targeted drug delivery systems and autonomous underwater vehicles where intricate trajectories are involved.

  19. How Insect Flight Steering Muscles Work

    OpenAIRE

    Walker, Simon M.; Schwyn, Daniel A.; Mokso, Rajmund; Wicklein, Martina; Müller, Tonya; Doube, Michael; Stampanoni, Marco; Krapp, Holger G.; Taylor, Graham K.

    2014-01-01

    Dipteran flies are amongst the smallest and most agile of flying animals. Their wings are driven indirectly by large power muscles, which cause cyclical deformations of the thorax that are amplified through the intricate wing hinge. Asymmetric flight manoeuvres are controlled by 13 pairs of steering muscles acting directly on the wing articulations. Collectively the steering muscles account for

  20. Steer-by-wire innovations and demonstrator

    NARCIS (Netherlands)

    Lupker, H.A.; Zuurbier, J.; Verschuren, R.M.A.F.; Jansen, S.T.H.; Willemsen, D.M.C.

    2002-01-01

    Arguments for 'by-wire' systems include production costs, packaging and traffic safety. Innovations concern both product and development process e.g. combined virtual engineering and Hardware-in-the-loop testing. Three Steer-by-wire systems are discussed: a steering system simulator used as a

  1. A new model to compute the desired steering torque for steer-by-wire vehicles and driving simulators

    Science.gov (United States)

    Fankem, Steve; Müller, Steffen

    2014-05-01

    This paper deals with the control of the hand wheel actuator in steer-by-wire (SbW) vehicles and driving simulators (DSs). A novel model for the computation of the desired steering torque is presented. The introduced steering torque computation does not only aim to generate a realistic steering feel, which means that the driver should not miss the basic steering functionality of a modern conventional steering system such as an electric power steering (EPS) or hydraulic power steering (HPS), and this in every driving situation. In addition, the modular structure of the steering torque computation combined with suitably selected tuning parameters has the objective to offer a high degree of customisability of the steering feel and thus to provide each driver with his preferred steering feel in a very intuitive manner. The task and the tuning of each module are firstly described. Then, the steering torque computation is parameterised such that the steering feel of a series EPS system is reproduced. For this purpose, experiments are conducted in a hardware-in-the-loop environment where a test EPS is mounted on a steering test bench coupled with a vehicle simulator and parameter identification techniques are applied. Subsequently, how appropriate the steering torque computation mimics the test EPS system is objectively evaluated with respect to criteria concerning the steering torque level and gradient, the feedback behaviour and the steering return ability. Finally, the intuitive tuning of the modular steering torque computation is demonstrated for deriving a sportier steering feel configuration.

  2. Wireless traffic steering for green cellular networks

    CERN Document Server

    Zhang, Shan; Zhou, Sheng; Niu, Zhisheng; Shen, Xuemin (Sherman)

    2016-01-01

    This book introduces wireless traffic steering as a paradigm to realize green communication in multi-tier heterogeneous cellular networks. By matching network resources and dynamic mobile traffic demand, traffic steering helps to reduce on-grid power consumption with on-demand services provided. This book reviews existing solutions from the perspectives of energy consumption reduction and renewable energy harvesting. Specifically, it explains how traffic steering can improve energy efficiency through intelligent traffic-resource matching. Several promising traffic steering approaches for dynamic network planning and renewable energy demand-supply balancing are discussed. This book presents an energy-aware traffic steering method for networks with energy harvesting, which optimizes the traffic allocated to each cell based on the renewable energy status. Renewable energy demand-supply balancing is a key factor in energy dynamics, aimed at enhancing renewable energy sustainability to reduce on-grid energy consum...

  3. Operator space approach to steering inequality

    International Nuclear Information System (INIS)

    Yin, Zhi; Marciniak, Marcin; Horodecki, Michał

    2015-01-01

    In Junge and Palazuelos (2011 Commun. Math. Phys. 306 695–746) and Junge et al (2010 Commun. Math. Phys. 300 715–39) the operator space theory was applied to study bipartite Bell inequalities. The aim of the paper is to follow this line of research and use the operator space technique to analyze the steering scenario. We obtain a bipartite steering functional with unbounded largest violation of steering inequality, as well as constructing all ingredients explicitly. It turns out that the unbounded largest violation is obtained by a non maximally entangled state. Moreover, we focus on the bipartite dichotomic case where we construct a steering functional with unbounded largest violation of steering inequality. This phenomenon is different to the Bell scenario where only the bounded largest violation can be obtained by any bipartite dichotomic Bell functional. (paper)

  4. Biogas production from steer manures in Vietnam

    DEFF Research Database (Denmark)

    Pham, Cuong H.; Saggar, Surinder; Vu, Cuong C.

    2017-01-01

    manures collected from two different experiments of steers fed diets containing feed supplements. BMP was 110.1 (NLkg-1 VS) for manure from steers receiving a control diet, significantly lower 79.0 (NL kg-1 VS) for manure from steers fed a diet containing 0.3% tannin (%DM), but then showed an increasing...... trend to 90.9 and 91.2 (NL kg-1 VS) for manures from steers receiving 0.4 and 0.5% tannin (%DM) supplements, respectively. Similarly, the CH4 production (NL kg-1 VS) of manure from steers was 174 for control, 142 for control supplemented concentrate (C), 143 for control added rice straw treated...

  5. Beam transport

    International Nuclear Information System (INIS)

    1988-01-01

    Considerable experience has now been gained with the various beam transport lines, and a number of minor changes have been made to improve the ease of operation. These include: replacement of certain little-used slits by profile monitors (harps or scanners); relocation of steering magnets, closer to diagnostic harps or profile scanners; installation of a scanner inside the isocentric neutron therapy system; and conversion of a 2-doublet quadrupole telescope (on the neutron therapy beamline) to a 2-triplet telescope. The beam-swinger project has been delayed by very late delivery of the magnet iron to the manufacturer, but is now progressing smoothly. The K=600 spectrometer magnets have now been delivered and are being assembled for field mapping. The x,y-table with its associated mapping equipment is complete, together with the driver software. One of the experimental areas has been dedicated to the production of collimated neutron beams and has been equipped with a bending magnet and beam dump, together with steel collimators fixed at 4 degrees intervals from 0 degrees to 16 degrees. Changes to the target cooling and shielding system for isotope production have led to a request for much smaller beam spot sizes on target, and preparations have been made for rearrangement of the isotope beamline to permit installation of quadrupole triplets on the three beamlines after the switching magnet. A practical system of quadrupoles for matching beam properties to the spectrometer has been designed. 6 figs

  6. Steering particles by breaking symmetries

    Science.gov (United States)

    Bet, Bram; Samin, Sela; Georgiev, Rumen; Burak Eral, Huseyin; van Roij, René

    2018-06-01

    We derive general equations of motions for highly-confined particles that perform quasi-two-dimensional motion in Hele-Shaw channels, which we solve analytically, aiming to derive design principles for self-steering particles. Based on symmetry properties of a particle, its equations of motion can be simplified, where we retrieve an earlier-known equation of motion for the orientation of dimer particles consisting of disks (Uspal et al 2013 Nat. Commun. 4), but now in full generality. Subsequently, these solutions are compared with particle trajectories that are obtained numerically. For mirror-symmetric particles, excellent agreement between the analytical and numerical solutions is found. For particles lacking mirror symmetry, the analytic solutions provide means to classify the motion based on particle geometry, while we find that taking the side-wall interactions into account is important to accurately describe the trajectories.

  7. 46 CFR 58.25-20 - Piping for steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Piping for steering gear. 58.25-20 Section 58.25-20... MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-20 Piping for steering gear. (a) Pressure piping must... the hydraulic system can be readily recharged from within the steering-gear compartment and must be...

  8. Genuine Multipartite Einstein-Podolsky-Rosen Steering

    Science.gov (United States)

    He, Q. Y.; Reid, M. D.

    2013-12-01

    We develop the concept of genuine N-partite Einstein-Podolsky-Rosen (EPR) steering. This nonlocality is the natural multipartite extension of the original EPR paradox. Useful properties emerge that are not guaranteed for genuine multipartite entangled states. In particular, there is a close link with the task of one-sided, device-independent quantum secret sharing. We derive inequalities to demonstrate multipartite EPR steering for Greenberger-Horne-Zeilinger and Gaussian continuous variable states in loophole-free scenarios.

  9. Steering, Entanglement, Nonlocality, and the EPR Paradox

    OpenAIRE

    Wiseman, H. M.; Jones, S. J.; Doherty, A. C.

    2006-01-01

    The concept of steering was introduced by Schrodinger in 1935 as a generalization of the EPR paradox for arbitrary pure bipartite entangled states and arbitrary measurements by one party. Until now, it has never been rigorously defined, so it has not been known (for example) what mixed states are steerable (that is, can be used to exhibit steering). We provide an operational definition, from which we prove (by considering Werner states and Isotropic states) that steerable states are a strict ...

  10. Design of a remote steering antenna for ECRH heating in the stellarator Wendelstein 7-X

    Energy Technology Data Exchange (ETDEWEB)

    Plaum, B., E-mail: plaum@igvp.uni-stuttgart.de [Institut für Grenzflächenverfahrenstechnik und Plasmatechnologie (IGVP), Univ. Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart (Germany); Lechte, C.; Kasparek, W.; Gaiser, S.; Zeitler, A. [Institut für Grenzflächenverfahrenstechnik und Plasmatechnologie (IGVP), Univ. Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart (Germany); Erckmann, V. [Max-Planck-Institut für Plasmaphysik, EURATOM-IPP, D-17491 Greifswald (Germany); Weißgerber, M. [Max-Planck-Institut für Plasmaphysik, EURATOM-IPP, D-85748 Garching (Germany); Bechtold, A. [NTG Neue Technologie GmbH & Co KG, D-63571 Gelnhausen (Germany); Busch, M.; Szcepaniak, B. [Galvano-T electroplating-electroforming GmbH, D-51570 Windeck-Rosbach (Germany)

    2015-10-15

    Highlights: • We report about the design activities for the remote steering antennas for the stellarator W7-X. • The integration into the W7-X system and the manufacturing procedure are described. • Simulations and loss measurements for the waveguide walls were done and are in good agreement. • A method for extending the steering range is presented. • A mechanical deformation analysis showed that the deformation is not critical for the beam quality. - Abstract: For the ECRH heating system of the stellarator Wendelstein 7-X, two remote steering antennas are developed and manufactured. The principle of remote steering antennas is based on the imaging characteristics of corrugated rectangular waveguides, which is well understood and can accurately be simulated. Several details, however, require deeper investigation. The antenna needs a miter-bend and a 24 mm gap. The positions of these elements need to be chosen carefully to reduce losses and stray radiation. The antennas are manufactured from copper by electroforming. This allows to integrate all components, including the corrugated inner walls and the cooling channels, in one vacuum-tight piece. This paper reviews the design process of the remote steering antennas for W7-X as well as technological issues and experimental results from test pieces.

  11. Beam-beam deflections as an interaction point diagnostic for the SLC

    International Nuclear Information System (INIS)

    Bambade, P.; Erickson, R.

    1986-05-01

    A technique is described for non-destructive measurement and monitoring of the steering offset of the electron and positron beams at the interaction point of the SLC, based on using stripline beam-position monitors to measure the centroid of one beam as it is deflected by the opposing beam. This technique is also expected to provide diagnostic information related to the spot size of the micron-size beams

  12. Improvement of motor inertia influence of electric power steering; Dendoshiki power steering no motor kansei no eikyo to hosho

    Energy Technology Data Exchange (ETDEWEB)

    Takehara, S; Sakamoto, K; Hanamoto, Y [Mazda Motor Corp., Hiroshima (Japan); Noritsugu, T [Okayama University, Okayama (Japan)

    1997-10-01

    Motor inertia of electric power steering affects not only steering characteristics but vehicle dynamics. We have investigated the influence of motor inertia and proposed a feedback strategy to compensate it. Weight of the test vehicle is 1100Kg and the steering system is pinion type electric power steering. By using simulation model and vehicle test, we have realized natural steering maneuvering and stable vehicle dynamics. 4 refs., 11 figs.

  13. Networks: structure and action : steering in and steering by policy networks

    NARCIS (Netherlands)

    Dassen, A.

    2010-01-01

    This thesis explores the opportunities to build a structural policy network model that is rooted in social network theories. By making a distinction between a process of steering in networks, and a process of steering by networks, it addresses the effects of network structures on network dynamics as

  14. Steering elastic SH waves in an anomalous way by metasurface

    Science.gov (United States)

    Cao, Liyun; Yang, Zhichun; Xu, Yanlong

    2018-03-01

    Metasurface, which does not exist in nature, has exhibited exotic essence on the manipulation of both electromagnetic and acoustic waves. In this paper, the concept of metasurface is extended to the field of elastic SH waves, and the anomalous refractions of SH waves across the designed elastic SH wave metasurfaces (SHWMs) are demonstrated numerically. Firstly, a SHWM is designed with supercells, each supercell is composed of four subunits. It is demonstrated that this configuration has the ability of deflecting the vertical and oblique incident waves in an arbitrary desired direction. Then, a unique SHWM with supercell composed of only two subunits is designed. Numerical simulation shows its ability of splitting the vertical and oblique incident waves into two tunable transmitted wave beams, respectively. In the process of steering SH waves, it is also found that two kinds of leakages of transmitted waves across the designed SHWM will occur in some particular situations, which will affect the desired transmitted wave. The mechanisms of the leakages, which are different from that of the common high-order diffraction mentioned in existing literatures, are revealed. The current study can offer theoretical guidance not only for designing devices of directional ultrasonic detection and splitting SH waves but also for steering other kinds of classical waves.

  15. Assessment of a Boat Fractured Steering Wheel

    Directory of Open Access Journals (Sweden)

    Vukelic Goran

    2016-09-01

    Full Text Available During regular use of the steering wheel mounted on a boat, two cracks emanating from a fastener hole were noticed which, consequently, caused final fracture of the wheel. To determine the behavior of a boat steering wheel with cracks present, assessment of a fractured wheel was performed. Torque moments of the fasteners were measured prior to removing the steering wheel from the boat. Visual and dye penetrant inspection followed along with the material detection. Besides using experimental procedures, assessment of the fractured wheel was performed using finite element analysis, i.e. stress intensity factor values were numerically determined. Variation of stress intensity factor with crack length is presented. Possible causes of crack occurrence are given and they include excessive values of fastener torque moments coupled with fretting between fastener and fastener hole that was poorly machined. Results obtained by this assessment can be taken for predicting fracture behavior of a cracked steering wheel and as a reference in the design, mounting and exploitation process of steering wheels improving that way their safety in transportation environment.

  16. Low-Absorption Liquid Crystals for Infrared Beam Steering

    Science.gov (United States)

    2015-09-30

    controlled the curing temperature at 0oC to obtain small domain size and fast response time is expected. Here, a UV light-emitting diode ( LED ) lamp ...absorption; def.=deformation; w =weak absorption; v.=variable intensity) [B. D. Mistry, A Handbook of Spectroscopic Data: Chemistry- UV , IR, PMR, CNMR and...contributed by the core structure and terminal groups. Due to UV instability of double bonds and carbon-carbon triple bonds, conjugated phenyl rings have

  17. Online optimized hysteresis-based steering feel model for steer-by-wire systems

    Directory of Open Access Journals (Sweden)

    Ahmet Kirli

    2016-06-01

    Full Text Available In rubber-wheeled road vehicles, the mechanical connection between steering wheel and front wheels provides steering-related feedback to the driver. The torque fed back to the driver through the steering linkages and steering wheel, which is called steering feel, helps the driver in controlling the vehicle. The torque feedback is reproduced via artificial methods in steer-by-wire systems due to the lack of mechanical connection. In this work, in order to minimize the physical workload and the lateral acceleration under the consideration of handling performance, optimization of a hysteresis-based steering feel has been studied. A 2-degree-of-freedom bicycle model based on the magic formula tire model has been used for simulations and hardware-in-the-loop experiments. A mathematical model is proposed in order to create an adaptive model-based optimization of the hysteresis parameters simultaneously while driving. A hardware-in-the-loop experimental setup has been used for the driving tests. The weave and the double-lane change tests have been performed with different drivers in order to demonstrate and quantify the optimization methods that are presented in this work.

  18. Drowsy Driver Detection via Steering Wheel

    Directory of Open Access Journals (Sweden)

    Herlina ABDUL RAHIM

    2010-09-01

    Full Text Available The main purpose of this project is to produce a safety system especially for fatigue car driver so as to prevent from accidents. The statistic on road fatality shows that human error constitute of 64.84 % road accidents fatality and 17.4 % due to technical factors. These systems encompassed the approach of hand pressure applied on the steering wheel. The steering will be installed with pressure sensors. At the same time these sensors can be used to measure gripping force while driving.

  19. Transverse centroid oscillations in solenoidially focused beam transport lattices

    International Nuclear Information System (INIS)

    Lund, Steven M.; Wootton, Christopher J.; Lee, Edward P.

    2009-01-01

    Transverse centroid oscillations are analyzed for a beam in a solenoid transport lattice. Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable 'alignment functions' and 'bending functions' that efficiently describe the characteristics of the centroid oscillations induced by both mechanical misalignments of the solenoids and dipole steering elements. The alignment and bending functions depend only on the properties of the ideal lattice in the absence of errors and steering, and have associated expansion amplitudes set by the misalignments and steering fields, respectively. Applications of this formulation are presented for statistical analysis of centroid oscillations, calculation of actual lattice misalignments from centroid measurements, and optimal beam steering.

  20. 46 CFR 182.620 - Auxiliary means of steering.

    Science.gov (United States)

    2010-10-01

    ... TONS) MACHINERY INSTALLATION Steering Systems § 182.620 Auxiliary means of steering. (a) Except as... personnel hazards during normal or heavy weather operation. (b) A suitable hand tiller may be acceptable as...

  1. Relative entropy of steering: on its definition and properties

    International Nuclear Information System (INIS)

    Kaur, Eneet; Wilde, Mark M

    2017-01-01

    In Gallego and Aolita (2015 Phys. Rev . X 5 041008), the authors proposed a definition for the relative entropy of steering and showed that the resulting quantity is a convex steering monotone. Here we advocate for a different definition for relative entropy of steering, based on well grounded concerns coming from quantum Shannon theory. We prove that this modified relative entropy of steering is a convex steering monotone. Furthermore, we establish that it is uniformly continuous and faithful, in both cases giving quantitative bounds that should be useful in applications. We also consider a restricted relative entropy of steering which is relevant for the case in which the free operations in the resource theory of steering have a more restricted form (the restricted operations could be more relevant in practical scenarios). The restricted relative entropy of steering is convex, monotone with respect to these restricted operations, uniformly continuous, and faithful. (paper)

  2. Beam Shaping for CARS Measurements in Turbulent Environments

    Science.gov (United States)

    Magnotti, Gaetano; Cutler, Andrew D.; Danehy, Paul M.

    2010-01-01

    This paper describes a new technique to mitigate the effect of beam steering on CARS measurements in turbulent, variable density environments. The new approach combines Planar BOXCARS phase-matching with elliptical shaping of one of the beams to generate a signal insensitive to beam steering, while keeping the same spatial resolution. Numerical and experimental results are provided to demonstrate the effectiveness of this approach. One set of experiments investigated the effect of beam shaping in the presence of a controlled and well quantified displacement of the beams at the focal plane. Another set of experiments, more qualitative, proved the effectiveness of the technique in the presence of severe beam steering due to turbulence.

  3. Design and manufacturing of mechanical steering system for ...

    African Journals Online (AJOL)

    Design and manufacturing of mechanical steering system for parallel parking, zero turning radius, minimum turning radius with traditional turning. ... of the steering system are designed so as to meet all the configuration of steering system and to be well-matched to the power train, suspension system and body of the car.

  4. Speed choice and steering behavior in curve driving

    NARCIS (Netherlands)

    Winsum, W. van; Godthelp, J.

    1996-01-01

    The relation between speed choice and steering performance during curve negotiation was studied in a driving simulator. The hypothesis was that curve radius and steering competence both affect steering error during curve driving, resulting in compensatory speed choice. In this, the control of safety

  5. 46 CFR 167.65-25 - Steering gear tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering gear tests. 167.65-25 Section 167.65-25... SHIPS Special Operating Requirements § 167.65-25 Steering gear tests. On all nautical school ships making voyages of more than 48 hours' duration, the entire steering gear, the whistle, the means of...

  6. 46 CFR 61.20-1 - Steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Steering gear. 61.20-1 Section 61.20-1 Shipping COAST... Periodic Tests of Machinery and Equipment § 61.20-1 Steering gear. (a) The marine inspector must inspect the steering gear at each inspection for certification for vessels whose Certificate of Inspections...

  7. Steering Dynamics in the Dutch Education System

    Science.gov (United States)

    Waslander, Sietske; Hooge, Edith; Drewes, Tineke

    2016-01-01

    Based on detailed empirical analyses, we paint a layered picture of emerging steering dynamics. Inspired by Foucault, we put the focus on roles stakeholders define both for themselves and others, how they give sense to policy, how they work together in policy elaboration and implementation, and the subtle and sometimes deceitful function of soft…

  8. Use of free steered vehicles. [United Kingdom

    Energy Technology Data Exchange (ETDEWEB)

    Ferris, W

    1986-01-01

    The UK National Coal Board's Western Area is currently producing 10.5 m/tons per annum from 16 collieries exploiting 26 different seams. This article looks at the use of free steered vehicles (FSV's) in Haig Colliery, Point of Ayr and Silverdale Colliery, covering general applications, installation of coal faces and face salvage by FSV's.

  9. Development of steering system in network environment

    International Nuclear Information System (INIS)

    Kanagawa, Fumihiro; Noguchi, So; Yamashita, Hideo

    2002-01-01

    We have been developing the steering system, which can successively observe the-data obtained during the numerical computation and change the parameters in the analysis. Moreover, this system is also extended to link the network. By using this system, a user can easily detect errors immediately and achieve the rapid and accurate analysis with lower computation cost. (Author)

  10. Quantum Steering Beyond Instrumental Causal Networks

    Science.gov (United States)

    Nery, R. V.; Taddei, M. M.; Chaves, R.; Aolita, L.

    2018-04-01

    We theoretically predict, and experimentally verify with entangled photons, that outcome communication is not enough for hidden-state models to reproduce quantum steering. Hidden-state models with outcome communication correspond, in turn, to the well-known instrumental processes of causal inference but in the one-sided device-independent scenario of one black-box measurement device and one well-characterized quantum apparatus. We introduce one-sided device-independent instrumental inequalities to test against these models, with the appealing feature of detecting entanglement even when communication of the black box's measurement outcome is allowed. We find that, remarkably, these inequalities can also be violated solely with steering, i.e., without outcome communication. In fact, an efficiently computable formal quantifier—the robustness of noninstrumentality—naturally arises, and we prove that steering alone is enough to maximize it. Our findings imply that quantum theory admits a stronger form of steering than known until now, with fundamental as well as practical potential implications.

  11. Beam dynamics in the SLC final focus system

    International Nuclear Information System (INIS)

    Bambade, P.S.

    1987-06-01

    The SLC luminosity is reached by colliding beams focused to about 2 μm transverse sizes. The Final Focus System (FFS) must enable, beyond its basic optical design, the detection and correction of errors accumulated in the system. In this paper, after summarizing the design, we review the sensitivity to such errors and the ability to correct them. The overall tuning strategy involves three phases: single beam spot minimization, steering the beams in collision and luminosity optimization with beam-beam effects

  12. Beam-Beam Effects

    International Nuclear Information System (INIS)

    Herr, W; Pieloni, T

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities

  13. Beam control and matching for the transport of intense beams

    International Nuclear Information System (INIS)

    Li, H.; Bernal, S.; Godlove, T.; Huo, Y.; Kishek, R.A.; Haber, I.; Quinn, B.; Walter, M.; Zou, Y.; Reiser, M.; O'Shea, P.G.

    2005-01-01

    The transport of intense beams for heavy-ion inertial fusion demands tight control of beam characteristics from the source to the target. The University of Maryland Electron Ring (UMER), which uses a low-energy (10 keV), high-current electron beam to model the transport physics of a future recirculator driver, employs real-time beam characterization and control in order to optimize beam quality throughout the strong focusing lattice. We describe the main components and operation of the diagnostics/control system in UMER. It employs phosphor screens, real-time image analysis, quadrupole scans and electronic skew correctors. The procedure is not only indispensable for optimum transport over a long distance, but also provides important insights into the beam physics involved. We discuss control/optimization issues related to beam steering, quadrupole rotation errors and rms envelope matching

  14. Improving Einstein–Podolsky–Rosen steering inequalities with state information

    International Nuclear Information System (INIS)

    Schneeloch, James; Broadbent, Curtis J.; Howell, John C.

    2014-01-01

    We discuss the relationship between entropic Einstein–Podolsky–Rosen (EPR)-steering inequalities and their underlying uncertainty relations along with the hypothesis that improved uncertainty relations lead to tighter EPR-steering inequalities. In particular, we discuss how using information about the state of a quantum system affects one's ability to witness EPR-steering. As an example, we consider the recent improvement to the entropic uncertainty relation between pairs of discrete observables (Berta et al., 2010 [10]). By considering the assumptions that enter into the development of a steering inequality, we derive correct steering inequalities from these improved uncertainty relations and find that they are identical to ones already developed (Schneeloch et al., 2013 [9]). In addition, we consider how one can use state information to improve our ability to witness EPR-steering, and develop a new continuous variable symmetric EPR-steering inequality as a result.

  15. Method of Controlling Steering of a Ground Vehicle

    Science.gov (United States)

    Dawson, Andrew D. (Inventor); Bluethmann, William J. (Inventor); Lee, Chunhao J. (Inventor); Vitale, Robert L. (Inventor); Guo, Raymond (Inventor); Atluri, Venkata Prasad (Inventor)

    2016-01-01

    A method of controlling steering of a vehicle through setting wheel angles of a plurality of modular electronic corner assemblies (eModules) is provided. The method includes receiving a driving mode selected from a mode selection menu. A position of a steering input device is determined in a master controller. A velocity of the vehicle is determined, in the master controller, when the determined position of the steering input device is near center. A drive mode request corresponding to the selected driving mode to the plurality of steering controllers is transmitted to the master controller. A required steering angle of each of the plurality of eModules is determined, in the master controller, as a function of the determined position of the steering input device, the determined velocity of the vehicle, and the selected first driving mode. The eModules are set to the respective determined steering angles.

  16. Steering of sub-GeV electrons by ultrashort Si and Ge bent crystals

    Energy Technology Data Exchange (ETDEWEB)

    Sytov, A.I. [Ferrara Univ. (Italy). Dipt. di Fisica e Scienze della Terra; Belarusian State Univ., Minsk (Belarus). Inst. for Nuclear Problems; INFN Sezione di Ferrara (Italy); Bandiera, L.; Mazzolari, A.; Bagli, E.; Germogli, G.; Guidi, V.; Romagnoni, M. [Ferrara Univ. (Italy). Dipt. di Fisica e Scienze della Terra; INFN Sezione di Ferrara (Italy); De Salvador, D.; Carturan, S.; Maggioni, G. [INFN, Laboratori Nazionali di Legnaro (Italy); Padova Univ. (Italy). Dipt. di Fisica; Berra, A.; Prest, M. [Univ. dell' Insubria, Como (Italy); INFN, Sezione di Milano Bicocca, Milan (Italy); Durighello, C. [Ferrara Univ. (Italy). Dipt. di Fisica e Scienze della Terra; INFN, Laboratori Nazionali di Legnaro (Italy); Padova Univ. (Italy). Dipt. di Fisica; INFN Sezione di Ferrara (Italy); Klag, P.; Lauth, W. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Tikhomirov, V.V. [Belarusian State Univ., Minsk (Belarus). Inst. for Nuclear Problems; Vallazza, E. [INFN, Sezione di Trieste (Italy)

    2017-12-15

    We report the observation of the steering of 855 MeV electrons by bent silicon and germanium crystals at the MAinzer MIkrotron. Crystals with 15 μm of length, bent along (111) planes, were exploited to investigate orientational coherent effects. By using a piezo-actuated mechanical holder, which allowed to remotely change the crystal curvature, it was possible to study the steering capability of planar channeling and volume reflection vs. the curvature radius and the atomic number, Z. For silicon, the channeling efficiency exceeds 35%, a record for negatively charged particles. This was possible due to the realization of a crystal with a thickness of the order of the dechanneling length. On the other hand, for germanium the efficiency is slightly below 10% due to the stronger contribution of multiple scattering for a higher-Z material. Nevertheless this is the first evidence of negative beam steering by planar channeling in a Ge crystal. Having determined for the first time the dechanneling length, one may design a Ge crystal based on such knowledge providing nearly the same channeling efficiency of silicon. The presented results are relevant for crystal-based beam manipulation as well as for the generation of e.m. radiation in bent and periodically bent crystals. (orig.)

  17. Steering of Sub-GeV electrons by ultrashort Si and Ge bent crystals

    Science.gov (United States)

    Sytov, A. I.; Bandiera, L.; De Salvador, D.; Mazzolari, A.; Bagli, E.; Berra, A.; Carturan, S.; Durighello, C.; Germogli, G.; Guidi, V.; Klag, P.; Lauth, W.; Maggioni, G.; Prest, M.; Romagnoni, M.; Tikhomirov, V. V.; Vallazza, E.

    2017-12-01

    We report the observation of the steering of 855 MeV electrons by bent silicon and germanium crystals at the MAinzer MIkrotron. Crystals with 15 μ m of length, bent along (111) planes, were exploited to investigate orientational coherent effects. By using a piezo-actuated mechanical holder, which allowed to remotely change the crystal curvature, it was possible to study the steering capability of planar channeling and volume reflection vs. the curvature radius and the atomic number, Z. For silicon, the channeling efficiency exceeds 35%, a record for negatively charged particles. This was possible due to the realization of a crystal with a thickness of the order of the dechanneling length. On the other hand, for germanium the efficiency is slightly below 10% due to the stronger contribution of multiple scattering for a higher-Z material. Nevertheless this is the first evidence of negative beam steering by planar channeling in a Ge crystal. Having determined for the first time the dechanneling length, one may design a Ge crystal based on such knowledge providing nearly the same channeling efficiency of silicon. The presented results are relevant for crystal-based beam manipulation as well as for the generation of e.m. radiation in bent and periodically bent crystals.

  18. Einstein-Podolsky-Rosen paradox and quantum steering in a three-mode optomechanical system

    Science.gov (United States)

    He, Qiongyi; Ficek, Zbigniew

    2014-02-01

    We study multipartite entanglement, the generation of Einstein-Podolsky-Rosen (EPR) states, and quantum steering in a three-mode optomechanical system composed of an atomic ensemble located inside a single-mode cavity with a movable mirror. The cavity mode is driven by a short laser pulse, has a nonlinear parametric-type interaction with the mirror and a linear beam-splitter-type interaction with the atomic ensemble. There is no direct interaction of the mirror with the atomic ensemble. A threshold effect for the dynamics of the system is found, above which the system works as an amplifier and below which as an attenuator of the output fields. The threshold is determined by the ratio of the coupling strengths of the cavity mode to the mirror and to the atomic ensemble. It is shown that above the threshold, the system effectively behaves as a two-mode system in which a perfect bipartite EPR state can be generated, while it is impossible below the threshold. Furthermore, a fully inseparable tripartite entanglement and even further a genuine tripartite entanglement can be produced above and below the threshold. In addition, we consider quantum steering and examine the monogamy relations that quantify the amount of bipartite steering that can be shared between different modes. It is found that the mirror is more capable for steering of entanglement than the cavity mode. The two-way steering is found between the mirror and the atomic ensemble despite the fact that they are not directly coupled to each other, while it is impossible between the output of cavity mode and the ensemble which are directly coupled to each other.

  19. Steering, Entanglement, Nonlocality, and the EPR Paradox

    Science.gov (United States)

    Wiseman, Howard; Jones, Steve; Andrew, Doherty

    2007-06-01

    The concept of steering was introduced by Schroedinger in 1935 as a generalization of the EPR paradox for arbitrary pure bipartite entangled states and arbitrary measurements by one party. Until now, it has never been rigorously defined, so it has not been known (for example) what mixed states are steerable (that is, can be used to exhibit steering). We provide an operational definition, from which we prove (by considering Werner states and Isotropic states) that steerable states are a strict subset of the entangled states, and a strict superset of the states that can exhibit Bell-nonlocality. For arbitrary bipartite Gaussian states we derive a linear matrix inequality that decides the question of steerability via Gaussian measurements, and we relate this to the original EPR paradox.

  20. Conditional steering under the von Neumann scenario

    Science.gov (United States)

    Mukherjee, Kaushiki; Paul, Biswajit; Karmakar, Sumana; Sarkar, Debasis; Mukherjee, Amit; Bhattacharya, Some Sankar; Roy, Arup

    2017-08-01

    In Phys. Lett. A 166, 293 (1992), 10.1016/0375-9601(92)90711-T, Popescu and Rohrlich characterized nonlocality of pure n -partite entangled systems by studying bipartite violation of local realism when n -2 number of parties perform projective measurements on their particles. A pertinent question in this scenario is whether similar characterization is possible for n -partite mixed entangled states also. In the present work we have followed an analogous approach so as to explore whether given a tripartite mixed entangled state the conditional bipartite states obtained by performing projective measurement on the third party demonstrate a weaker form of nonlocality, quantum steering. We also compare this phenomenon of conditional steering with existing notions of tripartite correlations.

  1. Pointing Device Performance in Steering Tasks.

    Science.gov (United States)

    Senanayake, Ransalu; Goonetilleke, Ravindra S

    2016-06-01

    Use of touch-screen-based interactions is growing rapidly. Hence, knowing the maneuvering efficacy of touch screens relative to other pointing devices is of great importance in the context of graphical user interfaces. Movement time, accuracy, and user preferences of four pointing device settings were evaluated on a computer with 14 participants aged 20.1 ± 3.13 years. It was found that, depending on the difficulty of the task, the optimal settings differ for ballistic and visual control tasks. With a touch screen, resting the arm increased movement time for steering tasks. When both performance and comfort are considered, whether to use a mouse or a touch screen for person-computer interaction depends on the steering difficulty. Hence, a input device should be chosen based on the application, and should be optimized to match the graphical user interface. © The Author(s) 2016.

  2. Electron cyclotron current drive experiments in LHCD plasmas using a remote steering antenna on the TRIAM-1M tokamak

    International Nuclear Information System (INIS)

    Idei, H.; Hanada, K.; Zushi, H.; Ohkubo, K.; Hasegawa, M.; Kubo, S.; Nishi, S.; Fukuyama, A.; Sato, K.N.; Nakamura, K.; Sakamoto, M.; Iyomasa, A.; Kawasaki, S.; Nakashima, H.; Higashijima, A.; Notake, T.; Shimozuma, T.; Ito, S.; Hoshika, H.; Maezono, N.; Nakashima, K.; Ogawa, M.

    2006-01-01

    A remote steering antenna was recently developed for electron cyclotron heating and current drive (ECH/ECCD) experiments on the TRIAM-1M tokamak. This is the first application of the remote steering antenna concept for ECH/ECCD experiments, which have conditions relevant to the International Thermonuclear Experimental Reactor (ITER). Fundamental ECH and ECCD experiments were conducted in the ITER frequency from the low field using this antenna system. In addition to the angles near 0 0 , the launcher was a symmetric direction antenna with an extended steering-angle capability of ±(8 0 -19 0 ). The output beam from the antenna was a well-defined Gaussian with a proper steering angle. The Gaussian content and the steering-angle accuracy were 0.85 and -0.5 0 , respectively. The high power tests measured the antenna transmission efficiency at 0.90-0.94. The efficiencies obtained in the low and high power tests were consistent with the calculations using higher-order modes. In order to excite the pure O/X-modes in the oblique injection, two polarizers were used to control the elliptical polarization of the incident beam for the ECCD experiments. The fundamental O/X-mode ECH/ECCD was applied to lower hyrid current drive plasmas at the optimized incident polarization. In the X-mode experiment, at medium density (∼1 x 10 19 m -3 ), clear differences in the plasma current and the hard x-ray intensity were observed between the co- and counter-steering injections due to the ECCD effect on the coupling of forward fast electrons

  3. Multipartite Einstein-Podolsky-Rosen steering and genuine tripartite entanglement with optical networks

    Science.gov (United States)

    Armstrong, Seiji; Wang, Meng; Teh, Run Yan; Gong, Qihuang; He, Qiongyi; Janousek, Jiri; Bachor, Hans-Albert; Reid, Margaret D.; Lam, Ping Koy

    2015-02-01

    Einstein, Podolsky and Rosen (EPR) pointed out in their famous paradox that two quantum-entangled particles can have perfectly correlated positions and momenta. Such correlations give evidence for the nonlocality of quantum mechanics and form the basis for quantum cryptography and teleportation. EPR steering is the nonlocality associated with the EPR paradox and has traditionally been investigated between only two parties. Using optical networks and efficient detection, we present experimental observations of multiparty EPR steering and of the genuine entanglement of three intense optical beams. We entangle the quadrature phase amplitudes of distinct fields, in analogy to the position-momentum entanglement of the original paradox. Our experiments complement tests of quantum mechanics that have entangled small systems or have demonstrated tripartite inseparability. Our methods establish principles for the development of multiparty quantum communication protocols with asymmetric observers, and can be extended to qubits, whether photonic, atomic, superconducting, or otherwise.

  4. Research on Precision Tracking on Fast Steering Mirror and Control Strategy

    Science.gov (United States)

    Di, Lin; Yi-ming, Wu; Fan, Zhu

    2018-01-01

    Fast steering mirror is a device used for controlling the beam direction precisely. Due to the short travel of the push-pull FSM, a compound fast steering mirror system driven by both limited-angle voice coil motor and push-pull FSM together is proposed. In the compound FSM system, limited-angle voice coil motor quickly swings at wide angle, while the push-pull FSM do high frequency movement in a small range, which provides the system with the high bandwidth and long travel. In the control strategy, the method of combining feed-forward control in Kalman filtering with auto-disturbance rejection control is used to improve trajectory tracking accuracy. The simulation result shows that tracking accuracy measured by the compound method can be improved by more than 5 times than that of the conventional PID.

  5. Self-testing through EPR-steering

    International Nuclear Information System (INIS)

    Šupić, Ivan; Hoban, Matty J

    2016-01-01

    The verification of quantum devices is an important aspect of quantum information, especially with the emergence of more advanced experimental implementations of quantum computation and secure communication. Within this, the theory of device-independent robust self-testing via Bell tests has reached a level of maturity now that many quantum states and measurements can be verified without direct access to the quantum systems: interaction with the devices is solely classical. However, the requirements for this robust level of verification are daunting and require high levels of experimental accuracy. In this paper we discuss the possibility of self-testing where we only have direct access to one part of the quantum device. This motivates the study of self-testing via EPR-steering, an intermediate form of entanglement verification between full state tomography and Bell tests. Quantum non-locality implies EPR-steering so results in the former can apply in the latter, but we ask what advantages may be gleaned from the latter over the former given that one can do partial state tomography? We show that in the case of self-testing a maximally entangled two-qubit state, or ebit, EPR-steering allows for simpler analysis and better error tolerance than in the case of full device-independence. On the other hand, this improvement is only a constant improvement and (up to constants) is the best one can hope for. Finally, we indicate that the main advantage in self-testing based on EPR-steering could be in the case of self-testing multi-partite quantum states and measurements. For example, it may be easier to establish a tensor product structure for a particular party’s Hilbert space even if we do not have access to their part of the global quantum system. (paper)

  6. Beam coupling impedance of fast stripline beam kickers

    International Nuclear Information System (INIS)

    Caporaso, G; Chen, Y J; Nelson, A D; Poole, B R

    1999-01-01

    A fast stripline beam kicker is used to dynamically switch a high current electron beam between two beamlines. The transverse dipole impedance of a stripline beam kicker has been previously determined from a simple transmission line model of the structure. This model did not include effects due to the long axial slots along the structure as well as the cavities and coaxial feed transition sections at the ends of the structure. 3-D time domain simulations show that the simple transmission line model underestimates the low frequency dipole beam coupling impedance by about 20% for our structure. In addition, the end cavities and transition sections can exhibit dipole impedances not included in the transmission line model. For high current beams, these additional dipole coupling terms can provide additional beam-induced steering effects not included in the transmission line model of the structure

  7. Ion Beam Propulsion Study

    Science.gov (United States)

    2008-01-01

    The Ion Beam Propulsion Study was a joint high-level study between the Applied Physics Laboratory operated by NASA and ASRC Aerospace at Kennedy Space Center, Florida, and Berkeley Scientific, Berkeley, California. The results were promising and suggested that work should continue if future funding becomes available. The application of ion thrusters for spacecraft propulsion is limited to quite modest ion sources with similarly modest ion beam parameters because of the mass penalty associated with the ion source and its power supply system. Also, the ion source technology has not been able to provide very high-power ion beams. Small ion beam propulsion systems were used with considerable success. Ion propulsion systems brought into practice use an onboard ion source to form an energetic ion beam, typically Xe+ ions, as the propellant. Such systems were used for steering and correction of telecommunication satellites and as the main thruster for the Deep Space 1 demonstration mission. In recent years, "giant" ion sources were developed for the controlled-fusion research effort worldwide, with beam parameters many orders of magnitude greater than the tiny ones of conventional space thruster application. The advent of such huge ion beam sources and the need for advanced propulsion systems for exploration of the solar system suggest a fresh look at ion beam propulsion, now with the giant fusion sources in mind.

  8. Research on Performance of Wire-controlled Hydraulic Steering System Based on Four-wheel Steering

    Science.gov (United States)

    Tao, P.; Jin, X. H.

    2018-05-01

    In this paper, the steering stability and control strategy of forklift are put forward. Drive based on yawing moment distribution of rotary torque coordination control method, through analyzing the linear two degree of freedom model of forklift truck, forklift yawing angular velocity and mass center side-slip Angle of expectations, as the control target parameters system, using fuzzy controller output driving forklift steering the yawing moment, to drive rotary torque distribution, make the forklift truck to drive horizontal pendulum angular velocity and side-slip Angle tracking reference model very well. In this paper, the lateral stability control system were designed, the joint simulation in MATLAB/Simulink, the simulation results show that under the different partial load, the control system can effectively to control side forklift lateral stability, enhanced the forklift driving safety, for the side forklift steering stability study provides a theoretical basis.

  9. Beam-Forming Concentrating Solar Thermal Array Power Systems

    Science.gov (United States)

    Cwik, Thomas A. (Inventor); Dimotakis, Paul E. (Inventor); Hoppe, Daniel J. (Inventor)

    2016-01-01

    The present invention relates to concentrating solar-power systems and, more particularly, beam-forming concentrating solar thermal array power systems. A solar thermal array power system is provided, including a plurality of solar concentrators arranged in pods. Each solar concentrator includes a solar collector, one or more beam-forming elements, and one or more beam-steering elements. The solar collector is dimensioned to collect and divert incoming rays of sunlight. The beam-forming elements intercept the diverted rays of sunlight, and are shaped to concentrate the rays of sunlight into a beam. The steering elements are shaped, dimensioned, positioned, and/or oriented to deflect the beam toward a beam output path. The beams from the concentrators are converted to heat at a receiver, and the heat may be temporarily stored or directly used to generate electricity.

  10. Working paper on public steering of privately owned sports facilities

    DEFF Research Database (Denmark)

    Iversen, Evald Bundgård

    This short paper discusses how municipalities can steer privately owned sports facilities. Firstly I analyse why steering of privately owned facilities is an interesting subject. Secondly I discuss what the advantages and drawbacks of using different approaches for steering sports facilities are........ Finally I discuss the methodological challenges of measuring activities in sports facilities – and take a closer look at the advantages and drawbacks of using manual and thermal techniques for registering activity.......This short paper discusses how municipalities can steer privately owned sports facilities. Firstly I analyse why steering of privately owned facilities is an interesting subject. Secondly I discuss what the advantages and drawbacks of using different approaches for steering sports facilities are...

  11. Steering Angle Function Algorithm of Morphing of Residential Area

    Directory of Open Access Journals (Sweden)

    XIE Tian

    2015-07-01

    Full Text Available A residential area feature morphing method based on steering angle function is presented. To residential area with the same representation under two different scales,transforming the representation of the residential area polygon from vector coordinates to steering angle function,then using the steering angle function to match,and finding out the similarity and the differences between the residential areas under different scale to get the steering angle function of the the residential areas under any middle scale,the final,transforming the middle scale steering angle function to vector coordinates form,and get the middle shape interpolation of the the residential area polygon.Experimental results show:the residential area morphing method by using steering angle function presented can realize the continuous multi-scale representation under the premise of keeping in shape for the residential area with the rectangular boundary features.

  12. Doublet vs. FODO structure: beam dynamics and layout

    CERN Document Server

    Eshraqi, M; CERN. Geneva. BE Department

    2010-01-01

    A FoDo (singlet) structure is designed for the CERN Superconducting Proton LINAC. This architecture is compared to the baseline (doublet) architecture of SPL on the basis of its beam dynamics performance and the required investment. The sensitivity of both layouts to quadrupole gradient errors and misalignment is checked and a correction scheme for beam steering is proposed. Finally a single quad beam dilution scheme is studied and designed for the pilot beam dump.

  13. Fault-tolerant Actuator System for Electrical Steering of Vehicles

    DEFF Research Database (Denmark)

    Sørensen, Jesper Sandberg; Blanke, Mogens

    2006-01-01

    is needed that meets this requirement. This paper studies the fault-tolerance properties of an electrical steering system. It presents a fault-tolerant architecture where a dedicated AC motor design used in conjunction with cheap voltage measurements can ensure detection of all relevant faults......Being critical to the safety of vehicles, the steering system is required to maintain the vehicles ability to steer until it is brought to halt, should a fault occur. With electrical steering becoming a cost-effective candidate for electrical powered vehicles, a fault-tolerant architecture...

  14. Analysis of Vehicle Steering and Driving Bifurcation Characteristics

    Directory of Open Access Journals (Sweden)

    Xianbin Wang

    2015-01-01

    Full Text Available The typical method of vehicle steering bifurcation analysis is based on the nonlinear autonomous vehicle model deriving from the classic two degrees of freedom (2DOF linear vehicle model. This method usually neglects the driving effect on steering bifurcation characteristics. However, in the steering and driving combined conditions, the tyre under different driving conditions can provide different lateral force. The steering bifurcation mechanism without the driving effect is not able to fully reveal the vehicle steering and driving bifurcation characteristics. Aiming at the aforementioned problem, this paper analyzed the vehicle steering and driving bifurcation characteristics with the consideration of driving effect. Based on the 5DOF vehicle system dynamics model with the consideration of driving effect, the 7DOF autonomous system model was established. The vehicle steering and driving bifurcation dynamic characteristics were analyzed with different driving mode and driving torque. Taking the front-wheel-drive system as an example, the dynamic evolution process of steering and driving bifurcation was analyzed by phase space, system state variables, power spectral density, and Lyapunov index. The numerical recognition results of chaos were also provided. The research results show that the driving mode and driving torque have the obvious effect on steering and driving bifurcation characteristics.

  15. Stress indicators in steers at slaughtering

    Directory of Open Access Journals (Sweden)

    A. Zarrilli

    2010-04-01

    Full Text Available This work aimed to assess the blood modifications of some slaughtering-linked stress hormones in cattle subject to butcher standardized procedures. The blood samples of 20 Limousine 12-13 months old steers have been collected before slaughtering, during lairage, and after stunning by captive bolt gun, during exsanguination. The plasma level of epinephrine, norepinephrine, cortisol and beta-endorphin have been assayed by EIA. The data indicate that catecholamines, cortisol and beta-endorphin did not significantly increase after stunning in these animals.

  16. Steering assistance for backing up articulated vehicles

    Directory of Open Access Journals (Sweden)

    Dieter Zoebel

    2003-10-01

    Full Text Available Articulated vehicles belong to the category of nonholonomous wheelers. Under the aspect of control theory they require a sophisticated handling. This corresponds to the experience of unexercised drivers, for instance maneuvering a car and its caravan into a parking box. In this context some adequate advice for the right steering movements would give an appreciable assistance. Here a visual assistance is proposed and realized. The decisive advice for the driver is derived from kinematic modeling. The system is designed to be integrated into standard cars and trucks. For testing purposes the actual system has been incorporated into an existing backing up simulator.

  17. Study on control schemes of flexible steering system of a multi-axle all-wheel-steering robot

    Directory of Open Access Journals (Sweden)

    Pingxia Zhang

    2016-05-01

    Full Text Available It is well known that a multi-axle wheeled robot possesses larger load capability and also higher drive performance. However, its steering flexibility is degraded due to the large number of wheels. In order to solve this problem, in this article, we proposed three control schemes based on the center of rotation or the steering angles of both the first- and last-axle wheels. To release these control schemes, steering mode selection and also the left wheel’s steering angle in a specific axle are added approaching a practical application. Thereafter, the remaining wheels’ steering angles can be calculated with the Ackerman steering theorem. In order to verify the control effects, a five-axle all-wheel-steering wheeled robot has been developed with the Bluetooth wireless monitor system. Based on the newly designed robot, validation experiments are carried out, such as lateral movement, situ rotation, and multi-mode steering within a narrow space. The results indicate that the proposed design in this article can ensure a more flexible and faster movement within a narrow space. It shows large potential in obstacle avoidance compared with the conventional partial-wheel steering mode.

  18. Spatial Steering of Cyclotron-Resonance Maser Array Antenna by Magnetic Fields

    International Nuclear Information System (INIS)

    Kesar, A.; Jerby, E.

    2001-01-01

    The novel concept of radiation lobe generation and steering by cyclotron-resonance maser (CRM) array is presented. In this scheme the gain and phase of each CRM-element in the array are tuned by magnetic fields which control the cyclotron synchronism condition and the pitch-ratio of each CRM-element. These operating parameters are controlled by the magnetic fields of the solenoid and the kicker, respectively. A numerical example of a CRM-array operating in a gyro-TWT mode is presented. The radiation pattern of a 10-element CRM phased array (15 kV, 1A each) is calculated. The radiation lobe steering by the magnetic field controls is demonstrated in this analysis. A 40 lobe steering range is shown for the 10-element CRM-array at 7.3 GHz. An experimental device is built in our laboratory to demonstrate the active CRM-array antenna concept. Preliminary experimental results of gain and phase-delay of a single CRM-element, as function of electron-beam parameters are presented. These results are compared to the numerical model

  19. A new method by steering kernel-based Richardson–Lucy algorithm for neutron imaging restoration

    International Nuclear Information System (INIS)

    Qiao, Shuang; Wang, Qiao; Sun, Jia-ning; Huang, Ji-peng

    2014-01-01

    Motivated by industrial applications, neutron radiography has become a powerful tool for non-destructive investigation techniques. However, resulted from a combined effect of neutron flux, collimated beam, limited spatial resolution of detector and scattering, etc., the images made with neutrons are degraded severely by blur and noise. For dealing with it, by integrating steering kernel regression into Richardson–Lucy approach, we present a novel restoration method in this paper, which is capable of suppressing noise while restoring details of the blurred imaging result efficiently. Experimental results show that compared with the other methods, the proposed method can improve the restoration quality both visually and quantitatively

  20. Experimental nonlocal steering of Bohmian trajectories.

    Science.gov (United States)

    Xiao, Ya; Kedem, Yaron; Xu, Jin-Shi; Li, Chuan-Feng; Guo, Guang-Can

    2017-06-26

    Interpretations of quantum mechanics (QM), or proposals for underlying theories, that attempt to present a definite realist picture, such as Bohmian mechanics, require strong non-local effects. Naively, these effects would violate causality and contradict special relativity. However if the theory agrees with QM the violation cannot be observed directly. Here, we demonstrate experimentally such an effect: we steer the velocity and trajectory of a Bohmian particle using a remote measurement. We use a pair of photons and entangle the spatial transverse position of one with the polarization of the other. The first photon is sent to a double-slit-like apparatus, where its trajectory is measured using the technique of Weak Measurements. The other photon is projected to a linear polarization state. The choice of polarization state, and the result, steer the first photon in the most intuitive sense of the word. The effect is indeed shown to be dramatic, while being easy to visualize. We discuss its strength and what are the conditions for it to occur.

  1. Optimization Under Uncertainty for Wake Steering Strategies

    Energy Technology Data Exchange (ETDEWEB)

    Quick, Julian [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Annoni, Jennifer [National Renewable Energy Laboratory (NREL), Golden, CO (United States); King, Ryan N [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fleming, Paul A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ning, Andrew [Brigham Young University

    2017-08-03

    Offsetting turbines' yaw orientations from incoming wind is a powerful tool that may be leveraged to reduce undesirable wake effects on downstream turbines. First, we examine a simple two-turbine case to gain intuition as to how inflow direction uncertainty affects the optimal solution. The turbines are modeled with unidirectional inflow such that one turbine directly wakes the other, using ten rotor diameter spacing. We perform optimization under uncertainty (OUU) via a parameter sweep of the front turbine. The OUU solution generally prefers less steering. We then do this optimization for a 60-turbine wind farm with unidirectional inflow, varying the degree of inflow uncertainty and approaching this OUU problem by nesting a polynomial chaos expansion uncertainty quantification routine within an outer optimization. We examined how different levels of uncertainty in the inflow direction effect the ratio of the expected values of deterministic and OUU solutions for steering strategies in the large wind farm, assuming the directional uncertainty used to reach said OUU solution (this ratio is defined as the value of the stochastic solution or VSS).

  2. Steering healthcare service delivery: a regulatory perspective.

    Science.gov (United States)

    Prakash, Gyan

    2015-01-01

    The purpose of this paper is to explore regulation in India's healthcare sector and makes recommendations needed for enhancing the healthcare service. The literature was reviewed to understand healthcare's regulatory context. To understand the current healthcare system, qualitative data were collected from state-level officials, public and private hospital staff. A patient survey was performed to assess service quality (QoS). Regulation plays a central role in driving healthcare QoS. India needs to strengthen market and institutional co-production based approaches for steering its healthcare in which delivery processes are complex and pose different challenges. This study assesses current healthcare regulation in an Indian state and presents a framework for studying and strengthening regulation. Agile regulation should be based on service delivery issues (pull approach) rather than monitoring and sanctions based regulatory environment (push approach). Healthcare pitfalls across the world seem to follow similar follies. India's complexity and experience is useful for emerging and developed economies. The author reviewed around 70 publications and synthesised them in healthcare regulatory contexts. Patient's perception of private providers could be a key input towards steering regulation. Identifying gaps across QoS dimensions would be useful in taking corrective measures.

  3. Beam profile monitors in the NLCTA

    International Nuclear Information System (INIS)

    Nantista, C.; Adolphsen, C.; Brown, R.L.; Fuller, R.; Rifkin, J.

    1997-05-01

    The transverse current profile in the Next Linear Collider Test Accelerator (NLCTA) electron beam can be monitored at several locations along the beam line by means of profile monitors. These consist of insertable phosphor screens, light collection and transport systems, CID cameras, a frame-grabber, and PC and VAX based image analysis software. In addition to their usefulness in tuning and steering the accelerator, the profile monitors are utilized for emittance measurement. A description of these systems and their performance is presented

  4. Theoretical and computational analysis of IFR beam transport on curved channels

    International Nuclear Information System (INIS)

    Rienstra, W.W.

    1987-01-01

    With the successful demonstration at Sandia National Laboratory and at Lawrence Livermore Laboratory of ion focused regime (IFR) electron beam guiding in accelerators there has developed interest in using IFR channels to steer beams along curved paths. The authors report the calculations of the expected emittance growth from such channels and the results of the TRACKER code simulations of IFR steering with the assistance of strong focus sector magnets

  5. The impact of force feedback level on steering performance

    NARCIS (Netherlands)

    Anand, S.; Terken, J.; Hogema, J.H.

    2013-01-01

    Steer-by-wire systems provide designers the ability to customize and personalize force feedback on the steering wheel, based on individual preferences. Earlier studies using subjective responses have shown that there are individual differences in preferences for force feedback. It has also been

  6. Revisiting path steering for 3D manipulation tasks

    NARCIS (Netherlands)

    L. Liu (Lei); J.-B. Martens; R. van Liere (Robert)

    2011-01-01

    htmlabstractThe law of path steering, as proposed by Accot and Zhai, describes a quantitative relationship between human temporal performance and the path spatial characteristics. The steering law is formulated as a continuous goal crossing task, in which a large number of goals are crossed along

  7. Revisiting path steering for 3D manipulation tasks

    NARCIS (Netherlands)

    L. Liu (Lei); J.-B. Martens; R. van Liere (Robert)

    2010-01-01

    htmlabstractThe law of path steering, as proposed by Accot and Zhai, describes a quantitative relationship between human temporal performance and the path spatial characteristics. The steering law is formulated as a continuous goal crossing task, in which a large number of goals are crossed along

  8. Robotic needle steering: design, modeling, planning, and image guidance

    NARCIS (Netherlands)

    Cowan, Noah J.; Goldberg, Ken; Chirikjian, Gregory S.; Fichtinger, Gabor; Alterovitz, Ron; Reed, Kyle B.; Kallem, Vinutha; Misra, Sarthak; Park, Wooram; Okamura, Allison M.; Rosen, Jacob; Hannaford, Blake; Satava, Richard M.

    2010-01-01

    This chapter describes how advances in needle design, modeling, planning, and image guidance make it possible to steer flexible needles from outside the body to reach specified anatomical targets not accessible using traditional needle insertion methods. Steering can be achieved using a variety of

  9. Evaluation of flexible endoscope steering using haptic guidance

    NARCIS (Netherlands)

    Reilink, Rob; Stramigioli, Stefano; Kappers, Astrid M L; Misra, Sarthak

    Background: Steering the tip of a flexible endoscope relies on the physician's dexterity and experience. For complex flexible endoscopes, conventional controls may be inadequate. Methods: A steering method based on a multi-degree-of-freedom haptic device is presented. Haptic cues are generated based

  10. Evaluation of flexible endoscope steering using haptic guidance

    NARCIS (Netherlands)

    Reilink, Rob; Stramigioli, Stefano; Kappers, Astrid M.L.; Misra, Sarthak

    2011-01-01

    Background - Steering the tip of a flexible endoscope relies on the physician’s dexterity and experience. For complex flexible endoscopes, conventional controls may be inadequate. Methods - A steering method based on a multi-degree-of-freedom haptic device is presented. Haptic cues are generated

  11. Airy beams on two dimensional materials

    Science.gov (United States)

    Imran, Muhammad; Li, Rujiang; Jiang, Yuyu; Lin, Xiao; Zheng, Bin; Dehdashti, Shahram; Xu, Zhiwei; Wang, Huaping

    2018-05-01

    We propose that quasi-transverse-magnetic (quasi-TM) Airy beams can be supported on two dimensional (2D) materials. By taking graphene as a typical example, the solution of quasi-TM Airy beams is studied under the paraxial approximation. The analytical field intensity in a bilayer graphene-based planar plasmonic waveguide is confirmed by the simulation results. Due to the tunability of the chemical potential of graphene, the self-accelerating behavior of the quasi-TM Airy beam can be steered effectively. 2D materials thus provide a good platform to investigate the propagation of Airy beams.

  12. Research on Handling Stability of Steering-by-wire System

    Directory of Open Access Journals (Sweden)

    Yuan Ying

    2017-01-01

    Full Text Available The main function of steer-by-wire (SBW system are improving steering characteristics, security and stability of the vehicle. In this paper, the variable steering ratio of SBW system is analyzed, and the method of steering ratio based on fuzzy control and neural network are researched. In order to solve the actual working condition, the wheel angle may not reach the expected value, this paper establishes a twodegree-of-freedom (2-DOF vehicle model, and a Matlab/Simulink simulation model, in which a control strategy based on PID controller is put forward to control the front wheel steering angle. Simulation results show that proposed control strategy based on fuzzy neural network can effectively reduce lateral deviation and improve the handling stability and comfortability of the vehicle.

  13. The Beam Profile Monitoring System for the CERN IRRAD Proton Facility

    CERN Document Server

    Ravotti, F; Glaser, M; Matli, E; Pezzullo, G; Gan, K K; Kagan, H; Smith, S; Warner, J D

    2017-01-01

    GeV/c proton beam is used. During beam steering and irradiation, the intensity and the transverse profile of the proton beam are monitored online with custom-made Beam Profile Monitor (BPM) devices. In this work, we present the design and the architecture of the IRRAD BPM system, some results on its performance with the proton beam, as well as its planned grades.

  14. Retrospective Review of Pectoralis Major Ruptures in Rodeo Steer Wrestlers

    Directory of Open Access Journals (Sweden)

    Breda H. F. Lau

    2013-01-01

    Full Text Available Background. Pectoralis major tendon ruptures have been reported in the literature as occupational injuries, accidental injuries, and sporting activities. Few cases have been reported with respect to rodeo activities. Purpose. To describe a series of PM tendon ruptures in professional steer wrestlers. Study Design. Case series, level of evidence, 4. Methods. A retrospective analysis of PM ruptures in a steer wrestling cohort was performed. Injury data between 1992 and 2008 were reviewed using medical records from the University of Calgary Sport Medicine Center. Results. Nine cases of pectoralis major ruptures in professional steer wrestlers were identified. Injuries occurred during the throwing phase of the steer or while breaking a fall. All athletes reported unexpected or abnormal behavior of the steer that contributed to the mechanism of injury. Seven cases were surgically repaired, while two cases opted for nonsurgical intervention. Eight cases reported successful return to competition following the injury. Conclusion. Steer wrestlers represent a unique cohort of PM rupture case studies. Steer wrestling is a demanding sport that involves throwing maneuvers that may predispose the muscle to rupture. All cases demonstrated good functional outcomes regardless of surgical or non-surgical treatment.

  15. Directional control-response compatibility of joystick steered shuttle cars.

    Science.gov (United States)

    Burgess-Limerick, Robin; Zupanc, Christine M; Wallis, Guy

    2012-01-01

    Shuttle cars are an unusual class of vehicle operated in underground coal mines, sometimes in close proximity to pedestrians and steering errors may have very serious consequences. A directional control-response incompatibility has previously been described in shuttle cars which are controlled using a steering wheel oriented perpendicular to the direction of travel. Some other shuttle car operators are seated perpendicular to the direction of travel and steer the car via a seat mounted joystick. A virtual simulation was utilised to determine whether the steering arrangement in these vehicles maintains directional control-response compatibility. Twenty-four participants were randomly assigned to either a condition corresponding to this design (consistent direction), or a condition in which the directional steering response was reversed while driving in-bye (visual field compatible). Significantly less accurate steering performance was exhibited by the consistent direction group during the in-bye trials only. Shuttle cars which provide the joystick steering mechanism described here require operators to accommodate alternating compatible and incompatible directional control-response relationships with each change of car direction. A virtual simulation of an underground coal shuttle car demonstrates that the design incorporates a directional control-response incompatibility when driving the vehicle in one direction. This design increases the probability of operator error, with potential adverse safety and productivity consequences.

  16. Electron Beam Size Measurements in a Cooling Solenoid

    CERN Document Server

    Kroc, Thomas K; Burov, Alexey; Seletsky, Sergey; Shemyakin, Alexander V

    2005-01-01

    The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide effective cooling of the antiprotons in the Recycler. A measurement system was developed using movable appertures and steering bumps to measure the beam size in a 20 m long, nearly continuous, solenoid. This paper discusses the required beam parameters, the implimentation of the measurement system and results for our application.

  17. Pion beam development for the LAMPF biomedical project

    International Nuclear Information System (INIS)

    Paciotti, M.; Amols, H.; Bradbury, J.; Rivera, O.; Hogstrom, K.; Smith, A.; Inoue, H.; Laubacher, D.; Sandford, S.

    1979-01-01

    Common to both static and dynamic patient irradiations at the LAMPF linac is the problem of maintaining good quality control of beams form a secondary channel. A major contributor to therapy beam variation has been change in electron contamination due to the change in target geometry and proton beam steering. The electron variation problem is described and a solution is presented that has been realized as a result o a new target geometry that allows some control of the electron fraction

  18. Computer codes for automatic tuning of the beam transport at the UNILAC

    International Nuclear Information System (INIS)

    Dahl, L.; Ehrich, A.

    1984-01-01

    For application in routine operation fully automatic computer controlled algorithms are developed for tuning of beam transport elements at the Unilac. Computations, based on emittance measurements, simulate the beam behaviour and evaluate quadrupole settings, in order to produce defined beam properties at specified positions along the accelerator. The interactive program is controlled using a graphic display on which the beam emittances and envelopes are plotted. To align the beam onto the ion-optical axis of the accelerator two automatic computer controlled procedures have been developed. The misalignment of the beam is determined by variation of quadrupole or steering magnet settings with simultaneous measurement of the beam distribution on profile grids. According to the result a pair of steering magnet settings are adjusted to bend the beam on the axis. The effects of computer controlled tuning on beam quality and operation are reported

  19. Preliminary results of spatially resolved ECR ion beam profile investigations

    International Nuclear Information System (INIS)

    Panitzsch, L.; Stalder, M.; Wimmer-Schweingruber, R.F.

    2012-01-01

    The profile of an ion beam produced in an Electron Cyclotron Resonance Ion Source (ECRIS) can vary greatly depending on the source settings and the ion-optical tuning. Strongly focussed ion beams form circular structures (hollow beams) as predicted by simulations and observed in experiments. Each of the rings is predicted to be dominated by ions with same or at least similar m/q-ratios due to ion-optical effects. To check this we performed a series of preliminary investigations to test the required tuning capabilities of our ion source. This includes beam focussing (A) and beam steering (B) using a 3D-movable extraction. Having tuned the source to deliver a beam of strongly focussed ions of different ion species and having steered this beam to match the transmittance area of the sector magnet we also recorded the ion charge state distribution of the strongly focussed beam profile at different, spatially limited positions (C). The preliminary results will be introduced within this paper: it appears that our 3D-movable extraction is very efficient to steer and to focus the beam strongly. The paper is followed by the slides of the presentation. (authors)

  20. 46 CFR 196.37-33 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Instructions for changing steering gear. 196.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering engineroom, relating in order, the different steps to be taken in changing to the emergency steering gear...

  1. 46 CFR 58.25-10 - Main and auxiliary steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Main and auxiliary steering gear. 58.25-10 Section 58.25... AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-10 Main and auxiliary steering gear. (a) Power-operated main and auxiliary steering gear must be separate systems that are independent throughout their...

  2. Strong Einstein-Podolsky-Rosen steering with unconditional entangled states

    Science.gov (United States)

    Steinlechner, Sebastian; Bauchrowitz, Jöran; Eberle, Tobias; Schnabel, Roman

    2013-02-01

    In 1935 Schrödinger introduced the terms entanglement and steering in the context of the famous gedanken experiment discussed by Einstein, Podolsky, and Rosen (EPR). Here, we report on a sixfold increase of the observed EPR-steering effect with regard to previous experiments, as quantified by the Reid criterion. We achieved an unprecedented low conditional variance product of about 0.04<1, where 1 is the upper bound below which steering is demonstrated. The steering effect was observed on an unconditional two-mode-squeezed entangled state that contained a total vacuum state contribution of less than 8%, including detection imperfections. Together with the achieved high interference contrast between the entangled state and a bright coherent laser field, our state is compatible with efficient applications in high-power laser interferometers and fiber-based networks for entanglement distribution.

  3. A Parallel and Distributed Surrogate Model Implementation for Computational Steering

    KAUST Repository

    Butnaru, Daniel; Buse, Gerrit; Pfluger, Dirk

    2012-01-01

    of the input parameters. Such an exploration process is however not possible if the simulation is computationally too expensive. For these cases we present in this paper a scalable computational steering approach utilizing a fast surrogate model as substitute

  4. CCCT - NCTN Steering Committees - Pediatric and Adolescent Tumor

    Science.gov (United States)

    The Pediatric and Adolescent Solid Tumor Steering Committee addresses the design, prioritization and evaluation of concepts for large phase 2 and phase 3 clinical trials in extracranial solid tumors of children and youth.

  5. Real-Time Application Performance Steering and Adaptive Control

    National Research Council Canada - National Science Library

    Reed, Daniel

    2002-01-01

    .... The objective of the Real-time Application Performance Steering and Adaptive Control project is to replace ad hoc, post-mortem performance optimization with an extensible, portable, and distributed...

  6. DSP-based electric power assisted steering using BLDC motor

    Indian Academy of Sciences (India)

    Bharat Electronics Limited, Nandambakkam, Chennai 600 089 e-mail: ... engine speed sensor, vehicle speed sensor, steering column, torsion bar and electronic control unit. Figure 1. .... IEEE Trans. on Industry Application 26(6):. 1144–1157.

  7. Sub-μrad laser beam tracking

    Science.gov (United States)

    Buske, Ivo; Riede, Wolfgang

    2006-09-01

    We compare active optical elements based on different technologies to accomplish the requirements of a 2-dim. fine tracking control system. A cascaded optically and electrically addressable spatial light modulator (OASLM) based on liquid crystals (LC) is used for refractive beam steering. Spatial light modulators provide a controllable phase wedge to generate a beam deflection. Additionally, a tip/tilt mirror approach operating with piezo-electric actuators is investigated. A digital PID controller is implemented for closed-loop control. Beam tracking with a root-mean-squared accuracy of Δα=30 nrad has been laboratory-confirmed.

  8. Computational steering of GEM based detector simulations

    Science.gov (United States)

    Sheharyar, Ali; Bouhali, Othmane

    2017-10-01

    Gas based detector R&D relies heavily on full simulation of detectors and their optimization before final prototypes can be built and tested. These simulations in particular those with complex scenarios such as those involving high detector voltages or gas with larger gains are computationally intensive may take several days or weeks to complete. These long-running simulations usually run on the high-performance computers in batch mode. If the results lead to unexpected behavior, then the simulation might be rerun with different parameters. However, the simulations (or jobs) may have to wait in a queue until they get a chance to run again because the supercomputer is a shared resource that maintains a queue of other user programs as well and executes them as time and priorities permit. It may result in inefficient resource utilization and increase in the turnaround time for the scientific experiment. To overcome this issue, the monitoring of the behavior of a simulation, while it is running (or live), is essential. In this work, we employ the computational steering technique by coupling the detector simulations with a visualization package named VisIt to enable the exploration of the live data as it is produced by the simulation.

  9. Applications of EPR steering in quantum teleportation and NOON states

    Science.gov (United States)

    Zárate, Laura Rosales

    2018-04-01

    Einstein-Podolsky-Rosen (EPR) steering refers to the type of correlations described in the EPR paradox, where one observer seems to affect ("steer") the state of other observer by using local measurements. There have been several works regarding characterization and quantification of EPR steering. One characteristic of this non-local correlation is that it can be asymmetric, while entanglement is symmetric. This asymmetric property is relevant for potential applications of EPR steering to quantum information, in particular to quantum cryptography and quantum teleportation. This latter refers to the process where one observer sends an unknown quantum state to Bob, who is in a different location. They communicate by classical means. Here we will show that EPR steering is a necessary resource to obtain secure continuous variable teleportation. We will also consider NOON states, which is an example of an entangled state. For this state, we will present a steering signature. This contribution reviews the work derived in Refs. [1] and [2], which was presented as an invited talk in ELAF 2017.

  10. Optimization Under Uncertainty for Wake Steering Strategies: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Quick, Julian [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Annoni, Jennifer [National Renewable Energy Laboratory (NREL), Golden, CO (United States); King, Ryan N [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, Katherine L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Fleming, Paul A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ning, Andrew [Brigham Young University

    2017-05-01

    Wind turbines in a wind power plant experience significant power losses because of aerodynamic interactions between turbines. One control strategy to reduce these losses is known as 'wake steering,' in which upstream turbines are yawed to direct wakes away from downstream turbines. Previous wake steering research has assumed perfect information, however, there can be significant uncertainty in many aspects of the problem, including wind inflow and various turbine measurements. Uncertainty has significant implications for performance of wake steering strategies. Consequently, the authors formulate and solve an optimization under uncertainty (OUU) problem for finding optimal wake steering strategies in the presence of yaw angle uncertainty. The OUU wake steering strategy is demonstrated on a two-turbine test case and on the utility-scale, offshore Princess Amalia Wind Farm. When we accounted for yaw angle uncertainty in the Princess Amalia Wind Farm case, inflow-direction-specific OUU solutions produced between 0% and 1.4% more power than the deterministically optimized steering strategies, resulting in an overall annual average improvement of 0.2%. More importantly, the deterministic optimization is expected to perform worse and with more downside risk than the OUU result when realistic uncertainty is taken into account. Additionally, the OUU solution produces fewer extreme yaw situations than the deterministic solution.

  11. Creation of quantum steering by interaction with a common bath

    Science.gov (United States)

    Sun, Zhe; Xu, Xiao-Qiang; Liu, Bo

    2018-05-01

    By applying the hierarchy equation method, we computationally study the creation of quantum steering in a two-qubit system interacting with a common bosonic bath. The calculation does not adopt conventional approximate approaches, such as the Born, Markov, rotating-wave, and other perturbative approximations. Three kinds of quantum steering, i.e., Einstein-Podolsky-Rosen steering (EPRS), temporal steering (TS), and spatiotemporal steering (STS), are considered. Since the initial state of the two qubits is chosen as a product state, there does not exist EPRS at the beginning. During the evolution, we find that STS as well as EPRS are generated at the same time. An inversion relationship between STS and TS is revealed. By varying the system-bath coupling strength from weak to ultrastrong regimes, we find the nonmonotonic dependence of STS, TS, and EPRS on the coupling strength. It is interesting to study the dynamics of the three kinds of quantum steering by using an exactly numerical method, which is not considered in previous researches.

  12. BEAMLINE-CONTROLLED STEERING OF SOURCE-POINT ANGLE AT THE ADVANCED PHOTON SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Emery, L.; Fystro, G.; Shang, H.; Smith, M.

    2017-06-25

    An EPICS-based steering software system has been implemented for beamline personnel to directly steer the angle of the synchrotron radiation sources at the Advanced Photon Source. A script running on a workstation monitors "start steering" beamline EPICS records, and effects a steering given by the value of the "angle request" EPICS record. The new system makes the steering process much faster than before, although the older steering protocols can still be used. The robustness features of the original steering remain. Feedback messages are provided to the beamlines and the accelerator operators. Underpinning this new steering protocol is the recent refinement of the global orbit feedback process whereby feedforward of dipole corrector set points and orbit set points are used to create a local steering bump in a rapid and seamless way.

  13. Nonlocality of a single photon: Paths to an Einstein-Podolsky-Rosen-steering experiment

    International Nuclear Information System (INIS)

    Jones, S. J.; Wiseman, H. M.

    2011-01-01

    A single-photon incident on a beam splitter produces an entangled field state, and in principle could be used to violate a Bell inequality, but such an experiment (without postselection) is beyond the reach of current experiments. Here we consider the somewhat simpler task of demonstrating Einstein-Podolsky-Rosen (EPR) steering with a single photon (also without postselection). We demonstrate that Alice's choice of measurement on her portion of the entangled state can affect Bob's portion of the entangled state in his laboratory, in a sense rigorously defined by us and Doherty [Phys. Rev. Lett. 98, 140402 (2007)]. Previous work by Lvovsky and coworkers [Phys. Rev. Lett. 92, 047903 (2004)] has addressed this phenomenon (which they called remote preparation) experimentally using homodyne measurements on a single photon. Here we show that, unfortunately, their experimental parameters do not meet the bounds necessary for a rigorous demonstration of EPR steering with a single photon. However, we also show that modest improvements in the experimental parameters, and the addition of photon counting to the arsenal of Alice's measurements, would be sufficient to allow such a demonstration.

  14. Beam-beam phenomenology

    International Nuclear Information System (INIS)

    Teng, L.C.

    1980-01-01

    In colliding beam storage rings the beam collision regions are generally so short that the beam-beam interaction can be considered as a series of evenly spaced non-linear kicks superimposed on otherwise stable linear oscillations. Most of the numerical studies on computers were carried out in just this manner. But for some reason this model has not been extensively employed in analytical studies. This is perhaps because all analytical work has so far been done by mathematicians pursuing general transcendental features of non-linear mechanics for whom this specific model of the specific system of colliding beams is too parochial and too repugnantly physical. Be that as it may, this model is of direct interest to accelerator physicists and is amenable to (1) further simplification, (2) physical approximation, and (3) solution by analogy to known phenomena

  15. Altered steering strategies for goal-directed locomotion in stroke

    Science.gov (United States)

    2013-01-01

    Background Individuals who have sustained a stroke can manifest altered locomotor steering behaviors when exposed to optic flows expanding from different locations. Whether these alterations persist in the presence of a visible goal and whether they can be explained by the presence of a perceptuo-motor disorder remain unknown. The purpose of this study was to compare stroke participants and healthy participants on their ability to control heading while exposed to changing optic flows and target locations. Methods Ten participants with stroke (55.6 ± 9.3 yrs) and ten healthy controls (57.0 ± 11.5 yrs) participated in a mouse-driven steering task (perceptuo-motor task) while seated and in a walking steering task. In the seated steering task, participants were instructed to head or ‘walk’ toward a target in the virtual environment by using a mouse while wearing a helmet-mounted display (HMD). In the walking task, participants performed a similar steering task in the same virtual environment while walking overground at their comfortable speed. For both experiments, the target and/or the focus of expansion (FOE) of the optic flow shifted to the side (±20°) or remained centered. The main outcome measure was net heading errors (NHE). Secondary outcomes included mediolateral displacement, horizontal head orientation, and onsets of heading and head reorientation. Results In the walking steering task, the presence of FOE shifts modulated the extent and timing of mediolateral displacement and head rotation changes, as well as NHE magnitudes. Participants overshot and undershot their net heading, respectively, in response to ipsilateral and contralateral FOE and target shifts. Stroke participants made larger NHEs, especially when the FOE was shifted towards the non-paretic side. In the seated steering task, similar NHEs were observed between stroke and healthy participants. Conclusions The findings highlight the fine coordination between rotational and

  16. Generation of electron Airy beams.

    Science.gov (United States)

    Voloch-Bloch, Noa; Lereah, Yossi; Lilach, Yigal; Gover, Avraham; Arie, Ady

    2013-02-21

    Within the framework of quantum mechanics, a unique particle wave packet exists in the form of the Airy function. Its counterintuitive properties are revealed as it propagates in time or space: the quantum probability wave packet preserves its shape despite dispersion or diffraction and propagates along a parabolic caustic trajectory, even though no force is applied. This does not contradict Newton's laws of motion, because the wave packet centroid propagates along a straight line. Nearly 30 years later, this wave packet, known as an accelerating Airy beam, was realized in the optical domain; later it was generalized to an orthogonal and complete family of beams that propagate along parabolic trajectories, as well as to beams that propagate along arbitrary convex trajectories. Here we report the experimental generation and observation of the Airy beams of free electrons. These electron Airy beams were generated by diffraction of electrons through a nanoscale hologram, which imprinted on the electrons' wavefunction a cubic phase modulation in the transverse plane. The highest-intensity lobes of the generated beams indeed followed parabolic trajectories. We directly observed a non-spreading electron wavefunction that self-heals, restoring its original shape after passing an obstacle. This holographic generation of electron Airy beams opens up new avenues for steering electronic wave packets like their photonic counterparts, because the wave packets can be imprinted with arbitrary shapes or trajectories.

  17. Observation of one-way Einstein-Podolsky-Rosen steering

    Science.gov (United States)

    Händchen, Vitus; Eberle, Tobias; Steinlechner, Sebastian; Samblowski, Aiko; Franz, Torsten; Werner, Reinhard F.; Schnabel, Roman

    2012-09-01

    The distinctive non-classical features of quantum physics were first discussed in the seminal paper by A. Einstein, B. Podolsky and N. Rosen (EPR) in 1935. In his immediate response, E. Schrödinger introduced the notion of entanglement, now seen as the essential resource in quantum information as well as in quantum metrology. Furthermore, he showed that at the core of the EPR argument is a phenomenon that he called steering. In contrast to entanglement and violations of Bell's inequalities, steering implies a direction between the parties involved. Recent theoretical works have precisely defined this property, but the question arose as to whether there are bipartite states showing steering only in one direction. Here, we present an experimental realization of two entangled Gaussian modes of light that in fact shows the steering effect in one direction but not in the other. The generated one-way steering gives a new insight into quantum physics and may open a new field of applications in quantum information.

  18. Sources of carbohydrates in the ingestive behavior of feedlot steers

    Directory of Open Access Journals (Sweden)

    Viviane Santos da Silva

    2014-05-01

    Full Text Available In this article we research the influence of different sources of carbohydrates (corn, soybean hulls or wheat bran upon the digestive behavior of 24 confined castrated steers with an initial average age and weight of 20 months and 330 kg born from the cross between Charolais and Nellore. The diet was composed of 40% sorghum silage and 60% concentrate. The time spent on total ruminating (an average of 454.6 min/day was not influenced by the source of carbohydrate. The animals from the wheat bran treatment spent less time idle (718 min in relation to those on the corn and soybean hulls treatments, which did not differ between themselves (an average of 792 min/day. The steers from the wheat bran treatment remained less time feeding (184 min/day compared with those fed the other treatments, whose average time of permanence in this activity was 214 minutes per day. The other studied variables did not present a significant difference between the treatments. Inclusion of wheat bran in the diet of the confined steers results in less spent time idle, while steers feeding on soybean hulls spend less time feeding. The use of corn, soybean hulls, or wheat bran in the diet of the confined steers does not affect the total cudding time.

  19. Design of patient-specific focused ultrasound arrays for non-invasive brain therapy with increased trans-skull transmission and steering range

    Science.gov (United States)

    Hughes, Alec; Hynynen, Kullervo

    2017-09-01

    The use of a phased array of ultrasound transducer elements to sonicate through the skull has opened the way for new treatments and the delivery of therapeutics beyond the blood-brain barrier. The limited steering range of current clinical devices, particularly at higher frequencies, limits the regions of the brain that are considered treatable by ultrasound. A new array design is introduced that allows for high levels of beam steering and increased transmission throughout the brain. These improvements are achieved using concave transducers normal to the outer-skull surface in a patient-specific configuration to target within the skull, so that the far-field of each beam is within the brain. It is shown that by using pulsed ultrasound waves timed to arrive in-phase at the desired target, sufficient levels of acoustic energy are delivered for blood-brain barrier opening throughout the brain.

  20. Steer wrestling : Hemisphere GPS hopes to bring its auto-steering technology to the oilsands

    Energy Technology Data Exchange (ETDEWEB)

    Bentein, J.

    2009-01-15

    Hemisphere GPS has developed a technology to guide giant dump trucks used in oilsand mining operations. The technology offers the possibility to haul oilsands from northern Alberta mines using driverless, remotely-guided trucks. The GPS system would ensure more accuracy than a human operator. The technology has the potential to be commercialized within the next year, and may be adapted for the mining industry. The unmanned technology would help oilsands mine operators lower their labour costs. Hemisphere GPS gained access to the steer-by-wire technology when it purchased the Australian software company Beeline Technologies Pty Ltd. Hemisphere GPS has also developed prototype unmanned drilling rig technology which has considerable potential in the energy industry. The company has won numerous awards in recognition of its commercial achievements in science and technology. 1 fig.

  1. Resonant Laser Manipulation of an Atomic Beam

    Science.gov (United States)

    2010-07-01

    Technical Paper 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Resonant Laser Manipulation of an Atomic Beam...steering and collimating flows with higher densities and energies than current common practice . One impediment to this extension is the development of...where Δεg is the ground state Stark shift, Ω is the Rabi frequency (related to intensity), Isat is the saturation intensity of the transition, and I(r

  2. On setting magnets in the PEP beam-transport line

    International Nuclear Information System (INIS)

    Peterson, J.M.

    1979-01-01

    This paper discusses magnets in the PEP beam-transport line. Topics discussed are: conditioning, direction of excitation, rate of excitation; determination of the excitation current for the principal bend magnets; steering mechanisms; bump magnets; and determination of excitation currents of the quadrupole magnets

  3. Fast and reliable control of steering mirrors with application to free-space communication

    KAUST Repository

    Ibrir, Salim; Su, Chun-Yi; Ooi, Boon S.; Alouini, Mohamed-Slim

    2018-01-01

    After modeling a laser beam pointing system actuated by a piezo-electric fast steering mirror (FSM), an observer-based linear feedback controller is developed to correct the position of the laser spot communicated by the position sensing detector (PSD). The modeling and the control actions have been considered with and without the hysteresis effect induced by the piezoelectric actuators of the FSM. The design of the feedback is given through the solution of parametric matrix inequalities. It was found that the integral feedback design is very efficient in handling input and system uncertainty. The linearity of the observer-based feedback has facilitated both the real-time implementation of the control strategy and the proof of stability using dynamic-output feedbacks.

  4. Fast and reliable control of steering mirrors with application to free-space communication

    KAUST Repository

    Ibrir, Salim

    2018-03-15

    After modeling a laser beam pointing system actuated by a piezo-electric fast steering mirror (FSM), an observer-based linear feedback controller is developed to correct the position of the laser spot communicated by the position sensing detector (PSD). The modeling and the control actions have been considered with and without the hysteresis effect induced by the piezoelectric actuators of the FSM. The design of the feedback is given through the solution of parametric matrix inequalities. It was found that the integral feedback design is very efficient in handling input and system uncertainty. The linearity of the observer-based feedback has facilitated both the real-time implementation of the control strategy and the proof of stability using dynamic-output feedbacks.

  5. Experimental EPR-steering using Bell-local states

    Science.gov (United States)

    Saunders, D. J.; Jones, S. J.; Wiseman, H. M.; Pryde, G. J.

    2010-11-01

    The concept of `steering' was introduced in 1935 by Schrödinger as a generalization of the EPR (Einstein-Podolsky-Rosen) paradox. It has recently been formalized as a quantum-information task with arbitrary bipartite states and measurements, for which the existence of entanglement is necessary but not sufficient. Previous experiments in this area have been restricted to an approach that followed the original EPR argument in considering only two different measurement settings per side. Here we demonstrate experimentally that EPR-steering occurs for mixed entangled states that are Bell local (that is, that cannot possibly demonstrate Bell non-locality). Unlike the case of Bell inequalities, increasing the number of measurement settings beyond two-we use up to six-significantly increases the robustness of the EPR-steering phenomenon to noise.

  6. Field test of wake steering at an offshore wind farm

    Directory of Open Access Journals (Sweden)

    P. Fleming

    2017-05-01

    Full Text Available In this paper, a field test of wake-steering control is presented. The field test is the result of a collaboration between the National Renewable Energy Laboratory (NREL and Envision Energy, a smart energy management company and turbine manufacturer. In the campaign, an array of turbines within an operating commercial offshore wind farm in China have the normal yaw controller modified to implement wake steering according to a yaw control strategy. The strategy was designed using NREL wind farm models, including a computational fluid dynamics model, Simulator fOr Wind Farm Applications (SOWFA, for understanding wake dynamics and an engineering model, FLOw Redirection and Induction in Steady State (FLORIS, for yaw control optimization. Results indicate that, within the certainty afforded by the data, the wake-steering controller was successful in increasing power capture, by amounts similar to those predicted from the models.

  7. Dissipation induced asymmetric steering of distant atomic ensembles

    Science.gov (United States)

    Cheng, Guangling; Tan, Huatang; Chen, Aixi

    2018-04-01

    The asymmetric steering effects of separated atomic ensembles denoted by the effective bosonic modes have been explored by the means of quantum reservoir engineering in the setting of the cascaded cavities, in each of which an atomic ensemble is involved. It is shown that the steady-state asymmetric steering of the mesoscopic objects is unconditionally achieved via the dissipation of the cavities, by which the nonlocal interaction occurs between two atomic ensembles, and the direction of steering could be easily controlled through variation of certain tunable system parameters. One advantage of the present scheme is that it could be rather robust against parameter fluctuations, and does not require the accurate control of evolution time and the original state of the system. Furthermore, the double-channel Raman transitions between the long-lived atomic ground states are used and the atomic ensembles act as the quantum network nodes, which makes our scheme insensitive to the collective spontaneous emission of atoms.

  8. A Parallel and Distributed Surrogate Model Implementation for Computational Steering

    KAUST Repository

    Butnaru, Daniel

    2012-06-01

    Understanding the influence of multiple parameters in a complex simulation setting is a difficult task. In the ideal case, the scientist can freely steer such a simulation and is immediately presented with the results for a certain configuration of the input parameters. Such an exploration process is however not possible if the simulation is computationally too expensive. For these cases we present in this paper a scalable computational steering approach utilizing a fast surrogate model as substitute for the time-consuming simulation. The surrogate model we propose is based on the sparse grid technique, and we identify the main computational tasks associated with its evaluation and its extension. We further show how distributed data management combined with the specific use of accelerators allows us to approximate and deliver simulation results to a high-resolution visualization system in real-time. This significantly enhances the steering workflow and facilitates the interactive exploration of large datasets. © 2012 IEEE.

  9. Autonomous Shepherding Behaviors of Multiple Target Steering Robots.

    Science.gov (United States)

    Lee, Wonki; Kim, DaeEun

    2017-11-25

    This paper presents a distributed coordination methodology for multi-robot systems, based on nearest-neighbor interactions. Among many interesting tasks that may be performed using swarm robots, we propose a biologically-inspired control law for a shepherding task, whereby a group of external agents drives another group of agents to a desired location. First, we generated sheep-like robots that act like a flock. We assume that each agent is capable of measuring the relative location and velocity to each of its neighbors within a limited sensing area. Then, we designed a control strategy for shepherd-like robots that have information regarding where to go and a steering ability to control the flock, according to the robots' position relative to the flock. We define several independent behavior rules; each agent calculates to what extent it will move by summarizing each rule. The flocking sheep agents detect the steering agents and try to avoid them; this tendency leads to movement of the flock. Each steering agent only needs to focus on guiding the nearest flocking agent to the desired location. Without centralized coordination, multiple steering agents produce an arc formation to control the flock effectively. In addition, we propose a new rule for collecting behavior, whereby a scattered flock or multiple flocks are consolidated. From simulation results with multiple robots, we show that each robot performs actions for the shepherding behavior, and only a few steering agents are needed to control the whole flock. The results are displayed in maps that trace the paths of the flock and steering robots. Performance is evaluated via time cost and path accuracy to demonstrate the effectiveness of this approach.

  10. Autonomous Shepherding Behaviors of Multiple Target Steering Robots

    Directory of Open Access Journals (Sweden)

    Wonki Lee

    2017-11-01

    Full Text Available This paper presents a distributed coordination methodology for multi-robot systems, based on nearest-neighbor interactions. Among many interesting tasks that may be performed using swarm robots, we propose a biologically-inspired control law for a shepherding task, whereby a group of external agents drives another group of agents to a desired location. First, we generated sheep-like robots that act like a flock. We assume that each agent is capable of measuring the relative location and velocity to each of its neighbors within a limited sensing area. Then, we designed a control strategy for shepherd-like robots that have information regarding where to go and a steering ability to control the flock, according to the robots’ position relative to the flock. We define several independent behavior rules; each agent calculates to what extent it will move by summarizing each rule. The flocking sheep agents detect the steering agents and try to avoid them; this tendency leads to movement of the flock. Each steering agent only needs to focus on guiding the nearest flocking agent to the desired location. Without centralized coordination, multiple steering agents produce an arc formation to control the flock effectively. In addition, we propose a new rule for collecting behavior, whereby a scattered flock or multiple flocks are consolidated. From simulation results with multiple robots, we show that each robot performs actions for the shepherding behavior, and only a few steering agents are needed to control the whole flock. The results are displayed in maps that trace the paths of the flock and steering robots. Performance is evaluated via time cost and path accuracy to demonstrate the effectiveness of this approach.

  11. Stochastic stability of four-wheel-steering system

    International Nuclear Information System (INIS)

    Huang Dongwei; Wang Hongli; Zhu Zhiwen; Feng Zhang

    2007-01-01

    A four-wheel-steering system subjected to white noise excitations was reduced to a two-degree-of-freedom quasi-non-integrable-Hamiltonian system. Subsequently we obtained an one-dimensional Ito stochastic differential equation for the averaged Hamiltonian of the system by using the stochastic averaging method for quasi-non-integrable-Hamiltonian systems. Thus, the stochastic stability of four-wheel-steering system was analyzed by analyzing the sample behaviors of the averaged Hamiltonian at the boundary H = 0 and calculating its Lyapunov exponent. An example given at the end demonstrated that the conclusion obtained is of considerable significance

  12. Steering of Educational Processes in a Digital Medium Environment

    DEFF Research Database (Denmark)

    Tække, Jesper; Paulsen, Michael

    2015-01-01

    by systems theory we outline a more adequate way of teaching in the new medium environment – a teaching that can manage the new situation and use the new possibilities provided by the digital media. The argumentation builds on empirical findings from the action research project Socio Media Education (SME......This paper is about challenges to steering and leadership of educational interaction in classrooms provided by the new medium environment that comes with digital media. In the new medium environment, the old way of steering what is going on in the classroom appears not to work since...

  13. BEAM LINE DESIGN FOR THE CERN HIRADMAT TEST FACILITY

    CERN Document Server

    Hessler, C; Goddard, B; Meddahi, M; Weterings, W

    2009-01-01

    The LHC phase II collimation project requires beam shock and impact tests of materials used for beam intercepting devices. Similar tests are also of great interest for other accelerator components such as beam entrance/exit windows and protection devices. For this purpose a dedicated High Radiation Material test facility (HiRadMat) is under study. This facility may be installed at CERN at the location of a former beam line. This paper describes the associated beam line which is foreseen to deliver a 450 GeV proton beam from the SPS with an intensity of up to 3×1013 protons per shot. Different beam line designs will be compared and the choice of the beam steering and diagnostic elements will be discussed, as well as operational issues.

  14. Beam Line Design for the CERN Hiradmat Test Facility

    CERN Document Server

    Hessler, C; Goddard, B; Meddahi, M; Weterings, W

    2010-01-01

    The LHC phase II collimation project requires beam shock and impact tests of materials used for beam intercepting devices. Similar tests are also of great interest for other accelerator components such as beam entrance/exit windows and protection devices. For this purpose a dedicated High Radiation Material test facility (HiRadMat) is under study. This facility may be installed at CERN at the location of a former beam line. This paper describes the associated beam line which is foreseen to deliver a 450 GeV proton beam from the SPS with an intensity of up to 3×10**13 protons per shot. Different beam line designs will be compared and the choice of the beam steering and diagnostic elements will be discussed, as well as operational issues.

  15. Initial alignment method for free space optics laser beam

    Science.gov (United States)

    Shimada, Yuta; Tashiro, Yuki; Izumi, Kiyotaka; Yoshida, Koichi; Tsujimura, Takeshi

    2016-08-01

    The authors have newly proposed and constructed an active free space optics transmission system. It is equipped with a motor driven laser emitting mechanism and positioning photodiodes, and it transmits a collimated thin laser beam and accurately steers the laser beam direction. It is necessary to introduce the laser beam within sensible range of the receiver in advance of laser beam tracking control. This paper studies an estimation method of laser reaching point for initial laser beam alignment. Distributed photodiodes detect laser luminescence at respective position, and the optical axis of laser beam is analytically presumed based on the Gaussian beam optics. Computer simulation evaluates the accuracy of the proposed estimation methods, and results disclose that the methods help us to guide the laser beam to a distant receiver.

  16. Effects of slow-release urea on ruminal digesta characteristics and growth performance in beef steers

    DEFF Research Database (Denmark)

    Taylor-Edwards, C C; Hibbard, G; Kitts, S E

    2009-01-01

    Two experiments were conducted to evaluate the effects of slow urea (SRU) versus feed-grade urea on ruminal metabolite characteristics in steers and DMI, gain, and G:F in growing beef steers.......Two experiments were conducted to evaluate the effects of slow urea (SRU) versus feed-grade urea on ruminal metabolite characteristics in steers and DMI, gain, and G:F in growing beef steers....

  17. Beam trajectories through the upgraded XTU tandem

    International Nuclear Information System (INIS)

    Guan Xialing

    1988-01-01

    The paper deals with a problem applicable to all electrostatic accelerators with inclined field accelerating tubes, how the trajectory of the central beam particle is affected if one of the accelerating gaps must be shorted out due to insulator failure. For the long tube of the Legnaro XTU tandem the effect of each accelerator gap is calculated and a method of compensation either by shorting out an appropriate gap with reversed incline or by appropriately steering the beam into the entrance of the low energy tube is given. (orig.)

  18. supplementation of energy and/or protein to steers grazing summer ...

    African Journals Online (AJOL)

    Some aspects of the effect of supplementary energy and/or protein, strategically ptovided to steers on summer veld, were investi gated. 40 Friesland steers in the age ... was posed whether the strategic provision of energy and or protein to steers grazing .... Definitions and abbreviotions was determined after cooling for 24 h ...

  19. Design, Modeling And Control Of Steering And Braking For An Urban Electric Vehicle

    OpenAIRE

    Maciua, Dragos

    1996-01-01

    This report describes research which involved the design modification, modeling and control of automatic steering and braking systems for an urban electric vehicle. The vehicle is equipped with four-wheel independent drive, four-wheel independent braking and four-wheel steering. Control algorithms were developed for steering and braking. Simulation results show the feasibility of the algorithms.

  20. Chromium supplementation enhances the acute phase response of steers to a lipopolysaccharide (LPS) challenge

    Science.gov (United States)

    The study examined the effect of chromium supplementation on the response of steers to an LPS challenge. Twenty crossbred steers (235±4 kg BW) received 0 ppb (Control; C) or 200 ppb chromium propionate (CHR) for 55 days. Steers were fitted with jugular catheters and rectal temperature (RT) recording...

  1. Enhancement of the acute phase response to lipopolysaccharide (LPS) challenge in steers supplemented with chromium

    Science.gov (United States)

    The study examined the effect of chromium supplementation on the response of steers to an LPS challenge. Twenty steers received a premix that added 0 (control) or 0.2 mg/kg of chromium (KemTRACE®brandChromiumProprionate 0.04%, Kemin Industries) to the total diet on a dry matter basis for 55 d. Steer...

  2. 46 CFR 78.47-55 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Instructions for changing steering gear. 78.47-55... OPERATIONS Markings for Fire and Emergency Equipment, Etc. § 78.47-55 Instructions for changing steering gear..., relating in order, the different steps to be taken in changing to the emergency steering gear. Each clutch...

  3. 46 CFR 97.37-33 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 97.37-33... steering gear. (a) Instructions in at least 1/2 inch letters and figures shall be posted in the steering... gear. Each clutch, gear, wheel, lever, valve, or switch which is used during the changeover shall be...

  4. Steering a Steady Course in the South China Sea

    Science.gov (United States)

    2017-10-27

    NUMBER (Include area code ) 401-841-3556 Standard Form 298 (Rev. 8-98) Prescribed by ANSI-Std Z39-18 Steering a Steady Course in the South...minor features claimed by a Filipino civilian in the SCS are not worth US blood, talent , or treasure defending against the PRC. The PRC, on the other

  5. CLOSTAT alters the serum metabolome of Holstein Steer Calves

    Science.gov (United States)

    Probiotics are gaining increased interest in calf feeding operations as some producers seek novel, non-antibiotic technologies to improve health and performance. Therefore, the objective of this study was to evaluate changes in serum metabolomic compounds of Holstein steer calves supplemented with C...

  6. Trailer steering control of a tractor-trailer Robot

    NARCIS (Netherlands)

    Ritzen, P.J.; Roebroek, E.J.W.; Van De Wouw, N.; Jiang, Z.P.; Nijmeijer, H.

    2016-01-01

    In this paper, we consider active trailer steering control as a means to improve the maneuverability of (long) truck-trailer combinations during cornering. Hereto, we formulate the problem of reducing the so-called swept path width during cornering and that of eliminating unsafe tail swing of the

  7. Sliding mode observer design for automatic steering of vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.R.; Rachid, A. [LSA, Amiens (France); Xu, S.J. [Harbin Inst. of Tech. (China)]|[IUT de Longwy, Cosnes et Romain (France); Darouach, M. [IUT de Longwy, Cosnes et Romain (France)

    2000-07-01

    This paper deals with the observer design problem for automatic steering of vehicles. The lateral motion of the vehicles is considered. A sliding mode observer is derived such that the observation errors converge to zero asymptotically in finite time. The simulation results have shown that the design is very effective. (orig.)

  8. Steering Micro-Robotic Swarm by Dynamic Actuating Fields

    NARCIS (Netherlands)

    Chao, Q.; Yu, J; Dai, C.; Xu, T; Zhang, L.; Wang, C.C.; Jin, X.

    2016-01-01

    We present a general solution for steering microrobotic
    swarm by dynamic actuating fields. In our approach, the
    motion of micro-robots is controlled by changing the actuating
    direction of a field applied to them. The time-series sequence
    of actuating field’s directions can be

  9. Complex Education Systems: From Steering Change to Governance

    Science.gov (United States)

    Michel, Alain

    2016-01-01

    The theories and approaches of steering/monitoring a process of change within education systems have evolved over the last 20 years or so as a result of many factors such as globalisation and decentralisation, a faster pace of change, increasing expectations and demands from various stakeholders (parents, employers, teacher unions, etc.) and the…

  10. Multifunctional Converter Drive for Automotive Electric Power Steering Systems

    NARCIS (Netherlands)

    Hackner, T.J.

    2013-01-01

    In this thesis it is shown that in the case of an automotive electric power steering system, critical pulse power loads can be decoupled from the power net with a storage element and a multifunctional converter. A multifunctional converter system is proposed because it uses the motor drive system as

  11. Improving yaw dynamics by feedforward rear wheel steering

    NARCIS (Netherlands)

    Besselink, I.J.M.; Veldhuizen, T.J.; Nijmeijer, H.

    2008-01-01

    Active rear wheel steering can be applied to improve vehicle yaw dynamics. In this paper two possible control algorithms are discussed. The first method is a yaw rate feedback controller with a reference model, which has been reported in a similar form previously in literature. The second controller

  12. Auditory orientation in crickets: Pattern recognition controls reactive steering

    Science.gov (United States)

    Poulet, James F. A.; Hedwig, Berthold

    2005-10-01

    Many groups of insects are specialists in exploiting sensory cues to locate food resources or conspecifics. To achieve orientation, bees and ants analyze the polarization pattern of the sky, male moths orient along the females' odor plume, and cicadas, grasshoppers, and crickets use acoustic signals to locate singing conspecifics. In comparison with olfactory and visual orientation, where learning is involved, auditory processing underlying orientation in insects appears to be more hardwired and genetically determined. In each of these examples, however, orientation requires a recognition process identifying the crucial sensory pattern to interact with a localization process directing the animal's locomotor activity. Here, we characterize this interaction. Using a sensitive trackball system, we show that, during cricket auditory behavior, the recognition process that is tuned toward the species-specific song pattern controls the amplitude of auditory evoked steering responses. Females perform small reactive steering movements toward any sound patterns. Hearing the male's calling song increases the gain of auditory steering within 2-5 s, and the animals even steer toward nonattractive sound patterns inserted into the speciesspecific pattern. This gain control mechanism in the auditory-to-motor pathway allows crickets to pursue species-specific sound patterns temporarily corrupted by environmental factors and may reflect the organization of recognition and localization networks in insects. localization | phonotaxis

  13. Carcass mass gains of steers grazing star grass, with different ...

    African Journals Online (AJOL)

    Carcass mass gains of steers grazing dryland Cynodon aethiopicus cv. No. 2 Star grass pastures during the growing season were determined for each of 16 treatments comprising four levels of nitrogen fertilisation in combination with four overlapping sets of stocking rates. The treatments were repeated over four growing ...

  14. Slow-release urea in supplement fed to beef steers

    Directory of Open Access Journals (Sweden)

    Ana Paula Gonçalves

    2015-02-01

    Full Text Available Replacing regular urea (RU by slow-release urea (SRU at two levels of non-protein nitrogen (NPN in concentrate, offered with low-quality roughage, was evaluated in beef steers on dry matter intake (DMI, ruminal fermentation parameters, plasma urea nitrogen (PUN, total tract apparent digestibility of diets and in situ degradability of nitrogen sources. Eight ruminally cannulated steers were allocated into two 4x4 Latin squares, totalizing four treatments: 40 NPN/0 SRU: 40% of concentrate crude protein (CP as NPN, resulting from 0% of SRU and 100% of RU; 40 NPN/50 SRU: 40% of concentrate CP as NPN, resulting from 50% of SRU and 50% of RU; 40 NPN/100 SRU: 40% of concentrate CP as NPN, resulting from 100% of SRU and 0% of RU; 80 NPN/100 SRU: 80% of concentrate CP as NPN, resulting from 100% of SRU and 0% of RU. Results showed that partial substitution of regular urea by slow-release urea did not alter dry matter intake, pattern of ruminal fermentation or plasma urea nitrogen concentrations and increased the total tract apparent digestibility of crude protein in steers diets. The increase in non-protein nitrogen content in crude protein of the concentrate could compromise feed intake and the efficiency of nutrient utilization in the steers fed complete diets based on low quality forage.

  15. Steering with big words: articulating ideographs in research programs

    NARCIS (Netherlands)

    Bos, Colette; Walhout, Bart; Walhout, Bart; Peine, Alexander; van Lente, Harro

    2014-01-01

    Nowadays, science should address societal challenges, such as ‘sustainability’, or ‘responsible research and innovation’. This emerging form of steering toward broad and generic goals involves the use of ‘big words’: encompassing concepts that are uncontested themselves, but that allow for multiple

  16. Steering with big words: articulating ideographs in nanotechnology

    NARCIS (Netherlands)

    Bos, Colette; Walhout, Albert; Peine, Alex; van Lente, Harro

    2014-01-01

    Nowadays, science should address societal challenges, such as ‘sustainability’, or ‘responsible research and innovation’. This emerging form of steering toward broad and generic goals involves the use of ‘big words’: encompassing concepts that are uncontested themselves, but that allow for multiple

  17. and alkali treatment of maize intake and utilization by steers

    African Journals Online (AJOL)

    mixture of urea and sunflower oilcake was used as a N supplement. These were given in a mixture with Ca, P, NaCl, minerals and vitamins (A.R.C.,. 1965) directly into the feed trough when the maize supplement was given. Digestibility study: Faeces was collected for 6 days. Collection periods for the 32 steers were.

  18. The Analysis of The Fault of Electrical Power Steering

    Directory of Open Access Journals (Sweden)

    Zhang Li Wen

    2016-01-01

    Full Text Available This paper analysis the common fault types of primary Electrical Power Steering system, meanwhile classify every fault. It provides the basis for further troubleshooting and maintenance. At the same time this paper propose a practical working principle of fault-tolerant, in order to make the EPS system more security and durability.

  19. Steering characteristic of an articulated bus under quasi steady maneuvering

    Science.gov (United States)

    Ubaidillah, Setiawan, Budi Agus; Aridharma, Airlangga Putra; Lenggana, Bhre Wangsa; Caesar, Bernardus Placenta Previo

    2018-02-01

    Articulated buses have been being preferred as public transportation modes due to their operational capacity. Therefore, passenger safety must be the priority of this public service vehicle. This research focused on the analytical approach of steering characteristics of an articulated bus when it maneuvered steadily. Such turning condition could be referred as a stability parameter of the bus for preliminary handling assessment. The analytical approach employed kinematics relationship between front and rear bodies as well as steering capabilities. The quasi steady model was developed to determine steering parameters such as turning radius, oversteer, and understeer. The mathematical model was useful for determining both coefficients of understeer and oversteer. The dimension of articulated bus followed a commonly used bus as utilized in Trans Jakarta busses. Based on the simulation, for one minimum center of the body, the turning radius was calculated about 8.8 m and 7.6 m at steady turning speed of 10 km/h. In neutral condition, the minimum road radius should be 6.5 m at 10 km/h and 6.9 m at 40 km/h. For two centers of the body and oversteer condition, the front body has the turning radius of 8.8 m, while, the rear body has the turning radius of 9.8 m at both turning speeds of 40 km/h. The other steering parameters were discussed accordingly.

  20. High power neutral beam injection in LHD

    International Nuclear Information System (INIS)

    Tsumori, K.; Takeiri, Y.; Nagaoka, K.

    2005-01-01

    The results of high power injection with a neutral beam injection (NBI) system for the large helical device (LHD) are reported. The system consists of three beam-lines, and two hydrogen negative ion (H - ion) sources are installed in each beam-line. In order to improve the injection power, the new beam accelerator with multi-slot grounded grid (MSGG) has been developed and applied to one of the beam-lines. Using the accelerator, the maximum powers of 5.7 MW were achieved in 2003 and 2004, and the energy of 189 keV reached at maximum. The power and energy exceeded the design values of the individual beam-line for LHD. The other beam-lines also increased their injection power up to about 4 MW, and the total injection power of 13.1 MW was achieved with three beam-lines in 2003. Although the accelerator had an advantage in high power beam injection, it involved a demerit in the beam focal condition. The disadvantage was resolved by modifying the aperture shapes of the steering grid. (author)

  1. Current steering with partial tripolar stimulation mode in cochlear implants.

    Science.gov (United States)

    Wu, Ching-Chih; Luo, Xin

    2013-04-01

    The large spread of excitation is a major cause of poor spectral resolution for cochlear implant (CI) users. Partial tripolar (pTP) mode has been proposed to reduce current spread by returning an equally distributed fraction (0.5 × σ) of current to two flanking electrodes and the rest to an extra-cochlear ground. This study tested the efficacy of incorporating current steering into pTP mode to add spectral channels. Different proportions of current [α × σ and (1 - α) × σ] were returned to the basal and apical flanking electrodes respectively to shape the electric field. Loudness and pitch perception with α from 0 to 1 in steps of 0.1 was simulated with a computational model of CI stimulation and tested on the apical, middle, and basal electrodes of six CI subjects. The highest σ allowing for full loudness growth within the implant compliance limit was chosen for each main electrode. Pitch ranking was measured between pairs of loudness-balanced steered pTP stimuli with an α interval of 0.1 at the most comfortable level. Results demonstrated that steered pTP stimuli with α around 0.5 required more current to achieve equal loudness than those with α around 0 or 1, maybe due to more focused excitation patterns. Subjects usually perceived decreasing pitches as α increased from 0 to 1, somewhat consistent with the apical shift of the center of gravity of excitation pattern in the model. Pitch discrimination was not better with α around 0.5 than with α around 0 or 1, except for some subjects and electrodes. For three subjects with better pitch discrimination, about half of the pitch ranges of two adjacent main electrodes overlapped with each other in steered pTP mode. These results suggest that current steering with focused pTP mode may improve spectral resolution and pitch perception with CIs.

  2. Collective multipartite Einstein-Podolsky-Rosen steering: more secure optical networks.

    Science.gov (United States)

    Wang, Meng; Gong, Qihuang; He, Qiongyi

    2014-12-01

    Collective multipartite Einstein-Podolsky-Rosen (EPR) steering is a type of quantum correlation shared among N parties, where the EPR paradox of one party can only be realized by performing local measurements on all the remaining N-1 parties. We formalize the collective tripartite steering in terms of local hidden state model and give the steering inequalities that act as signatures and suggest how to optimize collective tripartite steering in specific optical schemes. The special entangled states with property of collective multipartite steering may have potential applications in ultra-secure multiuser communication networks where the issue of trust is critical.

  3. The Impact of Analog and Bang-Bang Steering Gear Control on Ship's Fuel Economy

    DEFF Research Database (Denmark)

    Nørtoft Thomsen, J. C.; Blanke, Mogens; Reid, R. E.

    1982-01-01

    it is found to be at least equally important regarding steering performance and fuel economy. The paper presents a comprehensive survey of steering gear principles commonly used, including relevant details of three analog steering gear servo principles, which have outperformed conventional designs. Control......The latest years have shown considerable efforts towards improving steering generated propulsion losses of ships by the introduction of various sophisticated control algorithms in the autopilots. However, little previous attention has been given to the steering gear control loop, although...

  4. Beam Dynamics Design Studies of a Superconducting Radioactive Ion Beam Post-accelerator

    CERN Document Server

    Fraser, MA; Pasini, M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently post- accelerated by the normal conducting REX linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of trans- verse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wa...

  5. Coherent beam-beam effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1992-01-01

    There are two physical pictures that describe the beam-beam interaction in a storage ring collider: The weak-strong and the strong-strong pictures. Both pictures play a role in determining the beam-beam behavior. This review addresses only the strong-strong picture. The corresponding beam dynamical effects are referred to as the coherent beam-beam effects. Some basic knowledge of the weak-strong picture is assumed. To be specific, two beams of opposite charges are considered. (orig.)

  6. Neutral beam injection optimization at TJ-II

    International Nuclear Information System (INIS)

    Fuentes, C.; Liniers, M.; Wolfers, G.; Alonso, J.; Marcon, G.; Carrasco, R.; Guasp, J.; Acedo, M.; Sanchez, E.; Medrano, M.; Garcia, A.; Doncel, J.; Alejaldre, C.; Tsai, C.C.; Barber, G.; Sparks, D.

    2005-01-01

    Neutral beam injection (NBI) heating has been used on the TJ-II stellarator for the first time. The beam has a port-through power between 200 and 400 kW and injection energy 28 kV. Beam transmission is limited by beam interception at the injection port and the first toroidal field coil, therefore, beam steering optimization is of critical importance. The beam interaction areas inside TJ-II vacuum chamber are surveyed by infrared thermography. Beam reionization can be a problem due to the presence of residual gas in the duct region. Halpha emission is used to monitor the reionization at the duct. A careful optimization of the injected gas has been carried out

  7. LINAC4 low energy beam measurements

    CERN Document Server

    Hein, L M; Lallement, J B; Lombardi, A M; Midttun, O; Posocco, P; Scrivens, R

    2012-01-01

    Linac4 is a 160 MeV normal-conducting linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton Linac (Linac2) as linear injector for the CERN accelerators. The low energy part, comprising a 45 keV Low Energy Beam Transport system (LEBT), a 3 MeV Radiofrequency Quadrupole (RFQ) and a Medium Energy Beam Transport (MEBT) is being assembled in a dedicated test stand for pre-commissioning with a proton beam. During 2011 extensive measurements were done after the source and after the LEBT with the aim of preparing the RFQ commissioning and validating the simulation tools, indispensable for future source upgrades. The measurements have been thoroughly simulated with a multi-particle code, including 2D magnetic field maps, error studies, steering studies and the generation of beam distribution from measurements. Emittance, acceptance and transmission measurements will be presented and compared to the results of the simulations.

  8. Beam control in the ETA-II linear induction accelerator

    International Nuclear Information System (INIS)

    Chen, Y.J.

    1992-01-01

    Corkscrew beam motion is caused by chromatic aberration and misalignment of a focusing system. We have taken some measures to control the corkscrew motion on the ETA-II induction accelerator. To minimize chromatic aberration, we have developed an energy compensation scheme which reduces energy sweep and differential phase advance within a beam pulse. To minimize the misalignment errors, we have developed a time-independent steering algorithm which minimizes the observed corkscrew amplitude averaged over the beam pulse. The steering algorithm can be used even if the monitor spacing is much greater than the system's cyclotron wavelength and the corkscrew motion caused by a given misaligned magnet is fully developed, i.e., the relative phase advance is greater than 2π. (Author) 5 figs., 11 refs

  9. Tests of beam-based alignement at FACET

    CERN Document Server

    Latina, A; Schulte, D; Adli, E

    2014-01-01

    The performance of future linear colliders will depend critically on beam-based alignment (BBA) and feedback systems, which will play a crucial role in guaranteeing the low emittance transport throughout such machines. BBA algorithms designed to improve the beam transmission in a linac by simultaneously optimising the trajectory and minimising the residual dispersion, have thoughtfully been studied in theory over the last years, and successfully verified experimentally. One such technique is called Dispersion-Free Steering (DFS). A careful study of the DFS performance at the SLAC test facility FACET lead us to design a beam-based technique specifically targeted to reduce the impact of transverse short-range wakefields, rather than of the dispersion, being the wakefields the limiting factor to the FACET performance. This technique is called Wakefield-Free Steering (WFS). The results of the first tests of WFS at FACET are presented in this paper.

  10. Study on a New Steering Mechanism for Point-the-Bit Rotary Steerable System

    Directory of Open Access Journals (Sweden)

    Yuanzhi Li

    2014-02-01

    Full Text Available This paper presents a novel steering mechanism embedded in a point-the-bit rotary steerable system (RSS for oilfield exploitation. The new steering mechanism adopts a set of universal joints to alleviate the high alternative strain on drilling mandrel and employs a specially designed planetary gear small tooth number difference (PGSTD to achieve directional steering. Its principle and characteristics are explained and examined through a series of analyses. First, the eccentric displacement vector of the offset point on the drilling mandrel is formulated and kinematic solutions are established. Next, structural design for the new steering mechanism is addressed. Then, procedures and program architectures for simulating offset state of the drilling mandrel and motion trajectory of the whole steering mechanism are presented. After that, steering motion simulations of the new steering mechanism for both 2D and 3D well trajectories are then performed by combining LabVIEW and SolidWorks. Finally, experiments on the steering motion control of the new steering mechanism prototype are carried out. The simulations and experiments reveal that the steering performance of the new steering mechanism is satisfied. The research can provide good guidance for further research and engineering application of the point-the-bit RSS.

  11. Development of active rear steer actuator. Development of four wheel steer actuator for active safety; Active rear steer actuator no kaihatsu. Yobo anzen ni muketa 4WS actuator no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, T [Aisin Seiki Co. Ltd., Aichi (Japan)

    1997-10-01

    Recently, ecology, energy saving and safety have become important issues. And Active Safety is spotlighted in vehicle control area. Many researches and developments on four wheel steer system have been done to improve vehicle stability. We have developed the Active Rear Steer system with electromechanical Actuator, which is mass-productive, compact, and high response and durable. 10 figs., 5 tabs.

  12. Modeling of Driver Steering Operations in Lateral Wind Disturbances toward Driver Assistance System

    Science.gov (United States)

    Kurata, Yoshinori; Wada, Takahiro; Kamiji, Norimasa; Doi, Shun'ichi

    Disturbances decrease vehicle stability and increase driver's mental and physical workload. Especially unexpected disturbances such as lateral winds have severe effect on vehicle stability and driver's workload. This study aims at building a driver model of steering operations in lateral wind toward developing effective driver assistance system. First, the relationship between the driver's lateral motion and its reactive quick steering behavior is investigated using driving simulator with lateral 1dof motion. In the experiments, four different wind patterns are displayed by the simulator. As the results, strong correlation was found between the driver's head lateral jerk by the lateral disturbance and the angular acceleration of the steering wheel. Then, we build a mathematical model of driver's steering model from lateral disturbance input to steering torque of the reactive quick feed-forward steering based on the experimental results. Finally, validity of the proposed model is shown by comparing the steering torque of experimental results and that of simulation results.

  13. Frequency dependent steering with backward leaky waves via photonic crystal interface layer.

    Science.gov (United States)

    Colak, Evrim; Caglayan, Humeyra; Cakmak, Atilla O; Villa, Alessandro D; Capolino, Filippo; Ozbay, Ekmel

    2009-06-08

    A Photonic Crystal (PC) with a surface defect layer (made of dimers) is studied in the microwave regime. The dispersion diagram is obtained with the Plane Wave Expansion Method. The dispersion diagram reveals that the dimer-layer supports a surface mode with negative slope. Two facts are noted: First, a guided (bounded) wave is present, propagating along the surface of the dimer-layer. Second, above the light line, the fast traveling mode couple to the propagating spectra and as a result a directive (narrow beam) radiation with backward characteristics is observed and measured. In this leaky mode regime, symmetrical radiation patterns with respect to the normal to the PC surface are attained. Beam steering is observed and measured in a 70 degrees angular range when frequency ranges in the 11.88-13.69 GHz interval. Thus, a PC based surface wave structure that acts as a frequency dependent leaky wave antenna is presented. Angular radiation pattern measurements are in agreement with those obtained via numerical simulations that employ the Finite Difference Time Domain Method (FDTD). Finally, the backward radiation characteristics that in turn suggest the existence of a backward leaky mode in the dimer-layer are experimentally verified using a halved dimer-layer structure.

  14. Theory of using magnetic deflections to combine charged particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Steckbeck, Mackenzie K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Doyle, Barney Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Several radiation effects projects in the Ion Beam Lab (IBL) have recently required two disparate charged particle beams to simultaneously strike a single sample through a single port of the target chamber. Because these beams have vastly different mass–energy products (MEP), the low-MEP beam requires a large angle of deflection toward the sample by a bending electromagnet. A second electromagnet located further upstream provides a means to compensate for the small angle deflection experienced by the high-MEP beam during its path through the bending magnet. This paper derives the equations used to select the magnetic fields required by these two magnets to achieve uniting both beams at the target sample. A simple result was obtained when the separation of the two magnets was equivalent to the distance from the bending magnet to the sample, and the equation is given by: Bs= 1/2(rc/rs) Bc, where Bs and Bc are the magnetic fields in the steering and bending magnet and rc/rs is the ratio of the radii of the bending magnet to that of the steering magnet. This result is not dependent upon the parameters of the high MEP beam, i.e. energy, mass, charge state. Therefore, once the field of the bending magnet is set for the low-MEP beam, and the field in the steering magnet is set as indicted in the equation, the trajectory path of any high-MEP beam will be directed into the sample.

  15. The role of steering groups and project workers in NDUs.

    Science.gov (United States)

    Christian, S

    In light of the challenges that many nursing development units (NDUs) have faced during the past four years, this paper assesses the usefulness, as perceived by their clinical leaders, of support structures that had to be in place to secure NDU status. The structures assessed were a steering group and the allocation of a project worker by the King's Fund. Well organised steering groups offer unique opportunities to the NDUs to gain access to the knowledge and expertise of key figures, marketing the NDU and ensuring the project progresses to plan. Influential project workers were found to support the clinical leader and NDU staff, act as an external advocate and provide a global knowledge of nursing developments. This is the second of two papers reporting on a Department of Health-funded review of NDUs. The first appeared in Nursing Times on November 20.

  16. Adiabatic photo-steering theory in topological insulators

    Science.gov (United States)

    Inoue, Jun-ichi

    2014-12-01

    Feasible external control of material properties is a crucial issue in condensed matter physics. A new approach to achieving this aim, named adiabatic photo-steering, is reviewed. The core principle of this scheme is that several material constants are effectively turned into externally tunable variables by irradiation of monochromatic laser light. Two-dimensional topological insulators are selected as the optimal systems that exhibit a prominent change in their properties following the application of this method. Two specific examples of photo-steered quantum phenomena, which reflect topological aspects of the electronic systems at hand, are presented. One is the integer quantum Hall effect described by the Haldane model, and the other is the quantum spin Hall effect described by the Kane-Mele model. The topological quantities associated with these phenomena are the conventional Chern number and spin Chern number, respectively. A recent interesting idea, time-reversal symmetry breaking via a temporary periodic external stimulation, is also discussed.

  17. Optimization of Steering System of Forklift Vehicle for Idle Performance

    Directory of Open Access Journals (Sweden)

    Yuan Shen

    2015-01-01

    Full Text Available This paper presents an optimal design process for the steering system of a forklift vehicle. An efficient procedure for minimizing the engine-induced idle vibration is developed in this study. Reciprocating unbalance and gas pressure torque as two major sources of engine excitation are studied. Using the field vibration tests and FEM analysis, the cause and characteristics of steering system’s idle vibration are recognized. So as to distribute the characteristic modes based on the optimization strategy, global sensitivity analysis of the main parameters is also carried out to achieve the optimal combination of the optimization factors. Based on all analysis above, some structure modifications for optimization are presented to control the idle vibration. The effectiveness and rationality of the improvements are also verified through experimental prototyping testing. This study also makes it possible to provide a design guideline using CAE (computer aided engineering analysis for some other objects.

  18. Spatially distributed multipartite entanglement enables EPR steering of atomic clouds

    Science.gov (United States)

    Kunkel, Philipp; Prüfer, Maximilian; Strobel, Helmut; Linnemann, Daniel; Frölian, Anika; Gasenzer, Thomas; Gärttner, Martin; Oberthaler, Markus K.

    2018-04-01

    A key resource for distributed quantum-enhanced protocols is entanglement between spatially separated modes. However, the robust generation and detection of entanglement between spatially separated regions of an ultracold atomic system remain a challenge. We used spin mixing in a tightly confined Bose-Einstein condensate to generate an entangled state of indistinguishable particles in a single spatial mode. We show experimentally that this entanglement can be spatially distributed by self-similar expansion of the atomic cloud. We used spatially resolved spin read-out to reveal a particularly strong form of quantum correlations known as Einstein-Podolsky-Rosen (EPR) steering between distinct parts of the expanded cloud. Based on the strength of EPR steering, we constructed a witness, which confirmed genuine 5-partite entanglement.

  19. Steering the dynamics within reduced space through quantum learning control

    International Nuclear Information System (INIS)

    Kim, Young Sik

    2003-01-01

    In quantum dynamics of many-body systems, to identify the Hamiltonian becomes more difficult very rapidly as the number of degrees of freedom increases. In order to simplify the dynamics and to deduce dynamically relevant Hamiltonian information, it is desirable to control the dynamics to lie within a reduced space. With a judicious choice for the cost functional, the closed loop optimal control experiments can be manipulated efficiently to steer the dynamics to lie within a subspace of the system eigenstates without requiring any prior detailed knowledge about the system Hamiltonian. The procedure is simulated for optimally controlled population transfer experiments in the system of two degrees of freedom. To show the feasibility of steering the dynamics to lie in a specified subspace, the learning algorithms guiding the dynamics are presented along with frequency filtering. The results demonstrate that the optimal control fields derive the system to the desired target state through the desired subspace

  20. Detailed field test of yaw-based wake steering

    DEFF Research Database (Denmark)

    Fleming, P.; Churchfield, M.; Scholbrock, A.

    2016-01-01

    production. In the first phase, a nacelle-mounted scanning lidar was used to verify wake deflection of a misaligned turbine and calibrate wake deflection models. In the second phase, these models were used within a yaw controller to achieve a desired wake deflection. This paper details the experimental......This paper describes a detailed field-test campaign to investigate yaw-based wake steering. In yaw-based wake steering, an upstream turbine intentionally misaligns its yaw with respect to the inflow to deflect its wake away from a downstream turbine, with the goal of increasing total power...... design and setup. All data collected as part of this field experiment will be archived and made available to the public via the U.S. Department of Energy’s Atmosphere to Electrons Data Archive and Portal....

  1. EFFECT OF POULTRY MEAL ON THE PERFORMANCE OF FEEDLOT STEERS

    Directory of Open Access Journals (Sweden)

    A. Cabrera-Nuñez

    2014-08-01

    Full Text Available The aim of this study was to evaluate the effect of poultry meal on weight gain and carcass yield, under a housing system. 30 Swiss x Zebu steers were used, with an approximate weight of 353 kg, which were assigned under a completely randomized design in three treatments. T1 (control concentrate without poultry meal; T2 concentrate + 30% poultry meal and T3 concentrate + 35% poultry meal. The composition of the concentrate was based on ground sorghum, maize grain, wheat bran, ground mineral salt bale with 18% crude protein and 70% TDN. A significant effect (p ≤ 0.05 on the percentage of carcass weight of 53.0 was observed; 59.5 and 58.8% for T1, T2 and T3, respectively. The results indicate that supplementation based poultry meal 35% promoted greater yield in feedlot steers.

  2. Steering and filtering white light with resonant waveguide gratings

    Science.gov (United States)

    Quaranta, Giorgio; Basset, Guillaume; Martin, Olivier J. F.; Gallinet, Benjamin

    2017-08-01

    A novel thin-film single-layer structure based on resonant waveguide gratings (RWGs) allows to engineer selective color filtering and steering of white light. The unit cell of the structure consists of two adjacent finite-length and cross-talking RWGs, where the former acts as in-coupler and the latter acts as out-coupler. The structure is made by only one nano-imprint lithography replication and one thin film layer deposition, making it fully compatible with up-scalable fabrication processes. We characterize a fabricated optical security element designed to work with the flash and the camera of a smartphone in off-axis light steering configuration, where the pattern is revealed only by placing the smartphone in the proper position. Widespread applications are foreseen in a variety of fields, such as multifocal or monochromatic lenses, solar cells, biosensors, security devices and seethrough optical combiners for near-eye displays.

  3. Human sperm steer with second harmonics of the flagellar beat.

    Science.gov (United States)

    Saggiorato, Guglielmo; Alvarez, Luis; Jikeli, Jan F; Kaupp, U Benjamin; Gompper, Gerhard; Elgeti, Jens

    2017-11-10

    Sperm are propelled by bending waves traveling along their flagellum. For steering in gradients of sensory cues, sperm adjust the flagellar waveform. Symmetric and asymmetric waveforms result in straight and curved swimming paths, respectively. Two mechanisms causing spatially asymmetric waveforms have been proposed: an average flagellar curvature and buckling. We image flagella of human sperm tethered with the head to a surface. The waveform is characterized by a fundamental beat frequency and its second harmonic. The superposition of harmonics breaks the beat symmetry temporally rather than spatially. As a result, sperm rotate around the tethering point. The rotation velocity is determined by the second-harmonic amplitude and phase. Stimulation with the female sex hormone progesterone enhances the second-harmonic contribution and, thereby, modulates sperm rotation. Higher beat frequency components exist in other flagellated cells; therefore, this steering mechanism might be widespread and could inspire the design of synthetic microswimmers.

  4. Planning analysis and political steering with New Public Management

    DEFF Research Database (Denmark)

    Sager, Tore Øivin; Sørensen, Claus Hedegaard

    2011-01-01

    of interviews sheds light on the apparent paradox that parliamentarians accept delegation of highway investment decisions despite their profound scepticism to the cost-benefit analyses and impact calculations that are essential to management by objectives and results, which was to give them continued political...... by the Government. The political concentration on strategic steering, the concomitant delegation, and management by objectives and results are central components of New Public Management....

  5. Automation of Armored Four Wheel Counter Steer Vehicles

    Science.gov (United States)

    2015-08-28

    additions to the cabin, such as displays, servos , and controls, require a small footprint and cannot impede critical systems (e.g., fire control) or...autopilot. The steering system engages until the man- ual/emergency override button is pressed . To engage the velocity control mode, the operator...engaged if the need arises. Once the error is cleared, pressing the manual override button places the system back into ready mode. FIGURE 3. The software

  6. Entanglement, Einstein-Podolsky-Rosen correlations, Bell nonlocality, and steering

    International Nuclear Information System (INIS)

    Jones, S. J.; Wiseman, H. M.; Doherty, A. C.

    2007-01-01

    In a recent work [Phys. Rev. Lett. 98, 140402 (2007)] we defined 'steering', a type of quantum nonlocality that is logically distinct from both nonseparability and Bell nonlocality. In the bipartite setting, it hinges on the question of whether Alice can affect Bob's state at a distance through her choice of measurement. More precisely and operationally, it hinges on the question of whether Alice, with classical communication, can convince Bob that they share an entangled state under the circumstances that Bob trusts nothing that Alice says. We argue that if she can, then this demonstrates the nonlocal effect first identified in the famous Einstein-Podolsky-Rosen paper [Phys. Rev. 47, 777 (1935)] as a universal effect for pure entangled states. This ability of Alice to remotely prepare Bob's state was subsequently called steering by Schroedinger, whose terminology we adopt. The phenomenon of steering has been largely overlooked, and prior to our work had not even been given a rigorous definition that is applicable to mixed states as well as pure states. Armed with our rigorous definition, we proved that steerable states are a strict subset of the entangled states, and a strict superset of the states that can exhibit Bell nonlocality. In this work we expand on these results and provide further examples of steerable states. We also elaborate on the connection with the original EPR paradox

  7. Entanglement, Einstein-Podolsky-Rosen correlations, Bell nonlocality, and steering

    Science.gov (United States)

    Jones, S. J.; Wiseman, H. M.; Doherty, A. C.

    2007-11-01

    In a recent work [Phys. Rev. Lett. 98, 140402 (2007)] we defined “steering,” a type of quantum nonlocality that is logically distinct from both nonseparability and Bell nonlocality. In the bipartite setting, it hinges on the question of whether Alice can affect Bob’s state at a distance through her choice of measurement. More precisely and operationally, it hinges on the question of whether Alice, with classical communication, can convince Bob that they share an entangled state under the circumstances that Bob trusts nothing that Alice says. We argue that if she can, then this demonstrates the nonlocal effect first identified in the famous Einstein-Podolsky-Rosen paper [Phys. Rev. 47, 777 (1935)] as a universal effect for pure entangled states. This ability of Alice to remotely prepare Bob’s state was subsequently called steering by Schrödinger, whose terminology we adopt. The phenomenon of steering has been largely overlooked, and prior to our work had not even been given a rigorous definition that is applicable to mixed states as well as pure states. Armed with our rigorous definition, we proved that steerable states are a strict subset of the entangled states, and a strict superset of the states that can exhibit Bell nonlocality. In this work we expand on these results and provide further examples of steerable states. We also elaborate on the connection with the original EPR paradox.

  8. Design of a steering stabilizer based on CAN bus

    Science.gov (United States)

    Zhan, Zhaomin; Yan, Yibin

    2018-04-01

    This design realizes a posture correction device of griping steering wheel based on CAN bus, which is embedded in the steering wheel of vehicles. The system aims to detect the drivers' abnormal griping postures and provides drivers with classification alerts, by combining the recorded griping postures data and the vehicle speed data that are obtained via the CAN bus. The warning information are automatically stored and retained in the device for 12 months. To enhance the alerting effect, the count of this warning message for both the latest month and the last 12 months are displayed on the dashboard panel. In addition to prevent itself from being blocked and self-detect any faults in advance, the appliance also provide a self-test function, which will communicate with the integrated instrument system in vehicle and do simulation test right after the vehicle power on. This appliance can help to urge and ensure drivers to operate the steering wheel correctly, effectively, and timely; prevent some typical incorrect behaviors which commonly happen along with the change of griping postures, such as the using cellphone, and ultimately, reduce the incidence of traffic accidents.

  9. Geometrodynamic steering principle reveals the determiners of inertia

    International Nuclear Information System (INIS)

    Wheeler, J.A.

    1988-01-01

    What shall the authors need to grasp the essence of quantum gravity? One requirement, at least, is essential: to understand the steering principle of classical geometrodynamics. The authors outline here the physical content of that steering principle - heat of the so-called initial value problem - in its J.W. York, Jr. formulation. The central idea epitomizes itself in a single simple sentence: Mass-energy there determines inertia here. They spell out this steering principle both in its precise form and in its poor man's version. At both levels of analysis considerations of physics and mathematics alike require that the effective mass-energy of gravity waves must make itself felt on the spacetime geometry - and therefore on the gyro-defined local inertial frame of reference - on the same level as matter itself. Additional to the (mass)/(distance) Newtonian potential so familiar as measure of the effect of a nearby mass on the local frame is the Thirring and Lense gravitomagnetic potential, proportional to (angular momentum) x (distance vector)/(distance). The recent proposal of Ciufolini for a dual laser-ranged LAGEOS satellite to detect the thus-predicted gravitomagnetism of the earth is briefly described

  10. Einstein-Podolsky-Rosen steering: Its geometric quantification and witness

    Science.gov (United States)

    Ku, Huan-Yu; Chen, Shin-Liang; Budroni, Costantino; Miranowicz, Adam; Chen, Yueh-Nan; Nori, Franco

    2018-02-01

    We propose a measure of quantum steerability, namely, a convex steering monotone, based on the trace distance between a given assemblage and its corresponding closest assemblage admitting a local-hidden-state (LHS) model. We provide methods to estimate such a quantity, via lower and upper bounds, based on semidefinite programming. One of these upper bounds has a clear geometrical interpretation as a linear function of rescaled Euclidean distances in the Bloch sphere between the normalized quantum states of (i) a given assemblage and (ii) an LHS assemblage. For a qubit-qubit quantum state, these ideas also allow us to visualize various steerability properties of the state in the Bloch sphere via the so-called LHS surface. In particular, some steerability properties can be obtained by comparing such an LHS surface with a corresponding quantum steering ellipsoid. Thus, we propose a witness of steerability corresponding to the difference of the volumes enclosed by these two surfaces. This witness (which reveals the steerability of a quantum state) enables one to find an optimal measurement basis, which can then be used to determine the proposed steering monotone (which describes the steerability of an assemblage) optimized over all mutually unbiased bases.

  11. Beam-based alignment technique for the SLC [Stanford Linear Collider] linac

    International Nuclear Information System (INIS)

    Adolphsen, C.E.; Lavine, T.L.; Atwood, W.B.

    1989-03-01

    Misalignment of quadrupole magnets and beam position monitors (BPMs) in the linac of the SLAC Linear Collider (SLC) cause the electron and positron beams to be steered off-center in the disk-loaded waveguide accelerator structures. Off-center beams produce wakefields which limit the SLC performance at high beam intensities by causing emittance growth. Here, we present a general method for simultaneously determining quadrupole magnet and BPM offsets using beam trajectory measurements. Results from the application of the method to the SLC linac are described. The alignment precision achieved is approximately 100 μm, which is significantly better than that obtained using optical surveying techniques. 2 refs., 4 figs

  12. An investigation on motor-driven power steering-based crosswind disturbance compensation for the reduction of driver steering effort

    Science.gov (United States)

    Kim, Kyuwon; Kim, Boemjun; Go, Youngil; Park, Jaeyong; Park, Joonhong; Suh, Insoo; Yi, Kyongsu

    2014-07-01

    This paper describes a lateral disturbance compensation algorithm for an application to a motor-driven power steering (MDPS)-based driver assistant system. The lateral disturbance including wind force and lateral load transfer by bank angle reduces the driver's steering refinement and at the same time increases the possibility of an accident. A lateral disturbance compensation algorithm is designed to determine the motor overlay torque of an MDPS system for reducing the manoeuvreing effort of a human driver under lateral disturbance. Motor overlay torque for the compensation of driver's steering torque induced by the lateral disturbance consists of human torque feedback and feedforward torque. Vehicle-driver system dynamics have been investigated using a combined dynamic model which consists of a vehicle dynamic model, driver steering dynamic model and lateral disturbance model. The human torque feedback input has been designed via the investigation of the vehicle-driver system dynamics. Feedforward input torque is calculated to compensate additional tyre self-aligning torque from an estimated lateral disturbance. The proposed compensation algorithm has been implemented on a developed driver model which represents the driver's manoeuvreing characteristics under the lateral disturbance. The developed driver model has been validated with test data via a driving simulator in a crosswind condition. Human-in-the-loop simulations with a full-scale driving simulator on a virtual test track have been conducted to investigate the real-time performance of the proposed lateral disturbance compensation algorithm. It has been shown from simulation studies and human-in-the-loop simulation results that the driver's manoeuvreing effort and a lateral deviation of the vehicle under the lateral disturbance can be significantly reduced via the lateral disturbance compensation algorithm.

  13. The Optimal Steering Control System using Imperialist Competitive Algorithm on Vehicles with Steer-by-Wire System

    Directory of Open Access Journals (Sweden)

    F. Hunaini

    2015-03-01

    Full Text Available Steer-by-wire is the electrical steering systems on vehicles that are expected with the development of an optimal control system can improve the dynamic performance of the vehicle. This paper aims to optimize the control systems, namely Fuzzy Logic Control (FLC and the Proportional, Integral and Derivative (PID control on the vehicle steering system using Imperialist Competitive Algorithm (ICA. The control systems are built in a cascade, FLC to suppress errors in the lateral motion and the PID control to minimize the error in the yaw motion of the vehicle. FLC is built has two inputs (error and delta error and single output. Each input and output consists of three Membership Function (MF in the form of a triangular for language term "zero" and two trapezoidal for language term "negative" and "positive". In order to work optimally, each MF optimized using ICA to get the position and width of the most appropriate. Likewise, in the PID control, the constant at each Proportional, Integral and Derivative control also optimized using ICA, so there are six parameters of the control system are simultaneously optimized by ICA. Simulations performed on vehicle models with 10 Degree Of Freedom (DOF, the plant input using the variables of steering that expressed in the desired trajectory, and the plant outputs are lateral and yaw motion. The simulation results showed that the FLC-PID control system optimized by using ICA can maintain the movement of vehicle according to the desired trajectory with lower error and higher speed limits than optimized with Particle Swarm Optimization (PSO.

  14. Fundamentals studies of a magnetically steered vacuum arc

    Science.gov (United States)

    Walke, Paul

    In recent years demand from production industry for high performance cutting tools, aero and automobile engine parts has prompted research into both existing and novel methods of laying down hard, low friction coatings . A key process for the production of such coatings has been Physical Vapour Deposition (PVD) which has proved to be a consistent and reliable tool for industry. For this technique to continue to be improved and more advanced coatings to be produced, research at the fundamental level is required. This thesis describes research investigating the behaviour of the steered arc cathode spot and methods of improving existing steered arc coating technology.The majority of existing steered arc systems use either permanent magnets or a combination of permanent and electromagnets to steer the arc. Described here is a novel system which employs a pair of electromagnetic coils of cylindrical geometry which enable the arc to be positioned on a circular orbit through a range of continuously variable radii. In addition to this the coils are capable of controlling the transverse and normal magnetic field profiles independently of the steering radius selected. This enables the behaviour of the arc spot to be investigated under a range of magnetic field conditions thus allowing the comparison of measured arc behaviour with a new model of arc motion. Care has described the motion of the arc spot as a biased random walk and has derived an analytical solution to describe the time dependent, probability density function for the arc position in two dimensions. Two distributions are proposed (one in each dimension); the first describes the probability density for the arc position in the direction of driven motion, the second the probability density in the direction of arc confinement. The shape of these distributions is dependent upon the transverse and normal components of the applied magnetic field.A series of experiments are described here that measure the shape of these

  15. The synchrotron and its related technology for ion beam therapy

    International Nuclear Information System (INIS)

    Hiramoto, Kazuo; Umezawa, Masumi; Saito, Kazuyoshi; Tootake, Satoshi; Nishiuchi, Hideaki; Hara, Shigemistu; Tanaka, Masanobu; Matsuda, Koji; Sakurabata, Hiroaki; Moriyama, Kunio

    2007-01-01

    Hitachi has developed several new technologies for the synchrotron and its related system to realize reliable and flexible operation of a proton therapy system. Especially important among them are a non-resonant RF acceleration cavity using FINEMET core with multiple power feeding and radio frequency driven beam extraction technique (RF-DE) for a synchrotron. Various treatment operations such as variable acceleration energy or respiration gating became possible and simple due to the above technique. For beam transport, a beam steering method for the beam, using transfer matrix realizes quick and precise correction of the beam orbit. A compact microwave ion source has also been developed for the injector to obtain further higher reliability and availability. Most of these technologies are also effective to enhance the reliability and flexibility of other ion beam therapy systems

  16. Beam loading

    OpenAIRE

    Boussard, Daniel

    1987-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superco...

  17. Molecular beams

    International Nuclear Information System (INIS)

    Pendelbury, J.M.; Smith, K.F.

    1987-01-01

    Studies with directed collision-free beams of particles continue to play an important role in the development of modern physics and chemistry. The deflections suffered by such beams as they pass through electric and magnetic fields or laser radiation provide some of the most direct information about the individual constituents of the beam; the scattering observed when two beams intersect yields important data about the intermolecular forces responsible for the scattering. (author)

  18. Electronic differential control of 2WD electric vehicle considering steering stability

    Science.gov (United States)

    Hua, Yiding; Jiang, Haobin; Geng, Guoqing

    2017-03-01

    Aiming at the steering wheel differential steering control technology of rear wheel independent driving electric wheel, considering the assisting effect of electronic differential control on vehicle steering, based on the high speed steering characteristic of electric wheel car, the electronic differential speed of auxiliary wheel steering is also studied. A yaw moment control strategy is applied to the vehicle at high speed. Based on the vehicle stability reference value, yaw rate is used to design the fuzzy controller to distribute the driving wheel torque. The simulation results show that the basic electronic differential speed function is realized based on the yaw moment control strategy, while the vehicle stability control is improved and the driving safety is enhanced. On the other hand, the torque control strategy can also assist steering of vehicle.

  19. Research on Sliding Mode Control for Steer-by-Wire System in Forklift

    Directory of Open Access Journals (Sweden)

    Huang Jun-Jie

    2017-01-01

    Full Text Available Aiming at steering stability and wheel angle tracking of steer-by-wire (SBW three wheeled forklift, steering dynamic model and SBW system mathematical model of three wheeled forklift are established. A control strategy for the ideal transmission ratio is introduced based on this model, which ensures forklift steering gain invariant. A sliding mode controller can then be designed based on the bound information of uncertain system parameters, uncertain self-aligning torque, and external disturbances. The results of simulation show the control strategies above can effectively reduce the sideslip angle when the forklift is steering and improve the sensitivity and stability of the steering forklift; at the same time can effectively restrain the parameter perturbation of internal system and external disturbance, which improves the tracking performance of the wheel angle.

  20. New receiving line for the remote-steering antenna of the 140 GHz CTS diagnostics in the FTU Tokamak

    Science.gov (United States)

    D'Arcangelo, O.; Bin, W.; Bruschi, A.; Cappelli, M.; Fanale, F.; Gittini, G.; Pallotta, F.; Rocchi, G.; Tudisco, O.; Garavaglia, S.; Granucci, G.; Moro, A.; Tuccillo, A. A.

    2018-01-01

    A new receiving antenna for collecting signals of the Collective Thomson Scattering (CTS) diagnostics in FTU Tokamak has been recently installed. The squared corrugated section and the precisely defined length make it possible to receive from different directions by remotely steering the receiving mirrors. This type of Remote-Steering (RS) antennas, being studied on FTU for the DEMO Electron Cyclotron Heating (ECH) system launch, is already installed on the W7- X stellarator and will be tested in the next campaign. The transmission of the signal from the antenna in the tokamak hall to the CTS diagnostics hall will be mainly realized by means of oversized circular corrugated waveguides carrying the hybrid HE11 (quasi-gaussian) waveguide mode, with inclusion of a special smooth-waveguide section and a short run of reduced-size square-corrugated waveguide through the tokamak bio-shield. The coupling between different waveguide types is made with ellipsoidal focusing mirrors, using quasi-optical matching formulas between the gaussian-shaped beams in input and output to the waveguides. In this work, after a complete study of feasibility of the overall line, a design for the receiving line will be proposed, in order to realize an executive layout to be used as a guideline for the commissioning phase.

  1. EVALUATION OF A CONCEPTUAL VEHICLE STEERING SYSTEM FOR INDEPENDENT WHEEL CONTROL

    Directory of Open Access Journals (Sweden)

    Ryszard BUCHALIK

    2017-03-01

    Full Text Available This paper presents a brief description of an unconventional steering system involving electronic stability control and its influence on vehicle motion. The proposed configuration enables individual changes in steering angle for each single wheel, in contrast to the mechanical linkage solution. An analysis of vehicle behaviour during emergency braking on a heterogeneous surface is conducted, especially with regard to the undesirable rotation of the vehicle body. The benefits of using this active steering system, implemented in the steer-by-wire mode, are characterized, while the problems for further consideration and the potential benefits of such a solution are described.

  2. Demonstration of Multisetting One-Way Einstein-Podolsky-Rosen Steering in Two-Qubit Systems

    Science.gov (United States)

    Xiao, Ya; Ye, Xiang-Jun; Sun, Kai; Xu, Jin-Shi; Li, Chuan-Feng; Guo, Guang-Can

    2017-04-01

    Einstein-Podolsky-Rosen (EPR) steering describes the ability of one party to remotely affect another's state through local measurements. One of the most distinguishable properties of EPR steering is its asymmetric aspect. Steering can work in one direction but fail in the opposite direction. This type of one-way steering, which is different from the symmetry concepts of entanglement and Bell nonlocality, has garnered much interest. However, an experimental demonstration of genuine one-way EPR steering in the simplest scenario, i.e., one that employs two-qubit systems, is still lacking. In this Letter, we experimentally demonstrate one-way EPR steering with multimeasurement settings for a class of two-qubit states, which are still one-way steerable even with infinite settings. The steerability is quantified by the steering radius, which represents a necessary and sufficient steering criterion. The demonstrated one-way steering in the simplest bipartite quantum system is of fundamental interest and may provide potential applications in one-way quantum information tasks.

  3. Integrated Design and Analysis Tools for Reduced Weight, Affordable Fiber Steered Composites

    National Research Council Canada - National Science Library

    Hale, Richard

    2004-01-01

    This report describes geometric design tools which encompass the overall process flow for fiber placed and fiber steered structures, to allow parallel considerations for manufacturability and mechanical performance...

  4. : Light Steering Projection Systems and Attributes for HDR Displays

    KAUST Repository

    Damberg, Gerwin

    2017-06-02

    New light steering projectors in cinema form images by moving light away from dark regions into bright areas of an image. In these systems, the peak luminance of small features can far exceed full screen white luminance. In traditional projectors where light is filtered or blocked in order to give shades of gray (or colors), the peak luminance is fixed. The luminance of chromatic features benefit in the same way as white features, and chromatic image details can be reproduced at high brightness leading to a much wider overall color gamut coverage than previously possible. Projectors of this capability are desired by the creative community to aid in and enhance storytelling. Furthermore, reduced light source power requirements of light steering projectors provide additional economic and environmental benefits. While the dependency of peak luminance level on (bright) image feature size is new in the digital cinema space, display technologies with identical characteristics such as OLED, LED LCD and Plasma TVs are well established in the home. Similarly, direct view LED walls are popular in events, advertising and architectural markets. To enable consistent color reproduction across devices in today’s content production pipelines, models that describe modern projectors and display attributes need to evolve together with HDR standards and available metadata. This paper is a first step towards rethinking legacy display descriptors such as contrast, peak luminance and color primaries in light of new display technology. We first summarize recent progress in the field of light steering projectors in cinema and then, based on new projector and existing display characteristics propose the inclusion of two simple display attributes: Maximum Average Luminance and Peak (Color) Primary Luminance. We show that the proposed attributes allow a better prediction of content reproducibility on HDR displays. To validate this assertion, we test professional content on a commercial HDR

  5. Beam diagnostics

    International Nuclear Information System (INIS)

    Bogaty, J.; Clifft, B.E.; Zinkann, G.P.; Pardo, R.C.

    1995-01-01

    The ECR-PII injector beam line is operated at a fixed ion velocity. The platform high voltage is chosen so that all ions have a velocity of 0.0085c at the PII entrance. If a previous tune configuration for the linac is to be used, the beam arrival time must be matched to the previous tune as well. A nondestructive beam-phase pickup detector was developed and installed at the entrance to the PII linac. This device provides continuous phase and beam current information and allows quick optimization of the beam injected into PII. Bunches traverse a short tubular electrode thereby inducing displacement currents. These currents are brought outside the vacuum interface where a lumped inductance resonates electrode capacitance at one of the bunching harmonic frequencies. This configuration yields a basic sensitivity of a few hundred millivolts signal per microampere of beam current. Beam-induced radiofrequency signals are summed against an offset frequency generated by our master oscillator. The resulting kilohertz difference frequency conveys beam intensity and bunch phase information which is sent to separate processing channels. One channel utilizes a phase locked loop which stabilizes phase readings if beam is unstable. The other channel uses a linear full wave active rectifier circuit which converts kilohertz sine wave signal amplitude to a D.C. voltage representing beam current. A prototype set of electronics is now in use with the detector and we began to use the system in operation to set the arrival beam phase. A permanent version of the electronics system for the phase detector is now under construction. Additional nondestructive beam intensity and phase monitors at the open-quotes Boosterclose quotes and open-quotes ATLASclose quotes linac sections are planned as well as on some of the high-energy beam lines. Such a monitor will be particularly useful for FMA experiments where the primary beam hits one of the electric deflector plates

  6. Steering the osteoclast through the demineralization-collagenolysis balance

    DEFF Research Database (Denmark)

    Søe, Kent; Merrild, Ditte Marie Horslev; Delaissé, Jean-Marie

    2013-01-01

    are generated when collagen degradation is slower than demineralization, and trenches when collagen degradation is as fast as demineralization. Next we treated the osteoclasts with a low dose of a carbonic anhydrase inhibitor to slightly decrease the rate of demineralization, thereby allowing collagen......, forming a pit, and continues parallel to the bone surface, forming a trench. Importantly, we show that the progress of the osteoclast along this route depends on the balance between the rate of collagenolysis and demineralization. We propose that the osteocytes and bone lining cells surrounding...... the osteoclast may act on this balance to steer the osteoclast resorptive activity in order to give the excavations a specific shape....

  7. Concept of navigation and automatic steering of the measuring dolphin

    Energy Technology Data Exchange (ETDEWEB)

    Majohr, J.; Buch, T.; Korte, C. [Rostock Univ. (Germany). Inst. fuer Automatisierungstechnik

    2000-07-01

    The Catamaran - Measuring Dolphin (MESSIN) is an unmanned and independently operated craft having been designed for carrying out multiple measuring tasks in the field of marine research and water monitoring especially in shallow waters. An introduction to the navigation, steering and safety systems is given. Furthermore the main components of the track control system and the electronic chart system used here are shown. Results of manoeuvring tests of the MESSIN are represented. This paper gives a contribution to the field of research ''autonomous and full automated vehicle''. (orig.)

  8. Creating virtual electrodes with 2D current steering

    Science.gov (United States)

    Spencer, Thomas C.; Fallon, James B.; Shivdasani, Mohit N.

    2018-06-01

    Objective. Current steering techniques have shown promise in retinal prostheses as a way to increase the number of distinct percepts elicitable without increasing the number of implanted electrodes. Previously, it has been shown that ‘virtual’ electrodes can be created between simultaneously stimulated electrode pairs, producing unique cortical response patterns. This study investigated whether virtual electrodes could be created using 2D current steering, and whether these virtual electrodes can produce cortical responses with predictable spatial characteristics. Approach. Normally-sighted eyes of seven adult anaesthetised cats were implanted with a 42-channel electrode array in the suprachoroidal space and multi-unit neural activity was recorded from the visual cortex. Stimuli were delivered to individual physical electrodes, or electrodes grouped into triangular, rectangular, and hexagonal arrangements. Varying proportions of charge were applied to each electrode in a group to ‘steer’ current and create virtual electrodes. The centroids of cortical responses to stimulation of virtual electrodes were compared to those evoked by stimulation of single physical electrodes. Main results. Responses to stimulation of groups of up to six electrodes with equal ratios of charge on each electrode resulted in cortical activation patterns that were similar to those elicited by the central physical electrode (centroids: RM ANOVA on ranks, p  >  0.05 neural spread: one-way ANOVA on Ranks, p  >  0.05). We were also able to steer the centroid of activation towards the direction of any of the electrodes of the group by applying a greater charge to that electrode, but the movement in the centroid was not found to be significant. Significance. The results suggest that current steering is possible in two dimensions between up to at least six electrodes, indicating it may be possible to increase the number of percepts in patients without increasing the number

  9. Adaptive feedback linearization applied to steering of ships

    Directory of Open Access Journals (Sweden)

    Thor I. Fossen

    1993-10-01

    Full Text Available This paper describes the application of feedback linearization to automatic steering of ships. The flexibility of the design procedure allows the autopilot to be optimized for both course-keeping and course-changing manoeuvres. Direct adaptive versions of both the course-keeping and turning controller are derived. The advantages of the adaptive controllers are improved performance and reduced fuel consumption. The application of nonlinear control theory also allows the designer in a systematic manner to compensate for nonlinearities in the control design.

  10. Geometric steering criterion for two-qubit states

    Science.gov (United States)

    Yu, Bai-Chu; Jia, Zhih-Ahn; Wu, Yu-Chun; Guo, Guang-Can

    2018-01-01

    According to the geometric characterization of measurement assemblages and local hidden state (LHS) models, we propose a steering criterion which is both necessary and sufficient for two-qubit states under arbitrary measurement sets. A quantity is introduced to describe the required local resources to reconstruct a measurement assemblage for two-qubit states. We show that the quantity can be regarded as a quantification of steerability and be used to find out optimal LHS models. Finally we propose a method to generate unsteerable states, and construct some two-qubit states which are entangled but unsteerable under all projective measurements.

  11. Electrical Steering of Vehicles - Fault-tolerant Analysis and Design

    DEFF Research Database (Denmark)

    Blanke, Mogens; Thomsen, Jesper Sandberg

    2006-01-01

    solutions and still meet strict requirements to functional safety. The paper applies graph-based analysis of functional system structure to find a novel fault-tolerant architecture for an electrical steering where a dedicated AC-motor design and cheap voltage measurements ensure ability to detect all......The topic of this paper is systems that need be designed such that no single fault can cause failure at the overall level. A methodology is presented for analysis and design of fault-tolerant architectures, where diagnosis and autonomous reconfiguration can replace high cost triple redundancy...

  12. Helicopter downwash measured by continuous-wave Doppler lidars with agile beam steering

    DEFF Research Database (Denmark)

    Sjöholm, Mikael; Angelou, Nikolas; Hansen, Per

    2012-01-01

    , minimizing the risk to aircraft and personnel when operating in a search and rescue role. The results from the application of the short-range WindScanner technology to the complex and turbulent helicopter downwash demonstrates the possibilities also within less demanding flows encountered within complex...

  13. Method of electronic beam steering for circular switched parasitic dipole arrays

    CSIR Research Space (South Africa)

    Mofolo, M

    2010-09-01

    Full Text Available is controlled by open- and shortcircuiting the parasitic elements. By appropriately selecting correct combination of short- and opencircuited parasitic elements together with the active element, a set of radiation patterns is formed covering the horizontal plane...

  14. Low Cost High Performance Phased Array Antennas with Beam Steering Capabilities

    Science.gov (United States)

    2009-12-01

    the target surface. The sputter gas is inert, typically argon. The extra argon ions created as a result of these collisions leads to a higher...a) Composition: Ba 0.5 Sr 0.5 Ti 1 O 3 Thickness: 1900 /cm2 (-2350 A, assuming density of BSTO as 5.62 g/cc) Energy (MeV) 60 1.0 1.5 HI Random...apart, particularly for Ba and Sr , at 800°C. Film thickness at 700°C and 750°C is 2900 A and drops to 2500 A at 800°C. Since same growth times were

  15. Modeling and Control of Risley Prism Beam Steering Including BLDC Motors

    OpenAIRE

    Gunnarsson, Oscar

    2016-01-01

    Saab AB Training & Simulation is specialized on military training, including laserbased training. To continue being the world leader in this area, a new generationof laser simulators needs to be developed. To simplify the development of thishighly complex system, this master thesis have resulted in a MATLAB/Simulinkmodel which simulates the electro-opto/mechanical system representing theirlaser based simulation platform. The focus of this master thesis has been to simulateand control the ...

  16. Infrared beam-steering using acoustically modulated surface plasmons over a graphene monolayer

    KAUST Repository

    Chen, Paiyen; Farhat, Mohamed; Askarpour, Amir Nader; Tymchenko, Mykhailo; Alù , Andrea

    2014-01-01

    We model and design a graphene-based infrared beamformer based on the concept of leaky-wave (fast traveling wave) antennas. The excitation of infrared surface plasmon polaritons (SPPs) over a 'one-atom-thick' graphene monolayer is typically

  17. Indoor optical wireless communication system using beam-steering by cascaded diffractive optical elements

    NARCIS (Netherlands)

    Oh, C.W.; Tangdiongga, E.; Koonen, A.M.J.; García-Blanco, S.M.; Boller, Kl.J.; Sefunc, M.A.; Geuzebroek, D.

    2014-01-01

    While the radio spectrum continues to struggle with a soaring bandwidth demand, the optical spectrum promises virtually unlimited license-free bandwidth. We report the feasibility of high-capacity point-to-point links for indoor optical wireless communication with cascaded diffractive optical

  18. Eye-safe diode laser Doppler lidar with a MEMS beam-scanner

    DEFF Research Database (Denmark)

    Hu, Qi; Pedersen, Christian; Rodrigo, Peter John

    2016-01-01

    We present a novel Doppler lidar that employs a cw diode laser operating at 1.5 μm and a micro-electro-mechanical-system scanning mirror (MEMS-SM). In this work, two functionalities of the lidar system are demonstrated. Firstly, we describe the capability to effectively steer the lidar probe beam...

  19. Growth, carcass characteristics, and profitability of organic versus conventional dairy beef steers.

    Science.gov (United States)

    Bjorklund, E A; Heins, B J; Dicostanzo, A; Chester-Jones, H

    2014-03-01

    Bull calves (n=49), born at the University of Minnesota West Central Research and Outreach Center (Morris) between March and May 2011, were used to compare growth measurements and profitability of conventional and organic dairy steers. Calves were assigned to 1 of 3 replicated groups at birth: conventional (CONV; n=16), organic (pasture and concentrate; ORG; n=16), or organic grass only (GRS; n=17), and analysis of variables was on a pen basis. Breed groups of calves were Holstein (HO; n=9); Holsteins (n=11) maintained at 1964 breed average level; crossbreds (n=19) including combinations of HO, Montbéliarde, and Swedish Red; and crossbreds (n=10) including combinations of HO, Jersey, Swedish Red, and Normande. The CONV steers were fed a diet of 80% concentrate and 20% forage. The ORG steers were fed a diet of organic corn, organic corn silage, and at least 30% of their diet consisted of organic pasture during the grazing season. The GRS steers grazed pasture during the grazing season and were fed high-quality hay or hay silage during the nongrazing season. Intakes of a total mixed ration were recorded daily with herd management software. A profit function was defined to include revenues and expenses for beef value, feed intake, pasture intake, health cost, and yardage. The GRS (358.6 kg) steers had lesser total gains from birth to slaughter than ORG (429.6 kg) and CONV (534.5 kg) steers. Furthermore, the GRS (0.61 kg/d) steers had lesser average daily gain from birth compared with ORG (0.81 kg/d) and CONV (1.1 kg/d) steers. The GRS and ORG steers had smaller rib eye area (49.5 and 65.8 cm(2), respectively) compared with CONV (75.4 cm(2)) steers. For profitability, GRS steers had 43% greater profit than CONV steers due to organic beef price premiums and lower feed costs. On the other hand, ORG steers had substantially less profit than CONV steers. The higher cost of production for the ORG steers is due to the extreme high value of organic corn. The results of the

  20. Adiabatic photo-steering theory in topological insulators

    International Nuclear Information System (INIS)

    Inoue, Jun-ichi

    2014-01-01

    Feasible external control of material properties is a crucial issue in condensed matter physics. A new approach to achieving this aim, named adiabatic photo-steering, is reviewed. The core principle of this scheme is that several material constants are effectively turned into externally tunable variables by irradiation of monochromatic laser light. Two-dimensional topological insulators are selected as the optimal systems that exhibit a prominent change in their properties following the application of this method. Two specific examples of photo-steered quantum phenomena, which reflect topological aspects of the electronic systems at hand, are presented. One is the integer quantum Hall effect described by the Haldane model, and the other is the quantum spin Hall effect described by the Kane–Mele model. The topological quantities associated with these phenomena are the conventional Chern number and spin Chern number, respectively. A recent interesting idea, time-reversal symmetry breaking via a temporary periodic external stimulation, is also discussed. (focus issue review)

  1. The steering committee for the marketing of radurised foods

    International Nuclear Information System (INIS)

    Wessels, P.J.

    1985-01-01

    After the very successful results obtained during the initial research stage of food irradiation, a need was felt for the commercial application of the process. Although few, if any, other food processing methods have been so thoroughly investigated prior to acceptance, several factors influenced the spontaneous implementation thereof. A definite need for co-ordination of commercial trials and proper commercial introduction of the process which invited so many discussions world-wide, led to the introduction of the Steering Committee for Radurised Foodstuffs in South Africa by the Minister of Agriculture during 1981. The Steering Committee was established to advise the Minister of Agriculture regarding the acceptability of the process and the progress made in this regard. The Minister of Agriculture (now Agricultural Economics and Water Affairs) fulfills an important role in the marketing of agricultural products in South Africa. Many decisions and recommendations of Organised Agriculture and of the different Marketing Boards are subject to the final approval or acceptance by the Minister. It is therefore important that he will be informed and advised regarding radurisation of foodstuffs and related aspects

  2. Mid-sized omnidirectional robot with hydraulic drive and steering

    Science.gov (United States)

    Wood, Carl G.; Perry, Trent; Cook, Douglas; Maxfield, Russell; Davidson, Morgan E.

    2003-09-01

    Through funding from the US Army-Tank-Automotive and Armaments Command's (TACOM) Intelligent Mobility Program, Utah State University's (USU) Center for Self-Organizing and Intelligent Systems (CSOIS) has developed the T-series of omni-directional robots based on the USU omni-directional vehicle (ODV) technology. The ODV provides independent computer control of steering and drive in a single wheel assembly. By putting multiple omni-directional (OD) wheels on a chassis, a vehicle is capable of uncoupled translational and rotational motion. Previous robots in the series, the T1, T2, T3, ODIS, ODIS-T, and ODIS-S have all used OD wheels based on electric motors. The T4 weighs approximately 1400 lbs and features a 4-wheel drive wheel configuration. Each wheel assembly consists of a hydraulic drive motor and a hydraulic steering motor. A gasoline engine is used to power both the hydraulic and electrical systems. The paper presents an overview of the mechanical design of the vehicle as well as potential uses of this technology in fielded systems.

  3. Reducing supplementation frequency for Nellore beef steers grazing tropical pastures

    Directory of Open Access Journals (Sweden)

    Roberta Carrilho Canesin

    2014-04-01

    Full Text Available Reduced supplementation frequency is a broadly applied management practice. Ruminants consuming low quality forages/pastures, supplemented less than once daily are able to maintain body weight gain (BWG, efficiency of use of dry matter, nitrogen and other nutrients, as compared with animals supplemented once daily. We evaluated the feeding behavior, dry matter intake (DMI, dry matter and organic matter digestibility (DMD and OMD, BWG, Longissimus muscle area and backfat depth of Nellore steers raised on Brachiaria brizantha cv. Marandu pastures during the dry season, with different supplementation patterns. Thirty six animals (338 ± 40.7 kg were distributed over nine paddocks according to a completely randomized design. Treatments were based on supplementation frequency: once daily (OD, once daily except Saturdays and Sundays (SS, or on alternate days (AD, at 1.0 %, 1.4 % and 2.0 % BW, respectively. Average total DMI accounted for 1.6 % BW day-1, with no effect of supplementation frequency. Supplementation frequency had no effect on BWG or grazing time during the day. There was no difference in Longissimus muscle area animals supplemented daily, SS and AD. The backfat depth was thinner in animals supplemented AD, but even in this case, it was within the standards considered satisfactory for a finishing steer. Reducing supplementation frequency seems a good option to lower labor costs without affecting feed efficiency or carcass quality in beef cattle grazing tropical pastures.

  4. Stability Simulation of a Vehicle with Wheel Active Steering

    Directory of Open Access Journals (Sweden)

    Brabec Pavel

    2016-01-01

    Full Text Available This paper deals with the possibility of increasing the vehicle driving stability at a higher speed. One of the ways how to achieve higher stability is using the 4WS system. Mathematical description of vehicle general movement is a very complex task. For simulation, models which are aptly simplified are used. For the first approach, so-called single-truck vehicle model (often linear is usually used. For the simulation, we have chosen to extend the model into a two-truck one, which includes the possibility to input more vehicle parameters. Considering the 4WS system, it is possible to use a number of potential regulations. In our simulation model, the regulation system with compound coupling was used. This type of regulation turns the rear wheels depending on the input parameters of the system (steering angle of the front wheels and depending on the output moving quantities of the vehicle, most frequently the yaw rate. Criterion for compensation of lateral deflection centre of gravity angle is its zero value, or more precisely the zero value of its first-order derivative. Parameters and set-up of the simulation model were done in conjunction with the dSAPACE software. Reference performances of the vehicle simulation model were made through the defined manoeuvres. But the simulation results indicate that the rear-wheels steering can have a positive effect on the vehicle movement stability, especially when changing the driving direction at high speed.

  5. Beam loading

    CERN Document Server

    Gamp, Alexander

    2013-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.

  6. Beam loading

    International Nuclear Information System (INIS)

    Gamp, Alexander

    2013-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed. (author)

  7. Automatic beam position control at Los Alamos Spallation Radiation Effects Facility (LASREF)

    International Nuclear Information System (INIS)

    Oothoudt, M.; Pillai, C.; Zumbro, M.

    1997-01-01

    Historically the Los Alamos Spallation Radiation Effects Facility (LASREF) has used manual methods to control the position of the 800 kW, 800 MeV proton beam on targets. New experiments, however, require more stringent position control more frequently than can be done manually for long periods of time. Data from an existing harp is used to automatically adjust steering magnets to maintain beam position to required tolerances

  8. How to Steer and Lead Educational Processes in a Digital Medium Environment?

    DEFF Research Database (Denmark)

    Tække, Jesper

    This paper is about challenges to steering and leadership of educational interaction in classrooms provided by the new medium environment that comes with digital media. In the new medium environment, the old way of steering what is going on in the classroom appears not to work any more since...

  9. Alteration in gene expression in the jejunum mucosa of Angus steers with divergent ADG

    Science.gov (United States)

    The objective of this study was to determine the association of differentially expressed genes in the jejunum of steers with average DMI and high or low ADG. Feed intake and growth were measured in a cohort of 144 commercial Angus steers consuming a finishing ration containing (on a DM basis) 67.8% ...

  10. Exogenous administration of lipids to steers alters aspects of the innate immune response to endotoxin challenge

    Science.gov (United States)

    Limitations in energy availability are known to impede the efficiency of the immune response to endotoxemia. Therefore, this study examined the effects of increasing energy availability on the pro-inflammatory response to LPS in Holstein steers. Steers were randomly assigned to 1 of 3 groups (n = 7 ...

  11. A theoretical model of speed-dependent steering torque for rolling tyres

    Science.gov (United States)

    Wei, Yintao; Oertel, Christian; Liu, Yahui; Li, Xuebing

    2016-04-01

    It is well known that the tyre steering torque is highly dependent on the tyre rolling speed. In limited cases, i.e. parking manoeuvre, the steering torque approaches the maximum. With the increasing tyre speed, the steering torque decreased rapidly. Accurate modelling of the speed-dependent behaviour for the tyre steering torque is a key factor to calibrate the electric power steering (EPS) system and tune the handling performance of vehicles. However, no satisfactory theoretical model can be found in the existing literature to explain this phenomenon. This paper proposes a new theoretical framework to model this important tyre behaviour, which includes three key factors: (1) tyre three-dimensional transient rolling kinematics with turn-slip; (2) dynamical force and moment generation; and (3) the mixed Lagrange-Euler method for contact deformation solving. A nonlinear finite-element code has been developed to implement the proposed approach. It can be found that the main mechanism for the speed-dependent steering torque is due to turn-slip-related kinematics. This paper provides a theory to explain the complex mechanism of the tyre steering torque generation, which helps to understand the speed-dependent tyre steering torque, tyre road feeling and EPS calibration.

  12. Modulation of the acute phase response in feedlot steers supplemented with Saccharomyces cerevisiae

    Science.gov (United States)

    This study was designed to determine the effect of supplementing feedlot steers with Saccharomyces cerevisiae CNCM I-1079 (SC) on the acute phase response to a lipopolysaccharide (LPS) challenge. Steers (n = 18; 266 ± 4 kilograms body weight) were separated into three treatment groups (n = 6/treatm...

  13. Application of washed rumen technique for rapid determination of fasting heat production in steers

    Science.gov (United States)

    Two experiments were conducted to evaluate the use of a washed rumen technique as an alternative approach for determining fasting HP in cattle. In Exp. 1, 8 Holstein steers (322±30 kg) were adapted to a cubed alfalfa-based diet (1.5xNEm) for 10 d. After which steers were placed into individual hea...

  14. Effects of steering demand on lane keeping behaviour, self-reports, and physiology : A simulator study

    NARCIS (Netherlands)

    Dijksterhuis, Chris; Brookhuis, Karel A.; De Waard, Dick

    In this study a driving simulator was used to determine changes in mental effort in response to manipulations of steering demand. Changes in mental effort were assessed by using subjective effort ratings, physiology, and the standard deviation of the lateral position. Steering demand was increased

  15. 46 CFR 185.320 - Steering gear, controls, and communication system tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests. 185.320 Section 185.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Miscellaneous Operating Requirements § 185.320 Steering...

  16. 46 CFR 122.320 - Steering gear, controls, and communication system tests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests... communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel prior to getting underway for a...

  17. Reducing Digging Losses by Using Automated Steering to Plant and Invert Peanuts

    Directory of Open Access Journals (Sweden)

    George Vellidis

    2014-07-01

    Full Text Available GPS guidance of farm machinery has been increasingly adopted by farmers because of the perceived gains in efficiency that it provides. In the southeastern USA one of the reasons farmers adopt GPS guidance, and specifically automated steering (auto-steer, is that it can theoretically result in large yield gains when used to plant and invert peanuts—one of the region’s most important crops. The goal of our study was to quantify the yield benefit of using real time kinematic (RTK-based auto-steer to plant and invert peanuts under a variety of terrain conditions. Yield benefits result from reduced digging losses. The study was conducted for two consecutive years (2010 and 2011 on a private farm in Georgia, USA. When all data are grouped together, auto-steer outperformed conventional by 579 kg/ha in 2010 and 451 kg/ha in 2011. We also evaluated the performance of auto-steer under different curvature conditions using low, medium, and high curvature rows. The results showed that auto-steer outperformed conventional under all curvature by a minimum of 338 kg/ha. Finally, we evaluated passive implement guidance in combination with auto-steer and found that it holds tremendous potential for further reducing digging losses. In many cases, auto-steer will pay for itself within a year.

  18. On Using Current Steering Logic in Mixed Analogue-digital Circuits

    DEFF Research Database (Denmark)

    Lehmann, Torsten

    1998-01-01

    The authors investigate power supply noise in mixed analogue-digital circuits, arising from communication between the analogue and digital parts of the circuit. Current steering techniques and proper buffering are used to show which noise currents can be reduced and which cannot. In addition......, a high-swing current steering buffer for driving analogue switches or external digital signals is proposed....

  19. Does pedalling on a recumbent bicycle influence the cyclist’s steering behaviour?

    NARCIS (Netherlands)

    Boon, K.M.; Klap, P.; Van Lanen, J.A.; Letsoin, G.J.; Jansen, A.J.

    2014-01-01

    The paper presents the answer to the question how pedalling on a specific recumbent bicycle, such as the VeloX3, influences a cyclist’s ability to steer the bicycle. The research aims to find the correlation between pedalling and the undesired steering movements it creates. To test this assumption a

  20. Modelling and Simulation of a Hydrostatic Steering System for Agricultural Tractors

    Directory of Open Access Journals (Sweden)

    Barbara Zardin

    2018-01-01

    Full Text Available The steering system of a vehicle impacts on the vehicle performance, safety and on the driver’s comfort. Moreover, in off-road vehicles using hydrostatic steering systems, the energy dissipation also becomes a critical issue. These aspects push and motivate innovation, research and analysis in the field of agricultural tractors. This paper proposes the modelling and analysis of a hydrostatic steering system for an agricultural tractor to calculate the performance of the system and determine the influence of its main design parameters. The focus here is on the driver’s steering feel, which can improve the driver’s behavior reducing unnecessary steering corrections during the working conditions. The hydrostatic steering system is quite complex and involves a hydraulic circuit and a mechanical mechanism to transmit the steering to the vehicle tires. The detailed lumped parameters model here proposed allows to simulate the dynamic behavior of the steering system and to both enhance the understanding of the system and to improve the design through parameters sensitivity analysis.

  1. comparative beef production from buli,s, steers and heifers under

    African Journals Online (AJOL)

    steers, although statistically significant, were much srnaller than differences obtained in the present study. Out of a maximum possible grading of 20 points, bulls obtained an average of 12,3 points (Grade I -) which is considerably lower than the grading points obtained by steers (16,3 = Prime) or by heifers (17,5 = Prime+).

  2. Using carbon emissions, oxygen consumption, and retained energy to calculate dietary ME intake by beef steers

    Science.gov (United States)

    Eight cross-bred beef steers (initial BW = 241 ± 4.10 kg) were used in a 77-d feeding experiment to determine if ME intake can be determined from carbon emissions, oxygen consumption, and energy retention estimates. Steers were housed in a pen equipped with individual feed bunks and animal access w...

  3. Quasi-ideal dynamics of vortex solitons embedded in flattop nonlinear Bessel beams.

    Science.gov (United States)

    Porras, Miguel A; Ramos, Francisco

    2017-09-01

    The applications of vortex solitons are severely limited by the diffraction and self-defocusing spreading of the background beam where they are nested. Nonlinear Bessel beams in self-defocusing media are nondiffracting, flattop beams where the nested vortex solitons can survive for propagation distances that are one order of magnitude larger than in the Gaussian or super-Gaussian beams. The dynamics of the vortex solitons is studied numerically and found to approach that in the ideal, uniform background, preventing vortex spiraling and decay, which eases vortex steering for applications.

  4. Improving beam set-up using an online beam optics tool

    International Nuclear Information System (INIS)

    Richter, S.; Barth, W.; Franczak, B.; Scheeler, U.; Wilms, D.

    2004-01-01

    The GSI accelerator facility [1] consists of the Universal Linear Accelerator (Unilac), the heavy ion synchrotron SIS, and the Experimental Storage Ring (ESR). Two Unilac injectors with three ion source terminals provide ion species from the lightest such as hydrogen up to uranium. The High Current Injector (HSI) for low charge state ion beams provides mostly high intense but short pulses, whereas the High Charge State Injector (HLI) supplies long pulses with a high duty factor of up to 27%. Before entering the Alvarez section of the Unilac the ion beam from the HSI is stripped in a supersonic gas jet. Up to three different ion species can be accelerated for up to five experiments in a time-sharing mode. Frequent changes of beam energy and intensity during a single beam time period may result in time consuming set-up and tuning especially of the beam transport lines. To shorten these changeover times an online optics tool (MIRKO EXPERT) had been developed. Based on online emittance measurements at well-defined locations the beam envelopes are calculated using the actual magnet settings. With this input improved calculated magnet settings can be directly sent to the magnet power supplies. The program reads profile grid measurements, such that an atomized beam alignment is established and that steering times are minimized. Experiences on this tool will be reported. At the Unilac a special focus is put on high current operation with short but intense beam pulses. Limitations like missing non-destructive beam diagnostics, insufficient longitudinal beam diagnostics, insufficient longitudinal beam matching, and influence of the hard edged model for magnetic fields will be discussed. Special attention will be put on the limits due to high current effects with bunched beams. (author)

  5. Phosphate steering by Flap Endonuclease 1 promotes 5′-flap specificity and incision to prevent genome instability

    KAUST Repository

    Tsutakawa, Susan E.; Thompson, Mark J.; Arvai, Andrew S.; Neil, Alexander J.; Shaw, Steven J.; Algasaier, Sana I.; Kim, Jane C.; Finger, L. David; Jardine, Emma; Gotham, Victoria J.B.; Sarker, Altaf H.; Her, Mai Z.; Rashid, Fahad; Hamdan, Samir; Mirkin, Sergei M.; Grasby, Jane A.; Tainer, John A.

    2017-01-01

    and large-scale trinucleotide (GAA) repeat expansions in vivo, implying failed phosphate-steering promotes an unanticipated lagging-strand template-switch mechanism during replication. Thus, phosphate steering is an unappreciated FEN1 function that enforces

  6. Collision-model approach to steering of an open driven qubit

    Science.gov (United States)

    Beyer, Konstantin; Luoma, Kimmo; Strunz, Walter T.

    2018-03-01

    We investigate quantum steering of an open quantum system by measurements on its environment in the framework of collision models. As an example we consider a coherently driven qubit dissipatively coupled to a bath. We construct local nonadaptive and adaptive as well as nonlocal measurement scenarios specifying explicitly the measured observable on the environment. Our approach shows transparently how the conditional evolution of the open system depends on the type of the measurement scenario and the measured observables. These can then be optimized for steering. The nonlocal measurement scenario leads to maximal violation of the used steering inequality at zero temperature. Further, we investigate the robustness of the constructed scenarios against thermal noise. We find generally that steering becomes harder at higher temperatures. Surprisingly, the system can be steered even when bipartite entanglement between the system and individual subenvironments vanishes.

  7. Superresolution beams

    CSIR Research Space (South Africa)

    Ngcobo, S

    2011-11-01

    Full Text Available The transformation of a Gaussian beam (GB) into a symmetrical higher order TEMp0 Laguerre Gaussian beam (LGB) intensity distribution of which is further rectified and transformed into a Gaussian intensity distribution in the plane of a converging...

  8. Avoiding Internal Capsule Stimulation With a New Eight-Channel Steering Deep Brain Stimulation Lead.

    Science.gov (United States)

    van Dijk, Kees J; Verhagen, Rens; Bour, Lo J; Heida, Ciska; Veltink, Peter H

    2017-10-15

    Novel deep brain stimulation (DBS) lead designs are currently entering the market, which are hypothesized to provide a way to steer the stimulation field away from neural populations responsible for side effects and towards populations responsible for beneficial effects. The objective of this study is to assess the performances of a new eight channel steering-DBS lead and compare this with a conventional cylindrical contact (CC) lead. The two leads were evaluated in a finite element electric field model combined with multicompartment neuron and axon models, representing the internal capsule (IC) fibers and subthalamic nucleus (STN) cells. We defined the optimal stimulation setting as the configuration that activated the highest percentage of STN cells, without activating any IC fibers. With this criterion, we compared monopolar stimulation using a single contact of the steering-DBS lead and CC lead, on three locations and four orientations of the lead. In addition, we performed a current steering test case by dividing the current over two contacts with the steering-DBS lead in its worst-case orientation. In most cases, the steering-DBS lead is able to stimulate a significantly higher percentage of STN cells compared to the CC lead using single contact stimulation or using a two contact current steering protocol when there is approximately a 1 mm displacement of the CC lead. The results also show that correct placement and orientation of the lead in the target remains an important aspect in achieving the optimal stimulation outcome. Currently, clinical trials are set up in Europe with a similar design as the steering-DBS lead. Our results illustrate the importance of the orientation of the new steering-DBS lead in avoiding side effects induced by stimulation of IC fibers. Therefore, in clinical trials sufficient attention should be paid to implanting the steering DBS-lead in the most effective orientation. © 2017 International Neuromodulation Society.

  9. An Expert System For Tuning Particle-Beam Accelerators

    Science.gov (United States)

    Lager, Darrel L.; Brand, Hal R.; Maurer, William J.; Searfus, Robert M.; Hernandez, Jose E.

    1989-03-01

    We have developed a proof-of-concept prototype of an expert system for tuning particle beam accelerators. It is designed to function as an intelligent assistant for an operator. In its present form it implements the strategies and reasoning followed by the operator for steering through the beam transport section of the Advanced Test Accelerator at Lawrence Livermore Laboratory's Site 300. The system is implemented in the language LISP using the Artificial Intelligence concepts of frames, daemons, and a representation we developed called a Monitored Decision Script.

  10. Mechanical design aspects of a "Long-Waveguide" version of the remote steering ECRH upper port launcher for ITER

    NARCIS (Netherlands)

    Ronden, D. M. S.; van den Berg, M.; Bongers, W. A.; Elzendoorn, B. S. Q.; M. F. Graswinckel,; Lamers, B.; Van Nigtevecht, K.; Verhoeven, A. G. A.; Henderson, M. A.

    2008-01-01

    The current status of the mechanical design of the remote steering electron cyclotron resonance heating upper port launching system for ITER is presented. Although an alternative front steering launcher has now been selected as the reference design for ITER, the development of a remote steering

  11. The influence of grid positioning on the beam optics in the neutral beam injectors for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Veltri, Pierluigi, E-mail: pierluigi.veltri@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, Padova (Italy); INFN—Laboratori Nazionali di Legnaro, Viale dell’Università 2, 35020 Legnaro, Padova (Italy); Agostinetti, Piero; Marcuzzi, Diego; Sartori, Emanuele; Serianni, Gianluigi [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, Padova (Italy)

    2016-06-15

    Neutral beam injectors are routinely used to increase the ion temperature in magnetically confined plasmas. Typically, the beam is produced by neutralizing a bundle of hundreds of ion beamlets, energized in a multi-grid multi-stage accelerator. Precise aiming of each beamlet is required in order to focus the full beam to the plasma, avoiding any interception with beamline surfaces and with the beam duct. This paper describes the effects of grid in-plane and out-of-plane displacements (mispositioning, thermal expansion, grid tilting, etc…) in the case of the MITICA electrostatic accelerator, which is the full scale prototype of the ITER heating neutral beam injector. Various simulations have been carried out with the OPERA 3D code, by self-consistently simulating the beam charged particles travelling in an externally applied electric and magnetic field. The accelerator grids act like a series of electrostatic lenses, and produce a net deflection of the particles when one or more grids are offset. The numerical simulations were used to evaluate the “steering constant” of each grid and also showed that the linear superposition of effects was applicable, multiple causes of mispositioning are combined and used to quantify the overall effect in terms of beam misalignment.

  12. The influence of grid positioning on the beam optics in the neutral beam injectors for ITER

    International Nuclear Information System (INIS)

    Veltri, Pierluigi; Agostinetti, Piero; Marcuzzi, Diego; Sartori, Emanuele; Serianni, Gianluigi

    2016-01-01

    Neutral beam injectors are routinely used to increase the ion temperature in magnetically confined plasmas. Typically, the beam is produced by neutralizing a bundle of hundreds of ion beamlets, energized in a multi-grid multi-stage accelerator. Precise aiming of each beamlet is required in order to focus the full beam to the plasma, avoiding any interception with beamline surfaces and with the beam duct. This paper describes the effects of grid in-plane and out-of-plane displacements (mispositioning, thermal expansion, grid tilting, etc…) in the case of the MITICA electrostatic accelerator, which is the full scale prototype of the ITER heating neutral beam injector. Various simulations have been carried out with the OPERA 3D code, by self-consistently simulating the beam charged particles travelling in an externally applied electric and magnetic field. The accelerator grids act like a series of electrostatic lenses, and produce a net deflection of the particles when one or more grids are offset. The numerical simulations were used to evaluate the “steering constant” of each grid and also showed that the linear superposition of effects was applicable, multiple causes of mispositioning are combined and used to quantify the overall effect in terms of beam misalignment

  13. Adiabatically steered open quantum systems: Master equation and optimal phase

    International Nuclear Information System (INIS)

    Salmilehto, J.; Solinas, P.; Ankerhold, J.; Moettoenen, M.

    2010-01-01

    We introduce an alternative way to derive the generalized form of the master equation recently presented by J. P. Pekola et al. [Phys. Rev. Lett. 105, 030401 (2010)] for an adiabatically steered two-level quantum system interacting with a Markovian environment. The original derivation employed the effective Hamiltonian in the adiabatic basis with the standard interaction picture approach but without the usual secular approximation. Our approach is based on utilizing a master equation for a nonsteered system in the first superadiabatic basis. It is potentially efficient in obtaining higher-order equations. Furthermore, we show how to select the phases of the adiabatic eigenstates to minimize the local adiabatic parameter and how this selection leads to states which are invariant under a local gauge change. We also discuss the effects of the adiabatic noncyclic geometric phase on the master equation.

  14. Lightweight computational steering of very large scale molecular dynamics simulations

    International Nuclear Information System (INIS)

    Beazley, D.M.

    1996-01-01

    We present a computational steering approach for controlling, analyzing, and visualizing very large scale molecular dynamics simulations involving tens to hundreds of millions of atoms. Our approach relies on extensible scripting languages and an easy to use tool for building extensions and modules. The system is extremely easy to modify, works with existing C code, is memory efficient, and can be used from inexpensive workstations and networks. We demonstrate how we have used this system to manipulate data from production MD simulations involving as many as 104 million atoms running on the CM-5 and Cray T3D. We also show how this approach can be used to build systems that integrate common scripting languages (including Tcl/Tk, Perl, and Python), simulation code, user extensions, and commercial data analysis packages

  15. Microstructure, Macrostructure and the Steering of Material Proclivities

    DEFF Research Database (Denmark)

    Ayres, Phil

    2012-01-01

    This article reports upon recent and initial explorations by the author in the hydroforming of steel. The material processes involved and the resulting artefacts are reflected upon, providing a ground from which to speculate about implications for architecture as both artefact and practice...... are steerable but not exclusively dependant upon profile geometry. The definition of geometry leading to physical outcome is familiar design territory. The forming method can be arrested and resumed arbitrarily. The notion of an extended forming process presents interesting implications to the linear...... the ideal, predictive and pre‐determined. This is less familiar design territory. This work begins to define both a material language for, and a non‐deterministic design paradigm of, steered proclivity. A conceptual framework for this paradigm is sketched out and presented in the form of the Persistent...

  16. Fractional Control of An Active Four-wheel-steering Vehicle

    Science.gov (United States)

    Wang, Tianting; Tong, Jun; Chen, Ning; Tian, Jie

    2018-03-01

    A four-wheel-steering (4WS) vehicle model and reference model with a drop filter are constructed. The decoupling of 4WS vehicle model is carried out. And a fractional PIλDμ controller is introduced into the decoupling strategy to reduce the effects of the uncertainty of the vehicle parameters as well as the unmodelled dynamics on the system performance. Based on optimization techniques, the design of fractional controller are obtained to ensure the robustness of 4WS vehicle during the special range of frequencies through proper choice of the constraints. In order to compare with fractional robust controller, an optimal controller for the same vehicle is also designed. The simulations of the two control systems are carried out and it reveals that the decoupling and fractional robust controller is able to make vehicle model trace the reference model very well with better robustness.

  17. Influence of orographically steered winds on Mutsu Bay surface currents

    Science.gov (United States)

    Yamaguchi, Satoshi; Kawamura, Hiroshi

    2005-09-01

    Effects of spatially dependent sea surface wind field on currents in Mutsu Bay, which is located at the northern end of Japanese Honshu Island, are investigated using winds derived from synthetic aperture radar (SAR) images and a numerical model. A characteristic wind pattern over the bay was evidenced from analysis of 118 SAR images and coincided with in situ observations. Wind is topographically steered with easterly winds entering the bay through the terrestrial gap and stronger wind blowing over the central water toward its mouth. Nearshore winds are weaker due to terrestrial blockages. Using the Princeton Ocean Model, we investigated currents forced by the observed spatially dependent wind field. The predicted current pattern agrees well with available observations. For a uniform wind field of equal magnitude and average direction, the circulation pattern departs from observations demonstrating that vorticity input due to spatially dependent wind stress is essential in generation of the wind-driven current in Mutsu Bay.

  18. Model projections of atmospheric steering of Sandy-like superstorms.

    Science.gov (United States)

    Barnes, Elizabeth A; Polvani, Lorenzo M; Sobel, Adam H

    2013-09-17

    Superstorm Sandy ravaged the eastern seaboard of the United States, costing a great number of lives and billions of dollars in damage. Whether events like Sandy will become more frequent as anthropogenic greenhouse gases continue to increase remains an open and complex question. Here we consider whether the persistent large-scale atmospheric patterns that steered Sandy onto the coast will become more frequent in the coming decades. Using the Coupled Model Intercomparison Project, phase 5 multimodel ensemble, we demonstrate that climate models consistently project a decrease in the frequency and persistence of the westward flow that led to Sandy's unprecedented track, implying that future atmospheric conditions are less likely than at present to propel storms westward into the coast.

  19. Sugar transport across lactose permease probed by steered molecular dynamics

    DEFF Research Database (Denmark)

    Jensen, Morten Østergaard; Yin, Ying; Tajkhorshid, Emad

    2007-01-01

    Escherichia coli lactose permease (LacY) transports sugar across the inner membrane of the bacterium using the proton motive force to accumulate sugar in the cytosol. We have probed lactose conduction across LacY using steered molecular dynamics, permitting us to follow molecular and energetic...... details of lactose interaction with the lumen of LacY during its permeation. Lactose induces a widening of the narrowest parts of the channel during permeation, the widening being largest within the periplasmic half-channel. During permeation, the water-filled lumen of LacY only partially hydrates lactose......, forcing it to interact with channel lining residues. Lactose forms a multitude of direct sugar-channel hydrogen bonds, predominantly with residues of the flexible N-domain, which is known to contribute a major part of LacY's affinity for lactose. In the periplasmic half-channel lactose predominantly...

  20. DYNAMICS BASED CONTROL OF A SKID STEERING MOBILE ROBOT

    Directory of Open Access Journals (Sweden)

    Osama Elshazly

    2016-06-01

    Full Text Available In this paper, development of a reduced order, augmented dynamics-drive model that combines both the dynamics and drive subsystems of the skid steering mobile robot (SSMR is presented. A Linear Quadratic Regulator (LQR control algorithm with feed-forward compensation of the disturbances part included in the reduced order augmented dynamics-drive model is designed. The proposed controller has many advantages such as its simplicity in terms of design and implementation in comparison with complex nonlinear control schemes that are usually designed for this system. Moreover, the good performance is also provided by the controller for the SSMR comparable with a nonlinear controller based on the inverse dynamics which depends on the availability of an accurate model describing the system. Simulation results illustrate the effectiveness and enhancement provided by the proposed controller.

  1. Coherent beam-beam effect

    International Nuclear Information System (INIS)

    Chao, A.W.; Keil, E.

    1979-06-01

    The stability of the coherent beam-beam effect between rigid bunches is studied analytically and numerically for a linear force by evaluating eigenvalues. For a realistic force, the stability is investigated by following the bunches for many revolutions. 4 refs., 13 figs., 2 tabs

  2. Generalized internal model robust control for active front steering intervention

    Science.gov (United States)

    Wu, Jian; Zhao, Youqun; Ji, Xuewu; Liu, Yahui; Zhang, Lipeng

    2015-03-01

    Because of the tire nonlinearity and vehicle's parameters' uncertainties, robust control methods based on the worst cases, such as H ∞, µ synthesis, have been widely used in active front steering control, however, in order to guarantee the stability of active front steering system (AFS) controller, the robust control is at the cost of performance so that the robust controller is a little conservative and has low performance for AFS control. In this paper, a generalized internal model robust control (GIMC) that can overcome the contradiction between performance and stability is used in the AFS control. In GIMC, the Youla parameterization is used in an improved way. And GIMC controller includes two sections: a high performance controller designed for the nominal vehicle model and a robust controller compensating the vehicle parameters' uncertainties and some external disturbances. Simulations of double lane change (DLC) maneuver and that of braking on split- µ road are conducted to compare the performance and stability of the GIMC control, the nominal performance PID controller and the H ∞ controller. Simulation results show that the high nominal performance PID controller will be unstable under some extreme situations because of large vehicle's parameters variations, H ∞ controller is conservative so that the performance is a little low, and only the GIMC controller overcomes the contradiction between performance and robustness, which can both ensure the stability of the AFS controller and guarantee the high performance of the AFS controller. Therefore, the GIMC method proposed for AFS can overcome some disadvantages of control methods used by current AFS system, that is, can solve the instability of PID or LQP control methods and the low performance of the standard H ∞ controller.

  3. Combining coordination of motion actuators with driver steering interaction.

    Science.gov (United States)

    Tagesson, Kristoffer; Laine, Leo; Jacobson, Bengt

    2015-01-01

    A new method is suggested for coordination of vehicle motion actuators; where driver feedback and capabilities become natural elements in the prioritization. The method is using a weighted least squares control allocation formulation, where driver characteristics can be added as virtual force constraints. The approach is in particular suitable for heavy commercial vehicles that in general are over actuated. The method is applied, in a specific use case, by running a simulation of a truck applying automatic braking on a split friction surface. Here the required driver steering angle, to maintain the intended direction, is limited by a constant threshold. This constant is automatically accounted for when balancing actuator usage in the method. Simulation results show that the actual required driver steering angle can be expected to match the set constant well. Furthermore, the stopping distance is very much affected by this set capability of the driver to handle the lateral disturbance, as expected. In general the capability of the driver to handle disturbances should be estimated in real-time, considering driver mental state. By using the method it will then be possible to estimate e.g. stopping distance implied from this. The setup has the potential of even shortening the stopping distance, when the driver is estimated as active, this compared to currently available systems. The approach is feasible for real-time applications and requires only measurable vehicle quantities for parameterization. Examples of other suitable applications in scope of the method would be electronic stability control, lateral stability control at launch and optimal cornering arbitration.

  4. Fast-steering solutions for cubesat-scale optical communications

    Science.gov (United States)

    Kingsbury, R. W.; Nguyen, T.; Riesing, K.; Cahoy, K.

    2017-11-01

    We describe the design of a compact free-space optical communications module for use on a nanosatellite and present results from a detailed trade study to select an optical fine steering mechanism compatible with our stringent size, weight and power (SWaP) constraints. This mechanism is an integral component of the compact free-space optical communications system that is under development at the MIT Space Systems Laboratory [1]. The overall goal of this project is to develop a laser communications (lasercom) payload that fits within the SWaP constraints of a typical ``3U'' CubeSat. The SWaP constraints for the entire lasercom payload are 5 cm × 10 cm × 10 cm, 600 g and 10W. Although other efforts are underway to qualify MEMS deformable mirrors for use in CubeSats [2], there has been very little work towards qualifying tip-tilt MEMS mirrors [3]. Sec. II provides additional information on how the fast steering mechanism is used in our lasercom system. Performance requirements and desirable traits of the mechanism are given. In Sec. III we describe the various types of compact tip-tilt mirrors that are commercially available as well as the justification for selecting a MEMS-based device for our application. Sec. IV presents an analysis of the device's transfer function characteristics and ways of predicting this behavior that are suitable for use in the control processor. This analysis is based upon manufacturer-provided test data which was collected at standard room conditions. In the final section, we describe on-going work to build a testbed that will be used to measure device performance in a thermal chamber.

  5. Beam-bending in spatially variant photonic crystals at telecommunications wavelengths

    Science.gov (United States)

    Digaum, Jennefir L.; Sharma, Rashi; Batista, Daniel; Pazos, Javier J.; Rumpf, Raymond C.; Kuebler, Stephen M.

    2016-03-01

    This work reports the fabrication of micron-scale spatially variant photonic crystals (SVPCs) and their use for steering light beams through turns with bending radius Rbend on the order of ten times the optical wavelength λ0. Devices based on conventional photonic crystals, metamaterials, plasmonics and transformation optics have all been explored for controlling light beams and steering them through tight turns. These devices offer promise for photonic interconnects, but they are based on exotic materials, including metals, that make them impractically lossy or difficult to fabricate. Waveguides can also be used to steer light using total internal reflection; however, Rbend of a waveguide must be hundreds of times λ0 to guide light efficiently, which limits their use in optical circuits. SVPCs are spatially variant 3D lattices which can be created in transparent, low-refractive-index media and used to control the propagation of light through the self-collimation effect. SVPCs were fabricated by multi-photon lithography using the commercially available photo-polymer IP-DIP. The SVPCs were structurally and optically characterized and found to be capable of bending light having λ0 = 1.55 μm through a 90-degree turn with Rbend = 10 μm. Curved waveguides with Rbend = 15 μm and 35 μm were also fabricated using IP-DIP and optically characterized. The SVPCs were able to steer the light beams through tighter turns than either waveguide and with higher efficiency.

  6. Monogamy inequalities for the Einstein-Podolsky-Rosen paradox and quantum steering

    Science.gov (United States)

    Reid, M. D.

    2013-12-01

    Monogamy inequalities for the way bipartite Einstein-Podolsky-Rosen (EPR) steering can be distributed among N systems are derived. One set of inequalities is based on witnesses with two measurement settings, and may be used to demonstrate correlation of outcomes between two parties, that cannot be shared with more parties. It is shown that the monogamy for steering is directional. Two parties cannot independently demonstrate steering of a third system, using the same two-setting steering witness, but it is possible for one party to steer two independent systems. This result explains the monogamy of two-setting Bell inequality violations and the sensitivity of the continuous variable (CV) EPR criterion to losses on the steering party. We generalize to m settings. A second type of monogamy relation gives the quantitative amount of sharing possible, when the number of parties is less than or equal to m, and takes a form similar to the Coffman-Kundu-Wootters relation for entanglement. The results enable characterization of the tripartite steering for CV Gaussian systems and qubit Greenberger-Horne-Zeilinger and W states.

  7. Test of Einstein-Podolsky-Rosen steering based on the all-versus-nothing proof.

    Science.gov (United States)

    Wu, Chunfeng; Chen, Jing-Ling; Ye, Xiang-Jun; Su, Hong-Yi; Deng, Dong-Ling; Wang, Zhenghan; Oh, C H

    2014-03-06

    In comparison with entanglement and Bell nonlocality, Einstein-Podolsky-Rosen steering is a newly emerged research topic and in its incipient stage. Although Einstein-Podolsky-Rosen steering has been explored via violations of steering inequalities both theoretically and experimentally, the known inequalities in the literatures are far from well-developed. As a result, it is not yet possible to observe Einstein-Podolsky-Rosen steering for some steerable mixed states. Recently, a simple approach was presented to identify Einstein-Podolsky-Rosen steering based on all-versus-nothing argument, offering a strong condition to witness the steerability of a family of two-qubit (pure or mixed) entangled states. In this work, we show that the all-versus-nothing proof of Einstein-Podolsky-Rosen steering can be tested by measuring the projective probabilities. Through the bound of probabilities imposed by local-hidden-state model, the proposed test shows that steering can be detected by the all-versus-nothing argument experimentally even in the presence of imprecision and errors. Our test can be implemented in many physical systems and we discuss the possible realizations of our scheme with non-Abelian anyons and trapped ions.

  8. Chaos vibration of pinion and rack steering trapezoidal mechanism containing two clearances

    Science.gov (United States)

    Wei, Daogao; Wang, Yu; Jiang, Tong; Zheng, Sifa; Zhao, Wenjing; Pan, Zhijie

    2017-08-01

    The multi-clearances of breaking type steering trapezoidal mechanism joints influences vehicle steering stability. Hence, to ascertain the influence of clearance value on steering stability, this paper takes the steering mechanism of a certain vehicle type as a prototype that can be simplified into a planar six-bar linkage, then establishes the system dynamic differential equations after considering the two clearances of tie rods and the steering knuckle arms. The influence of the clearance parameters on the movement stability of the steering mechanism is studied using a numerical computation method. Results show that when the two clearances are equal, the planar movement of the tie rods changes from period-doubling to chaos as the clearances increase. When the two clearances are 0.25 mm and 1.5 mm respectively, the planar movements of the two side tie rods come into chaos, causing the steering stability to deteriorate. Moreover, with the increase of clearances, turning moment fluctuates more intensively and the peak value increases.

  9. A laser-based beam profile monitor for the SLC/SLD interaction region

    International Nuclear Information System (INIS)

    Alley, R.; Arnett, D.; Bong, E.; Colocho, W.; Frisch, J.; Horton-Smith, S.; Inman, W.; Jobe, K.; Kotseroglou, T.; McCormick, D.; Nelson, J.; Scheeff, M.; Wagner, S.; Ross, M.C.

    1996-01-01

    Beam size estimates made using beam-beam deflections are used for optimization of the Stanford linear collider (SLC) electron-positron beam sizes. Typical beam sizes and intensities expected for 1996 operations are 2.1 x 0.6 μm (x, y) at 4.0.10 10 particles per pulse. Conventional profile monitors, such as scanning wires, fail at charge densities well below this. The laser-based profile monitor uses a finely-focused 350-nm wavelength tripled YLF laser pulse that traverses the particle beam path about 29 cm away from the e + /e - IP. Compton scattered photons and degraded e + /e - are detected as the beam is steered across the laser pulse. The laser pulse has a transverse size of 380 nm and a Rayleigh range of about 5 μm. (orig.)

  10. Feed efficiency differences and reranking in beef steers fed grower and finisher diets.

    Science.gov (United States)

    Durunna, O N; Mujibi, F D N; Goonewardene, L; Okine, E K; Basarab, J A; Wang, Z; Moore, S S

    2011-01-01

    This 3-yr study used 490 steers to determine whether feedlot steers changed their feed efficiency (FE) ranking when fed a grower diet, then a finisher diet. The steers were crossbreds and were between 5 to 7 mo of age. There were 2 feeding periods each year. Within each year, approximately 90 steers had their diet switched from a grower to a finisher diet (feed-swap group), whereas another 90 steers were fed either the grower (grower-fed group) or the finisher (finisher-fed group) diet throughout the feeding trial. Each feeding test lasted for a minimum of 10 wk, and all steers were fed ad libitum. Individual animal feed intakes were collected using the GrowSafe feeding system, and BW were measured every 2 wk. Residual feed intake (RFI), G:F, and Kleiber ratio (KR) were computed at the end of each feeding period. For each measure of efficiency, animals were classified as low, medium, or high based on 0.5 SD from the mean. The majority of steers did not maintain the previous efficiency class in the second period. Approximately 58, 51, and 51% of steers in the feed-swap group, finisher-fed group, and the grower-fed group, respectively, changed their RFI measure by 0.5 SD. A low rank correlation occurred in all test groups but was less in the feed-swap group. Spearman rank correlations between the 2 feeding periods in the feed-swap group were 0.33, 0.20, and 0.31 for RFI, G:F, and KR, respectively. Classifications based on G:F and KR showed that a greater number of steers (P 0.05) between the proportions of individuals that changed or maintained their FE class. In the groups without a feed-swap, there was no difference (P > 0.05) in the proportion of steers that changed or maintained the same FE class for all FE measures. Our results suggest that diet type and feeding period affect the FE ranking in beef steers. A feedlot diet is ideal for evaluating the FE potential of steers for feedlot profitability; however, we suggest that tests involving less dense diets should

  11. Effects of steering demand on lane keeping behaviour, self-reports, and physiology. A simulator study.

    Science.gov (United States)

    Dijksterhuis, Chris; Brookhuis, Karel A; De Waard, Dick

    2011-05-01

    In this study a driving simulator was used to determine changes in mental effort in response to manipulations of steering demand. Changes in mental effort were assessed by using subjective effort ratings, physiology, and the standard deviation of the lateral position. Steering demand was increased by exposure to narrow lane widths and high density oncoming traffic while speed was fixed in all conditions to prevent a compensatory reaction. Results indicated that both steering demand factors influence mental effort expenditure and using multiple measures contributes to effort assessment. Application of these outcomes for adaptive automation is envisaged. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. Analysis of ultrasonic beam profile due to change of elements' number for phased array transducer (part 2)

    International Nuclear Information System (INIS)

    Choi, Sang Woo; Lee, Joon Hyun

    1998-01-01

    The phased array offers many advantages and improvements over conventional single-element transducers such as the straight-beam and angle-beam. The advantages of array sensors for large structures are two folds; firstly, array transducers provide a method of rapid beam steering and sequential addressing of a large area of interest without requiring mechanical or manual scanning which is particularly important in real-time application. Secondly, array transducer provide a method of dynamic focusing, in which the focal length of the ultrasonic beam varies as the pulse propagates through the material. There are some parameters such as number, size, center to center space of elements to design phased array transducer. In previous study. the characteristics of beam steering and dynamic focusing had been simulated for ultrasonic SH-wave with varying the number of phased array transducer's element. In this study, the characteristic of beam steering for phased array transducer has been simulated for ultrasonic SH-wave on the basis of Huygen's principle with varying center to center space of elements. Ultrasonic beam directivity and focusing due to change of time delay of each element were discussed with varying center to center space of elements.

  13. Summary of mirror experiments relevant to beam-plasma neutron source

    International Nuclear Information System (INIS)

    Molvik, A.W.

    1988-01-01

    A promising design for a deuterium-tritium (DT) neutron source is based on the injection of neutral beams into a dense, warm plasma column. Its purpose is to test materials for possible use in fusion reactors. A series of designs have evolved, from a 4-T version to an 8-T version. Intense fluxes of 5--10 MW/m 2 is achieved at the plasma surface, sufficient to complete end-of-life tests in one to two years. In this report, we review data from earlier mirror experiments that are relevant to such neutron sources. Most of these data are from 2XIIB, which was the only facility to ever inject 5 MW of neutral beams into a single mirror call. The major physics issues for a beam-plasma neutron source are magnetohydrodynamic (MHD) equilibrium and stability, microstability, startup, cold-ion fueling of the midplane to allow two-component reactions, and operation in the Spitzer conduction regime, where the power is removed to the ends by an axial gradient in the electron temperature T/sub e/. We show in this report that the conditions required for a neutron source have now been demonstrated in experiments. 20 refs., 15 figs., 3 tabs

  14. Quantum beams

    International Nuclear Information System (INIS)

    Uesaka, Mitsuru

    2003-01-01

    Present state and future prospect are described on quantum beams for medical use. Efforts for compactness of linac for advanced cancer therapy have brought about the production of machines like Accuray's CyberKnife and TOMOTHERAPY (Tomo Therapy Inc.) where the acceleration frequency of X-band (9-11 GHz) is used. For cervical vein angiography by the X-band linac, a compact hard X-ray source is developed which is based on the (reverse) Compton scattering through laser-electron collision. More intense beam and laser are necessary at present. A compact machine generating the particle beam of 10 MeV-1 GeV (laser-plasma accelerator) for cancer therapy is also developed using the recent compression technique (chirped-pulse amplification) to generate laser of >10 TW. Tokyo University is studying for the electron beam with energy of GeV order, for the laser-based synchrotron X-ray, and for imaging by the short pulse ion beam. Development of advanced compact accelerators is globally attempted. In Japan, a virtual laboratory by National Institute of Radiological Sciences (NIRS), a working group of universities and research facilities through the Ministry of Education, Culture, Sports, Science and Technology, started in 2001 for practical manufacturing of the above-mentioned machines for cancer therapy and for angiography. Virtual Factory (Inc.), a business venture, is to be stood in future. (N.I.)

  15. Effect of chronological age of beef steers of different maturity types ...

    African Journals Online (AJOL)

    Effect of chronological age of beef steers of different maturity types on their growth ... and carcass studies have been conducted in the sourveld regions of the country. ... different beef maturity types which differ in body frame size were used, viz.

  16. Violation of Continuous-Variable Einstein-Podolsky-Rosen Steering with Discrete Measurements

    Science.gov (United States)

    Schneeloch, James; Dixon, P. Ben; Howland, Gregory A.; Broadbent, Curtis J.; Howell, John C.

    2013-03-01

    In this Letter, we derive an entropic Einstein-Podolsky-Rosen (EPR) steering inequality for continuous-variable systems using only experimentally measured discrete probability distributions and details of the measurement apparatus. We use this inequality to witness EPR steering between the positions and momenta of photon pairs generated in spontaneous parametric down-conversion. We examine the asymmetry between parties in this inequality, and show that this asymmetry can be used to reduce the technical requirements of experimental setups intended to demonstrate the EPR paradox. Furthermore, we develop a more stringent steering inequality that is symmetric between parties, and use it to show that the down-converted photon pairs also exhibit symmetric EPR steering.

  17. Effects of clay on fat necrosis and carcass characteristics in Japanese Black steers.

    Science.gov (United States)

    Oka, Akio; Iwamoto, Eiji; Tatsuda, Ken

    2015-10-01

    Twenty 10-month-old Japanese Black steers were used to evaluate the effects of clay on fat necrosis and carcass characteristics. Ten steers (Clay group) were fed the clay (50 g/day) during 10-30 months of age. The other 10 steers (Control group) were not fed it. There was no significant difference in body weight or average daily gain between the two groups (P > 0.05). The occurrence of fat necrotic mass in the Clay group (30%) was lower (P Clay group was smaller (P clay prevented the occurrence of fat necrosis and did not affect the carcass characteristics in Japanese Black steers. © 2015 Japanese Society of Animal Science.

  18. Ka-Band Electronically Steered CubeSat Antenna, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Kymeta Government Solutions (KGS) designed, analyzed, built, tested, and delivered a small, lightweight, low-cost, low-power electronically steered Ka-band prototype...

  19. Comparison of vibration damping of standard and PDCPD housing of the electric power steering system

    Science.gov (United States)

    Płaczek, M.; Wróbel, A.; Baier, A.

    2017-08-01

    A comparison of two different types of electric power steering system housing is presented. The first considered type of the housing was a standard one that is made of an aluminium alloy. The second one is made of polydicyclopentadiene polymer (PDCPD) and was produced using the RIM technology. Considered elements were analysed in order to verify their properties of vibrations damping. This property is very important taking into account noise generated by elements of a car’s power steering system. During the carried out tests vibrations of analysed power steering housings were measured using Marco Fiber Composite (MFC) piezoelectric transducers. Results obtained for both considered power steering housings in case of the same parameters of vibrations excitations were measured and juxtaposed. Obtained results were analysed in order to verify if the housing made of PDCPD polymer has better properties of vibration damping than the standard one.

  20. Steering a Course through Work and Life the Narratives of a ...

    African Journals Online (AJOL)

    Steering a Course through Work and Life the Narratives of a Zimbabwean Migrant ... Journal of Social Development in Africa ... of migrant life and the ways in which connections are continually forged and experience and agency enacted.

  1. Evaluation of four steering wheels to determine driver hand placement in a static environment.

    Science.gov (United States)

    Mossey, Mary E; Xi, Yubin; McConomy, Shayne K; Brooks, Johnell O; Rosopa, Patrick J; Venhovens, Paul J

    2014-07-01

    While much research exists on occupant packaging both proprietary and in the literature, more detailed research regarding user preferences for subjective ratings of steering wheel designs is sparse in published literature. This study aimed to explore the driver interactions with production steering wheels in four vehicles by using anthropometric data, driver hand placement, and driver grip design preferences for Generation-Y and Baby Boomers. In this study, participants selected their preferred grip diameter, responded to a series of questions about the steering wheel grip as they sat in four vehicles, and rank ordered their preferred grip design. Thirty-two male participants (16 Baby Boomers between ages 47 and 65 and 16 Generation-Y between ages 18 and 29) participated in the study. Drivers demonstrated different gripping behavior between vehicles and between groups. Recommendations for future work in steering wheel grip design and naturalistic driver hand positioning are discussed. Copyright © 2014. Published by Elsevier Ltd.

  2. National Status and Trends: Bioeffects Program - St. Thomas East End Reserves (STEER) Database

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of this effort was to characterize the extent and magnitude of chemical contamination in the St. Thomas East End Reserves or STEER, as part of a larger...

  3. Demonstration of Einstein-Podolsky-Rosen steering with enhanced subchannel discrimination

    Science.gov (United States)

    Sun, Kai; Ye, Xiang-Jun; Xiao, Ya; Xu, Xiao-Ye; Wu, Yu-Chun; Xu, Jin-Shi; Chen, Jing-Ling; Li, Chuan-Feng; Guo, Guang-Can

    2018-03-01

    Einstein-Podolsky-Rosen (EPR) steering describes a quantum nonlocal phenomenon in which one party can nonlocally affect the other's state through local measurements. It reveals an additional concept of quantum non-locality, which stands between quantum entanglement and Bell nonlocality. Recently, a quantum information task named as subchannel discrimination (SD) provides a necessary and sufficient characterization of EPR steering. The success probability of SD using steerable states is higher than using any unsteerable states, even when they are entangled. However, the detailed construction of such subchannels and the experimental realization of the corresponding task are still technologically challenging. In this work, we designed a feasible collection of subchannels for a quantum channel and experimentally demonstrated the corresponding SD task where the probabilities of correct discrimination are clearly enhanced by exploiting steerable states. Our results provide a concrete example to operationally demonstrate EPR steering and shine a new light on the potential application of EPR steering.

  4. Fault Risk Assessment of Underwater Vehicle Steering System Based on Virtual Prototyping and Monte Carlo Simulation

    Directory of Open Access Journals (Sweden)

    He Deyu

    2016-09-01

    Full Text Available Assessing the risks of steering system faults in underwater vehicles is a human-machine-environment (HME systematic safety field that studies faults in the steering system itself, the driver’s human reliability (HR and various environmental conditions. This paper proposed a fault risk assessment method for an underwater vehicle steering system based on virtual prototyping and Monte Carlo simulation. A virtual steering system prototype was established and validated to rectify a lack of historic fault data. Fault injection and simulation were conducted to acquire fault simulation data. A Monte Carlo simulation was adopted that integrated randomness due to the human operator and environment. Randomness and uncertainty of the human, machine and environment were integrated in the method to obtain a probabilistic risk indicator. To verify the proposed method, a case of stuck rudder fault (SRF risk assessment was studied. This method may provide a novel solution for fault risk assessment of a vehicle or other general HME system.

  5. 46 CFR 130.140 - Steering on OSVs of 100 or more gross tons.

    Science.gov (United States)

    2010-10-01

    ... means of steering so as not to impair the reliability and availability of the control required by paragraph (b)(7) of this section. (15) Manual capability to center and steady the rudder if the vessel loses...

  6. Influence of Road Excitation and Steering Wheel Input on Vehicle System Dynamic Responses

    OpenAIRE

    Zhen-Feng Wang; Ming-Ming Dong; Liang Gu; Jagat-Jyoti Rath; Ye-Chen Qin; Bin Bai

    2017-01-01

    Considering the importance of increasing driving safety, the study of safety is a popular and critical topic of research in the vehicle industry. Vehicle roll behavior with sudden steering input is a main source of untripped rollover. However, previous research has seldom considered road excitation and its coupled effect on vehicle lateral response when focusing on lateral and vertical dynamics. To address this issue, a novel method was used to evaluate effects of varying road level and steer...

  7. Excitation Patterns of Standard and Steered Partial Tripolar Stimuli in Cochlear Implants

    OpenAIRE

    Wu, Ching-Chih; Luo, Xin

    2015-01-01

    Current steering in partial tripolar (pTP) mode has been shown to improve pitch perception and spectral resolution with cochlear implants (CIs). In this mode, a fraction (?) of the main electrode current is returned within the cochlea and steered between the basal and apical flanking electrodes (with a proportion of ? and 1????, respectively). Pitch generally decreases when ? increases from 0 to 1, although the salience of pitch change varies across CI users. This study aimed to identify the ...

  8. Throughput-Based Traffic Steering in LTE-Advanced HetNet Deployments

    DEFF Research Database (Denmark)

    Gimenez, Lucas Chavarria; Kovacs, Istvan Z.; Wigard, Jeroen

    2015-01-01

    The objective of this paper is to propose traffic steering solutions that aim at optimizing the end-user throughput. Two different implementations of an active mode throughput-based traffic steering algorithm for Heterogeneous Networks (HetNet) are introduced. One that always forces handover of t...... throughput is generally higher, reaching values of 36% and 18% for the medium- and high-load conditions....

  9. Deriving Einstein-Podolsky-Rosen steering inequalities from the few-body Abner Shimony inequalities

    Science.gov (United States)

    Zhou, Jie; Meng, Hui-Xian; Jiang, Shu-Han; Xu, Zhen-Peng; Ren, Changliang; Su, Hong-Yi; Chen, Jing-Ling

    2018-04-01

    For the Abner Shimony (AS) inequalities, the simplest unified forms of directions attaining the maximum quantum violation are investigated. Based on these directions, a family of Einstein-Podolsky-Rosen (EPR) steering inequalities is derived from the AS inequalities in a systematic manner. For these inequalities, the local hidden state (LHS) bounds are strictly less than the local hidden variable (LHV) bounds. This means that the EPR steering is a form of quantum nonlocality strictly weaker than Bell nonlocality.

  10. Driver assistance system for lane departure avoidance by steering and differential braking

    OpenAIRE

    MINOIU-ENACHE, N; MAMMAR, S; GLASER, S; LUSETTI, B

    2010-01-01

    Lane departure avoidance systems assist actively the driver during inattention or drowsiness and increase driving safety. Most of the lane departure avoidance systems use for the lateral control of the vehicle in closed loop a DC motor similar to the electrical powered steering (EPS) assistance. Important difficulties and limits of this approach are the shared control with the driver on the steering wheel and the vehicle handling at limits. In this paper a combined lateral control using a DC ...

  11. Importance of beam-beam tune spread to collective beam-beam instability in hadron colliders

    International Nuclear Information System (INIS)

    Jin Lihui; Shi Jicong

    2004-01-01

    In hadron colliders, electron-beam compensation of beam-beam tune spread has been explored for a reduction of beam-beam effects. In this paper, effects of the tune-spread compensation on beam-beam instabilities were studied with a self-consistent beam-beam simulation in model lattices of Tevatron and Large Hodron Collider. It was found that the reduction of the tune spread with the electron-beam compensation could induce a coherent beam-beam instability. The merit of the compensation with different degrees of tune-spread reduction was evaluated based on beam-size growth. When two beams have a same betatron tune, the compensation could do more harm than good to the beams when only beam-beam effects are considered. If a tune split between two beams is large enough, the compensation with a small reduction of the tune spread could benefit beams as Landau damping suppresses the coherent beam-beam instability. The result indicates that nonlinear (nonintegrable) beam-beam effects could dominate beam dynamics and a reduction of beam-beam tune spread by introducing additional beam-beam interactions and reducing Landau damping may not improve the stability of beams

  12. Beam dynamics

    International Nuclear Information System (INIS)

    Abell, D; Adelmann, A; Amundson, J; Dragt, A; Mottershead, C; Neri, F; Pogorelov, I; Qiang, J; Ryne, R; Shalf, J; Siegerist, C; Spentzouris, P; Stern, E; Venturini, M; Walstrom, P

    2006-01-01

    We describe some of the accomplishments of the Beam Dynamics portion of the SciDAC Accelerator Science and Technology project. During the course of the project, our beam dynamics software has evolved from the era of different codes for each physical effect to the era of hybrid codes combining start-of-the-art implementations for multiple physical effects to the beginning of the era of true multi-physics frameworks. We describe some of the infrastructure that has been developed over the course of the project and advanced features of the most recent developments, the interplay betwen beam studies and simulations and applications to current machines at Fermilab. Finally we discuss current and future plans for simulations of the International Linear Collider

  13. Nudging and Boosting: Steering or Empowering Good Decisions.

    Science.gov (United States)

    Hertwig, Ralph; Grüne-Yanoff, Till

    2017-11-01

    In recent years, policy makers worldwide have begun to acknowledge the potential value of insights from psychology and behavioral economics into how people make decisions. These insights can inform the design of nonregulatory and nonmonetary policy interventions-as well as more traditional fiscal and coercive measures. To date, much of the discussion of behaviorally informed approaches has emphasized "nudges," that is, interventions designed to steer people in a particular direction while preserving their freedom of choice. Yet behavioral science also provides support for a distinct kind of nonfiscal and noncoercive intervention, namely, "boosts." The objective of boosts is to foster people's competence to make their own choices-that is, to exercise their own agency. Building on this distinction, we further elaborate on how boosts are conceptually distinct from nudges: The two kinds of interventions differ with respect to (a) their immediate intervention targets, (b) their roots in different research programs, (c) the causal pathways through which they affect behavior, (d) their assumptions about human cognitive architecture, (e) the reversibility of their effects, (f) their programmatic ambitions, and (g) their normative implications. We discuss each of these dimensions, provide an initial taxonomy of boosts, and address some possible misconceptions.

  14. Carcass characteristics and sensorial evaluation of meat from Nellore steers and crossbred Angus vs. Nellore bulls

    Directory of Open Access Journals (Sweden)

    Vinicius Cunha Barcellos

    2017-09-01

    Full Text Available This study evaluated animal performance, carcass characteristics and meat quality of 36-month old Nellore steers finished in pastures (n = 10 and 20-month old Angus vs. Nellore bulls finished in feedlot (n = 10. Final body weight, carcass weight, characteristics, conformation and fat thickness, were higher (p 0.05 throughout the ageing period for the Angus vs. Nellore bulls, but higher in meat from the Nellore steers (p 0.05 on meat a* value (redness. Likewise, ageing time had no effect on a* in both genetic groups, and genetic group had no effect (p > 0.05 on meat b* value (yellowness. On the other hand, b* was increased after day 7 of ageing for the bulls from the two genetic groups. Thawing and cooking losses were lower for Nellore steers after day 7 of aging (p 0.05 on lipid oxidation; however, lipid oxidation increased after day7. Meat from Nellore steers contained a higher percentage of saturated fatty acids (SFA, a lower percentage of unsaturated (UFA and monounsaturated fatty acids (MUFA and a similar percentage of polyunsaturated fatty acids (PUFA than the meat from Angus vs. Nellore bulls. Intramuscular fat from Nellore steers had a more favourable n-6:n-3 fatty acid ratio than that from Angus vs. Nellore bulls (4.37 vs. 11.45, respectively. Tenderness, flavour and overall acceptability were higher (p < 0.001 for meats of the Nellore steers, regardless of ageing time (1, 4, 7 and 14 days.

  15. Design of Model-based Controller with Disturbance Estimation in Steer-by-wire System

    Directory of Open Access Journals (Sweden)

    Jung Sanghun

    2018-01-01

    Full Text Available The steer-by-wire system is a next generation steering control technology that has been actively studied because it has many advantages such as fast response, space efficiency due to removal of redundant mechanical elements, and high connectivity with vehicle chassis control, such as active steering. Steer-by-wire system has disturbance composed of tire friction torque and self-aligning torque. These disturbances vary widely due to the weight or friction coefficient change. Therefore, disturbance compensation logic is strongly required to obtain desired performance. This paper proposes model-based controller with disturbance compensation to achieve the robust control performance. Targeted steer-by-wire system is identified through the experiment and system identification method. Moreover, model-based controller is designed using the identified plant model. Disturbance of targeted steer-by-wire is estimated using disturbance observer(DOB, and compensate the estimated disturbance into control input. Experiment of various scenarios are conducted to validate the robust performance of proposed model-based controller.

  16. On Optimizing Steering Performance of Multi-axle Vehicle Based on Driving Force Control

    Directory of Open Access Journals (Sweden)

    Wu Zhicheng

    2017-01-01

    Full Text Available The steering performance of multi-axle vehicle with independent driving system is affected by the distribution of the wheel driving force. A nonlinear vehicle dynamics model including magic formula tire model for describing 11 DoF four-axle vehicle with dual-front-axle-steering (DFAS system was presented. The influence of different driving force distribution scheme on the steering performance of the vehicle was analyzed. A control strategy for improving the steady response and transient response of the vehicle steering is proposed. The results show: For the steady response, setting different drive force for internal and external wheels according to the actual steering characteristics of the vehicle can effectively improve its steering characteristics; For the transient response, adopting the zero sideslip angle control strategy and using the PID control algorithm to control the driving force of the outside wheel of tear-two-axle, under angle step input, the vehicle sideslip angle can quickly stabilize to 0 and yaw rate also significantly decreases.

  17. Adaptive Sliding Mode Control Method Based on Nonlinear Integral Sliding Surface for Agricultural Vehicle Steering Control

    Directory of Open Access Journals (Sweden)

    Taochang Li

    2014-01-01

    Full Text Available Automatic steering control is the key factor and essential condition in the realization of the automatic navigation control of agricultural vehicles. In order to get satisfactory steering control performance, an adaptive sliding mode control method based on a nonlinear integral sliding surface is proposed in this paper for agricultural vehicle steering control. First, the vehicle steering system is modeled as a second-order mathematic model; the system uncertainties and unmodeled dynamics as well as the external disturbances are regarded as the equivalent disturbances satisfying a certain boundary. Second, a transient process of the desired system response is constructed in each navigation control period. Based on the transient process, a nonlinear integral sliding surface is designed. Then the corresponding sliding mode control law is proposed to guarantee the fast response characteristics with no overshoot in the closed-loop steering control system. Meanwhile, the switching gain of sliding mode control is adaptively adjusted to alleviate the control input chattering by using the fuzzy control method. Finally, the effectiveness and the superiority of the proposed method are verified by a series of simulation and actual steering control experiments.

  18. A Vehicle Steering Recognition System Based on Low-Cost Smartphone Sensors

    Directory of Open Access Journals (Sweden)

    Xinhua Liu

    2017-03-01

    Full Text Available Recognizing how a vehicle is steered and then alerting drivers in real time is of utmost importance to the vehicle and driver’s safety, since fatal accidents are often caused by dangerous vehicle maneuvers, such as rapid turns, fast lane-changes, etc. Existing solutions using video or in-vehicle sensors have been employed to identify dangerous vehicle maneuvers, but these methods are subject to the effects of the environmental elements or the hardware is very costly. In the mobile computing era, smartphones have become key tools to develop innovative mobile context-aware systems. In this paper, we present a recognition system for dangerous vehicle steering based on the low-cost sensors found in a smartphone: i.e., the gyroscope and the accelerometer. To identify vehicle steering maneuvers, we focus on the vehicle’s angular velocity, which is characterized by gyroscope data from a smartphone mounted in the vehicle. Three steering maneuvers including turns, lane-changes and U-turns are defined, and a vehicle angular velocity matching algorithm based on Fast Dynamic Time Warping (FastDTW is adopted to recognize the vehicle steering. The results of extensive experiments show that the average accuracy rate of the presented recognition reaches 95%, which implies that the proposed smartphone-based method is suitable for recognizing dangerous vehicle steering maneuvers.

  19. Robust H2/H∞ Control for the Electrohydraulic Steering System of a Four-Wheel Vehicle

    Directory of Open Access Journals (Sweden)

    Min Ye

    2014-01-01

    Full Text Available To shorten the steer diameter and to improve the maneuverability flexibility of a construction vehicle, four wheels’ steering system is presented. This steering system consists of mechanical-electrical-hydraulic assemblies. Its diagram and principle are depicted in detail. Then the mathematical models are derived step by step, including the whole vehicle model and the hydraulic route model. Considering the nonlinear and time-varying uncertainty of the steering system, robust H2/H∞ controller is put forward to guarantee both the system performance and the robust stability. The H∞ norm of the sensitive function from the parameter perturbation of the hydraulic system to the yaw velocity of the vehicle is taken as the evaluating index of the robustness and the H2 norm of the transfer function from the external disturbance to the steering angle of the wheel as the index of linear quadratic Gaussian. The experimental results showed that the proposed scheme was superior to classical PID controller and can guarantee both the control performance and the robustness of the steering system.

  20. TRACK The New Beam Dynamics Code

    CERN Document Server

    Mustapha, Brahim; Ostroumov, Peter; Schnirman-Lessner, Eliane

    2005-01-01

    The new ray-tracing code TRACK was developed* to fulfill the special requirements of the RIA accelerator systems. The RIA lattice includes an ECR ion source, a LEBT containing a MHB and a RFQ followed by three SC linac sections separated by two stripping stations with appropriate magnetic transport systems. No available beam dynamics code meet all the necessary requirements for an end-to-end simulation of the RIA driver linac. The latest version of TRACK was used for end-to-end simulations of the RIA driver including errors and beam loss analysis.** In addition to the standard capabilities, the code includes the following new features: i) multiple charge states ii) realistic stripper model; ii) static and dynamic errors iii) automatic steering to correct for misalignments iv) detailed beam-loss analysis; v) parallel computing to perform large scale simulations. Although primarily developed for simulations of the RIA machine, TRACK is a general beam dynamics code. Currently it is being used for the design and ...

  1. Car Gestures - Advisory warning using additional steering wheel angles.

    Science.gov (United States)

    Maag, Christian; Schneider, Norbert; Lübbeke, Thomas; Weisswange, Thomas H; Goerick, Christian

    2015-10-01

    Advisory warning systems (AWS) notify the driver about upcoming hazards. This is in contrast to the majority of currently deployed advanced driver assistance systems (ADAS) that manage emergency situations. The target of this study is to investigate the effectiveness, acceptance, and controllability of a specific kind of AWS that uses the haptic information channel for warning the driver. This could be beneficial, as alternatives for using the visual modality can help to reduce the risk of visual overload. The driving simulator study (N=24) compared an AWS based on additional steering wheel angle control (Car Gestures) with a visual warning presented in a simulated head-up display (HUD). Both types of warning were activated 3.5s before the hazard object was reached. An additional condition of unassisted driving completed the experimental design. The subjects encountered potential hazards in a variety of urban situations (e.g. a pedestrian standing on the curbs). For the investigated situations, subjective ratings show that a majority of drivers prefer visual warnings over haptic information via gestures. An analysis of driving behavior indicates that both warning approaches guide the vehicle away from the potential hazard. Whereas gestures lead to a faster lateral driving reaction (compared to HUD warnings), the visual warnings result in a greater safety benefit (measured by the minimum distance to the hazard object). A controllability study with gestures in the wrong direction (i.e. leading toward the hazard object) shows that drivers are able to cope with wrong haptic warnings and safety is not reduced compared to unassisted driving as well as compared to (correct) haptic gestures and visual warnings. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Phase control of entanglement and quantum steering in a three-mode optomechanical system

    Science.gov (United States)

    Sun, F. X.; Mao, D.; Dai, Y. T.; Ficek, Z.; He, Q. Y.; Gong, Q. H.

    2017-12-01

    The theory of phase control of coherence, entanglement and quantum steering is developed for an optomechanical system composed of a single mode cavity containing a partially transmitting dielectric membrane and driven by short laser pulses. The membrane divides the cavity into two mutually coupled optomechanical cavities resulting in an effective three-mode closed loop system, two field modes of the two cavities and a mechanical mode representing the oscillating membrane. The closed loop in the coupling creates interfering channels which depend on the relative phase of the coupling strengths of the field modes to the mechanical mode. Populations and correlations of the output modes are calculated analytically and show several interesting phase dependent effects such as reversible population transfer from one field mode to the other, creation of collective modes, and induced coherence without induced emission. We find that these effects result from perfect mutual coherence between the field modes which is preserved even if one of the modes is not populated. The inseparability criterion for the output modes is also investigated and we find that entanglement may occur only between the field modes and the mechanical mode. We show that depending on the phase, the field modes can act on the mechanical mode collectively or individually resulting, respectively, in tripartite or bipartite entanglement. In addition, we examine the phase sensitivity of quantum steering of the mechanical mode by the field modes. Deterministic phase transfer of the steering from bipartite to collective is predicted and optimum steering corresponding to perfect EPR state can be achieved. These different types of quantum steering can be distinguished experimentally by measuring the coincidence rate between two detectors adjusted to collect photons of the output cavity modes. In particular, we find that the minima of the interference pattern of the coincidence rate signal the bipartite steering

  3. Substrate-Integrated Waveguide PCB Leaky-Wave Antenna Design Providing Multiple Steerable Beams in the V-Band

    Directory of Open Access Journals (Sweden)

    Matthias Steeg

    2017-12-01

    Full Text Available A periodic leaky-wave antenna (LWA design based on low loss substrate-integrated waveguide (SIW technology with inset half-wave microstrip antennas is presented. The developed LWA operates in the V-band between 50 and 70 GHz and has been fabricated using standard printed circuit board (PCB technology. The presented LWA is highly functional and very compact supporting 1D beam steering and multibeam operation with only a single radio frequency (RF feeding port. Within the operational 50–70 GHz bandwidth, the LWA scans through broadside, providing over 40° H-plane beam steering. When operated within the 57–66 GHz band, the maximum steering angle is 18.2°. The maximum gain of the fabricated LWAs is 15.4 dBi with only a small gain variation of +/−1.5 dB across the operational bandwidth. The beam steering and multibeam capability of the fabricated LWA is further utilized to support mobile users in a 60 GHz hot-spot. For a single user, a maximum wireless on-off keying (OOK data rate of 2.5 Gbit/s is demonstrated. Multibeam operation is achieved using the LWA in combination with multiple dense wavelength division multiplexing (WDM channels and remote optical heterodyning. Experimentally, multibeam operation supporting three users within a 57–66 GHz hot-spot with a total wireless cell capacity of 3 Gbit/s is achieved.

  4. Adaptive cascaded beam-based feedback at the SLC

    International Nuclear Information System (INIS)

    Himel, T.; Allison, S.; Grossberg, P.; Hendrickson, L.; Sass, R.; Shoaee, H.

    1993-05-01

    The SLAC Linear Collider now has a total of twenty-four beam-steering feedback loops used to keep the electron and positron beams on their desired trajectories. Seven of these loops measure and control the same beam as it proceeds down the linac through the arcs to the final focus. Ideally each loop should correct only for disturbances that occur between it and the immediate upstream loop. In fact, in the original system each loop corrected for all upstream disturbances. This resulted in undesirable over-correction and ringing. We added MIMO (Multiple Input Multiple Output) adaptive noise cancellers to separate the signal we wish to correct from disturbances further up-stream. This adaptive control improved performance in the 1992 run

  5. Beam transport

    International Nuclear Information System (INIS)

    1988-01-01

    The beam diagnostic components for both the transfer and the high-energy beamlines perform well except for some of the scanners whose noise pick-up has become a problem, especially at low beam intensities. This noise pick-up is primarily due to deterioration of the bearings in the scanner. At some locations in the high-energy beamlines, scanners were replaced by harps as the scanners proved to be practically useless for the low-intensity beams required in the experimental areas. The slits in the low-energy beamline, which are not water-cooled, have to be repaired at regular intervals because of vacuum leaks. Overheating causes the ceramic feedthroughs to deteriorate resulting in the vacuum leaks. Water-cooled slits have been ordered to replace the existing slits which will later be used in the beamlines associated with the second injector cyclotron SPC2. The current-measurement system will be slightly modified and should then be much more reliable. 3 figs

  6. A method of detecting a structure in a field, a method of steering an agricultural vehicle and an agricultural vehicle

    DEFF Research Database (Denmark)

    2011-01-01

    An agricultural vehicle (2) comprises a steering system providing steering signals, said steering system comprising an imaging device (11) for imaging surroundings of the vehicle and an image processing device (13), said steering system operating to provide by means of the imaging device (11......) an image of the field (21), analyse the image to obtain texture information, assign to a plurality of areas of the image probability-values reflecting the likelihood that the respective area relates to a specific structure (12), assume at least one geometric property of said specific structure (12...

  7. Evaluation of metal matrix composite to replace spheroidal graphite iron for a critical component, steering knuckle

    International Nuclear Information System (INIS)

    Vijayarangan, S.; Rajamanickam, N.; Sivananth, V.

    2013-01-01

    Highlights: ► A FE model is developed to study the suitability of MMC for steering knuckle. ► Structural analysis of steering knuckle is carried out for 12 load cases. ► The cross section of the critical region is optimized using genetic algorithm. ► The life of the MMC (Al-10 wt.% TiC) knuckle is compared before and after optimization. ► MMC material could replace SG iron for automotive steering knuckle. -- Abstract: Steering knuckle is considered as one of the critical component in automotive suspension system. It is subjected to time varying loads during its service life, leading to fatigue failure. Therefore, its design is an important aspect in the product development cycle. Currently, spheroidal graphite (SG) iron is widely used to manufacture steering knuckle in the commercial automobile sector. It has been observed from the knuckle manufacturers that advanced materials and weight reduction are the real need for the current automobile industry. Due to their high strength to weight ratio, Metal Matrix Composites (MMCs) have the potential to meet the demanded design requirements of the automotive industry, compared to conventional materials. In this work, an aluminum alloy reinforced with titanium carbide particulate is suggested as an alternate material in place of existing SG iron. Structural analysis of steering knuckle made of alternate material Al-10 wt.% TiC was performed using commercial code ANSYS. The results of steering knuckle made of MMC (Al-10 wt.% TiC) were compared with that of aluminum alloy and SG iron steering knuckles for its performance based on real time load cases. It is found from this analysis, the knuckle strut region has maximum stress and deflection during its life time. The critical strut region cross section area of knuckle was analyzed and geometrically optimized for minimum bending stress and deflection using genetic algorithm available in MatLab. Since, the knuckle experiences time varying loads, fatigue analysis also

  8. Design of a Path-Tracking Steering Controller for Autonomous Vehicles

    Directory of Open Access Journals (Sweden)

    Chuanyang Sun

    2018-06-01

    Full Text Available This paper presents a linearization method for the vehicle and tire models under the model predictive control (MPC scheme, and proposes a linear model-based MPC path-tracking steering controller for autonomous vehicles. The steering controller is designed to minimize lateral path-tracking deviation at high speeds. The vehicle model is linearized by a sequence of supposed steering angles, which are obtained by assuming the vehicle can reach the desired path at the end of the MPC prediction horizon and stay in a steady-state condition. The lateral force of the front tire is directly used as the control input of the model, and the rear tire’s lateral force is linearized by an equivalent cornering stiffness. The course-direction deviation, which is the angle between the velocity vector and the path heading, is chosen as a control reference state. The linearization model is validated through the simulation, and the results show high prediction accuracy even in regions of large steering angle. This steering controller is tested through simulations on the CarSim-Simulink platform (R2013b, MathWorks, Natick, MA, USA, showing the improved performance of the present controller at high speeds.

  9. Static load simulation of steering knuckle for a formula student race car

    Science.gov (United States)

    Saputro, Bagus Aulia; Ubaidillah, Triono, Dicky Agus; Pratama, Dzaky Roja; Cahyono, Sukmaji Indro; Imaduddin, Fitrian

    2018-02-01

    This research aims to determine the stress distribution which occurs on the steering knuckle and to define its safety factor number. Steering knuckle is the most critical part of a car's steering system. Steering knuckle supports the tie rod, brake caliper, and the wheels to provide stability. Steering knuckle withstands the load which given on the front wheels and functions as the wheel's axis. Balljoint and king support the rotation of the suspension arm. When the car is in idle position, knuckle hold the weight of the car, it gets braking force when it's braking and cornering. Knuckle is designed to have the strength that could withstand load and to have a good safety factor value. Knuckle is designed using Fusion software then simulated using Fusion simulation software with a static load, moment braking force, and cornering force as the loads in this simulation. The simulation works in ideal condition. The result of this simulation is satisfying. This simulation produces a maximum displacement of 0.01281mm, the maximum shear stress is 3.707 MPa on the stub hole, and the safety factor is 5.24. The material used for this product is mild steel AISI 1018.

  10. Networked Control System for the Guidance of a Four-Wheel Steering Agricultural Robotic Platform

    Directory of Open Access Journals (Sweden)

    Eduardo Paciência Godoy

    2012-01-01

    Full Text Available A current trend in the agricultural area is the development of mobile robots and autonomous vehicles for precision agriculture (PA. One of the major challenges in the design of these robots is the development of the electronic architecture for the control of the devices. In a joint project among research institutions and a private company in Brazil a multifunctional robotic platform for information acquisition in PA is being designed. This platform has as main characteristics four-wheel propulsion and independent steering, adjustable width, span of 1,80 m in height, diesel engine, hydraulic system, and a CAN-based networked control system (NCS. This paper presents a NCS solution for the platform guidance by the four-wheel hydraulic steering distributed control. The control strategy, centered on the robot manipulators control theory, is based on the difference between the desired and actual position and considering the angular speed of the wheels. The results demonstrate that the NCS was simple and efficient, providing suitable steering performance for the platform guidance. Even though the simplicity of the NCS solution developed, it also overcame some verified control challenges in the robot guidance system design such as the hydraulic system delay, nonlinearities in the steering actuators, and inertia in the steering system due the friction of different terrains.

  11. Quantum steering of multimode Gaussian states by Gaussian measurements: monogamy relations and the Peres conjecture

    International Nuclear Information System (INIS)

    Ji, Se-Wan; Nha, Hyunchul; Kim, M S

    2015-01-01

    It is a topic of fundamental and practical importance how a quantum correlated state can be reliably distributed through a noisy channel for quantum information processing. The concept of quantum steering recently defined in a rigorous manner is relevant to study it under certain circumstances and here we address quantum steerability of Gaussian states to this aim. In particular, we attempt to reformulate the criterion for Gaussian steering in terms of local and global purities and show that it is sufficient and necessary for the case of steering a 1-mode system by an N-mode system. It subsequently enables us to reinforce a strong monogamy relation under which only one party can steer a local system of 1-mode. Moreover, we show that only a negative partial-transpose state can manifest quantum steerability by Gaussian measurements in relation to the Peres conjecture. We also discuss our formulation for the case of distributing a two-mode squeezed state via one-way quantum channels making dissipation and amplification effects, respectively. Finally, we extend our approach to include non-Gaussian measurements, more precisely, all orders of higher-order squeezing measurements, and find that this broad set of non-Gaussian measurements is not useful to demonstrate steering for Gaussian states beyond Gaussian measurements. (paper)

  12. A Vehicle Haptic Steering by Wire System Based on High Gain GPI Observers

    Directory of Open Access Journals (Sweden)

    A. Rodriguez-Angeles

    2014-01-01

    Full Text Available A vehicle steering by wire (SBW haptic system based on high gain generalized proportional integral (GPI observers is introduced. The observers are considered for the estimation of dynamic perturbations that are present at the tire and steering wheel. To ensure efficient tracking between the commanded steering wheel angle and the tire orientation angle, the estimated perturbations are on line canceled. As to provide a haptic interface with the driver, the estimated dynamic effects at the steering rack are fed back to the steering wheel, yielding a master-slave haptic system with bilateral communication. For implementation purposes few sensors and minimum knowledge of the dynamic model are required, which is a major advantage compared to other approaches. Only position tracking errors are fed back, while all other signals are estimated by the high gain GPI observers. The scheme is robust to uncertainty on the input gain and cancels dynamic perturbation effects such as friction and aligning forces on the tire. Experimental results are presented on a prototype platform.

  13. Einstein-Podolsky-Rosen-steering swapping between two Gaussian multipartite entangled states

    Science.gov (United States)

    Wang, Meihong; Qin, Zhongzhong; Wang, Yu; Su, Xiaolong

    2017-08-01

    Multipartite Einstein-Podolsky-Rosen (EPR) steering is a useful quantum resource for quantum communication in quantum networks. It has potential applications in secure quantum communication, such as one-sided device-independent quantum key distribution and quantum secret sharing. By distributing optical modes of a multipartite entangled state to space-separated quantum nodes, a local quantum network can be established. Based on the existing multipartite EPR steering in a local quantum network, secure quantum communication protocol can be accomplished. In this manuscript, we present swapping schemes for EPR steering between two space-separated Gaussian multipartite entangled states, which can be used to connect two space-separated quantum networks. Two swapping schemes, including the swapping between a tripartite Greenberger-Horne-Zeilinger (GHZ) entangled state and an EPR entangled state and that between two tripartite GHZ entangled states, are analyzed. Various types of EPR steering are presented after the swapping of two space-separated independent multipartite entanglement states without direct interaction, which can be used to implement quantum communication between two quantum networks. The presented schemes provide technical reference for more complicated quantum networks with EPR steering.

  14. Beam testing of the lab model 2700 head magnet

    International Nuclear Information System (INIS)

    Hutcheon, R.M.; Gillies, B.A.

    1981-07-01

    A modern cancer therapy electron accelerator unit must satisfy many design constraints, one of which is the isocentric height above floor level. Usually 130 cm is considered the maximum height at which a nurse can work with a patient. The advent of higher energy machines has increasingly made this more difficult to achieve, as higher magnetic fields are required in the magnet that directs the beam onto the patient. A new 270 0 doubly achromatic magnet configuration has been developed which minimizes the isocentre height for a given maximum energy and maximum magnetic field. The system is an asymmetric two magnet configuration, with zero field index, equal fields and a bend of greater than 180 0 in the first magnet. It is compact, easy to manufacture and relatively insensitive to assembly tolerances. Energy defining slits are easily incorporated in the design and can readily be radiation shielded. Input and output beam matching and steering is easily accomplished with a compact input quadrupole doublet and small steering windings. The design and bench testing of such a head magnet for a 25 MeV electron accelerator is described in report AECL-7057. The present report details the testing of the magnet at both 10 and 21 MeV using the variable energy electron beam from the Therac 25 cancer therapy accelerator

  15. Advanced Lyapunov control of a novel laser beam tracking system

    Science.gov (United States)

    Nikulin, Vladimir V.; Sofka, Jozef; Skormin, Victor A.

    2005-05-01

    Laser communication systems developed for mobile platforms, such as satellites, aircraft, and terrain vehicles, require fast wide-range beam-steering devices to establish and maintain a communication link. Conventionally, the low-bandwidth, high-steering-range part of the beam-positioning task is performed by gimbals that inherently constitutes the system bottleneck in terms of reliability, accuracy and dynamic performance. Omni-WristTM, a novel robotic sensor mount capable of carrying a payload of 5 lb and providing a full 180-deg hemisphere of azimuth/declination motion is known to be free of most of the deficiencies of gimbals. Provided with appropriate controls, it has the potential to become a new generation of gimbals systems. The approach we demonstrate describes an adaptive controller enabling Omni-WristTM to be utilized as a part of a laser beam positioning system. It is based on a Lyapunov function that ensures global asymptotic stability of the entire system while achieving high tracking accuracy. The proposed scheme is highly robust, does not require knowledge of complex system dynamics, and facilitates independent control of each channel by full decoupling of the Omni-WristTM dynamics. We summarize the basic algorithm and demonstrate the results obtained in the simulation environment.

  16. Provenance for Runtime Workflow Steering and Validation in Computational Seismology

    Science.gov (United States)

    Spinuso, A.; Krischer, L.; Krause, A.; Filgueira, R.; Magnoni, F.; Muraleedharan, V.; David, M.

    2014-12-01

    Provenance systems may be offered by modern workflow engines to collect metadata about the data transformations at runtime. If combined with effective visualisation and monitoring interfaces, these provenance recordings can speed up the validation process of an experiment, suggesting interactive or automated interventions with immediate effects on the lifecycle of a workflow run. For instance, in the field of computational seismology, if we consider research applications performing long lasting cross correlation analysis and high resolution simulations, the immediate notification of logical errors and the rapid access to intermediate results, can produce reactions which foster a more efficient progress of the research. These applications are often executed in secured and sophisticated HPC and HTC infrastructures, highlighting the need for a comprehensive framework that facilitates the extraction of fine grained provenance and the development of provenance aware components, leveraging the scalability characteristics of the adopted workflow engines, whose enactment can be mapped to different technologies (MPI, Storm clusters, etc). This work looks at the adoption of W3C-PROV concepts and data model within a user driven processing and validation framework for seismic data, supporting also computational and data management steering. Validation needs to balance automation with user intervention, considering the scientist as part of the archiving process. Therefore, the provenance data is enriched with community-specific metadata vocabularies and control messages, making an experiment reproducible and its description consistent with the community understandings. Moreover, it can contain user defined terms and annotations. The current implementation of the system is supported by the EU-Funded VERCE (http://verce.eu). It provides, as well as the provenance generation mechanisms, a prototypal browser-based user interface and a web API built on top of a NoSQL storage

  17. How automation helps steer the revenue cycle process.

    Science.gov (United States)

    Colpas, Phil

    2013-06-01

    top-of-mind issue as we see how healthcare reform plays out. Here's what our select group of experts had to say about how automation helps to steer the revenue cycle process.

  18. Expanded R&D by Jet-engine-steering Revolution

    Science.gov (United States)

    Gal-Or, Benjamin

    2017-11-01

    Since 1987 [1,2,3,4,5] the global jet engine community is facing the historical fact that jet engine steering is gradually replacing canards and the common, often dangerous and obsolete, aerodynamic-only flight control - a fact that (i) has already affected the defense-industrial complex in the US, Russia, China, Japan, S-Korea and India, (ii) has integrated the traditional jet-engine components R&D with advanced aero-electro-physics, stealth technology, thrust vectoring aerodynamics and material science. Moreover, this military revolution is historically due to expand into the civil transport jets domain, [6,7,8,9]. The historical aim of the JES-Revolution remains the same: Replace the common, stall-spin sensitive canards [6] and Aerodynamic-Only-Obsolete-Flight Control ("AOOF Control"). Invented about 100 years ago for propeller-driven air vehicles, it has already been partially replaced for failure to function in WVR-combat post-stall domain, and for the following reasons: In comparison with complete Tail-Less, Canard-Less, Stealth-JES (Figure 5 and References [1,2,3,4,5,6]), the common AOOF Control increases drag, weight, fuel consumption, complexity, cost, and reduces flight safety, stealth, [Low Detectability] and provides zero post-stall, WVR air combat capability while its CANARDS KILL LD & REDUCE JES. Examples of stealth fighter aircraft that have already replaced canards and AOOF-Control where JES provides at least 64 to 0 KILL-RATIO advantage over AOOF-Controlled conventional fighter aircraft: The U.S. JES F-22 and, apparently, the Russian JES-Su-T-50 & 35S, China 2016-J-31, Indian HAL AMCA & FGFA, Japanese JES IHHI ATD-X, S-Korean JES KF-X. Cf. X-44 in Figure 5. Consequently, the jet engine is no longer defined as providing only brute force forward. Instead, it successfully competes with and wins over the wrong, dominating AOOF-Control, at least as a backup flight control whose sole factual domain is currently a well-established, primary flight

  19. Emittance measurements of the CLIO electron beam

    Science.gov (United States)

    Chaput, R.; Devanz, G.; Joly, P.; Kergosien, B.; Lesrel, J.

    1997-02-01

    We have designed a setup to measure the transverse emittance at the CLIO accelerator exit, based on the "3 gradients" method. The beam transverse size is measured simply by scanning it with a steering coil across a fixed jaw and recording the transmitted current, at various quadrupole strengths. A code then performs a complete calculation of the emittance using the transfer matrix of the quadrupole instead of the usual classical lens approximation. We have studied the influence of various parameters on the emittance: Magnetic field on the e-gun and the peak current. We have also improved a little the emittance by replacing a mismatched pipe between the buncher and accelerating section to avoid wake-field effects; The resulting improvements of the emittance have led to an increase in the FEL emitted power.

  20. Long radiation detector system for beam loss monitoring

    International Nuclear Information System (INIS)

    Balsamo, J.; Fewell, N.M.; Klein, J.D.; Witkover, R.L.

    1977-01-01

    The Long Radiation Monitor (LRM) system installed at the 200 MeV linac at Brookhaven National Laboratory is described. This system allows observation of both the spatial and temporal character of the losses in the linac and its transport lines. An array of large diameter gas filled coaxial cables are used as extended ion chambers to detect the losses. The output signals are available as a histogram, video waveforms, and numerical data via the computer. A fast beam interrupt is also provided. The detector characteristics and details of the processing electronics are presented. Results of studies of longitudinal, steering and focusing losses are described

  1. Long radiation detector system for beam loss monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Balsamo, J.; Fewell, N.M.; Klein, J.D.; Witkover, R.L.

    1977-01-01

    The Long Radiation Monitor (LRM) system installed at the 200 MeV linac at Brookhaven National Laboratory is described. This system allows observation of both the spatial and temporal character of the losses in the linac and its transport lines. An array of large diameter gas filled coaxial cables are used as extended ion chambers to detect the losses. The output signals are available as a histogram, video waveforms, and numerical data via the computer. A fast beam interrupt is also provided. The detector characteristics and details of the processing electronics are presented. Results of studies of longitudinal, steering and focusing losses are described.

  2. Beam divergence scaling in neutral beam injectors

    International Nuclear Information System (INIS)

    Holmes, A.J.T.

    1976-01-01

    One of the main considerations in the design of neutral beam injectors is to monimize the divergence of the primary ion beam and hence maximize the beam transport and minimize the input of thermal gas. Experimental measurements of the divergence of a cylindrical ion beam are presented and these measurements are used to analyze the major components of ion beam divergence, namely: space charge expansion, gas-ion scattering, emittance and optical aberrations. The implication of these divergence components in the design of a neutral beam injector system is discussed and a method of maximizing the beam current is described for a given area of source plasma

  3. Automated steering systems applied to complex horizontal well in South Italy

    Energy Technology Data Exchange (ETDEWEB)

    Calderoni, A.; Ligrone, A.; Trampini, A. [ENI AGIP (Italy); Oppelt, J.; Gauld, S. [Baker Hughes INTEQ (United States)

    1998-12-31

    A new drilling system that not only improved the quality of the borehole trajectory, but also resulted in significant savings in capital cost is described. The new concept in drilling is the result of a joint development between a major oil company and an oilfield service provider. Through providing a breakthrough technology in directional steering systems the accuracy of the borehole steering has been substantially improved. The new concept involves the use of a straight hole drilling system (SDD) in the upper hole section, in combination with the rotary steering system, AutoTrak, in the 8.5 inch hole size. By synergistically using the new automated tools, the well was drilled much more efficiently than offset wells, producing substantial time savings, a smoother trajectory and less friction. Details of the different automated directional drilling systems that were used together in a well for the first time at Monte Enoc 9 in South Italy are described. 2 refs., 3 tabs., 9 figs.

  4. Steering Angle Control of Car for Dubins Path-tracking Using Model Predictive Control

    Science.gov (United States)

    Kusuma Rahma Putri, Dian; Subchan; Asfihani, Tahiyatul

    2018-03-01

    Car as one of transportation is inseparable from technological developments. About ten years, there are a lot of research and development on lane keeping system(LKS) which is a system that automaticaly controls the steering to keep the vehicle especially car always on track. This system can be developed for unmanned cars. Unmanned system car requires navigation, guidance and control which is able to direct the vehicle to move toward the desired path. The guidance system is represented by using Dubins-Path that will be controlled by using Model Predictive Control. The control objective is to keep the car’s movement that represented by dinamic lateral motion model so car can move according to the path appropriately. The simulation control on the four types of trajectories that generate the value for steering angle and steering angle changes are at the specified interval.

  5. Arbitrary vehicle steering characteristics with changing ratio rack and pinion transmission

    Directory of Open Access Journals (Sweden)

    András G Bendefy

    2015-12-01

    Full Text Available In order to achieve arbitrary steering characteristics at vehicles, a steering mechanism was developed, in which changing ratio rack and pinion connections have been applied. In contrary to a regular steering mechanism where only a single rack is used, two racks were applied in order to make arbitrary characteristics possible. The turning wheel’s required motion functions had to be defined first, thereafter could we determine the changing ratio rack and pinion geometry which produces this motion. First, a simplified two-dimensional mockup was created in order to study the difficulties and possibilities of a real construction. Later, a fully functional assembly was designed and manufactured to make further experiments possible.

  6. A Car-Steering Model Based on an Adaptive Neuro-Fuzzy Controller

    Science.gov (United States)

    Amor, Mohamed Anis Ben; Oda, Takeshi; Watanabe, Shigeyoshi

    This paper is concerned with the development of a car-steering model for traffic simulation. Our focus in this paper is to propose a model of the steering behavior of a human driver for different driving scenarios. These scenarios are modeled in a unified framework using the idea of target position. The proposed approach deals with the driver’s approximation and decision-making mechanisms in tracking a target position by means of fuzzy set theory. The main novelty in this paper lies in the development of a learning algorithm that has the intention to imitate the driver’s self-learning from his driving experience and to mimic his maneuvers on the steering wheel, using linear networks as local approximators in the corresponding fuzzy areas. Results obtained from the simulation of an obstacle avoidance scenario show the capability of the model to carry out a human-like behavior with emphasis on learned skills.

  7. Progress on the ITER ECRH upper launcher steering mirror identification and control

    International Nuclear Information System (INIS)

    Collazos, Andres; Bertizzolo, Robert; Chavan, Rene; Dolizy, Frederic; Felici, Federico; Henderson, Mark A.; Landis, Jean-Daniel; Sanchez, Francisco

    2009-01-01

    The main objective of the ITER ECRH upper launcher (UL) is to control magnetohydrodynamic activity, in particular neoclassical tearing modes (NTMs), by driving several MW of EC current near the q = 1, 3/2, 2 flux surfaces, where NTMs are expected to occur. The steering of the EC power is done by the steering mechanism assembly (SMA) that comprises a reflecting mirror and a frictionless and backlash free pneumo-mechanical system actuated with pressurised helium gas. The control requirements for this component in terms of steering accuracy and speed are reviewed. With respect to these requirements, the performance of the first SMA prototype is assessed in a mock up of the UL pneumatic configuration. The expected design characteristics of the SMA have been verified and an overall satisfactory performance has been assessed. Furthermore, the main challenges for the future work, such as the pressure and angular position control, have been identified.

  8. Dynamical chaos and beam-beam models

    International Nuclear Information System (INIS)

    Izrailev, F.M.

    1990-01-01

    Some aspects of the nonlinear dynamics of beam-beam interaction for simple one-dimensional and two-dimensional models of round and flat beams are discussed. The main attention is paid to the stochasticity threshold due to the overlapping of nonlinear resonances. The peculiarities of a round beam are investigated in view of using the round beams in storage rings to get high luminosity. 16 refs.; 7 figs

  9. Shielding NSLS-II light source: Importance of geometry for calculating radiation levels from beam losses

    Science.gov (United States)

    Kramer, S. L.; Ghosh, V. J.; Breitfeller, M.; Wahl, W.

    2016-11-01

    Third generation high brightness light sources are designed to have low emittance and high current beams, which contribute to higher beam loss rates that will be compensated by Top-Off injection. Shielding for these higher loss rates will be critical to protect the projected higher occupancy factors for the users. Top-Off injection requires a full energy injector, which will demand greater consideration of the potential abnormal beam miss-steering and localized losses that could occur. The high energy electron injection beam produces significantly higher neutron component dose to the experimental floor than a lower energy beam injection and ramped operations. Minimizing this dose will require adequate knowledge of where the miss-steered beam can occur and sufficient EM shielding close to the loss point, in order to attenuate the energy of the particles in the EM shower below the neutron production threshold (weaknesses in the design before a high radiation incident occurs. The effort required to adequately define the accelerator geometry for these codes has been greatly reduced with the implementation of the graphical interface of FLAIR to FLUKA. This made the effective shielding process for NSLS-II quite accurate and reliable. The principles used to provide supplemental shielding to the NSLS-II accelerators and the lessons learned from this process are presented.

  10. Excitation Patterns of Standard and Steered Partial Tripolar Stimuli in Cochlear Implants.

    Science.gov (United States)

    Wu, Ching-Chih; Luo, Xin

    2016-04-01

    Current steering in partial tripolar (pTP) mode has been shown to improve pitch perception and spectral resolution with cochlear implants (CIs). In this mode, a fraction (σ) of the main electrode current is returned within the cochlea and steered between the basal and apical flanking electrodes (with a proportion of α and 1 - α, respectively). Pitch generally decreases when α increases from 0 to 1, although the salience of pitch change varies across CI users. This study aimed to identify the mechanism of pitch changes with pTP-mode current steering and the factors contributing to the intersubject variability in pitch-ranking sensitivity. The electrical fields were measured for steered pTP stimuli on the same main electrode with α = 0, 0.5, and 1 in five implanted ears using electrical field imaging (EFI). The related excitation patterns were also measured physiologically using evoked compound action potential (ECAP) and psychophysically using psychophysical forward masking (PFM). Consistent with the pitch-ranking results in this study, the EFI, ECAP, and PFM centroids shifted apically with increasing α. An apical shift was also observed for the PFM peak but not for the EFI or ECAP peak. The pattern width was similar with different α values within a given measure (e.g., EFI, ECAP, or PFM), but the ECAP patterns were broader than the EFI and PFM patterns, possibly because ECAP was measured with smaller σ values than EFI and PFM. The amount of pattern shift with α depended on σ (i.e., the total amount of current used for steering) but was not correlated with the pitch-ranking sensitivity across subjects. The results revealed that the pitch changes elicited by pTP-mode current steering were not only driven by the shifts of excitation centroid.

  11. Alfalfa leaf meal in finishing steer diets. Quarterly report, July 1, 1997--September 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Zehnder, C.M.; DiCostanzo, A.; Smith, L.B.; Brown, D.B.; Hall, J.M.

    1997-10-30

    Ninety-six medium frame, Angus and Angus cross steer calves (average initial weight 540 lb.) were allotted to a heavy or light weight block and then randomly assigned to one of four dietary treatments for a 167 or 189-day finishing phase, respectively. Treatments were control (supplemental soybean meal), alfalfa leaf meal (ALM) providing 33%, 66%, 100% of supplemental protein. Finishing diets were formulated to contain .61 Mcal NE{sub g}/lb dry matter, 12.5% crude protein, .6 % Ca and .3 % P. There were no significant (P >.05) effects of dietary treatments on daily gain or dry matter required /lb of gain. Steers fed 100 % ALM consumed more (P <.05) dry matter than steers fed either of the other three treatments. Dry matter consumption increased linearly (P >.05) with increasing ALM. There was no significant (P >.05) dietary treatment effect on marbling, KPH %, yield grade, quality grade, or liver abscesses. There was an apparent trend in reduced liver abscess incidence in steers fed 100 % ALM. Steers fed 66 % ALM had significantly (P <.05) greater backfat measurements, backfat also had a cubic effect (P <.05). Hot carcass weight had a quadratic relation (P <.05) with level of ALM. Substituting alfalfa leaf meal for soybean meal in diets of finishing steers increased DM intake, but this increase was accompanied by an increase in gain which resulted in similar feed efficiency. There may be an advantage in blending ALM and soybean meal as feed efficiency was improved when cattle were fed the blend. Also, feeding ALM may result in lower incidence of liver abscess.

  12. Animal performance and meat characteristics in steers reared in intensive conditions fed with different vegetable oils.

    Science.gov (United States)

    Castro, T; Cabezas, A; De la Fuente, J; Isabel, B; Manso, T; Jimeno, V

    2016-03-01

    Enhancing the quality of beef meat is an important goal in terms of improving both the nutritional value for the consumer and the commercial value for producers. The aim of this work was to study the effects of different vegetable oil supplements on growth performance, carcass quality and meat quality in beef steers reared under intensive conditions. A total of 240 Blonde D' Aquitaine steers (average BW=293.7±38.88 kg) were grouped into 24 batches (10 steers/batch) and were randomly assigned to one of the three dietary treatments (eight batches per treatment), each supplemented with either 4% hydrogenated palm oil (PALM) or fatty acids (FAs) from olive oil (OLI) or soybean oil (SOY). No differences in growth performance or carcass quality were observed. For the meat quality analysis, a steer was randomly selected from each batch and the 6th rib on the left half of the carcass was dissected. PALM meat had the highest percentage of 16:0 (P<0.05) and the lowest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio (P<0.05), OLI had the highest content of t11-18:1 (P<0.01) and c9,t11-18:2 (P<0.05) and SOY showed the lowest value of monounsaturated fatty acids (MUFA) (P<0.001), the highest percentage of PUFA (P<0.01) and a lower index of atherogenicity (P=0.07) than PALM. No significant differences in the sensory characteristics of the meat were noted. However, the results of the principal component analysis of meat characteristics enabled meat from those steers that consumed fatty acids from olive oil to be differentiated from that of steers that consumed soybean oil.

  13. Beam propagation

    International Nuclear Information System (INIS)

    Hermansson, B.R.

    1989-01-01

    The main part of this thesis consists of 15 published papers, in which the numerical Beam Propagating Method (BPM) is investigated, verified and used in a number of applications. In the introduction a derivation of the nonlinear Schroedinger equation is presented to connect the beginning of the soliton papers with Maxwell's equations including a nonlinear polarization. This thesis focuses on the wide use of the BPM for numerical simulations of propagating light and particle beams through different types of structures such as waveguides, fibers, tapers, Y-junctions, laser arrays and crystalline solids. We verify the BPM in the above listed problems against other numerical methods for example the Finite-element Method, perturbation methods and Runge-Kutta integration. Further, the BPM is shown to be a simple and effective way to numerically set up the Green's function in matrix form for periodic structures. The Green's function matrix can then be diagonalized with matrix methods yielding the eigensolutions of the structure. The BPM inherent transverse periodicity can be untied, if desired, by for example including an absorptive refractive index at the computational window edges. The interaction of two first-order soliton pulses is strongly dependent on the phase relationship between the individual solitons. When optical phase shift keying is used in coherent one-carrier wavelength communication, the fiber attenuation will suppress or delay the nonlinear instability. (orig.)

  14. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  15. Opportunities to Investigate the Steering System for Improvement of Truck Driving Properties under Critical Road Conditions

    Science.gov (United States)

    Gidlewski, Mirosław

    2011-09-01

    Application of an electric steering system in a truck gives new opportunities to obtain desirable and safe motion path under critical road conditions. Analysis of the opportunity to take advantage of the steering system for improvement of truck driving properties will be carried out on the basis of the results of model tests. The paper describes model of the vehicle applied in simulation tests and methodology as well as anticipated results. The scheduled tests will be carried out within the framework of an research project No. NN509 568439 headed by the author.

  16. Steering population transfer of the Na2 molecule by an ultrashort pulse train

    Science.gov (United States)

    Niu, Dong-Hua; Wang, Shuo; Zhan, Wei-Shen; Tao, Hong-Cai; Wang, Si-Qi

    2018-05-01

    We theoretically investigate the complete population transfer among quantum states of the Na2 molecule using ultrashort pulse trains using the time-dependent wave packet method. The population accumulation of the target state can be steered by controlling the laser parameters, such as the variable pulse pairs, the different pulse widths, the time delays and the repetition period between two contiguous pulses; in particular, the pulse pairs and the pulse widths have a great effect on the population transfer. The calculations show that the ultrashort pulse train is a feasible solution, which can steer the population transfer from the initial state to the target state efficiently with lower peak intensities.

  17. Remote-Steering Antennas for 140 GHz Electron Cyclotron Heating of the Stellarator W7-X

    Directory of Open Access Journals (Sweden)

    Lechte C.

    2017-01-01

    Full Text Available For electron cyclotron resonance heating of the stellarator W7-X at IPP Greifswald, a 140 GHz/10 MW cw millimeter wave system has been built. Two out of 12 launchers will employ a remote-steering design. This paper describes the overall design of the two launchers, and design issues like input coupling structures, manufacturing of corrugated waveguides, optimization of the steering range, integration of vacuum windows, mitrebends and vacuum valves into the launchers, as well as low power tests of the finished waveguides.

  18. Beef steers with average dry matter intake and divergent average daily gain have altered gene expression in the jejunum

    Science.gov (United States)

    The objective of this study was to determine the association of differentially expressed genes (DEG) in the jejunum of steers with average DMI and high or low ADG. Feed intake and growth were measured in a cohort of 144 commercial Angus steers consuming a finishing diet containing (on a DM basis) 67...

  19. Effects of zilpaterol hydrochloride on methane production, total body oxygen consumption, and blood metabolites in finishing beef steers

    Science.gov (United States)

    An indirect calorimetry experiment was conducted to determine the effects of feeding zilpaterol hydrochloride (ZH) for 20 d on total body oxygen consumption, respiratory quotient, methane production, and blood metabolites in finishing beef steers. Sixteen Angus steers (initial BW = 555 ± 12.7 kg) w...

  20. Genetic algorithm–based varying parameter linear quadratic regulator control for four-wheel independent steering vehicle

    Directory of Open Access Journals (Sweden)

    Linlin Gao

    2015-11-01

    Full Text Available From the perspective of vehicle dynamics, the four-wheel independent steering vehicle dynamics stability control method is studied, and a four-wheel independent steering varying parameter linear quadratic regulator control system is proposed with the help of expert control method. In the article, a four-wheel independent steering linear quadratic regulator controller for model following purpose is designed first. Then, by analyzing the four-wheel independent steering vehicle dynamic characteristics and the influence of linear quadratic regulator control parameters on control performance, a linear quadratic regulator control parameter adjustment strategy based on vehicle steering state is proposed to achieve the adaptive adjustment of linear quadratic regulator control parameters. In addition, to further improve the control performance, the proposed varying parameter linear quadratic regulator control system is optimized by genetic algorithm. Finally, simulation studies have been conducted by applying the proposed control system to the 8-degree-of-freedom four-wheel independent steering vehicle dynamics model. The simulation results indicate that the proposed control system has better performance and robustness and can effectively improve the stability and steering safety of the four-wheel independent steering vehicle.

  1. Effects of grazing system on production and parasitism of dairy breed heifers and steers grazing wet marginal grasslands

    DEFF Research Database (Denmark)

    Kristensen, Troels; Thamsborg, S.M.; Andersen, Refsgaard

    2006-01-01

    Production and endoparasitism of first grazing season Holstein heifers and steers were investigated over two grazing seasons. Studies were conducted on low-lying peaty soil. In year 2000, 40 animals were included in a 2x2 factorial, replicated experiment with two sexes (steers v. heifers) and two...

  2. Issues and opportunities: beam simulations for heavy ion fusion

    International Nuclear Information System (INIS)

    Friedman, A

    1999-01-01

    UCRL- JC- 134975 PREPRINT code offering 3- D, axisymmetric, and ''transverse slice'' (steady flow) geometries, with a hierarchy of models for the ''lattice'' of focusing, bending, and accelerating elements. Interactive and script- driven code steering is afforded through an interpreter interface. The code runs with good parallel scaling on the T3E. Detailed simulations of machine segments and of complete small experiments, as well as simplified full- system runs, have been carried out, partially benchmarking the code. A magnetoinductive model, with module impedance and multi- beam effects, is under study. experiments, including an injector scalable to multi- beam arrays, a high- current beam transport and acceleration experiment, and a scaled final- focusing experiment. These ''phase I'' projects are laying the groundwork for the next major step in HIF development, the Integrated Research Experiment (IRE). Simulations aimed directly at the IRE must enable us to: design a facility with maximum power on target at minimal cost; set requirements for hardware tolerances, beam steering, etc.; and evaluate proposed chamber propagation modes. Finally, simulations must enable us to study all issues which arise in the context of a fusion driver, and must facilitate the assessment of driver options. In all of this, maximum advantage must be taken of emerging terascale computer architectures, requiring an aggressive code development effort. An organizing principle should be pursuit of the goal of integrated and detailed source- to- target simulation. methods for analysis of the beam dynamics in the various machine concepts, using moment- based methods for purposes of design, waveform synthesis, steering algorithm synthesis, etc. Three classes of discrete- particle models should be coupled: (1) electrostatic/ magnetoinductive PIC simulations should track the beams from the source through the final- focusing optics, passing details of the time- dependent distribution function to

  3. Simple beam profile monitor

    Energy Technology Data Exchange (ETDEWEB)

    Gelbart, W.; Johnson, R. R.; Abeysekera, B. [ASD Inc. Garden Bay, BC (Canada); Best Theratronics Ltd Ottawa Ontario (Canada); PharmaSpect Ltd., Burnaby BC (Canada)

    2012-12-19

    An inexpensive beam profile monitor is based on the well proven rotating wire method. The monitor can display beam position and shape in real time for particle beams of most energies and beam currents up to 200{mu}A. Beam shape, position cross-section and other parameters are displayed on a computer screen.

  4. Crystalline beams

    International Nuclear Information System (INIS)

    Schiffer, J.P.

    1989-01-01

    Ions in a storage ring are confined to a mean orbit by focusing elements. To a first approximation these may be described by a constant harmonic restoring force: F = -Kr. If the particles in the frame moving along with the beam have small random thermal energies, then they will occupy a cylindrical volume around the mean orbit and the focusing force will be balanced by that from the mutual repulsion of the particles. Inside the cylinder only residual two-particle interactions will play a significant role and some form of ordering might be expected to take place. The results of some of the first MD calculations showed a surprising result: not only were the particles arranged in the form of a tube, but they formed well-defined layers: concentric shells, with the particles in each shell arranged in a hexagonal lattice that is characteristic of two-dimensional Coulomb systems. This paper discusses the condense layer structure

  5. Beam Diagnostics Challenges in the FAIR Project at GSI

    International Nuclear Information System (INIS)

    Peters, Andreas; Forck, Peter

    2006-01-01

    The planned FAIR (Facility for Antiproton and Ion Research) project consists of two heavy ion synchrotrons and four large storage rings, the existing GSI facility together with a new high-current proton linac will be used as the injector chain. The fast cycling, superconducting synchrotrons are build for high current operation with the aim of secondary ion and antiproton production. A large variety of low current secondary beams as well as the antiprotons are stored and cooled in the four storage rings. A complex operation scheme with multiple use of transport lines is foreseen. This demands an exceptional high dynamic range for the beam instrumentation. Due to the enormous beam power, non-destructive methods are mandatory for high currents as well as for the low current secondary beams due to the low repetition rate. Precise measurements of all beam parameters and automatic steering or feedback capabilities are required due to the necessary exploitation of the full ring acceptances. Moreover, online beam-corrections with short response times are mandatory for the fast ramping super-conducting magnets. An overview of the challenges and projected innovative solutions for various diagnostic installations will be given

  6. Development of a Computational Steering Framework for High Performance Computing Environments on Blue Gene/P Systems

    KAUST Repository

    Danani, Bob K.

    2012-07-01

    Computational steering has revolutionized the traditional workflow in high performance computing (HPC) applications. The standard workflow that consists of preparation of an application’s input, running of a simulation, and visualization of simulation results in a post-processing step is now transformed into a real-time interactive workflow that significantly reduces development and testing time. Computational steering provides the capability to direct or re-direct the progress of a simulation application at run-time. It allows modification of application-defined control parameters at run-time using various user-steering applications. In this project, we propose a computational steering framework for HPC environments that provides an innovative solution and easy-to-use platform, which allows users to connect and interact with running application(s) in real-time. This framework uses RealityGrid as the underlying steering library and adds several enhancements to the library to enable steering support for Blue Gene systems. Included in the scope of this project is the development of a scalable and efficient steering relay server that supports many-to-many connectivity between multiple steered applications and multiple steering clients. Steered applications can range from intermediate simulation and physical modeling applications to complex computational fluid dynamics (CFD) applications or advanced visualization applications. The Blue Gene supercomputer presents special challenges for remote access because the compute nodes reside on private networks. This thesis presents an implemented solution and demonstrates it on representative applications. Thorough implementation details and application enablement steps are also presented in this thesis to encourage direct usage of this framework.

  7. Beam-Beam Interaction Studies at LHC

    CERN Document Server

    Schaumann, Michaela; Alemany Fernandez, R

    2011-01-01

    The beam-beam force is one of the most important limiting factors in the performance of a collider, mainly in the delivered luminosity. Therefore, it is essential to measure the effects in LHC. Moreover, adequate understanding of LHC beam-beam interaction is of crucial importance in the design phases of the LHC luminosity upgrade. Due to the complexity of this topic the work presented in this thesis concentrates on the beam-beam tune shift and orbit effects. The study of the Linear Coherent Beam-Beam Parameter at the LHC has been determined with head-on collisions with small number of bunches at injection energy (450 GeV). For high bunch intensities the beam-beam force is strong enough to expect orbit effects if the two beams do not collide head-on but with a crossing angle or with a given offset. As a consequence the closed orbit changes. The closed orbit of an unperturbed machine with respect to a machine where the beam-beam force becomes more and more important has been studied and the results are as well ...

  8. Installation And Test Of Electron Beam Generation System To Produce Far-Infrared Radiation And X-Ray Pulses

    International Nuclear Information System (INIS)

    Wichaisirimongkol, Pathom; Jinamoon, Witoon; Khangrang, Nopadon; Kusoljariyakul, Keerati; Rhodes, Michael W.; Rimjaem, Sakhorn; Saisut, Jatuporn; Chitrlada, Thongbai; Vilaithong, Thiraphat; Wiedemann, Helmut

    2005-10-01

    SURIYA project at the Fast Neutron Research Facility, Chiang Mai University, aims to establish a facility to generate femtosecond electron beams. This electron beam can be used to generate high intensity far-infrared radiation and ultra-short X-ray pulses. The main components of the system are a 3 MeV RF electron gun with a thermionic cathode, an a-magnet as a bunch compressor, and post acceleration 15-20 MeV by a linear accelerator (linac). Between the main components, there are focusing quadrupole magnets and steering magnets to maintain the electron beam within a high vacuum tube. At the end of the beam transport line, a dipole magnet has been installed to function as a beam dump and an energy spectrometer. After the installation and testing of individual major components were completed, we have been investigating the generation of the electron beam, intense far- infrared radiation and ultra short X-ray pulses

  9. Wheeled Vehicle Steering Systems. Military Curriculum Materials for Vocational and Technical Education.

    Science.gov (United States)

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle steering systems. It provides the basic theory, and also includes…

  10. 49 CFR 571.204 - Standard No. 204; Steering control rearward displacement.

    Science.gov (United States)

    2010-10-01

    ... September 1, 1991. When a passenger car or a truck, bus, or multipurpose passenger vehicle with a gross... manufactured on or after September 1, 1991. When a passenger car or a truck, bus or multipurpose passenger... the steering control into the passenger compartment to reduce the likelihood of chest, neck, or head...

  11. Design Optimization of Steering Mechanisms for Articulated Off-Road Vehicles Based on Genetic Algorithms

    Directory of Open Access Journals (Sweden)

    Chen Zhou

    2018-02-01

    Full Text Available Two cylinders arranged symmetrically on a frame have become a major form of steering mechanism for articulated off-road vehicles (AORVs. However, the differences of stroke and arm lead to pressure fluctuation, vibration noise, and a waste of torque. In this paper, the differences of stroke and arm are reduced based on a genetic algorithm (GA. First, the mathematical model of the steering mechanism is put forward. Then, the difference of stroke and arm are optimized using a GA. Finally, a FW50GLwheel loader is used as an example to demonstrate the proposed GA-based optimization method, and its effectiveness is verified by means of automatic dynamic analysis of mechanical systems (ADAMS. The stroke difference of the steering hydraulic cylinders was reduced by 92% and the arm difference reached a decrease of 78% through GA optimization, in comparison with unoptimized structures. The simulation result shows that the steering mechanism optimized by GA behaved better than by previous methods.

  12. Super-resolution post-processing for satellites with yaw-steering capability

    CSIR Research Space (South Africa)

    Van den Dool, R

    2012-10-01

    Full Text Available We describe a method for improving Earth observation satellite image resolution, for specific areas of interest where the sensor design resolution is insufficient. Our method may be used for satellites with yaw-steering capability, such as Nigeria...

  13. Soliton Steering by Longitudinal Modulation of the Nonlinearity in Waveguide Arrays

    OpenAIRE

    Assanto, Gaetano; Cisneros, Luis A.; Minzoni, Antonmaria A.; Skuse, Benjamin D.; Smyth, Noel F.; Worthy, Annette L.

    2010-01-01

    We show how discrete solitary waves in one and two-dimensional waveguide arrays can be steered across the lattice via the introduction of a longitudinal periodic modulation of the nonlinear response. Through parametric energy transfer from the modulation to the solitary wave, the latter can increase its width and overcome the Peierls-Nabarro potential to propagate freely.

  14. Design of power steering systems for heavy-duty long-haul vehicles

    NARCIS (Netherlands)

    Silvas, E.; Backx, E.A.; Hofman, T.; Voets, H.; Steinbuch, M.

    2014-01-01

    Conventionally, all auxiliaries present in a heavy-duty vehicle (e.g., power-steering pump, air-conditioning compressor) are engine-driven systems, which put high constraints on their performance. Outputs (e.g., speed, temperature) and energy consumption are dictated by engine speed, while most

  15. Alteration of fasting heat production during fescue toxicosis in Holstein steers

    Science.gov (United States)

    This study was designed to examine alteration of fasting heat production (FHP) during fescue toxicosis. Six ruminally cannulated Holstein steers (BW=348 ±13 kg) were weight-matched into pairs and utilized in a two period crossover design experiment. Each period consisted of two temperature segments,...

  16. Weight gain and behavior of Raramuri Criollo versus Corriente steers developed on Chihuahuan Desert rangeland

    Science.gov (United States)

    Ranchers that raise Criollo cattle must overcome the challenge of lack of markets for weaned calves. Raramuri Criollo (RC) steers are commonly raised for beef and finished on rangelands, while Corriente (CR) are often raised for rodeo sports. No data exist on weight gains and grazing behavior of ran...

  17. Weight gain and behavior of Raramuri Criollo versus crossbred steers developed on Chihuahuan Desert rangeland

    Science.gov (United States)

    Ranchers that raise Raramuri Criollo (RC) cattle must overcome the challenge of lack of markets for weaned calves. Growing and finishing RC or RC-crossbred steers on rangeland pastures is increasingly common; however, no data exist on their weight gains or grazing behavior. We tracked the weight a...

  18. Braking, steering, and wear performance of radial-belted and bias-ply aircraft tires

    Science.gov (United States)

    Yager, Thomas J.; Davis, Pamela A.; Stubbs, Sandy M.; Martinson, Veloria J.

    1992-01-01

    Preliminary steering, braking, and tread wear performance results from testing of radial-belted and bias-ply aircraft tires at NASA Langley are described. An overview of the joint NASA/FAA/industry START program is presented. Attention is given to the Langley Test Facility, equipment and future activities.

  19. Displacement and force coupling control design for automotive active front steering system

    Science.gov (United States)

    Zhao, Wanzhong; Zhang, Han; Li, Yijun

    2018-06-01

    A displacement and force coupling control design for active front steering (AFS) system of vehicle is proposed in this paper. In order to investigate the displacement and force characteristics of the AFS system of the vehicle, the models of AFS system, vehicle, tire as well as the driver model are introduced. Then, considering the nonlinear characteristics of the tire force and external disturbance, a robust yaw rate control method is designed by applying a steering motor to generate an active steering angle to adjust the yaw stability of the vehicle. Based on mixed H2/H∞ control, the system robustness and yaw rate tracking performance are enforced by H∞ norm constraint and the control effort is captured through H2 norm. In addition, based on the AFS system, a planetary gear set and an assist motor are both added to realize the road feeling control in this paper to dismiss the influence of extra steering angle through a compensating method. Evaluation of the overall system is accomplished by simulations and experiments under various driving condition. The simulation and experiment results show the proposed control system has excellent tracking performance and road feeling performance, which can improve the cornering stability and maneuverability of vehicle.

  20. 78 FR 15062 - Cohen & Steers Real Assets Fund, Inc., et al.; Notice of Application

    Science.gov (United States)

    2013-03-08

    ... Board minutes, that such change is in the best interests of the Corporation and its shareholders, and... shareholder approval and would grant relief from certain disclosure requirements. Applicants: Cohen & Steers... unless the Commission orders a hearing. Interested persons may request a hearing by writing to the...

  1. 46 CFR 58.25-40 - Arrangement of the steering-gear compartment.

    Science.gov (United States)

    2010-10-01

    ..., separated from any machinery space; (2) Ensure working access to machinery and controls in the compartment; and (3) Include handrails and either gratings or other non-slip surfaces to ensure a safe working environment if hydraulic fluid leaks. Note: Where practicable, all steering gear should be located in the...

  2. Advanced emergency braking under split friction conditions and the influence of a destabilising steering wheel torque

    Science.gov (United States)

    Tagesson, Kristoffer; Cole, David

    2017-07-01

    The steering system in most heavy trucks is such that it causes a destabilising steering wheel torque when braking on split friction, that is, different friction levels on the two sides of the vehicle. Moreover, advanced emergency braking systems are now mandatory in most heavy trucks, making vehicle-induced split friction braking possible. This imposes higher demands on understanding how the destabilising steering wheel torque affects the driver, which is the focus here. Firstly, an experiment has been carried out involving 24 subjects all driving a truck where automatic split friction braking was emulated. Secondly, an existing driver-vehicle model has been adapted and implemented to improve understanding of the observed outcome. A common conclusion drawn, after analysing results, is that the destabilising steering wheel torque only has a small effect on the motion of the vehicle. The underlying reason is a relatively slow ramp up of the disturbance in comparison to the observed cognitive delay amongst subjects; also the magnitude is low and initially suppressed by passive driver properties.

  3. Speeding up IA mechanically-steered multistatic radar scheduling with GP-GPUs

    CSIR Research Space (South Africa)

    Focke, RW

    2016-07-01

    Full Text Available In this paper, the authors investigate speeding up the execution time of Interval Algebra (IA) mechanically-steered multistatic and multisite radar scheduling using a general-purpose graphical processing unit (GP-GPU). Multistatic/multisite radar...

  4. Chromium supplementation enhances the metabolic response of steers to lipopolysaccharide (LPS) challenge

    Science.gov (United States)

    The effect of chromium (Cr; KemTRACE®brandChromiumProprionate 0.04%, Kemin Industries) supplementation on the metabolic response to LPS challenge was examined. Steers (n=20; 235±4 kg body weight (BW)) received a premix that added 0 (Con) or 0.2 mg/kg Cr to the total diet (DM (dry matter) basis) for ...

  5. Modeling Human Steering Behavior During Path Following in Teleoperation of Unmanned Ground Vehicles.

    Science.gov (United States)

    Mirinejad, Hossein; Jayakumar, Paramsothy; Ersal, Tulga

    2018-04-01

    This paper presents a behavioral model representing the human steering performance in teleoperated unmanned ground vehicles (UGVs). Human steering performance in teleoperation is considerably different from the performance in regular onboard driving situations due to significant communication delays in teleoperation systems and limited information human teleoperators receive from the vehicle sensory system. Mathematical models capturing the teleoperation performance are a key to making the development and evaluation of teleoperated UGV technologies fully simulation based and thus more rapid and cost-effective. However, driver models developed for the typical onboard driving case do not readily address this need. To fill the gap, this paper adopts a cognitive model that was originally developed for a typical highway driving scenario and develops a tuning strategy that adjusts the model parameters in the absence of human data to reflect the effect of various latencies and UGV speeds on driver performance in a teleoperated path-following task. Based on data collected from a human subject test study, it is shown that the tuned model can predict both the trend of changes in driver performance for different driving conditions and the best steering performance of human subjects in all driving conditions considered. The proposed model with the tuning strategy has a satisfactory performance in predicting human steering behavior in the task of teleoperated path following of UGVs. The established model is a suited candidate to be used in place of human drivers for simulation-based studies of UGV mobility in teleoperation systems.

  6. 7 CFR 59.103 - Mandatory weekly reporting for steers and heifers.

    Science.gov (United States)

    2010-01-01

    ... MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) LIVESTOCK MANDATORY REPORTING Cattle Reporting § 59.103 Mandatory weekly reporting for steers and...

  7. 7 CFR 59.101 - Mandatory daily reporting for steers and heifers.

    Science.gov (United States)

    2010-01-01

    ... MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS INSPECTION ACT (CONTINUED) LIVESTOCK MANDATORY REPORTING Cattle Reporting § 59.101 Mandatory daily reporting for steers and...

  8. The effect of cognitive load on adaptation to differences in steering wheel force feedback level

    NARCIS (Netherlands)

    Anand, S.; Terken, J.; Hogema, J.

    2013-01-01

    In an earlier study it was found that drivers can adjust quickly to different force feedback levels on the steering wheel, even for such extreme levels as zero feedback. It was hypothesized that, due to lack of cognitive load, participants could easily and quickly learn how to deal with extreme

  9. Driver Steering Support Interfaces Near the Vehicle’s Handling Limits

    NARCIS (Netherlands)

    Katzourakis, D.

    2012-01-01

    The goal of this thesis is to propose steering support systems that can reduce the driver’s control effort, mental load and promote safety. The driver dictates the vehicle’s motion and the support should centralize him/her in the control loop; thus our design philosophy is to increase driver’s

  10. The Use of a Steering Shaping Function to Improve Human Performance in By-Wire Vehicles

    Science.gov (United States)

    2008-03-01

    nontrivial ways. Included in the problems induced by the staffing of automated systems are biomechanical (Sirouspour & Salcudean, 2003; Sövényi...device (e.g., brake pedal ) and the actuators of the system (e.g., calipers). In this report, we are specifically interested in steer-by-wire subsystems

  11. Steering disturbance rejection using a physics-based neuromusculoskeletal driver model

    Science.gov (United States)

    Mehrabi, Naser; Sharif Razavian, Reza; McPhee, John

    2015-10-01

    The aim of this work is to develop a comprehensive yet practical driver model to be used in studying driver-vehicle interactions. Drivers interact with their vehicle and the road through the steering wheel. This interaction forms a closed-loop coupled human-machine system, which influences the driver's steering feel and control performance. A hierarchical approach is proposed here to capture the complexity of the driver's neuromuscular dynamics and the central nervous system in the coordination of the driver's upper extremity activities, especially in the presence of external disturbance. The proposed motor control framework has three layers: the first (or the path planning) plans a desired vehicle trajectory and the required steering angles to perform the desired trajectory; the second (or the musculoskeletal controller) actuates the musculoskeletal arm to rotate the steering wheel accordingly; and the final layer ensures the precision control and disturbance rejection of the motor control units. The physics-based driver model presented here can also provide insights into vehicle control in relaxed and tensed driving conditions, which are simulated by adjusting the driver model parameters such as cognition delay and muscle co-contraction dynamics.

  12. International Linear Collider Steering Committee issues charge to Technology Recommendation Panel

    CERN Multimedia

    2003-01-01

    "Following its November 19 meeting in Paris, the International Linear Collider Steering Committee, a subcommittee of the International Committee for Future Accelerators, has published the charge http://www.fnal.gov/directorate/icfa/ITRP_Charge.pdf to the International Technology Recommendation Panel appointed by ICFA" (2 paragraphs).

  13. Fatty acid composition of beef steers as affected by diet and fat depot

    African Journals Online (AJOL)

    Subcutaneous and perirenal fatty acid (FA) profiles were compared in steers fed a control diet (70 : 30 red clover silage (RC) : barley concentrate), a diet with sunflower seed (SS) substituted for barley, and diets with 15% or 30% wheat dried distillers' grain with solubles (DDGS-15 and DDGS-30) substituted for RC and SS.

  14. V-TECS Guide for Auto Mechanics: Suspension Systems, Brakes and Steering.

    Science.gov (United States)

    Moore, Charles G.; And Others

    The materials in this document are an extension of a catalog of occupational duties, tasks, and performance objectives relevant to maintaining automotive suspension systems, brakes, and steering mechanisms. This document provides the following for each occupational task within each duty: (1) a standard of performance; (2) the conditions under…

  15. Alignment Adjustment Procedures. Automotive Mechanics. Steering & Suspension. Instructor's Guide [and] Student Guide.

    Science.gov (United States)

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automotive steering and suspension, consists of a student guide and an instructor guide dealing with automobile alignment and adjustment procedures. Covered in the module are identifying positive and negative cambers, positive and negative casters, and toe-ins;…

  16. Front-End Types. Automotive Mechanics. Steering & Suspension. Instructor's Guide [and] Student Guide.

    Science.gov (United States)

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automotive steering and suspension, consists of a student guide and an instructor guide dealing with automobile front-end types. Covered in the module are three common types of passenger car front suspension systems and their major components as well as two types…

  17. Pre-Alignment Checks. Automotive Mechanics. Steering & Suspension. Instructor's Guide [and] Student Guide.

    Science.gov (United States)

    Spignesi, B.

    This instructional package, one in a series of individualized instructional units on automotive steering and suspension, consists of a student guide and an instructor guide dealing with prealignment checks. Covered in the module are the following steps in a prealignment check: checking the ride height of a vehicle, checking the ball joints and the…

  18. A Neural Model of Visually Guided Steering, Obstacle Avoidance, and Route Selection

    Science.gov (United States)

    Elder, David M.; Grossberg, Stephen; Mingolla, Ennio

    2009-01-01

    A neural model is developed to explain how humans can approach a goal object on foot while steering around obstacles to avoid collisions in a cluttered environment. The model uses optic flow from a 3-dimensional virtual reality environment to determine the position of objects on the basis of motion discontinuities and computes heading direction,…

  19. Influence of Road Excitation and Steering Wheel Input on Vehicle System Dynamic Responses

    Directory of Open Access Journals (Sweden)

    Zhen-Feng Wang

    2017-06-01

    Full Text Available Considering the importance of increasing driving safety, the study of safety is a popular and critical topic of research in the vehicle industry. Vehicle roll behavior with sudden steering input is a main source of untripped rollover. However, previous research has seldom considered road excitation and its coupled effect on vehicle lateral response when focusing on lateral and vertical dynamics. To address this issue, a novel method was used to evaluate effects of varying road level and steering wheel input on vehicle roll behavior. Then, a 9 degree of freedom (9-DOF full-car roll nonlinear model including vertical and lateral dynamics was developed to study vehicle roll dynamics with or without of road excitation. Based on a 6-DOF half-car roll model and 9-DOF full-car nonlinear model, relationship between three-dimensional (3-D road excitation and various steering wheel inputs on vehicle roll performance was studied. Finally, an E-Class (SUV level car model in CARSIM® was used, as a benchmark, with and without road input conditions. Both half-car and full-car models were analyzed under steering wheel inputs of 5°, 10° and 15°. Simulation results showed that the half-car model considering road input was found to have a maximum accuracy of 65%. Whereas, the full-car model had a minimum accuracy of 85%, which was significantly higher compared to the half-car model under the same scenario.

  20. Steers grazing of a rye cover crop influences growth of rye and no-till cotton

    Science.gov (United States)

    Small grain cover crops offer opportunities for grazing but effects on following row crops are not well understood. From 1999 through 2008, stocker steers sequence grazed small grains in a 2-paddock rye-cotton-wheat-fallow- rye rotation. Treatments imposed on rye included 1) zero-grazing from 1999; ...

  1. Educational Leaders' Doctoral Research That Informed Strategies to Steer Their Organizations towards Cultural Alignment

    Science.gov (United States)

    Taysum, Alison

    2016-01-01

    This research generates new knowledge about how 24 educational leaders in the USA and England used their doctoral research to build narrative capital to inform strategies to steer their organizations towards cultural alignment. Cultural alignment prevents forms of segregation rooted in nation-states' wider historiography of education segregation…

  2. Protein and starch digestion in steers fed feedlot diets differing in ...

    African Journals Online (AJOL)

    Department of Livestock Science, University of Pretoria, Pretoria, 0002 Republic of South Africa. Twelve steers fistulated in the rumen and duodenum were allocated to one of three diets and fed 80g DM/kg WO.75/d. The diets consisted of .... 2.1: 1. 1 Calorie 3000. 2 Premix contained vitamins, trace minerals, salt, NaHC03,.

  3. Avoiding Internal Capsule Stimulation With a New Eight-Channel Steering Deep Brain Stimulation Lead

    NARCIS (Netherlands)

    van Dijk, Kees J.; Verhagen, Rens; Bour, Lo J.; Heida, Ciska; Veltink, Peter H.

    2017-01-01

    Objective: Novel deep brain stimulation (DBS) lead designs are currently entering the market, which are hypothesized to provide a way to steer the stimulation field away from neural populations responsible for side effects and towards populations responsible for beneficial effects. The objective of

  4. Avoiding Internal Capsule Stimulation With a New Eight-Channel Steering Deep Brain Stimulation Lead

    NARCIS (Netherlands)

    van Dijk, Kees J.; Verhagen, Rens; Bour, Lo J.; Heida, Ciska; Veltink, Peter H.

    2017-01-01

    Novel deep brain stimulation (DBS) lead designs are currently entering the market, which are hypothesized to provide a way to steer the stimulation field away from neural populations responsible for side effects and towards populations responsible for beneficial effects. The objective of this study

  5. Younger Children in ECEC: Focus on the National Steering Documents in the Nordic Countries

    Science.gov (United States)

    Hännikäinen, Maritta

    2016-01-01

    The aim of this study was to review the national steering documents on early childhood education and care (ECEC) in Denmark, Finland, Iceland, Norway and Sweden, with the focus on children up to the age of three, posing the question: What do these documents tell us about ECEC for younger children in the Nordic early childhood settings?…

  6. Temporal steering and security of quantum key distribution with mutually unbiased bases against individual attacks

    Czech Academy of Sciences Publication Activity Database

    Bartkiewicz, K.; Černoch, Antonín; Lemr, K.; Miranowicz, A.; Nori, F.

    2016-01-01

    Roč. 93, č. 6 (2016), 1-7, č. článku 062345. ISSN 2469-9926 R&D Projects: GA ČR GAP205/12/0382 Institutional support: RVO:68378271 Keywords : quantum key distribution * Einstein-Podolsky-Rosen steering * temporal quantum correlations Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.925, year: 2016

  7. Driver hand positions on the steering wheel while merging into motorway traffic

    NARCIS (Netherlands)

    De Waard, D.; Van den Bold, T.G.M.P.R.; Lewis Evans, B.

    2010-01-01

    It has been suggested that a driver's hand position on the steering wheel can reflect the perceived risk of the road context (Walton, D., & Thomas, J. A. (2005). Naturalistic observations of driver hand positions. Transportation Research Part F, 8. 229-238, Thomas, J. A., & Walton, D. (2007).

  8. Effects of Tall Fescue Forage Mass on Steer Ingestive Behavior and Performance

    Science.gov (United States)

    Tall fescue [Lolium arundinaceum (Schreb.) Darbysh] is a well adapted perennial pasture species utilized across the north-south transition zone of the United States and in similar environments worldwide. This 3-yr trial evaluated the influence of three forage masses (FM) on steer and pasture respons...

  9. Beam halo in high-intensity beams

    International Nuclear Information System (INIS)

    Wangler, T.P.

    1993-01-01

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which in projection to the 2-D phase spaces results in a 2-component beam consisting of an inner core and a diffuse outer halo. The beam-halo is of concern for a next generation of cw, high-power proton linacs that could be applied to intense neutron generators for nuclear materials processing. The author describes what has been learned about beam halo and the evolution of space-charge dominated beams using numerical simulations of initial laminar beams in uniform linear focusing channels. Initial results are presented from a study of beam entropy for an intense space-charge dominated beam

  10. Beam-beam issues in asymmetric colliders

    International Nuclear Information System (INIS)

    Furman, M.A.

    1992-07-01

    We discuss generic beam-beam issues for proposed asymmetric e + - e - colliders. We illustrate the issues by choosing, as examples, the proposals by Cornell University (CESR-B), KEK, and SLAC/LBL/LLNL (PEP-II)

  11. Effects of Stocking Density or Group Size on Intake, Growth, and Meat Quality of Hanwoo Steers (

    Directory of Open Access Journals (Sweden)

    Sang Moo Lee

    2012-11-01

    Full Text Available This study was conducted to investigate the effects of stocking density or group size on feed intake, daily gain, and carcass characteristics of Hanwoo (Korean indigenous breed steers reared from 7 months to 31 months of age. Thirty Hanwoo steers were divided into four groups with three replicates each (a total of 12 pens. In each group, one (G1, two (G2, three (G3, and four steers (G4 per pen were allocated as treatments. Pen size was 32.0 m2, and therefore Hanwoo steers in G1, G2, G3, and G4 were reared under different space allowances, i.e. 32.0, 16.0, 10.6, and 8.0 m2/steer, respectively. Steers were reared following a conventional beef cattle management method in Korea, and were offered a fixed amount of commercial concentrate with ad libitum forages. Results were subjected to analysis of variance with stocking density as the main effect, and significance was declared at p<0.05. Although total feed intake was not significantly altered, it numerically increased in animals of low stocking density (G1 compared to those subjected to high stocking density treatment (i.e. G4. Feed conversion ratio was higher (p<0.05 in G3 compared to G1 and G2. Animals in G1 (low stocking density grew faster (p<0.05 than those of high stocking density (G3 and G4. Back fat thickness, meat yield index, and meat yield grade were similar among all levels of stocking density. However, longissimus muscle area was larger in G1 and G2 (p<0.01 compared to G3 and G4, and animals in G3 produced smaller carcasses (p<0.05. Carcass quality traits, including marbling score, meat color, fat color, texture, maturity and meat quality grade, as determined by a group of experts, were not significantly different among the treatments. In conclusion, lower stocking density resulted in increased feed efficiency, daily gain, and carcass weight in Hanwoo steers. However it remains unclear whether such differences are the results of stocking density or group size, or a combination of both

  12. The effects of different flooring types on the behavior, health, and welfare of finishing beef steers.

    Science.gov (United States)

    Elmore, M R P; Elischer, M F; Claeys, M C; Pajor, E A

    2015-03-01

    Raising beef cattle on concrete floors can negatively impact their welfare by increasing joint swelling and body lesions, as well as abnormalities in resting behavior and postural changes. We hypothesized that the addition of rubber mats to concrete pens would improve beef cattle welfare by improving performance, health, hygiene, and resting behavior. Forty-eight crossbred Angus steers were housed in pens of 4 and randomly assigned to a single flooring treatment: (1) fully slatted concrete (CON), (2) fully slatted rubber mat (SLAT), or (3) solid rubber mat (SOLID; 60% of pen floor) from 36 to 48 wk of age. Weight, ADG, lesions, gait score, joint swelling, and animal and pen cleanliness were collected every 2 wk. Behavioral time budgets and frequency of postural changes (an indicator of floor traction and comfort) were collected at 0, 6, and 12 wk. No differences in weight gain or ADG were observed. Steers on SOLID flooring (0.80 ± 0.08) showed increased lesions compared to SLAT (0.38 ± 0.08) and CON (0.37 ± 0.08; both, = 0.05); however, there was no difference between SLAT and CON. SLAT steers (1.69 ± 0.04) showed a reduced gait score compared to SOLID (1.95 ± 0.04) and CON (1.98 ± 0.04; both, flooring had less joint swelling (both knees and hocks) compared to SOLID and CON (all comparisons, flooring were dirtier than those on SLAT (2.27 ± 0.05) and CON (2.19 ± 0.05; both, flooring preferred to rest on the rubber mat vs. slatted concrete ( = 0.001). Steers on SLAT flooring changed their posture more frequently than those on SOLID and CON flooring (both, < 0.05), but SOLID and CON did not differ. Compared to CON steers, SOLID steers showed an increase in lesions and a reduction in cleanliness, whereas SLAT steers showed a decrease in gait score and joint swelling and an increase in postural changes. Combined, these data suggest that the addition of slatted rubber mats to concrete pens may improve beef cattle welfare.

  13. Control of intravascular catheters using an array of active steering coils.

    Science.gov (United States)

    Gudino, N; Heilman, J A; Derakhshan, J J; Sunshine, J L; Duerk, J L; Griswold, M A

    2011-07-01

    To extend the concept of deflecting the tip of a catheter with the magnetic force created in an MRI system through the use of an array of independently controllable steering coils located in the catheter tip, and to present methods for visualization of the catheter and/or surrounding areas while the catheter is deflected. An array of steering coils made of 42-gauge wire was built over a 2.5 Fr (0.83 mm) fiber braided microcatheter. Two of the coils were 70 turn axial coils separated by 1 cm, and the third was a 15-turn square side coil that was 2 x 4 mm2. Each coil was driven independently by a pulse width modulation (PWM) current source controlled by a microprocessor that received commands from a MATLAB routine that dynamically set current amplitude and direction for each coil. The catheter was immersed in a water phantom containing 1% Gd-DTPA that was placed at the isocenter of a 1.5 T MRI scanner. Deflections of the catheter tip were measured from image-based data obtained with a real-time radio frequency (RF) spoiled gradient echo sequence (GRE). The small local magnetic fields generated by the steering coils were exploited to generate a hyperintense signal at the catheter tip by using a modified GRE sequence that did not include slice-select rewinding gradients. Imaging and excitation modes were implemented by synchronizing the excitation of the steering coil array with the scanner by ensuring that no current was driven through the coils during the data acquisition window; this allowed visualization of the surrounding tissue while not affecting the desired catheter position. Deflections as large as 2.5 cm were measured when exciting the steering coils sequentially with a 100 mA maximum current per coil. When exciting a single axial coil, the deflection was half this value with 30% higher current. A hyperintense catheter tip useful for catheter tracking was obtained by imaging with the modified GRE sequence. Clear visualization of the areas surrounding the

  14. Studies of steered arc motion and macroparticle production in PVD processing

    International Nuclear Information System (INIS)

    Craven, A.L.

    2000-03-01

    During the past decade the production industry has constantly strived to improve performance and cut costs, this has been aided by the development of high performance tools. The advancement of these tools has been accomplished by the application of hard wearing, low friction, coatings. A key process in the production of such coatings is Physical Vapour Deposition (PVD). Interest in such thin films has led to much research effort, both academic and industrial, being devoted to the area. In order that these advancements in technology continue, research into the fundamental aspects of PVD is required. This thesis describes research and experimental studies which have been performed to study the effect of 'steering' an electric arc on various aspects of its behaviour. 'Steering' of the arc is achieved by applying external magnetic fields which allow the guidance of the path of the arc. Work by earlier authors has aimed to control the arc more fully. The research presented here is based of a novel electromagnetic three coil steering array of cylindrical geometry. With such coils it is possible to vary the field profiles to a greater degree than has been previously achieved, permitting a greater range of steering arrangements/fields to be applied. The research presented is divided into two distinct areas: Firstly a number of experiments were performed to assess the effectiveness of the new steering coils on the motion of the arc. A personal computer was used here along with new arc motion monitoring electronics. This enabled the simultaneous measurement of the orbital transit times and also the degree of travel perpendicular to the steered direction of motion of the arc, as it traversed the surface of the cathode. Such information was then used to produce values for standard deviation of the arc from its steered path, velocity of the arc and a diffusion constant related to the motion of the are. Such values then allowed evaluation of the stochastic model of arc motion

  15. Performance of a slow positron beam using a hybrid lens design

    International Nuclear Information System (INIS)

    Cheung, C.K.; Naik, P.S.; Beling, C.D.; Fung, S.; Weng, H.M.

    2006-01-01

    The University of Hong Kong positron beam employs conventional magnetic field transport to the target, but has a special hybrid lens design around the positron moderator that allows the beam to be focused to millimeter spot sizes at the target. The good focusing capabilities of the beam are made possible by extracting work-function positrons from the moderator in a magnetic field free region using a conventional Soa lens thus minimizing beam canonical angular momentum. An Einzel lens is used to focus the positrons into the magnetic funnel at the end of transportation magnetic field while at the same time bringing up the beam energy to the intermediate value of 7.5 keV. The beam is E x B filtered at this intermediate energy. The final beam energy is obtained by floating the Soa-Einzel system, E x B filter and flight tube, and accelerating the positrons just before the target. External beam steering saddle coils fine tune the position, and the magnetic field around the target chamber is adjusted so as to keep one of the beam foci always on the target. The system is fully computer controlled. Variable energy-Doppler broadened annihilation radiation (VEDBAR) data for a GaN sample are shown which demonstrate the performance of the positron beam system

  16. PBFA II lithium beam characterization from inner-shell x-ray images

    International Nuclear Information System (INIS)

    Moats, A.R.; Derzon, M.S.; Chandler, G.A.; Dukart, R.J.; Haill, T.A.

    1994-01-01

    The Particle Beam Fusion Accelerator (PBFA II) is not driving targets with ICF-relevant lithium ion beams. During the most recent lithium beam target series, time-integrated x-ray pinhole cameras viewed the ion-induced inner-shell x-ray fluorescence from the central gold cone target and a titanium-coated strip. Ion beam profiles at a nominal 10 mm radius and fixed azimuthal direction were obtained from images of the Ti K α , fluorescence of a Ti-coated Al diagnostic wire. The gold cone gave us beam profiles at a nominal 3 mm radius and at all azimuthal angles from the Au L α fluorescence. From these profiles, we obtained the ion beam vertical focus position, full-width-at-half-maximum, and the degree of azimuthal uniformity for the lithium target shots. For these initial results, beam steering problems were evident. Azimuthal uniformity was measured from the ion beam footprint on the outer Au case (predominantly Au L α ) of the hohlraum target and were found to be in the same range (up to 30%) as for previous proton beam target series. We then present plans for Li beam diagnostics for an upcoming target experimental series

  17. Loophole-free Einstein-Podolsky-Rosen experiment via quantum steering

    International Nuclear Information System (INIS)

    Wittmann, Bernhard; Ramelow, Sven; Zeilinger, Anton; Steinlechner, Fabian; Langford, Nathan K; Ursin, Rupert; Brunner, Nicolas; Wiseman, Howard M

    2012-01-01

    Tests of the predictions of quantum mechanics for entangled systems have provided increasing evidence against local realistic theories. However, there remains the crucial challenge of simultaneously closing all major loopholes—the locality, freedom-of-choice and detection loopholes—in a single experiment. An important sub-class of local realistic theories can be tested with the concept of ‘steering’. The term ‘steering’ was introduced by Schrödinger in 1935 for the fact that entanglement would seem to allow an experimenter to remotely steer the state of a distant system as in the Einstein-Podolsky-Rosen (EPR) argument. Einstein called this ‘spooky action at a distance’. EPR-steering has recently been rigorously formulated as a quantum information task opening it up to new experimental tests. Here, we present the first loophole-free demonstration of EPR-steering by violating three-setting quadratic steering inequality, tested with polarization-entangled photons shared between two distant laboratories. Our experiment demonstrates this effect while simultaneously closing all loopholes: both the locality loophole and a specific form of the freedom-of-choice loophole are closed by having a large separation of the parties and using fast quantum random number generators, and the fair-sampling loophole is closed by having high overall detection efficiency. Thereby, we exclude—for the first time loophole-free—an important class of local realistic theories considered by EPR. Besides its foundational importance, loophole-free steering also allows the distribution of quantum entanglement secure event in the presence of an untrusted party. (paper)

  18. Loophole-free Einstein-Podolsky-Rosen experiment via quantum steering

    Science.gov (United States)

    Wittmann, Bernhard; Ramelow, Sven; Steinlechner, Fabian; Langford, Nathan K.; Brunner, Nicolas; Wiseman, Howard M.; Ursin, Rupert; Zeilinger, Anton

    2012-05-01

    Tests of the predictions of quantum mechanics for entangled systems have provided increasing evidence against local realistic theories. However, there remains the crucial challenge of simultaneously closing all major loopholes—the locality, freedom-of-choice and detection loopholes—in a single experiment. An important sub-class of local realistic theories can be tested with the concept of ‘steering’. The term ‘steering’ was introduced by Schrödinger in 1935 for the fact that entanglement would seem to allow an experimenter to remotely steer the state of a distant system as in the Einstein-Podolsky-Rosen (EPR) argument. Einstein called this ‘spooky action at a distance’. EPR-steering has recently been rigorously formulated as a quantum information task opening it up to new experimental tests. Here, we present the first loophole-free demonstration of EPR-steering by violating three-setting quadratic steering inequality, tested with polarization-entangled photons shared between two distant laboratories. Our experiment demonstrates this effect while simultaneously closing all loopholes: both the locality loophole and a specific form of the freedom-of-choice loophole are closed by having a large separation of the parties and using fast quantum random number generators, and the fair-sampling loophole is closed by having high overall detection efficiency. Thereby, we exclude—for the first time loophole-free—an important class of local realistic theories considered by EPR. Besides its foundational importance, loophole-free steering also allows the distribution of quantum entanglement secure event in the presence of an untrusted party.

  19. DETERMINATION OF STEERING WHEEL ANGLES DURING CAR ALIGNMENT BY IMAGE ANALYSIS METHODS

    Directory of Open Access Journals (Sweden)

    M. Mueller

    2016-06-01

    Full Text Available Optical systems for automatic visual inspections are of increasing importance in the field of automation in the industrial domain. A new application is the determination of steering wheel angles during wheel track setting of the final inspection of car manufacturing. The camera has to be positioned outside the car to avoid interruptions of the processes and therefore, oblique images of the steering wheel must be acquired. Three different approaches of computer vision are considered in this paper, i.e. a 2D shape-based matching (by means of a plane to plane rectification of the oblique images and detection of a shape model with a particular rotation, a 3D shape-based matching approach (by means of a series of different perspectives of the spatial shape of the steering wheel derived from a CAD design model and a point-to-point matching (by means of the extraction of significant elements (e.g. multifunctional buttons of a steering wheel and a pairwise connection of these points to straight lines. The HALCON system (HALCON, 2016 was used for all software developments and necessary adaptions. As reference a mechanical balance with an accuracy of 0.1° was used. The quality assessment was based on two different approaches, a laboratory test and a test during production process. In the laboratory a standard deviation of ±0.035° (2D shape-based matching, ±0.12° (3D approach and ±0.029° (point-to-point matching could be obtained. The field test of 291 measurements (27 cars with varying poses and angles of the steering wheel results in a detection rate of 100% and ±0.48° (2D matching and ±0.24° (point-to-point matching. Both methods also fulfil the request of real time processing (three measurements per second.

  20. Effects of isobutyrate supplementation on ruminal microflora, rumen enzyme activities and methane emissions in Simmental steers.

    Science.gov (United States)

    Wang, C; Liu, Q; Zhang, Y L; Pei, C X; Zhang, S L; Wang, Y X; Yang, W Z; Bai, Y S; Shi, Z G; Liu, X N

    2015-02-01

    The objective of this study was to evaluate the effects of isobutyrate supplementation on rumen microflora, enzyme activities and methane emissions in Simmental steers consuming a corn stover-based diet. Eight ruminally cannulated Simmental steers were used in a replicated 4 × 4 Latin square experiment. The treatments were control (without isobutyrate), low isobutyrate (LIB), moderate isobutyrate (MIB) and high isobutyrate (HIB) with 8.4, 16.8 and 25.2 g isobutyrate per steer per day respectively. Isobutyrate was hand-mixed into the concentrate portion. Diet consisted of 60% corn stover and 40% concentrate [dry matter (DM) basis]. Dry matter intake (averaged 9 kg/day) was restricted to a maximum of 90% of ad libitum intake. Population of total bacteria, cellulolytic bacteria and anaerobic fungi were linearly increased, whereas that of protozoa and total methanogens was linearly reduced with increasing isobutyrate supplementation. Real-time PCR quantification of population of Ruminococcus albus, Ruminococcus flavefaciens, Butyrivibrio fibrisolvens and Fibrobacter succinogenes was linearly increased with increasing isobutyrate supplementation. Activities of carboxymethyl cellulase, xylanase and β-glucosidase were linearly increased, whereas that of protease was linearly reduced. Methane production was linearly decreased with increasing isobutyrate supplementation. Effective degradabilities of cellulose and hemicellulose of corn stover were linearly increased, whereas that of crude protein in diet was linearly decreased with increasing isobutyrate supplementation. The present results indicate that isobutyrate supplemented improved microflora, rumen enzyme activities and methane emissions in steers. It was suggested that the isobutyrate stimulated the digestive micro-organisms or enzymes in a dose-dependent manner. In the experimental conditions of this trial, the optimum isobutyrate dose was approximately 16.8 g isobutyrate per steer per day. Journal of Animal