WorldWideScience

Sample records for beam based alignment

  1. Mechanical alignment based on beam diagnostics

    International Nuclear Information System (INIS)

    Farvacque, L.; Martin, D.; Nagaoka, R.

    1999-01-01

    This article studies the consequences of misalignment of the different components on the displacement of the beam. 3 types of motion have been investigated: quadrupole vertical displacement, quadrupole tilt and sextupole vertical displacement. For each shift a response matrix has been designed and from this formulation, aligning quadrupoles means inverting this matrix. The strategy for correction depends on the accuracy of the response matrix and on the quality of the beam position measurements. A modelling of the corrections is proposed. (A.C.)

  2. Simulator for beam-based LHC collimator alignment

    Science.gov (United States)

    Valentino, Gianluca; Aßmann, Ralph; Redaelli, Stefano; Sammut, Nicholas

    2014-02-01

    In the CERN Large Hadron Collider, collimators need to be set up to form a multistage hierarchy to ensure efficient multiturn cleaning of halo particles. Automatic algorithms were introduced during the first run to reduce the beam time required for beam-based setup, improve the alignment accuracy, and reduce the risk of human errors. Simulating the alignment procedure would allow for off-line tests of alignment policies and algorithms. A simulator was developed based on a diffusion beam model to generate the characteristic beam loss signal spike and decay produced when a collimator jaw touches the beam, which is observed in a beam loss monitor (BLM). Empirical models derived from the available measurement data are used to simulate the steady-state beam loss and crosstalk between multiple BLMs. The simulator design is presented, together with simulation results and comparison to measurement data.

  3. Beam-based alignment of CLIC drive beam decelerator using girders movers

    CERN Document Server

    Sterbini, G

    2011-01-01

    The CLIC drive beams will provide the rf power to accelerate the colliding beams: in order to reach the design performance, an efficient transport of the drive beam has to be ensured in spite of its challenging energy spread and large current intensity. As shown in previous studies, the specifications can be met by coupling a convenient optics design with the state-of-the-art of pre-alignment and beambased alignment techniques. In this paper we consider a novel beam-based alignment scheme that does not require quadrupole movers or dipole correctors but uses the motors already foreseen for the pre-alignment system. This implies potential savings in terms of complexity and cost at the expense of the alignment flexibility: the performance, limitations and sensitivity to pre-alignment tolerances of this method are discussed.

  4. Beam based alignment at the KEK accelerator test facility

    International Nuclear Information System (INIS)

    Ross, M.; Nelson, J.; Woodley, M.; Wolski, A.

    2002-01-01

    The KEK Accelerator Test Facility (ATF) damping ring is a prototype low emittance source for the NLC/JLC linear collider. To achieve the goal normalized vertical emittance gey = 20 nm-rad, magnet placement accuracy better than 30 mm must be achieved. Accurate beam-based alignment (BBA) is required. The ATF arc optics uses a FOBO cell with two horizontally focusing quadrupoles, two sextupoles and a horizontally defocusing gradient dipole, all of which must be aligned with BBA. BBA at ATF uses the quadrupole and sextupole trim windings to find the trajectory through the center of each magnet. The results can be interpreted to assess the accuracy of the mechanical alignment and the beam position monitor offsets

  5. 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.

  6. Beam-based alignment of C-shaped quadrupole magnets

    International Nuclear Information System (INIS)

    Portmann, G.; Robin, D.

    1998-06-01

    Many storage rings have implemented a method of finding the positional offset between the electrical center of the beam position monitors (BPM) and the magnetic center of the adjacent quadrupole magnets. The algorithm for accomplishing this is usually based on modulating the current in the quadrupole magnet and finding the beam position that minimizes the orbit perturbation. When the quadrupole magnet is C-shaped, as it is for many light sources, the modulation method can produce an erroneous measurement of the magnetic center in the horizontal plane. When the current in a C-shaped quadrupole is changed, there is an additional dipole component in the vertical field. Due to nonlinearities in the hysteresis cycle of the C-magnet geometry, the beam-based alignment technique at the Advanced Light Source (ALS) deviated horizontally by .5 mm from the actual magnetic center. By modifying the technique, the offsets were measured to an accuracy of better than 50 microm

  7. Resolution and systematic limitations in beam based alignment

    Energy Technology Data Exchange (ETDEWEB)

    Tenenbaum, P.G.

    2000-03-15

    Beam based alignment of quadrupoles by variation of quadrupole strength is a widely-used technique in accelerators today. The authors describe the dominant systematic limitation of this technique, which arises from the change in the center position of the quadrupole as the strength is varied, and derive expressions for the resulting error. In addition, the authors derive an expression for the statistical resolution of such techniques in a periodic transport line, given knowledge of the line's transport matrices, the resolution of the beam position monitor system, and the details of the strength variation procedure. These results are applied to the Next Linear Collider main linear accelerator, an 11 kilometer accelerator containing 750 quadrupoles and 5,000 accelerator structures. The authors find that in principle a statistical resolution of 1 micron is easily achievable but the systematic error due to variation of the magnetic centers could be several times larger.

  8. ACCELERATORS: Beam based alignment of the SSRF storage ring

    Science.gov (United States)

    Zhang, Man-Zhou; Li, Hao-Hu; Jiang, Bo-Cheng; Liu, Gui-Min; Li, De-Ming

    2009-04-01

    There are 140 beam position monitors (BPMs) in the Shanghai Synchrotron Radiation Facility (SSRF) storage ring used for measuring the closed orbit. As the BPM pickup electrodes are assembled directly on the vacuum chamber, it is important to calibrate the electrical center offset of the BPM to an adjacent quadrupole magnetic center. A beam based alignment (BBA) method which varies individual quadrupole magnet strength and observes its effects on the orbit is used to measure the BPM offsets in both the horizontal and vertical planes. It is a completely automated technique with various data processing methods. There are several parameters such as the strength change of the correctors and the quadrupoles which should be chosen carefully in real measurement. After several rounds of BBA measurement and closed orbit correction, these offsets are set to an accuracy better than 10 μm. In this paper we present the method of beam based calibration of BPMs, the experimental results of the SSRF storage ring, and the error analysis.

  9. Quadrupole beam-based alignment in the RHIC interaction regions

    International Nuclear Information System (INIS)

    Ziegler, J.; Satogata, T.

    2011-01-01

    Continued beam-based alignment (BBA) efforts have provided significant benefit to both heavy ion and polarized proton operations at RHIC. Recent studies demonstrated previously unknown systematic beam position monitor (BPM) offset errors and produced accurate measurements of individual BPM offsets in the experiment interaction regions. Here we describe the algorithm used to collect and analyze data during the 2010 and early 2011 RHIC runs and the results of these measurements. BBA data has been collected over the past two runs for all three of the active experimental IRs at RHIC, updating results from the 2005 run which were taken with incorrectly installed offsets. The technique was successfully applied to expose a systematic misuse of the BPM survey offsets in the control system. This is likely to benefit polarized proton operations as polarization transmission through acceleration ramps depends on RMS orbit control in the arcs, but a quantitative understanding of its impact is still under active investigation. Data taking is ongoing as are refinements to the BBA technique aimed at reducing systematic errors and properly accounting for dispersive effects. Further development may focus on non-triplet BPMs such as those located near snakes, or arc quadrupoles that do not have individually shunted power supplies (a prerequisite for the current method) and as such, will require a modified procedure.

  10. Beam based alignment and its relevance in Indus-2

    Energy Technology Data Exchange (ETDEWEB)

    Jena, Saroj Kumar; Husain, Riyasat; Gandhi, M. L.; Agrawal, R. K.; Yadav, S.; Ghodke, A. D. [Raja Ramanna Centre for Advanced Technology, Indore (India)

    2015-09-15

    Initially in the Indus-2 storage ring, the closed orbit distortion (COD) could be best corrected to 1.3 mm rms in the horizontal and 0.43 mm rms in the vertical plane. The strength of the corrector magnets required high values for COD correction. This revealed that offsets in COD readout by the beam position monitors (BPMs) played a role in not achieving a rms COD lower than the above value. Thus, the offset between the electrical center of BPMs and the magnetic center of the nearest quadrupole magnet could be estimated using the beam based alignment (BBA) method. It prefers that the quadrupole magnet is able to be controlled individually and active shunt power supply (ASPS) system was designed for this purpose that works efficiently. This paper describes the methodology of BBA, topology of ASPS and its performance, and COD minimization using the measured BPM offsets. After BBA, the COD could be reduced to 0.45 mm rms and 0.2 mm rms in horizontal and vertical planes, respectively.

  11. Beam based alignment and its relevance in Indus-2

    Science.gov (United States)

    Jena, Saroj Kumar; Husain, Riyasat; Gandhi, M. L.; Agrawal, R. K.; Yadav, S.; Ghodke, A. D.

    2015-09-01

    Initially in the Indus-2 storage ring, the closed orbit distortion (COD) could be best corrected to 1.3 mm rms in the horizontal and 0.43 mm rms in the vertical plane. The strength of the corrector magnets required high values for COD correction. This revealed that offsets in COD readout by the beam position monitors (BPMs) played a role in not achieving a rms COD lower than the above value. Thus, the offset between the electrical center of BPMs and the magnetic center of the nearest quadrupole magnet could be estimated using the beam based alignment (BBA) method. It prefers that the quadrupole magnet is able to be controlled individually and active shunt power supply (ASPS) system was designed for this purpose that works efficiently. This paper describes the methodology of BBA, topology of ASPS and its performance, and COD minimization using the measured BPM offsets. After BBA, the COD could be reduced to 0.45 mm rms and 0.2 mm rms in horizontal and vertical planes, respectively.

  12. Beam based alignment of the SLC final focus sextupoles

    International Nuclear Information System (INIS)

    Emma, P.; Irwin, J.; Phinney, N.; Raimondi, P.; Toge, N.; Walker, N.J.; Ziemann, V.

    1993-05-01

    The strong demagnification inherent in final focus systems requires local cancellation of the resulting chromaticty. Strong sextupole pair separated by a -I transform are positioned π/2 in the betatron phase away from the Interaction Point (IP) in order to cancel chromatic aberrations primarily due to the final quadrupoles. Sextupole alignment is critical in order to provide orthogonal tuning of the chromaticty and, in the case of the SLC, to limit the third and higher order optical aberrations generated from misaligned and 'nested' horizontal and vertical sextupole pairs. Reported here is a novel technique for aligning the beam centroid to the sextupole centers, which uses measurements of the criticality dependent parameter - the beam size at the IP. Results for the SLC final focus sextupoles are presented, where a resolution of <50 μm is achieved

  13. Beam-Based Alignment of Magnetic Field in the Fermilab Electron Cooler Cooling Section

    International Nuclear Information System (INIS)

    Seletskiy, S. M.; Tupikov, V.

    2006-01-01

    The Fermilab Electron Cooling Project requires low effective anglular spread of electrons in the cooling section. One of the main components of the effective electron angles is an angle of electron beam centroid with respect to antiproton beam. This angle is caused by the poor quality of magnetic field in the 20 m long cooling section solenoid and by the mismatch of the beam centroid to the entrance of the cooling section. This paper focuses on the beam-based procedure of the alignment of the cooling section field and beam centroid matching. The discussed procedure allows to suppress the beam centroid angles below the critical value of 0.1 mrad

  14. Comparison of LHC collimator beam-based alignment to BPM-Interpolated centers

    CERN Document Server

    Valentino, G; Assmann, R W; Bruce, R; Muller, G J; Redaelli, S; Rossi, A; Lari, L

    2012-01-01

    The beam centers at the Large Hadron Collider collimators are determined by beam-based alignment, where both jaws of a collimator are moved in separately until a loss spike is detected on a Beam LossMonitor downstream. Orbit drifts of more than a few hundred micrometers cannot be tolerated, as they would compromise the performance of the collimation system. Beam Position Monitors (BPMs) are installed at various locations around the LHC ring, and a linear interpolation of the orbit can be obtained at the collimator positions. In this paper, the results obtained from beam-based alignment are compared with the orbit interpolated from the BPM data throughout the 2011 and 2012 LHC proton runs.

  15. Successive approximation algorithm for beam-position-monitor-based LHC collimator alignment

    Directory of Open Access Journals (Sweden)

    Gianluca Valentino

    2014-02-01

    Full Text Available Collimators with embedded beam position monitor (BPM button electrodes will be installed in the Large Hadron Collider (LHC during the current long shutdown period. For the subsequent operation, BPMs will allow the collimator jaws to be kept centered around the beam orbit. In this manner, a better beam cleaning efficiency and machine protection can be provided at unprecedented higher beam energies and intensities. A collimator alignment algorithm is proposed to center the jaws automatically around the beam. The algorithm is based on successive approximation and takes into account a correction of the nonlinear BPM sensitivity to beam displacement and an asymmetry of the electronic channels processing the BPM electrode signals. A software implementation was tested with a prototype collimator in the Super Proton Synchrotron. This paper presents results of the tests along with some considerations for eventual operation in the LHC.

  16. Successive approximation algorithm for beam-position-monitor-based LHC collimator alignment

    Science.gov (United States)

    Valentino, Gianluca; Nosych, Andriy A.; Bruce, Roderik; Gasior, Marek; Mirarchi, Daniele; Redaelli, Stefano; Salvachua, Belen; Wollmann, Daniel

    2014-02-01

    Collimators with embedded beam position monitor (BPM) button electrodes will be installed in the Large Hadron Collider (LHC) during the current long shutdown period. For the subsequent operation, BPMs will allow the collimator jaws to be kept centered around the beam orbit. In this manner, a better beam cleaning efficiency and machine protection can be provided at unprecedented higher beam energies and intensities. A collimator alignment algorithm is proposed to center the jaws automatically around the beam. The algorithm is based on successive approximation and takes into account a correction of the nonlinear BPM sensitivity to beam displacement and an asymmetry of the electronic channels processing the BPM electrode signals. A software implementation was tested with a prototype collimator in the Super Proton Synchrotron. This paper presents results of the tests along with some considerations for eventual operation in the LHC.

  17. Beam-based alignment at the KEK-ATF damping ring

    International Nuclear Information System (INIS)

    Woodley, Mark D.; Nelson, Janice; Ross, Marc; Turner, James; Wolski, A.; Kubo, Kiyoshi

    2004-01-01

    The damping rings of a future linear collider will have demanding alignment and stability requirements in order to achieve the low vertical emittance necessary for high luminosity. The Accelerator Test Facility (ATF) at KEK has successfully demonstrated the vertical emittance below 5 pm that is specified for the GLC/NLC Main Damping Rings. One contribution to this accomplishment has been the use of Beam Based Alignment (BBA) techniques. The mode of operation of the ATF presents particular challenges for BBA, and we describe here how we have deduced the offsets of the BPMs with respect to the quadrupoles. We also discuss a technique that allows for direct measurements of the beam-to-quad offsets

  18. Beam alignment based on two-dimensional power spectral density of a near-field image.

    Science.gov (United States)

    Wang, Shenzhen; Yuan, Qiang; Zeng, Fa; Zhang, Xin; Zhao, Junpu; Li, Kehong; Zhang, Xiaolu; Xue, Qiao; Yang, Ying; Dai, Wanjun; Zhou, Wei; Wang, Yuanchen; Zheng, Kuixing; Su, Jingqin; Hu, Dongxia; Zhu, Qihua

    2017-10-30

    Beam alignment is crucial to high-power laser facilities and is used to adjust the laser beams quickly and accurately to meet stringent requirements of pointing and centering. In this paper, a novel alignment method is presented, which employs data processing of the two-dimensional power spectral density (2D-PSD) for a near-field image and resolves the beam pointing error relative to the spatial filter pinhole directly. Combining this with a near-field fiducial mark, the operation of beam alignment is achieved. It is experimentally demonstrated that this scheme realizes a far-field alignment precision of approximately 3% of the pinhole size. This scheme adopts only one near-field camera to construct the alignment system, which provides a simple, efficient, and low-cost way to align lasers.

  19. Beam-based alignment and tuning procedures for e+e- collider final focus systems

    International Nuclear Information System (INIS)

    Bulos, F.; Burke, D.; Helm, R.; Irwin, J.; Odian, A.; Roy, G.; Ruth, R.; Yamamoto, N.

    1991-05-01

    For future linear colliders, with very small emittances and beam sizes and demanding tolerances on final focus system alignment and magnet errors, it becomes increasingly important to use the beam as a diagnostic tool. We report here procedures we have identified and will be implemented in the Final Focus Test Beam at SLAC incorporating (1) quadrupole strength changes, (2) central orbit modifications, (3) spot size measurements, and (4) beam stability monitoring. 3 refs., 4 figs., 3 tabs

  20. Beam-based alignment and tuning procedures for e+e- collider final focus systems

    International Nuclear Information System (INIS)

    Bulos, F.; Burke, D.; Helm, R.; Irwin, J.; Odian, A.; Roy, G.; Ruth, R.; Yamamoto

    1991-01-01

    For future linear colliders, with very small emittances and beam sizes and demanding tolerances on final focus system alignment and magnet errors, it becomes increasingly important to use the beam as a diagnostic tool. The authors report here procedures they have identified and will be implemented in the Final Focus Test Beam at SLAC incorporating (1) quadrupole strength changes, (2) central orbit modifications, (3) spot size measurements, and (4) beam stability monitoring

  1. 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

  2. CLIC main beam quadrupole active pre-alignment based on cam movers

    CERN Document Server

    Kemppinen, J; Leuxe, R; Mainaud Durand, H; Sandomierski, J; Sosin, M

    2012-01-01

    Compact Linear Collider (CLIC) is a study for a future 48 km long linear electron-positron collider in the multi TeV range. Its target luminosity can only be reached if the main beam quadrupoles (MB quads) are actively pre-aligned within 17 µm in sliding windows of 200 m with respect to a straight reference line. In addition to the positioning requirement, the pre-alignment system has to provide a rigid support for the nano-stabilization system to ensure that the first eigenfrequency is above 100 Hz. Re-adjustment based on cam movers was chosen for detailed studies to meet the stringent pre-alignment requirements. There are four different types of MB quads in CLIC. Their lengths and masses vary so that at least two types of cam movers have to be developed. The validation of the cams with less stringent space restrictions has proceeded to a test setup in 5 degrees of freedom (DOF). Prototypes of the more demanding, smaller cams have been manufactured and they are under tests in 1 DOF. This paper describes the...

  3. The beam based alignment technique for the measurements of beam position monitors offsets and beam offsets from quadrupoles in the Pohang Light Source

    International Nuclear Information System (INIS)

    Kim, K.H.; Huang, J.Y.; Ko, I.S.

    1999-01-01

    The beam based alignment (BBA) technique is applied to the 2-GeV storage ring of the Pohang Light Source to measure the offsets of beam position monitors. This measurement is particularly necessary for beam position monitors (BPMs) plugged into a long (∼10 m) aluminum chamber, since the mechanical deformation of the vacuum chamber is experienced after repeated heating for the outgassing process, and the BPM positions are changed accordingly. A part of the excitation current of each quadrupole magnet is shunted through an electronic shunt circuit. Then, the closed orbit receives a perturbation due to the current reduction. Using two quadrupole magnets, we can measure the offset of each BPM. Also, the BBA technique is applied to measure the beam offsets from the center of quadrupole magnets, and gives information to the survey team about which quadrupole magnets should be aligned mostly. In this process, we introduce the merit function to reduce various errors such as BPM characteristic changes and the lattice imperfection. By minimizing the merit function, we can get the beam offset as the maximized expectation value. This paper presents the BBA technique used and experimental results taken from the 2-GeV Pohang Light Source (PLS) storage ring. When the BPM offset is measured, it is observed that a 3% of the shunt current is suitable. (author)

  4. Development of an Eccentric CAM Based Active Pre-Alignment System for the CLIC Main Beam Quadrupole Magnet

    CERN Document Server

    Lackner, F; Collette, C; Mainaud Durand, H; Hauviller, C; Kemppinen, J; Leuxe, R

    2010-01-01

    CLIC (Compact Linear Collider) is a study for a future electron-positron collider that would allow physicists to explore a new energy region beyond the capabilities of today's particle accelerators. The demanding transverse and vertical beam sizes and emittance specifications are resulting in stringent alignment and a nanometre stability requirement. In the current feasibility study, the main beam quadrupole magnets have to be actively pre-aligned with a precision of 1 µm in 5 degrees of freedom (d.o.f.) before being mechanically stabilized to the nm scale above 1 Hz. This contribution describes the approach of performing this active pre-alignment based on an eccentric cam system. In order to limit the amplification of the vibration sources at resonant frequencies a sufficiently high Eigenfrequency is required. Therefore the contact region between cam and support was optimized for adequate stiffness based on the Hertzian theory. Furthermore, practical tests performed on a single degree of freedom mock-up wil...

  5. Antares automatic beam alignment system

    International Nuclear Information System (INIS)

    Appert, Q.; Swann, T.; Sweatt, W.; Saxman, A.

    1980-01-01

    Antares is a 24-beam-line CO 2 laser system for controlled fusion research, under construction at Los Alamos Scientific Laboratory (LASL). Rapid automatic alignment of this system is required prior to each experiment shot. The alignment requirements, operational constraints, and a developed prototype system are discussed. A visible-wavelength alignment technique is employed that uses a telescope/TV system to view point light sources appropriately located down the beamline. Auto-alignment is accomplished by means of a video centroid tracker, which determines the off-axis error of the point sources. The error is nulled by computer-driven, movable mirrors in a closed-loop system. The light sources are fiber-optic terminations located at key points in the optics path, primarily at the center of large copper mirrors, and remotely illuminated to reduce heating effects

  6. A beam-based alignment technique for correction of accelerator structure misalignments

    International Nuclear Information System (INIS)

    Kubo, K.; Raubenheimer, T.O.

    1994-08-01

    This paper describes a method of reducing the transverse emittance dilution in linear colliders due to transverse wakefields arising-from misaligned accelerator structures. The technique is a generalization of the Wake-Free correction algorithm. The structure alignment errors are measured locally by varying the bunch charge and/or bunch length and measuring the change in the beam trajectory. The misalignments can then be corrected by varying the beam trajectory or moving structures. The results of simulations are presented demonstrating the viability of the technique

  7. Antares beam-alignment-system performance

    International Nuclear Information System (INIS)

    Appert, Q.D.; Bender, S.C.

    1983-01-01

    The beam alignment system for the 24-beam-sector Antares CO 2 fusion laser automatically aligns more than 200 optical elements. A visible-wavelength alignment technique is employed which uses a telescope/TV system to view point-light sources appropriately located down the beamline. The centroids of the light spots are determined by a video tracker, which generates error signals used by the computer control system to move appropriate mirrors in a closed-loop system. Final touch-up alignment is accomplished by projecting a CO 2 alignment laser beam through the system and sensing its position at the target location. The techniques and control algorithms employed have resulted in alignment accuracies exceeding design requirements. By employing video processing to determine the centroids of diffraction images and by averaging over multiple TV frames, we achieve alignment accuracies better than 0.1 times system diffraction limits in the presence of air turbulence

  8. Generation and application of Bessel beam in alignment works

    International Nuclear Information System (INIS)

    Gale, D. M.

    2009-01-01

    The divergence of a Gaussian laser beam is a limiting factor for optical alignment tasks at large distances. Bessel beams have almost zero divergence but are still not widely used. We discuss the construction of an alignment telescope based on Bessel beam generation using a commercial laser diode module. The Bessel beam is generated with conical or plano-convex lenses, and projected using a commercial CCD camera lens to extend the useful range of the beam. Our Bessel beams have diameters of between 0.5 - 1mm over beam lengths of 15m, representing a six-fold improvement compared to Gaussian beams, while the transverse beam structure (Bessel pattern) provides an excellent alignment aid for use with beam target. Another advantage of Bessel beams is their self-regeneration property, which allows the use of multiple beam targets with minimum beam degradation. We are using our crosshair targets with crosshair targets to align optical components in a large astronomical telescope, and can achieve precisions of tens of microns over distances of 20m using purely visual methods. (Author)

  9. Laser alignment measurement model with double beam

    Science.gov (United States)

    Mo, Changtao; Zhang, Lili; Hou, Xianglin; Wang, Ming; Lv, Jia; Du, Xin; He, Ping

    2012-10-01

    Double LD-Double PSD schedule.employ a symmetric structure and there are a laser and a PSD receiver on each axis. The Double LD-Double PSD is used, and the rectangular coordinate system is set up by use of the relationship of arbitrary two points coordinates, and then the parameter formula is deduced by the knowledge of solid geometry. Using the data acquisition system and the data processing model of laser alignment meter with double laser beam and two detector , basing on the installation parameter of the computer, we can have the state parameter between the two shafts by more complicated calculation and correction. The correcting data of the four under chassis of the adjusted apparatus moving on the level and the vertical plane can be calculated using the computer. This will instruct us to move the apparatus to align the shafts.

  10. Fast Automatic Beam-Based Alignment of the LHC Collimator Jaws

    CERN Document Server

    AUTHOR|(CDS)2080813; Assmann, R W

    2014-01-01

    The CERN Large Hadron Collider (LHC) in Geneva, Switzerland is the largest and most powerful particle accelerator ever built. With a circumference of 27 km, it is designed to collide particles in two counter-rotating beams at a centre-of-mass energy of 14 TeV to explore the fundamental forces and constituents of matter. Due to its potentially destructive high energy particle beams, the LHC is equipped with several machine protection systems. The LHC collimation system is tasked with scattering and absorbing beam halo particles before they can quench the superconducting magnets. The 108 collimators also protect the machine from damage in the event of very fast beam losses, and shields sensitive devices in the tunnel from radiation over years of operation. Each collimator is made up of two blocks or ‘jaws’ of carbon, tungsten or copper material. The collimator jaws need be placed symmetrically on either side of the beam trajectory, to clean halo particles with maximum efficiency. The beam orbit and beam siz...

  11. Angular momentum alignment in molecular beam scattering

    International Nuclear Information System (INIS)

    Treffers, M.A.

    1985-01-01

    It is shown how the angular momentum alignment in a molecular beam can be determined using laser-induced fluorescence in combination with precession of the angular momenta in a magnetic field. After a general analysis of the method, some results are presented to illustrate the possibilities of the method. Experimental data are presented on the alignment production for Na 2 molecules that made a collision induced angular momentum transition. Magnitude as well as direction of the alignment have been determined for scattering with several scattering partners and for a large number of scattering angles and transitions. The last chapter deals with the total alignment production in a final J-state, i.e. without state selection of the initial rotational state. (orig.)

  12. Reducing beam shaper alignment complexity: diagnostic techniques for alignment and tuning

    Science.gov (United States)

    Lizotte, Todd E.

    2011-10-01

    Safe and efficient optical alignment is a critical requirement for industrial laser systems used in a high volume manufacturing environment. Of specific interest is the development of techniques to align beam shaping optics within a beam line; having the ability to instantly verify by a qualitative means that each element is in its proper position as the beam shaper module is being aligned. There is a need to reduce these types of alignment techniques down to a level where even a newbie to optical alignment will be able to complete the task. Couple this alignment need with the fact that most laser system manufacturers ship their products worldwide and the introduction of a new set of variables including cultural and language barriers, makes this a top priority for manufacturers. Tools and methodologies for alignment of complex optical systems need to be able to cross these barriers to ensure the highest degree of up time and reduce the cost of maintenance on the production floor. Customers worldwide, who purchase production laser equipment, understand that the majority of costs to a manufacturing facility is spent on system maintenance and is typically the largest single controllable expenditure in a production plant. This desire to reduce costs is driving the trend these days towards predictive and proactive, not reactive maintenance of laser based optical beam delivery systems [10]. With proper diagnostic tools, laser system developers can develop proactive approaches to reduce system down time, safe guard operational performance and reduce premature or catastrophic optics failures. Obviously analytical data will provide quantifiable performance standards which are more precise than qualitative standards, but each have a role in determining overall optical system performance [10]. This paper will discuss the use of film and fluorescent mirror devices as diagnostic tools for beam shaper module alignment off line or in-situ. The paper will also provide an overview

  13. 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.

  14. A feature alignment score for online cone-beam CT-based image-guided radiotherapy for prostate cancer.

    Science.gov (United States)

    Hargrave, Catriona; Deegan, Timothy; Poulsen, Michael; Bednarz, Tomasz; Harden, Fiona; Mengersen, Kerrie

    2018-05-17

    To develop a method for scoring online cone-beam CT (CBCT)-to-planning CT image feature alignment to inform prostate image-guided radiotherapy (IGRT) decision-making. The feasibility of incorporating volume variation metric thresholds predictive of delivering planned dose into weighted functions, was investigated. Radiation therapists and radiation oncologists participated in workshops where they reviewed prostate CBCT-IGRT case examples and completed a paper-based survey of image feature matching practices. For 36 prostate cancer patients, one daily CBCT was retrospectively contoured then registered with their plan to simulate delivered dose if (a) no online setup corrections and (b) online image alignment and setup corrections, were performed. Survey results were used to select variables for inclusion in classification and regression tree (CART) and boosted regression trees (BRT) modeling of volume variation metric thresholds predictive of delivering planned dose to the prostate, proximal seminal vesicles (PSV), bladder, and rectum. Weighted functions incorporating the CART and BRT results were used to calculate a score of individual tumor and organ at risk image feature alignment (FAS TV _ OAR ). Scaled and weighted FAS TV _ OAR were then used to calculate a score of overall treatment compliance (FAS global ) for a given CBCT-planning CT registration. The FAS TV _ OAR were assessed for sensitivity, specificity, and predictive power. FAS global thresholds indicative of high, medium, or low overall treatment plan compliance were determined using coefficients from multiple linear regression analysis. Thirty-two participants completed the prostate CBCT-IGRT survey. While responses demonstrated consensus of practice for preferential ranking of planning CT and CBCT match features in the presence of deformation and rotation, variation existed in the specified thresholds for observed volume differences requiring patient repositioning or repeat bladder and bowel

  15. Electron Beam Alignment Strategy in the LCLS Undulators

    International Nuclear Information System (INIS)

    Nuhn, H

    2007-01-01

    The x-ray FEL process puts very tight tolerances on the straightness of the electron beam trajectory (2 (micro)m rms) through the LCLS undulator system. Tight but less stringent tolerances of 80 (micro)m rms vertical and 140 (micro)m rms horizontally are to be met for the placement of the individual undulator segments with respect to the beam axis. The tolerances for electron beam straightness can only be met through beam-based alignment (BBA) based on electron energy variations. Conventional alignment will set the start conditions for BBA. Precision-fiducialization of components mounted on remotely adjustable girders and the use of beam-finder wires (BFW) will satisfy placement tolerances. Girder movement due to ground motion and temperature changes will be monitored continuously by an alignment monitoring system (ADS) and remotely corrected. This stabilization of components as well as the monitoring and correction of the electron beam trajectory based on BPMs and correctors will increase the time between BBA applications. Undulator segments will be periodically removed from the undulator Hall and measured to monitor radiation damage and other effects that might degrade undulator tuning

  16. A technique for aligning sextupole systems using beam optics

    International Nuclear Information System (INIS)

    Chao, Yu-Chiu.

    1992-03-01

    A technique for beam based alignment of sextupole system is developed exploiting the enhancement effect of orbit differences by the sextupoles. This technique can in principle be applied to sextupole or sextupole strings with controlled orbit pattern and BPM configurations. This paper will discuss the theoretical basis, special optimization considerations and expected accuracy. Application to the SLC final focus is also discussed

  17. Laser beam alignment and profilometry using diagnostic fluorescent safety mirrors

    Science.gov (United States)

    Lizotte, Todd E.

    2011-03-01

    There are a wide range of laser beam delivery systems in use for various purposes; including industrial and medical applications. Virtually all such beam delivery systems for practical purposes employ optical systems comprised of mirrors and lenses to shape, focus and guide the laser beam down to the material being processed. The goal of the laser beam delivery is to set the optimum parameters and to "fold" the beam path to reduce the mechanical length of the optical system, thereby allowing a physically compact system. In many cases, even a compact system can incorporate upwards of six mirrors and a comparable number of lenses all needing alignment so they are collinear. One of the major requirements for use of such systems in industry is a method of safe alignment. The alignment process requires that the aligner determine where the beam strikes each element. The aligner should also preferably be able to determine the shape or pattern of the laser beam at that point and its relative power. These alignments are further compounded in that the laser beams generated are not visible to the unaided human eye. Such beams are also often of relatively high power levels, and are thereby a significant hazard to the eyes of the aligner. Obvious an invisible beam makes it nearly impossible to align laser system without some form of optical assistance. The predominant method of visually aligning the laser beam delivery is the use of thermal paper, paper cards or fluorescing card material. The use of paper products which have limited power handling capability or coated plastics can produce significant debris and contaminants within the beam line that ultimately damage the optics. The use of the cards can also create significant laser light scatter jeopardizing the safety of the person aligning the system. This paper covers a new safety mirror design for use with at various UV and Near IR wavelengths (193 nm to 1064 nm) within laser beam delivery systems and how its use can

  18. A Dynamic Alignment System for the Final Focus Test Beam

    International Nuclear Information System (INIS)

    Ruland, R.E.; Bressler, V.E.; Fischer, G.; Plouffe, D.; SLAC

    2005-01-01

    The Final Focus Test Beam (FFTB) was conceived as a technological stepping stone on the way to the next linear collider. Nowhere is this more evident than with the alignment subsystems. Alignment tolerances for components prior to beam turn are almost an order of magnitude smaller than for previous projects at SLAC. Position monitoring systems which operate independent of the beam are employed to monitor motions of the components locally and globally with unprecedented precision. An overview of the FFTB alignment system is presented herein

  19. Utilization of cone-beam CT for offline evaluation of target volume coverage during prostate image-guided radiotherapy based on bony anatomy alignment.

    Science.gov (United States)

    Paluska, Petr; Hanus, Josef; Sefrova, Jana; Rouskova, Lucie; Grepl, Jakub; Jansa, Jan; Kasaova, Linda; Hodek, Miroslav; Zouhar, Milan; Vosmik, Milan; Petera, Jiri

    2012-01-01

    To assess target volume coverage during prostate image-guided radiotherapy based on bony anatomy alignment and to assess possibility of safety margin reduction. Implementation of IGRT should influence safety margins. Utilization of cone-beam CT provides current 3D anatomic information directly in irradiation position. Such information enables reconstruction of the actual dose distribution. Seventeen prostate patients were treated with daily bony anatomy image-guidance. Cone-beam CT (CBCT) scans were acquired once a week immediately after bony anatomy alignment. After the prostate, seminal vesicles, rectum and bladder were contoured, the delivered dose distribution was reconstructed. Target dose coverage was evaluated by the proportion of the CTV encompassed by the 95% isodose. Original plans employed a 1 cm safety margin. Alternative plans assuming a smaller 7 mm margin between CTV and PTV were evaluated in the same way. Rectal and bladder volumes were compared with the initial ones. Rectal and bladder volumes irradiated with doses higher than 75 Gy, 70 Gy, 60 Gy, 50 Gy and 40 Gy were analyzed. In 12% of reconstructed plans the prostate coverage was not sufficient. The prostate underdosage was observed in 5 patients. Coverage of seminal vesicles was not satisfactory in 3% of plans. Most of the target underdosage corresponded to excessive rectal or bladder filling. Evaluation of alternative plans assuming a smaller 7 mm margin revealed 22% and 11% of plans where prostate and seminal vesicles coverage, respectively, was compromised. These were distributed over 8 and 7 patients, respectively. Sufficient dose coverage of target volumes was not achieved for all patients. Reducing of safety margin is not acceptable. Initial rectal and bladder volumes cannot be considered representative for subsequent treatment.

  20. Strategy for alignment of electron beam trajectory in LEReC cooling section

    Energy Technology Data Exchange (ETDEWEB)

    Seletskiy, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kayran, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kewisch, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Michnoff, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pinayev, I. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-09-23

    We considered the steps required to align the electron beam trajectory through the LEReC cooling section. We devised a detailed procedure for the beam-based alignment of the cooling section solenoids. We showed that it is critical to have an individual control of each CS solenoid current. Finally, we modeled the alignment procedure and showed that with two BPM fitting the solenoid shift can be measured with 40 um accuracy and the solenoid inclination can be measured with 30 urad accuracy. These accuracies are well within the tolerances of the cooling section solenoid alignment.

  1. An optimal beam alignment method for large-scale distributed space surveillance radar system

    Science.gov (United States)

    Huang, Jian; Wang, Dongya; Xia, Shuangzhi

    2018-06-01

    Large-scale distributed space surveillance radar is a very important ground-based equipment to maintain a complete catalogue for Low Earth Orbit (LEO) space debris. However, due to the thousands of kilometers distance between each sites of the distributed radar system, how to optimally implement the Transmitting/Receiving (T/R) beams alignment in a great space using the narrow beam, which proposed a special and considerable technical challenge in the space surveillance area. According to the common coordinate transformation model and the radar beam space model, we presented a two dimensional projection algorithm for T/R beam using the direction angles, which could visually describe and assess the beam alignment performance. Subsequently, the optimal mathematical models for the orientation angle of the antenna array, the site location and the T/R beam coverage are constructed, and also the beam alignment parameters are precisely solved. At last, we conducted the optimal beam alignment experiments base on the site parameters of Air Force Space Surveillance System (AFSSS). The simulation results demonstrate the correctness and effectiveness of our novel method, which can significantly stimulate the construction for the LEO space debris surveillance equipment.

  2. UV beam shaper alignment sensitivity: grayscale versus binary designs

    Science.gov (United States)

    Lizotte, Todd E.

    2008-08-01

    What defines a good flat top beam shaper? What is more important; an ideal flat top profile or ease of alignment and stability? These are the questions designers and fabricators can not easily define, since they are a function of experience. Anyone can generate a theoretical beam shaper design and model it until it is clear that on paper the design looks good and meets the general needs of the end customer. However, the method of fabrication can add a twist that is not fully understood by either party until the beam shaper is actually tested for the first time in a system and also produced in high volume. This paper provides some insight into how grayscale and binary fabrication methods can produce the same style of beam shaper, with similar beam shaping performance; however provide a result wherein each fabricated design has separate degrees of sensitivity for alignment and stability. The paper will explain the design and fabrication approach for the two units and present alignment and testing data to provide a contrast comparison. Further data will show that over twenty sets of each fabricated design there is a consistency to the sensitivity issue. An understanding of this phenomenon is essential when considering the use of beam shapers on production equipment that is dedicated to producing micron-precision features within high value microelectronic and consumer products. We will present our findings and explore potential explanations and solutions.

  3. Alignment of the eight beams Octal 82 laser

    International Nuclear Information System (INIS)

    Josse, Michel.

    1982-10-01

    The OCTAL 82 laser facility is a Neodymium glass laser system, recently put in operation at Limeil, France. It is designed to create high energy light beams during very short periods of time in the nanosecond range and shorter, in order to irradiate and compress microscopic fusion targets to extremely high densities. The alignment is undertaken in two stages, each using a telescope with vidicon detectors connected to a real time computer named ''CENTROIDE'' which displays the digitized image on a color TV screen. First, a refracting telescope is used to inject the front-end beam into the preamplifier assembly and to align all its optical components. Second, a reflecting telescope and ten insertable mirrors are used to align the eight individual power chains and the beam splitter arrays. The alignment method works with a manually controlled closed loop which is the most flexible approach that can meet our dual objectives of reliability and accuracy. The over all alignment of OCTAL 82 was first completed in may 1982 and since that time only minor routine realignments have been made, thereby proving the feasibility of the method

  4. Anomalous foreshock field-aligned beams observed by Cluster

    Directory of Open Access Journals (Sweden)

    K. Meziane

    2011-10-01

    Full Text Available We report occasional observations of two simultaneously distinct ion foreshock components recorded by the Cluster spacecraft upstream of the Earth's bow shock. In most occurrences, the lower-energy population originates as a field-aligned beam (FAB associated with quasi-perpendicular regions, which loses energy as the IMF rotates into oblique geometries. A second beam, with energies in excess of ~10 keV, appears sometimes in association with the onset of ultra-low frequency (ULF waves, and sometimes ahead of the appearance of the latter. Measurements from the mass spectrometer indicate that both beams consist of protons. While the lower-speed beam is well-accounted for by a known reflection mechanism, the non-radial IMF orientations as well as other arguments seem to rule out magnetosheath or magnetospheric sources for the higher energy component. The wave characteristics are typical of the oblique foreshock and we have found that they are in cyclotron-resonance with the low speed beam (FAB. These observations constitute a theoretical challenge since conventional mechanisms described in the literature cannot account for the production of beams at two different energies.

  5. Development and Beam Tests of an Automatic Algorithm for Alignment of LHC Collimators with Embedded BPMs

    CERN Document Server

    Valentino, G; Gasior, M; Mirarchi, D; Nosych, A A; Redaelli, S; Salvachua, B; Assmann, R W; Sammut, N

    2013-01-01

    Collimators with embedded Beam Position Monitor (BPM) buttons will be installed in the LHC during the upcoming long shutdown period. During the subsequent operation, the BPMs will allow the collimator jaws to be kept centered around the beam trajectory. In this manner, the best possible beam cleaning efficiency and machine protection can be provided at unprecedented higher beam energies and intensities. A collimator alignment algorithm is proposed to center the jaws automatically around the beam. The algorithm is based on successive approximation, as the BPM measurements are affected by non-linearities, which vary with the distance between opposite buttons, as well as the difference between the beam and the jaw centers. The successful test results, as well as some considerations for eventual operation in the LHC are also presented.

  6. SRF cavity alignment detection method using beam-induced HOM with curved beam orbit

    Science.gov (United States)

    Hattori, Ayaka; Hayano, Hitoshi

    2017-09-01

    We have developed a method to obtain mechanical centers of nine cell superconducting radio frequency (SRF) cavities from localized dipole modes, that is one of the higher order modes (HOM) induced by low-energy beams. It is to be noted that low-energy beams, which are used as alignment probes, are easy to bend in fringe fields of accelerator cavities. The estimation of the beam passing orbit is important because only information about the beam positions measured by beam position monitors outside the cavities is available. In this case, the alignment information about the cavities can be obtained by optimizing the parameters of the acceleration components over the beam orbit simulation to consistently represent the position of the beam position monitors measured at every beam sweep. We discuss details of the orbit estimation method, and estimate the mechanical center of the localized modes through experiments performed at the STF accelerator. The mechanical center is determined as (x , y) =(0 . 44 ± 0 . 56 mm , - 1 . 95 ± 0 . 40 mm) . We also discuss the error and the applicable range of this method.

  7. Fast Beam-Based BPM Calibration

    International Nuclear Information System (INIS)

    Bertsche, Kirk

    2012-01-01

    The Alignment Diagnostic System (ADS) of the LCLS undulator system indicates that the 33 undulator quadrupoles have extremely high position stability over many weeks. However, beam trajectory straightness and lasing efficiency degrade more quickly than this. A lengthy Beam Based Alignment (BBA) procedure must be executed every two to four weeks to re-optimize the X-ray beam parameters. The undulator system includes RF cavity Beam Position Monitors (RFBPMs), several of which are utilized by an automatic feedback system to align the incoming electron-beam trajectory to the undulator axis. The beam trajectory straightness degradation has been traced to electronic drifts of the gain and offset of the BPMs used in the beam feedback system. To quickly recover the trajectory straightness, we have developed a fast beam-based procedure to recalibrate the BPMs. This procedure takes advantage of the high-precision monitoring capability of the ADS, which allows highly repeatable positioning of undulator quadrupoles. This report describes the ADS, the position stability of the LCLS undulator quadrupoles, and some results of the new recovery procedure.

  8. Image-guided small animal radiation research platform: calibration of treatment beam alignment

    International Nuclear Information System (INIS)

    Matinfar, Mohammad; Iordachita, Iulian; Kazanzides, Peter; Ford, Eric; Wong, John

    2009-01-01

    Small animal research allows detailed study of biological processes, disease progression and response to therapy with the potential to provide a natural bridge to the clinical environment. The small animal radiation research platform (SARRP) is a portable system for precision irradiation with beam sizes down to approximately 0.5 mm and optimally planned radiation with on-board cone-beam CT (CBCT) guidance. This paper focuses on the geometric calibration of the system for high-precision irradiation. A novel technique for the calibration of the treatment beam is presented, which employs an x-ray camera whose precise positioning need not be known. Using the camera system we acquired a digitally reconstructed 3D 'star shot' for gantry calibration and then developed a technique to align each beam to a common isocenter with the robotic animal positioning stages. The calibration incorporates localization by cone-beam CT guidance. Uncorrected offsets of the beams with respect to the calibration origin ranged from 0.4 mm to 5.2 mm. With corrections, these alignment errors can be reduced to the sub-millimeter range. The calibration technique was used to deliver a stereotactic-like arc treatment to a phantom constructed with EBT Gafchromic films. All beams were shown to intersect at a common isocenter with a measured beam (FWHM) of approximately 1.07 mm using the 0.5 mm collimated beam. The desired positioning accuracy of the SARRP is 0.25 mm and the results indicate an accuracy of 0.2 mm. To fully realize the radiation localization capabilities of the SARRP, precise geometric calibration is required, as with any such system. The x-ray camera-based technique presented here provides a straightforward and semi-automatic method for system calibration.

  9. Comparative genomics beyond sequence-based alignments

    DEFF Research Database (Denmark)

    Þórarinsson, Elfar; Yao, Zizhen; Wiklund, Eric D.

    2008-01-01

    Recent computational scans for non-coding RNAs (ncRNAs) in multiple organisms have relied on existing multiple sequence alignments. However, as sequence similarity drops, a key signal of RNA structure--frequent compensating base changes--is increasingly likely to cause sequence-based alignment me...

  10. MICA: Multiple interval-based curve alignment

    Science.gov (United States)

    Mann, Martin; Kahle, Hans-Peter; Beck, Matthias; Bender, Bela Johannes; Spiecker, Heinrich; Backofen, Rolf

    2018-01-01

    MICA enables the automatic synchronization of discrete data curves. To this end, characteristic points of the curves' shapes are identified. These landmarks are used within a heuristic curve registration approach to align profile pairs by mapping similar characteristics onto each other. In combination with a progressive alignment scheme, this enables the computation of multiple curve alignments. Multiple curve alignments are needed to derive meaningful representative consensus data of measured time or data series. MICA was already successfully applied to generate representative profiles of tree growth data based on intra-annual wood density profiles or cell formation data. The MICA package provides a command-line and graphical user interface. The R interface enables the direct embedding of multiple curve alignment computation into larger analyses pipelines. Source code, binaries and documentation are freely available at https://github.com/BackofenLab/MICA

  11. Beam plug replacement and alignment under high radiation conditions for cold neutron facilities at Hanaro

    International Nuclear Information System (INIS)

    Yeong-Garp, Cho; Jin-Won, Shin; Jung-Hee, Lee; Jeong-Soo, Ryu

    2010-01-01

    Full text : The HANARO, an open-tank-in-pool type research reactor of a 30 MWth power in Korea, has been operating for 15 years since its initial criticality in February 1995. The beam port assigned for the cold neutron at HANARO had been used for an 8-m SANS without neutron guides until it was replaced by a cold neutron guide system in 2008. It was developed a cold neutron guide system for the delivery of cold neutrons from the cold neutron source in the reactor to the neutron scattering instruments in the guide hall. Since the HANARO has been operated from 1995, it was a big challenge to replace the existing plug and shutter with the new facilities under high radiation conditions. When the old plug was removed from the beam port in 2008, the radiation level was 230 mSv/hr at the end of beam port. In addition to that, there were more difficult situations such as the poor as-built dimensions of the beam port, limited work space and time constraint due to other constructions in parallel in the reactor hall. Before the removal of the old plug the level of the radiation was measured coming out through a small hole of the plug to estimate the radiation level during the removal of the old plug and installation of a new plug. Based on the measurement and analysis results, special tools and various shielding facilities were developed for the removal of old in-pile plug and the installation of the new in-pile plug assembly safely. In 2008, the old plug and shutter were successfully replaced by the new plug and shutter as shown in this article with a minimum exposure to the workers. A laser tracker system was also one of the main factors in our successful installation and alignment under high radiation conditions and limited work space. The laser tracker was used to measure and align all the mechanical facilities and the neutron guides with a minimum radiation exposure to workers. The alignment of all the guides and accessories were possible during reactor operation because

  12. Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations

    International Nuclear Information System (INIS)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2011-01-01

    A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid or angle is measured, then accurate alignment is provided by minimizing laser centroid motion at the channel exit as the channel properties are scanned. The improvement in alignment accuracy provided by this technique is important for minimizing electron beam pointing errors in laser plasma accelerators.

  13. THE ATLAS INNER DETECTOR TRACK BASED ALIGNMENT

    CERN Document Server

    Marti i Garcia, Salvador; The ATLAS collaboration

    2018-01-01

    The alignment of the ATLAS Inner Detector is performed with a track-based alignment algorithm. Its goal is to provide an accurate description of the detector geometry such that track parameters are accurately determined and free from biases. Its software implementation is modular and configurable, with a clear separation of the alignment algorithm from the detector system specifics and the database handling. The alignment must cope with the rapid movements of the detector as well as with the slow drift of the different mechanical units. Prompt alignment constants are derived for every run at the calibration stage. These sets of constants are then dynamically split from the beginning of the run in many chunks, allowing to describe the tracker geometry as it evolves with time. The alignment of the Inner Detector is validated and improved by studying resonance decays (Z and J/psi to mu+mu-), as well as using information from the calorimeter system with the E/p method with electrons. A detailed study of these res...

  14. Minimal-effort planning of active alignment processes for beam-shaping optics

    Science.gov (United States)

    Haag, Sebastian; Schranner, Matthias; Müller, Tobias; Zontar, Daniel; Schlette, Christian; Losch, Daniel; Brecher, Christian; Roßmann, Jürgen

    2015-03-01

    In science and industry, the alignment of beam-shaping optics is usually a manual procedure. Many industrial applications utilizing beam-shaping optical systems require more scalable production solutions and therefore effort has been invested in research regarding the automation of optics assembly. In previous works, the authors and other researchers have proven the feasibility of automated alignment of beam-shaping optics such as collimation lenses or homogenization optics. Nevertheless, the planning efforts as well as additional knowledge from the fields of automation and control required for such alignment processes are immense. This paper presents a novel approach of planning active alignment processes of beam-shaping optics with the focus of minimizing the planning efforts for active alignment. The approach utilizes optical simulation and the genetic programming paradigm from computer science for automatically extracting features from a simulated data basis with a high correlation coefficient regarding the individual degrees of freedom of alignment. The strategy is capable of finding active alignment strategies that can be executed by an automated assembly system. The paper presents a tool making the algorithm available to end-users and it discusses the results of planning the active alignment of the well-known assembly of a fast-axis collimator. The paper concludes with an outlook on the transferability to other use cases such as application specific intensity distributions which will benefit from reduced planning efforts.

  15. Beam-Based Procedures for RF Guns

    CERN Document Server

    Krasilnikov, Mikhail; Grabosch, H J; Hartrott, Michael; Hui Han, Jang; Miltchev, Velizar; Oppelt, Anne; Petrosyan, Bagrat; Staykov, Lazar; Stephan, Frank

    2005-01-01

    A wide range of rf photo injector parameters has to be optimized in order to achieve an electron source performance as required for linac based high gain FELs. Some of the machine parameters can not be precisely controlled by direct measurements, whereas the tolerance on them is extremely tight. Therefore, this should be met with beam-based techniques. Procedures for beam-based alignment (BBA) of the laser on the photo cathode as well as solenoid alignment have been developed. They were applied at the Photo Injector Test facility at DESY Zeuthen (PITZ) and at the photo injector of the VUV-FEL at DESY Hamburg. A field balance of the accelerating mode in the 1 ½ cell gun cavity is one of the key beam dynamics issues of the rf gun. Since no direct field measurement in the half and full cell of the cavity is available for the PITZ gun, a beam-based technique to determine the field balance has been proposed. A beam-based rf phase monitoring procedure has been developed as well.

  16. Alignment of the CMS Muon System with Cosmic-Ray and Beam-Halo Muons

    CERN Document Server

    Chatrchyan, S; Sirunyan, A M; Adam, W; Arnold, B; Bergauer, H; Bergauer, T; Dragicevic, M; Eichberger, M; Erö, J; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hänsel, S; Hoch, M; Hörmann, N; Hrubec, J; Jeitler, M; Kasieczka, G; Kastner, K; Krammer, M; Liko, D; Magrans de Abril, I; Mikulec, I; Mittermayr, F; Neuherz, B; Oberegger, M; Padrta, M; Pernicka, M; Rohringer, H; Schmid, S; Schöfbeck, R; Schreiner, T; Stark, R; Steininger, H; Strauss, J; Taurok, A; Teischinger, F; Themel, T; Uhl, D; Wagner, P; Waltenberger, W; Walzel, G; Widl, E; Wulz, C E; Chekhovsky, V; Dvornikov, O; Emeliantchik, I; Litomin, A; Makarenko, V; Marfin, I; Mossolov, V; Shumeiko, N; Solin, A; Stefanovitch, R; Suarez Gonzalez, J; Tikhonov, A; Fedorov, A; Karneyeu, A; Korzhik, M; Panov, V; Zuyeuski, R; Kuchinsky, P; Beaumont, W; Benucci, L; Cardaci, M; De Wolf, E A; Delmeire, E; Druzhkin, D; Hashemi, M; Janssen, X; Maes, T; Mucibello, L; Ochesanu, S; Rougny, R; Selvaggi, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Adler, V; Beauceron, S; Blyweert, S; D'Hondt, J; De Weirdt, S; Devroede, O; Heyninck, J; Kalogeropoulos, A; Maes, J; Maes, M; Mozer, M U; Tavernier, S; Van Doninck, W; Van Mulders, P; Villella, I; Bouhali, O; Chabert, E C; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Elgammal, S; Gay, A P R; Hammad, G H; Marage, P E; Rugovac, S; Vander Velde, C; Vanlaer, P; Wickens, J; Grunewald, M; Klein, B; Marinov, A; Ryckbosch, D; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Basegmez, S; Bruno, G; Caudron, J; Delaere, C; Demin, P; Favart, D; Giammanco, A; Grégoire, G; Lemaitre, V; Militaru, O; Ovyn, S; Piotrzkowski, K; Quertenmont, L; Schul, N; Beliy, N; Daubie, E; Alves, G A; Pol, M E; Souza, M H G; Carvalho, W; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Mundim, L; Oguri, V; Santoro, A; Silva Do Amaral, S M; Sznajder, A; Fernandez Perez Tomei, T R; Ferreira Dias, M A; Gregores, E M; Novaes, S F; Abadjiev, K; Anguelov, T; Damgov, J; Darmenov, N; Dimitrov, L; Genchev, V; Iaydjiev, P; Piperov, S; Stoykova, S; Sultanov, G; Trayanov, R; Vankov, I; Dimitrov, A; Dyulendarova, M; Kozhuharov, V; Litov, L; Marinova, E; Mateev, M; Pavlov, B; Petkov, P; Toteva, Z; Chen, G M; Chen, H S; Guan, W; Jiang, C H; Liang, D; Liu, B; Meng, X; Tao, J; Wang, J; Wang, Z; Xue, Z; Zhang, Z; Ban, Y; Cai, J; Ge, Y; Guo, S; Hu, Z; Mao, Y; Qian, S J; Teng, H; Zhu, B; Avila, C; Baquero Ruiz, M; Carrillo Montoya, C A; Gomez, A; Gomez Moreno, B; Ocampo Rios, A A; Osorio Oliveros, A F; Reyes Romero, D; Sanabria, J C; Godinovic, N; Lelas, K; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Dzelalija, M; Brigljevic, V; Duric, S; Kadija, K; Morovic, S; Fereos, R; Galanti, M; Mousa, J; Papadakis, A; Ptochos, F; Razis, P A; Tsiakkouri, D; Zinonos, Z; Hektor, A; Kadastik, M; Kannike, K; Müntel, M; Raidal, M; Rebane, L; Anttila, E; Czellar, S; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Klem, J; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; 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Avery, P; Barashko, V; Bourilkov, D; Chen, M; Di Giovanni, G P; Dobur, D; Drozdetskiy, A; Field, R D; Fu, Y; Furic, I K; Gartner, J; Holmes, D; Kim, B; Klimenko, S; Konigsberg, J; Korytov, A; Kotov, K; Kropivnitskaya, A; Kypreos, T; Madorsky, A; Matchev, K; Mitselmakher, G; Pakhotin, Y; Piedra Gomez, J; Prescott, C; Rapsevicius, V; Remington, R; Schmitt, M; Scurlock, B; Wang, D; Yelton, J; Ceron, C; Gaultney, V; Kramer, L; Lebolo, L M; Linn, S; Markowitz, P; Martinez, G; Rodriguez, J L; Adams, T; Askew, A; Baer, H; Bertoldi, M; Chen, J; Dharmaratna, W G D; Gleyzer, S V; Haas, J; Hagopian, S; Hagopian, V; Jenkins, M; Johnson, K F; Prettner, E; Prosper, H; Sekmen, S; Baarmand, M M; Guragain, S; Hohlmann, M; Kalakhety, H; Mermerkaya, H; Ralich, R; Vodopiyanov, I; Abelev, B; Adams, M R; Anghel, I M; Apanasevich, L; Bazterra, V E; Betts, R R; Callner, J; Castro, M A; Cavanaugh, R; Dragoiu, C; Garcia-Solis, E J; Gerber, C E; Hofman, D J; Khalatian, S; Mironov, C; Shabalina, E; Smoron, A; Varelas, N; Akgun, U; Albayrak, E A; Ayan, A S; Bilki, B; Briggs, R; Cankocak, K; Chung, K; Clarida, W; Debbins, P; Duru, F; Ingram, F D; Lae, C K; McCliment, E; Merlo, J P; Mestvirishvili, A; Miller, M J; Moeller, A; Nachtman, J; Newsom, C R; Norbeck, E; Olson, J; Onel, Y; Ozok, F; Parsons, J; Schmidt, I; Sen, S; Wetzel, J; Yetkin, T; Yi, K; Barnett, B A; Blumenfeld, B; Bonato, A; Chien, C Y; Fehling, D; Giurgiu, G; Gritsan, A V; Guo, Z J; Maksimovic, P; Rappoccio, S; Swartz, M; Tran, N V; Zhang, Y; Baringer, P; Bean, A; Grachov, O; Murray, M; Radicci, V; Sanders, S; Wood, J S; Zhukova, V; Bandurin, D; Bolton, T; Kaadze, K; Liu, A; Maravin, Y; Onoprienko, D; Svintradze, I; Wan, Z; Gronberg, J; Hollar, J; Lange, D; Wright, D; Baden, D; Bard, R; Boutemeur, M; Eno, S C; Ferencek, D; Hadley, N J; Kellogg, R G; Kirn, M; Kunori, S; Rossato, K; Rumerio, P; Santanastasio, F; Skuja, A; Temple, J; Tonjes, M B; Tonwar, S C; Toole, T; Twedt, E; Alver, B; Bauer, G; Bendavid, J; Busza, W; Butz, E; Cali, I A; Chan, M; D'Enterria, D; Everaerts, P; Gomez Ceballos, G; Hahn, K A; Harris, P; Jaditz, S; Kim, Y; Klute, M; Lee, Y J; Li, W; Loizides, C; Ma, T; Miller, M; Nahn, S; Paus, C; Roland, C; Roland, G; Rudolph, M; Stephans, G; Sumorok, K; Sung, K; Vaurynovich, S; Wenger, E A; Wyslouch, B; Xie, S; Yilmaz, Y; Yoon, A S; Bailleux, D; Cooper, S I; Cushman, P; Dahmes, B; De Benedetti, A; Dolgopolov, A; Dudero, P R; Egeland, R; Franzoni, G; Haupt, J; Inyakin, A; Klapoetke, K; Kubota, Y; Mans, J; Mirman, N; Petyt, D; Rekovic, V; Rusack, R; Schroeder, M; Singovsky, A; Zhang, J; Cremaldi, L M; Godang, R; Kroeger, R; Perera, L; Rahmat, R; Sanders, D A; Sonnek, P; Summers, D; Bloom, K; Bockelman, B; Bose, S; Butt, J; Claes, D R; Dominguez, A; Eads, M; Keller, J; Kelly, T; Kravchenko, I; Lazo-Flores, J; Lundstedt, C; Malbouisson, H; Malik, S; Snow, G R; Baur, U; Iashvili, I; Kharchilava, A; Kumar, A; Smith, K; Strang, M; Alverson, G; Barberis, E; Boeriu, O; Eulisse, G; Govi, G; McCauley, T; Musienko, Y; Muzaffar, S; Osborne, I; Paul, T; Reucroft, S; Swain, J; Taylor, L; Tuura, L; Anastassov, A; Gobbi, B; Kubik, A; Ofierzynski, R A; Pozdnyakov, A; Schmitt, M; Stoynev, S; Velasco, M; Won, S; Antonelli, L; Berry, D; Hildreth, M; Jessop, C; Karmgard, D J; Kolberg, T; Lannon, K; Lynch, S; Marinelli, N; Morse, D M; Ruchti, R; Slaunwhite, J; Warchol, J; Wayne, M; Bylsma, B; Durkin, L S; Gilmore, J; Gu, J; Killewald, P; Ling, T Y; Williams, G; Adam, N; Berry, E; Elmer, P; Garmash, A; Gerbaudo, D; Halyo, V; Hunt, A; Jones, J; Laird, E; Marlow, D; Medvedeva, T; Mooney, M; Olsen, J; Piroué, P; Stickland, D; Tully, C; Werner, J S; Wildish, T; Xie, Z; Zuranski, A; Acosta, J G; Bonnett Del Alamo, M; Huang, X T; Lopez, A; Mendez, H; Oliveros, S; Ramirez Vargas, J E; Santacruz, N; Zatzerklyany, A; Alagoz, E; Antillon, E; Barnes, V E; Bolla, G; Bortoletto, D; Everett, A; Garfinkel, A F; Gecse, Z; Gutay, L; Ippolito, N; Jones, M; Koybasi, O; Laasanen, A T; Leonardo, N; Liu, C; Maroussov, V; Merkel, P; Miller, D H; Neumeister, N; Sedov, A; Shipsey, I; Yoo, H D; Zheng, Y; Jindal, P; Parashar, N; Cuplov, V; Ecklund, K M; Geurts, F J M; Liu, J H; Maronde, D; Matveev, M; Padley, B P; Redjimi, R; Roberts, J; Sabbatini, L; Tumanov, A; Betchart, B; Bodek, A; Budd, H; Chung, Y S; de Barbaro, P; Demina, R; Flacher, H; Gotra, Y; Harel, A; Korjenevski, S; Miner, D C; Orbaker, D; Petrillo, G; Vishnevskiy, D; Zielinski, M; Bhatti, A; Demortier, L; Goulianos, K; Hatakeyama, K; Lungu, G; Mesropian, C; Yan, M; Atramentov, O; Bartz, E; Gershtein, Y; Halkiadakis, E; Hits, D; Lath, A; Rose, K; Schnetzer, S; Somalwar, S; Stone, R; Thomas, S; Watts, T L; Cerizza, G; Hollingsworth, M; Spanier, S; Yang, Z C; York, A; Asaadi, J; Aurisano, A; Eusebi, R; Golyash, A; Gurrola, A; Kamon, T; Nguyen, C N; Pivarski, J; Safonov, A; Sengupta, S; Toback, D; Weinberger, M; Akchurin, N; Berntzon, L; Gumus, K; Jeong, C; Kim, H; Lee, S W; Popescu, S; Roh, Y; Sill, A; Volobouev, I; Washington, E; Wigmans, R; Yazgan, E; Engh, D; Florez, C; Johns, W; Pathak, S; Sheldon, P; Andelin, D; Arenton, M W; Balazs, M; Boutle, S; Buehler, M; Conetti, S; Cox, B; Hirosky, R; Ledovskoy, A; Neu, C; Phillips II, D; Ronquest, M; Yohay, R; Gollapinni, S; Gunthoti, K; Harr, R; Karchin, P E; Mattson, M; Sakharov, A; Anderson, M; Bachtis, M; Bellinger, J N; Carlsmith, D; Crotty, I; Dasu, S; Dutta, S; Efron, J; Feyzi, F; Flood, K; Gray, L; Grogg, K S; Grothe, M; Hall-Wilton, R; Jaworski, M; Klabbers, P; Klukas, J; Lanaro, A; Lazaridis, C; Leonard, J; Loveless, R; Magrans de Abril, M; Mohapatra, A; Ott, G; Polese, G; Reeder, D; Savin, A; Smith, W H; Sourkov, A; Swanson, J; Weinberg, M; Wenman, D; Wensveen, M; White, A

    2010-01-01

    The CMS muon system has been aligned using cosmic-ray muons collected in 2008 and beam-halo muons from the 2008 LHC circulating beam tests. After alignment, the resolution of the most sensitive coordinate is 80 microns for the relative positions of superlayers in the same barrel chamber and 270 microns for the relative positions ofendcap chambers in the same ring structure. The resolution on the position of the central barrel chambers relative to the tracker is comprised between two extreme estimates, 200 and 700 microns, provided by two complementary studies. With minor modifications, the alignment procedures can be applied using muons from LHC collisions, leading to additional significant improvements.

  17. Survey, alignment, and beam stability at the Advanced Light Source

    International Nuclear Information System (INIS)

    Krebs, G.F.

    1997-10-01

    This paper describes survey and alignment at the Lawrence Berkeley Laboratories Advanced Light Source (ALS) accelerators from 1993 to 1997. The ALS is a third generation light source requiring magnet alignment to within 150 microns. To accomplish this, a network of monuments was established and maintained. Monthly elevation surveys show the movement of the floor over time. Inclinometers have recently been employed to give real time information about magnet, vacuum tank and magnet girder motion in the ALS storage ring

  18. Unsupervised image matching based on manifold alignment.

    Science.gov (United States)

    Pei, Yuru; Huang, Fengchun; Shi, Fuhao; Zha, Hongbin

    2012-08-01

    This paper challenges the issue of automatic matching between two image sets with similar intrinsic structures and different appearances, especially when there is no prior correspondence. An unsupervised manifold alignment framework is proposed to establish correspondence between data sets by a mapping function in the mutual embedding space. We introduce a local similarity metric based on parameterized distance curves to represent the connection of one point with the rest of the manifold. A small set of valid feature pairs can be found without manual interactions by matching the distance curve of one manifold with the curve cluster of the other manifold. To avoid potential confusions in image matching, we propose an extended affine transformation to solve the nonrigid alignment in the embedding space. The comparatively tight alignments and the structure preservation can be obtained simultaneously. The point pairs with the minimum distance after alignment are viewed as the matchings. We apply manifold alignment to image set matching problems. The correspondence between image sets of different poses, illuminations, and identities can be established effectively by our approach.

  19. Beam geometry, alignment, and wavefront aberration effects on interferometric differential wavefront sensing

    International Nuclear Information System (INIS)

    Yu, Xiangzhi; Gillmer, S R; Ellis, J D

    2015-01-01

    Heterodyne interferometry is a widely accepted methodology with high resolution in many metrology applications. As a functionality enhancement, differential wavefront sensing (DWS) enables simultaneous measurement of displacement, pitch, and yaw using a displacement interferometry system and a single beam incident on a plane mirror target. The angular change is measured using a weighted phase average between symmetrically adjacent quadrant photodiode pairs. In this paper, we present an analytical model to predict the scaling of differential phase signals based on fundamental Gaussian beams. Several numerical models are presented to discuss the effects of physical beam parameters, detector size, system alignment errors, and beam wavefront aberrations on the DWS technique. The results of our modeling predict rotational scaling factors and a usable linear range. Furthermore, experimental results show the analytically predicted scaling factor is in good agreement with empirical calibration. Our three degree-of-freedom interferometer can achieve a resolution of 0.4 nm in displacement and 0.2 μrad in pitch and yaw simultaneously. (paper)

  20. Opto-mechanical devices for the Antares automatic beam alignment system

    International Nuclear Information System (INIS)

    Swann, T.; Combs, C.; Witt, J.

    1981-01-01

    Antares is a 24-beam CO 2 laser system for controlled fusion research, under construction at Los Alamos National Laboratory. Rapid automatic alignment of this system is required prior to each experimental shot. Unique opto-mechanical alignment devices, which have been developed specifically for this automatic alignment system, are discussed. A variable focus alignment telescope views point light sources. A beam expander/spatial filter processes both a visible Krypton Ion and a 10.6 μm CO 2 alignment laser. The periscope/carousel device provides the means by which the alignment telescope can sequentially view each of twelve optical trains in each power amplifier. The polyhedron alignment device projects a point-light source for both centering and pointing alignment at the polyhedron mirror. The rotating wedge alignment device provides a sequencing point-light source and also compensates for dispersion between visible and 10.6 μm radiation. The back reflector flip in remotely positions point-light sources at the back reflector mirrors. A light source box illuminates optic fibers with high intensity white light which is distributed to the various point-light sources in the system

  1. SU-E-J-24: Image-Guidance Using Cone-Beam CT for Stereotactic Body Radiotherapy (SBRT) of Lung Cancer Patients: Bony Alignment or Soft Tissue Alignment?

    Science.gov (United States)

    Wang, L; Turaka, A; Meyer, J; Spoka, D; Jin, L; Fan, J; Ma, C

    2012-06-01

    To assess the reliability of soft tissue alignment by comparing pre- and post-treatment cone-beam CT (CBCT) for image guidance in stereotactic body radiotherapy (SBRT) of lung cancers. Our lung SBRT procedures require all patients undergo 4D CT scan in order to obtain patient-specific target motion information through reconstructed 4D data using the maximum-intensity projection (MIP) algorithm. The internal target volume (ITV) was outlined directly from the MIP images and a 3-5 mm margin expansion was then applied to the ITV to create the PTV. Conformal treatment planning was performed on the helical images, to which the MIP images were fused. Prior to each treatment, CBCT was used for image guidance by comparing with the simulation CT and for patient relocalization based on the bony anatomy. Any displacement of the patient bony structure would be considered as setup errors and would be corrected by couch shifts. Theoretically, as the PTV definition included target internal motion, no further shifts other than setup corrections should be made. However, it is our practice to have treating physicians further check target localization within the PTV. Whenever the shifts based on the soft-tissue alignment (that is, target alignment) exceeded a certain value (e.g. 5 mm), a post-treatment CBCT was carried out to ensure that the tissue alignment is reliable by comparing between pre- and post-treatment CBCT. Pre- and post-CBCT has been performed for 7 patients so far who had shifts beyond 5 mm despite bony alignment. For all patients, post CBCT confirmed that the visualized target position was kept in the same position as before treatment after adjusting for soft-tissue alignment. For the patient population studied, it is shown that soft-tissue alignment is necessary and reliable in the lung SBRT for individual cases. © 2012 American Association of Physicists in Medicine.

  2. Triangular Alignment (TAME). A Tensor-based Approach for Higher-order Network Alignment

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, Shahin [Purdue Univ., West Lafayette, IN (United States); Gleich, David F. [Purdue Univ., West Lafayette, IN (United States); Kolda, Tamara G. [Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Grama, Ananth [Purdue Univ., West Lafayette, IN (United States)

    2015-11-01

    Network alignment is an important tool with extensive applications in comparative interactomics. Traditional approaches aim to simultaneously maximize the number of conserved edges and the underlying similarity of aligned entities. We propose a novel formulation of the network alignment problem that extends topological similarity to higher-order structures and provide a new objective function that maximizes the number of aligned substructures. This objective function corresponds to an integer programming problem, which is NP-hard. Consequently, we approximate this objective function as a surrogate function whose maximization results in a tensor eigenvalue problem. Based on this formulation, we present an algorithm called Triangular AlignMEnt (TAME), which attempts to maximize the number of aligned triangles across networks. We focus on alignment of triangles because of their enrichment in complex networks; however, our formulation and resulting algorithms can be applied to general motifs. Using a case study on the NAPABench dataset, we show that TAME is capable of producing alignments with up to 99% accuracy in terms of aligned nodes. We further evaluate our method by aligning yeast and human interactomes. Our results indicate that TAME outperforms the state-of-art alignment methods both in terms of biological and topological quality of the alignments.

  3. Alignment and orientation effects in beam-foil experiments

    International Nuclear Information System (INIS)

    Band, Y.B.

    1975-01-01

    A theory of the orientation and alignment of atoms observed upon emergence from tilted foils is presented. The interaction with the foil surface is taken into account in the production process of particular states. Once they are produced, the evolution of these states, under the influence of the residual field near the surface, is calculated in the fashion introduced by Eck. The most general effect of this evolution is presented

  4. Final focus test beam alignment: A draft proposal

    International Nuclear Information System (INIS)

    Fischer, G.E.; Ruland, R.E.

    1989-03-01

    The Final Focus Test Beam is a transport line designed to transmit 50 GeV electron beams of SLC emittance (3 x 10 -10 radian-meters) straight through the central arm of the Beam Switchyard (BSY C line) with a final focus point out in the Research Yard but relatively near the end of the switchyard tunnel. The hardware, methods and procedures outlined in this proposal are dedicated to measuring the placement of mechanical objects with respect to certain defined geometric axes. We wish to emphasize that the very difficult problems of locating the effective magnetic axes of focusing elements, the effective electrical center of beam position monitors and even the effective axis of the incident beam relative to mechanical reference surfaces is outside the scope of this work. Further, this proposal is restricted to the act of measurement and does not consider the vital task of on-line mechanical repositioning of elements that will, in likelihood, be called upon during operation of the system. 16 refs., 16 figs., 4 tabs

  5. Study and Development of a Laser Based Alignment System

    CERN Multimedia

    Stern, G

    2014-01-01

    CLIC (Compact Linear Collider) has tight requirements regarding pre-alignment of beam related components: 10 µm accuracy over a sliding window of 200 m along the 20 km of linac. To perform such an alignment, a new system is proposed combining laser beam as straight line reference and camera/shutter assemblies as sensors. The poster describes the alignment system and shows results regarding laser pointing stability with respect to time, shutter type, distance and environment. These results give a frame for future building and calibrating of sensors.

  6. Feasibility study of multipoint based laser alignment system for CLIC

    CERN Document Server

    Stern, G; Mainaud-Durand, H; Piedigrossi, D; Geiger, A

    2012-01-01

    CLIC (Compact LInear Collider) is a study for a future electron-positron collider that would allow physicists to explore a new energy region beyond the capabilities oftoday’s particle accelerators. Alignment is one of the major challenges within the CLIC study in order to achieve the high requirement of a multi-TeV center of mass colliding beam energy range (nominal 3 TeV). To reach this energy in a realistic and cost efficient scenario all accelerator components have to be aligned with an accuracy of 10 μm over a sliding window of 200 m. The demand for a straight line reference is so far based on stretched wires coupled with Wire Positioning Sensors (WPS). These solutions are currently further developed inorder to reduce the drawbacks which are mainly given by their costs and difficult implementation. However, it should be validated through inter-comparison with a solution ideally based on a different physical principle. Therefore, a new metrological approach is proposed using a laser beam as straight lin...

  7. Ion beam alignment in the MSX-4 mass spectrometer

    International Nuclear Information System (INIS)

    Busygin, A.I.; Nevzorov, A.A.; Ul'masbaev, B.Sh.

    1977-01-01

    A method for electrically adjusting an ion beam in an MSKh-4 mass-spectrometer has been developed. The adjusting system consists of two deflecting plates fastened to the frame of the ion source. By adjusting the potential difference at the plates in the range 0-150 v, one can increase the intensity of the mass-spectrum by a factor of 3 to 5

  8. Conception and realisation of a system for the automatic alignment of a CO2 laser beam

    International Nuclear Information System (INIS)

    Mardon, Nathalie

    1983-01-01

    The present paper deals with the continuous control of the direction of a CO 2 laser beam, with a view to laser machining. Slow deviations, due to the cavity instability, move away the beam from the focusing system axis. An automatic alignment device acting on the last flat mirror of the optical line has been designed. This mirror is actuated by 2 motors which vary its inclination in 2 directions x,y. The first part of the present paper deals with the alignment principle worked according to the specific constraints to be faced and to the characteristics of the beam. It uses the revolution symmetry of the energy distribution of the beam: 4 thermocouples surrounding the beam on a same circumference yield equals signals if the beam is centered onto the 4 sensors. An angular displacement is characterised by the difference between the signals of 2 opposed detectors. The second part presents the digital feedback system: the divergence or the beam is computed from the differential signal by a coefficient K experimentally valued. The motor commands proceed from optical geometry laws. The filtering of the thermocouple signals is necessary in order to sort the slowly changing signal related to the beam displacement, from the higher frequency signal related to the laser system instability. The system has been implemented on a 16 bit microprocessor. (author) [fr

  9. An improved Hough transform-based fingerprint alignment approach

    CSIR Research Space (South Africa)

    Mlambo, CS

    2014-11-01

    Full Text Available An improved Hough Transform based fingerprint alignment approach is presented, which improves computing time and memory usage with accurate alignment parameter (rotation and translation) results. This is achieved by studying the strengths...

  10. Effect of upflowing field-aligned electron beams on the electron ...

    Indian Academy of Sciences (India)

    The role of low density upflowing field-aligned electron beams (FEBs) on the growth rate of the electron cyclotron waves at the frequencies r < e, propagating downward in the direction of the Earth's magnetic field, has been analysed in the auroral region at e/e < 1 where e is the plasma frequency and e is the ...

  11. Alignment tools used to locate a wire and a laser beam in the VISA undulator project

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Z.; Ruland, R.; Dix, B.; Arnett, D. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1999-07-01

    Within the framework of the LCLS (Linac Coherent Light Source), a small experiment VISA (Visual to Infrared SASE (Self Amplified Stimulated Emission) Amplifier) is being performed at Brookhaven National Laboratory. VISA consists of four wiggler segments, each 0.99 m long. The four segments are required to be aligned to the beam axis with an rms error less than 50 {mu}m. This very demanding alignment is carried out in two steps. First the segments are fiducialized using a pulsed wire system. Then the wiggler segments are placed along a reference laser beam which coincides with the electron beam axis. In the wiggler segment fiducialization, a wire is stretched through a wiggler segment and a current pulse is sent down the wire. The deflection of the wire is monitored. The deflection gives information about the electron beam trajectory. The wire is moved until its x position, the coordinate without wire sag, is on the ideal beam trajectory. (The y position is obtained by rotating the wiggler 90 deg C.) Once the wire is on the ideal beam trajectory, the wire's location is measured relative to tooling balls on the wiggler segment. To locate the wire, a device was constructed which measures the wire position relative to tooling balls on the device. The device is called the wire finder. It will be discussed in this paper. To place the magnets along the reference laser beam, the position of the laser beam must be determined. A device which can locate the laser beam relative to tooling balls was constructed and is also discussed in this paper. This device is called the laser finder. With a total alignment error budget less than 50 {mu}m, both the fiducialization and magnet placement must be performed with errors much smaller than 50 {mu}m. It is desired to keep the errors from the wire finder and laser finder at the few {mu}m level. (authors)

  12. Design process for NIF laser alignment and beam diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Grey, A., LLNL

    1998-06-09

    In a controller for an adaptive optic system designed to correct phase aberrations in a high power laser, the wavefront sensor is a discrete Hartmann-Shack design. It uses an army of lenslets (like a fly` s eye) to focus the laser into 77 spots on a CCD camera. Average local tilt of the wavefront across each lenslet changes the position of its focal spot. The system requires 0.1 pixel accuracy in determining the focal spot location. We determine a small area around each spot` s previous location. Within this area, we calculate the centroid of the light intensity in x and y. This calculation fails if the spot regions overlap. Especially during initial acquisition of a highly distorted beam, distinguishing overlapping spots is difficult. However, low resolution analysis of the overlapping spots allows the system to estimate their positions. With this estimate, it can use the deformable mirror to correct the beam enough so we can detect the spots using conventional image processing.

  13. Alignment of the Pixel and SCT Modules for the 2004 ATLAS Combined Test Beam

    Energy Technology Data Exchange (ETDEWEB)

    ATLAS Collaboration; Ahmad, A.; Andreazza, A.; Atkinson, T.; Baines, J.; Barr, A.J.; Beccherle, R.; Bell, P.J.; Bernabeu, J.; Broklova, Z.; Bruckman de Renstrom, P.A.; Cauz, D.; Chevalier, L.; Chouridou, S.; Citterio, M.; Clark, A.; Cobal, M.; Cornelissen, T.; Correard, S.; Costa, M.J.; Costanzo, D.; Cuneo, S.; Dameri, M.; Darbo, G.; de Vivie, J.B.; Di Girolamo, B.; Dobos, D.; Drasal, Z.; Drohan, J.; Einsweiler, K.; Elsing, M.; Emelyanov, D.; Escobar, C.; Facius, K.; Ferrari, P.; Fergusson, D.; Ferrere, D.; Flick,, T.; Froidevaux, D.; Gagliardi, G.; Gallas, M.; Gallop, B.J.; Gan, K.K.; Garcia, C.; Gavrilenko, I.L.; Gemme, C.; Gerlach, P.; Golling, T.; Gonzalez-Sevilla, S.; Goodrick, M.J.; Gorfine, G.; Gottfert, T.; Grosse-Knetter, J.; Hansen, P.H.; Hara, K.; Hartel, R.; Harvey, A.; Hawkings, R.J.; Heinemann, F.E.W.; Henss, T.; Hill, J.C.; Huegging, F.; Jansen, E.; Joseph, J.; Unel, M. Karagoz; Kataoka, M.; Kersten, S.; Khomich, A.; Klingenberg, R.; Kodys, P.; Koffas, T.; Konstantinidis, N.; Kostyukhin, V.; Lacasta, C.; Lari, T.; Latorre, S.; Lester, C.G.; Liebig, W.; Lipniacka, A.; Lourerio, K.F.; Mangin-Brinet, M.; Marti i Garcia, S.; Mathes, M.; Meroni, C.; Mikulec, B.; Mindur, B.; Moed, S.; Moorhead, G.; Morettini, P.; Moyse, E.W.J.; Nakamura, K.; Nechaeva, P.; Nikolaev, K.; Parodi, F.; Parzhitskiy, S.; Pater, J.; Petti, R.; Phillips, P.W.; Pinto, B.; Poppleton, A.; Reeves, K.; Reisinger, I.; Reznicek, P.; Risso, P.; Robinson, D.; Roe, S.; Rozanov, A.; Salzburger, A.; Sandaker, H.; Santi, L.; Schiavi, C.; Schieck, J.; Schultes, J.; Sfyrla, A.; Shaw, C.; Tegenfeldt, F.; Timmermans, C.J.W.P.; Toczek, B.; Troncon, C.; Tyndel, M.; Vernocchi, F.; Virzi, J.; Anh, T. Vu; Warren, M.; Weber, J.; Weber, M.; Weidberg, A.R.; Weingarten, J.; Wellsf, P.S.; Zhelezkow, A.

    2008-06-02

    A small set of final prototypes of the ATLAS Inner Detector silicon tracking system(Pixel Detector and SemiConductor Tracker), were used to take data during the 2004 Combined Test Beam. Data were collected from runs with beams of different flavour (electrons, pions, muons and photons) with a momentum range of 2 to 180 GeV/c. Four independent methods were used to align the silicon modules. The corrections obtained were validated using the known momenta of the beam particles and were shown to yield consistent results among the different alignment approaches. From the residual distributions, it is concluded that the precision attained in the alignmentof the silicon modules is of the order of 5 mm in their most precise coordinate.

  14. Alignment of Duke free electron laser storage ring and optical beam delivery system

    International Nuclear Information System (INIS)

    Emamian, M.; Hower, N.

    1999-01-01

    Duke Free Electron Laser Laboratory (DFELL) hosts a 1.1 GeV electron beam storage ring facility which is capable of generating beams in the range of nearly monochromatic gamma rays to high peak power infra red (IR) laser. In this report specifications and procedures for alignment of OK-4 /Duke storage ring FEL wiggler and optical cavity mirrors will be discussed. The OK-4 FEL lasing has demonstrated a series of world record in the last few years. In August of this year the OK-4 FEL successfully commissioned to laser at 193.7 nm. Also in this article, alignment of the γ-ray and UV optical beam delivery system that is currently in progress will be described. (authors)

  15. The proposed alignment system for the Final Focus Test Beam at SLAC

    International Nuclear Information System (INIS)

    Ruland, R.E.; Fischer, G.E.

    1990-09-01

    This report describes the current state of work in progress with respect to the geometry, alignment requirements, scenarios, and hardware for meeting the tolerances of the Final Focus Test Beam (FFTB) at SLAC. The methods and systems proposed acknowledge that component motion at the micron level, from whatever cause (ground motion, thermal effects, etc.) must be measured on-line and compensated for on relatively short time scales. To provide an integrated alignment/positioning package, some unique designs for reference systems, calibration of effect electric and magnetic centers, and component movers are introduced. 24 refs., 28 figs

  16. Automatic laser beam alignment using blob detection for an environment monitoring spectroscopy

    Science.gov (United States)

    Khidir, Jarjees; Chen, Youhua; Anderson, Gary

    2013-05-01

    This paper describes a fully automated system to align an infra-red laser beam with a small retro-reflector over a wide range of distances. The component development and test were especially used for an open-path spectrometer gas detection system. Using blob detection under OpenCV library, an automatic alignment algorithm was designed to achieve fast and accurate target detection in a complex background environment. Test results are presented to show that the proposed algorithm has been successfully applied to various target distances and environment conditions.

  17. A fast cross-validation method for alignment of electron tomography images based on Beer-Lambert law

    Science.gov (United States)

    Yan, Rui; Edwards, Thomas J.; Pankratz, Logan M.; Kuhn, Richard J.; Lanman, Jason K.; Liu, Jun; Jiang, Wen

    2015-01-01

    In electron tomography, accurate alignment of tilt series is an essential step in attaining high-resolution 3D reconstructions. Nevertheless, quantitative assessment of alignment quality has remained a challenging issue, even though many alignment methods have been reported. Here, we report a fast and accurate method, tomoAlignEval, based on the Beer-Lambert law, for the evaluation of alignment quality. Our method is able to globally estimate the alignment accuracy by measuring the goodness of log-linear relationship of the beam intensity attenuations at different tilt angles. Extensive tests with experimental data demonstrated its robust performance with stained and cryo samples. Our method is not only significantly faster but also more sensitive than measurements of tomogram resolution using Fourier shell correlation method (FSCe/o). From these tests, we also conclude that while current alignment methods are sufficiently accurate for stained samples, inaccurate alignments remain a major limitation for high resolution cryo-electron tomography. PMID:26455556

  18. Development and commissioning of an x-ray beam alignment flag for NSLS-II

    Energy Technology Data Exchange (ETDEWEB)

    Kosciuk, B., E-mail: bkosciuk@bnl.gov; Hu, Y.; Keister, J.; Seletskiy, S. [National Synchrotron Light Source-II, Brookhaven National Laboratory, Upton, New York 11973 (United States)

    2016-07-27

    The NSLS-II Synchrotron Light Source is a 3 GeV electron storage ring recently commissioned and is now entering operations at Brookhaven National Laboratory. One of the major tasks was to commission the six project beamline front ends which required a diagnostic to resolve x-ray beam position for the purpose of beam alignment at low current. Since none of the front ends were outfitted with any x-ray diagnostics in the baseline design, an x-ray beam profile monitor or “flag” that could be easily installed into existing front end vacuum chambers was proposed to satisfy this requirement. Here we present the development of this novel device which utilizes a polycrystalline CVD diamond luminescent screen to produce a visible image of the x-ray beam cross-section and is then captured with a CCD camera.

  19. Alignment of dipole magnet in micro-beam line of HIRFL

    International Nuclear Information System (INIS)

    Wang Shaoming; Chen Wenjun; Yang Shengli; Cai Guozhu; Guo Yizhen; Zhou Guangming; Man Kaidi; Song Mingtao

    2010-01-01

    Microbeam irradiation facility is an experiment platform, which can reduce the beam-spot on the irradiated sample to micrometer level, and can accurately locate and count the radioactive particles. It is a powerful research tool for the irradiation material science, irradiation biology, irradiation biomedicine and micro mechanical machining. The microbeam irradiation facility requires the precise work for installation and alignment. These conditions make magnet's change for directions and positions because the location space of dipole magnets in micro-beam line of HIRFL (Heavy Ion Research Facility in Lanzhou) is very small. It is a challenge for the installation and alignment work of magnets. It was solved by transforming coordinates of benchmarks of magnets, which controlled the error of magnet setup within error tolerance range. (authors)

  20. Effect of upflowing field-aligned electron beams on the electron ...

    Indian Academy of Sciences (India)

    Abstract. The role of low density upflowing field-aligned electron beams (FEBs) on the growth rate of the electron cyclotron waves at the frequencies ωr < Ωe, propagating downward in the direction of the Earth's magnetic field, has been analysed in the auroral region at ωe/Ωe < 1 where ωe is the plasma frequency and Ωe is ...

  1. Scattering of field-aligned beam ions upstream of Earth's bow shock

    Directory of Open Access Journals (Sweden)

    A. Kis

    2007-03-01

    Full Text Available Field-aligned beams are known to originate from the quasi-perpendicular side of the Earth's bow shock, while the diffuse ion population consists of accelerated ions at the quasi-parallel side of the bow shock. The two distinct ion populations show typical characteristics in their velocity space distributions. By using particle and magnetic field measurements from one Cluster spacecraft we present a case study when the two ion populations are observed simultaneously in the foreshock region during a high Mach number, high solar wind velocity event. We present the spatial-temporal evolution of the field-aligned beam ion distribution in front of the Earth's bow shock, focusing on the processes in the deep foreshock region, i.e. on the quasi-parallel side. Our analysis demonstrates that the scattering of field-aligned beam (FAB ions combined with convection by the solar wind results in the presence of lower-energy, toroidal gyrating ions at positions deeper in the foreshock region which are magnetically connected to the quasi-parallel bow shock. The gyrating ions are superposed onto a higher energy diffuse ion population. It is suggested that the toroidal gyrating ion population observed deep in the foreshock region has its origins in the FAB and that its characteristics are correlated with its distance from the FAB, but is independent on distance to the bow shock along the magnetic field.

  2. Scattering of field-aligned beam ions upstream of Earth's bow shock

    Directory of Open Access Journals (Sweden)

    A. Kis

    2007-03-01

    Full Text Available Field-aligned beams are known to originate from the quasi-perpendicular side of the Earth's bow shock, while the diffuse ion population consists of accelerated ions at the quasi-parallel side of the bow shock. The two distinct ion populations show typical characteristics in their velocity space distributions. By using particle and magnetic field measurements from one Cluster spacecraft we present a case study when the two ion populations are observed simultaneously in the foreshock region during a high Mach number, high solar wind velocity event. We present the spatial-temporal evolution of the field-aligned beam ion distribution in front of the Earth's bow shock, focusing on the processes in the deep foreshock region, i.e. on the quasi-parallel side. Our analysis demonstrates that the scattering of field-aligned beam (FAB ions combined with convection by the solar wind results in the presence of lower-energy, toroidal gyrating ions at positions deeper in the foreshock region which are magnetically connected to the quasi-parallel bow shock. The gyrating ions are superposed onto a higher energy diffuse ion population. It is suggested that the toroidal gyrating ion population observed deep in the foreshock region has its origins in the FAB and that its characteristics are correlated with its distance from the FAB, but is independent on distance to the bow shock along the magnetic field.

  3. Beam based systems and controls

    CERN Document Server

    Jacquet, D

    2012-01-01

    This presentation will give a review from the operations team of the performance and issues of the beam based systems, namely RF, ADT, beam instrumentation, controls and injection systems. For each of these systems, statistics on performance and availability will be presented with the main issues encountered in 2012. The possible improvements for operational efficiency and safety will be discussed, with an attempt to answer the question "Are we ready for the new challenges brought by the 25ns beam and increased energy after LSI? ".

  4. Squid based beam current meter

    International Nuclear Information System (INIS)

    Kuchnir, M.

    1983-01-01

    A SQUID based beam current meter has the capability of measuring the current of a beam with as little as 30 x 155 antiprotons (with a signal to noise ratio of 2). If low noise dc current is used to cancel most of the beam or an up-down counter is used to count auto-resets this sensitivity will be available at any time in the acumulation process. This current meter will therefore be a unique diagnostic tool for optimizing the performance of several Tev I components. Besides requiring liquid helium it seems that its only drawback is not to follow with the above sensitivity a sudden beam change larger than 16 μA, something that could be done using a second one in a less sensitive configuration

  5. 2D kV orthogonal imaging with fiducial markers is more precise for daily image guided alignments than soft-tissue cone beam computed tomography for prostate radiation therapy

    Directory of Open Access Journals (Sweden)

    Peter H. Goff, MD, PhD

    2017-07-01

    Conclusions: The kV-FM–based daily IG alignment for IMRT of prostate cancer is more precise than ST-CBCT, as assessed by a physician's ability to reproducibly align images. Given the magnitude of the error introduced by inconsistency in making ST-CBCT alignments, these data support a role for daily kV imaging of FM to enhance the precision of external beam dose delivery to the prostate.

  6. Codebook-based interference alignment for uplink MIMO interference channels

    KAUST Repository

    Lee, Hyun Ho; Park, Kihong; Ko, Youngchai; Alouini, Mohamed-Slim

    2014-01-01

    In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multipleoutput (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base

  7. Systematic Image Based Optical Alignment and Tensegrity

    Science.gov (United States)

    Zeiders, Glenn W.; Montgomery, Edward E, IV (Technical Monitor)

    2001-01-01

    This presentation will review the objectives and current status of two Small Business Innovative Research being performed by the Sirius Group, under the direction of MSFC. They all relate to the development of advanced optical systems technologies for automated segmented mirror alignment techniques and fundamental design methodologies for ultralight structures. These are important to future astronomical missions in space.

  8. Novel method for the production of spin-aligned RI beams in projectile fragmentation reaction with the dispersion matching technique

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Y., E-mail: yuichikawa@phys.titech.ac.jp [Tokyo Institute of Technology, Department of Physics (Japan); Ueno, H. [RIKEN Nishina Center (Japan); Ishii, Y. [Tokyo Institute of Technology, Department of Physics (Japan); Furukawa, T. [Tokyo Metropolitan University, Department of Physics (Japan); Yoshimi, A. [Okayama University, Research Core for Extreme Quantum World (Japan); Kameda, D.; Watanabe, H.; Aoi, N. [RIKEN Nishina Center (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan); Balabanski, D. L. [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energy (Bulgaria); Chevrier, R.; Daugas, J. M. [CEA, DAM, DIF (France); Fukuda, N. [RIKEN Nishina Center (Japan); Georgiev, G. [CSNSM, IN2P3-CNRS, Universite Paris-sud (France); Hayashi, H.; Iijima, H. [Tokyo Institute of Technology, Department of Physics (Japan); Inabe, N. [RIKEN Nishina Center (Japan); Inoue, T. [Tokyo Institute of Technology, Department of Physics (Japan); Ishihara, M.; Kubo, T. [RIKEN Nishina Center (Japan); and others

    2013-05-15

    A novel method to produce spin-aligned rare-isotope (RI) beam has been developed, that is the two-step projectile fragmentation method with a technique of dispersion matching. The present method was verified in an experiment at the RIKEN RIBF, where an RI beam of {sup 32}Al with spin alignment of 8(1) % was successfully produced from a primary beam of {sup 48}Ca, with {sup 33}Al as an intermediate nucleus. Figure of merit of the present method was found to be improved by a factor larger than 50 compared with a conventional method employing single-step projectile fragmentation.

  9. Cell Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath

    Science.gov (United States)

    2017-07-01

    to subsequently guide tissue regeneration , for example, by seeded tissue progenitor cells . To achieve this objective, the first step is to develop...AWARD NUMBER: W81XWH-15-1-0104 TITLE: Cell -Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath PRINCIPAL INVESTIGATOR...SUBTITLE 5a. CONTRACT NUMBER Cell -Based Meniscal Repair Using an Aligned Bioactive Nanofibrous Sheath 5b. GRANT NUMBER W81XWH-15-1-0104 5c. PROGRAM

  10. Progress in ETA-II magnetic field alignment using stretched wire and low energy electron beam techniques

    International Nuclear Information System (INIS)

    Griffith, L.V.; Deadrick, F.J.

    1991-01-01

    Flux line alignment of the solenoidal focus magnets used on the ETA-II linear induction accelerator is a key element leading to a reduction of beam corkscrew motion. Two techniques have been used on the ETA-II accelerator to measure and establish magnet alignment. A low energy electron beam has been used to directly map magnetic field lines, and recent work has utilized a pulsed stretched wire technique to measure magnet tilts and offsets with respect to a reference axis. This paper reports on the techniques used in the ETA-II accelerator alignment, and presents results from those measurements which show that accelerator is magnetically aligned to within ∼ ± 200 microns

  11. Feature-based Alignment of Volumetric Multi-modal Images

    Science.gov (United States)

    Toews, Matthew; Zöllei, Lilla; Wells, William M.

    2014-01-01

    This paper proposes a method for aligning image volumes acquired from different imaging modalities (e.g. MR, CT) based on 3D scale-invariant image features. A novel method for encoding invariant feature geometry and appearance is developed, based on the assumption of locally linear intensity relationships, providing a solution to poor repeatability of feature detection in different image modalities. The encoding method is incorporated into a probabilistic feature-based model for multi-modal image alignment. The model parameters are estimated via a group-wise alignment algorithm, that iteratively alternates between estimating a feature-based model from feature data, then realigning feature data to the model, converging to a stable alignment solution with few pre-processing or pre-alignment requirements. The resulting model can be used to align multi-modal image data with the benefits of invariant feature correspondence: globally optimal solutions, high efficiency and low memory usage. The method is tested on the difficult RIRE data set of CT, T1, T2, PD and MP-RAGE brain images of subjects exhibiting significant inter-subject variability due to pathology. PMID:24683955

  12. Search for Anisotropic Light Propagation as a Function of Laser Beam Alignment Relative to the Earth's Velocity Vector

    Directory of Open Access Journals (Sweden)

    Navia C. E.

    2007-01-01

    Full Text Available A laser diffraction experiment was conducted to study light propagation in air. The experiment is easy to reproduce and it is based on simple optical principles. Two optical sensors (segmented photo-diodes are used for measuring the position of diffracted light spots with a precision better than 0.1 μ m. The goal is to look for signals of anisotropic light propagation as function of the laser beam alignment to the Earth’s motion (solar barycenter motion obtained by COBE. Two raster search techniques have been used. First, a laser beam fixed in the laboratory frame scans in space due to Earth’s rotation. Second, a laser beam mounted on a turntable system scans actively in space by turning the table. The results obtained with both methods show that the course of light rays are affected by the motion of the Earth, and a predominant first order quantity with a Δ c/c = − β (1 + 2 a cos θ signature with ˉ a = − 0.393 ± 0.032 describes well the experimental results. This result differs in amount of 21% from the Special Relativity Theory prediction and that supplies the value of a = − 1 2 (isotropy.

  13. The magnetized electron-acoustic instability driven by a warm, field-aligned electron beam

    International Nuclear Information System (INIS)

    Sooklal, A.; Mace, R.L.

    2004-01-01

    The electron-acoustic instability in a magnetized plasma having three electron components, one of which is a field-aligned beam of intermediate temperature, is investigated. When the plasma frequency of the cool electrons exceeds the electron gyrofrequency, the electron-acoustic instability 'bifurcates' at sufficiently large propagation angles with respect to the magnetic field to yield an obliquely propagating, low-frequency electron-acoustic instability and a higher frequency cyclotron-sound instability. Each of these instabilities retains certain wave features of its progenitor, the quasiparallel electron-acoustic instability, but displays also new magnetic qualities through its dependence on the electron gyrofrequency. The obliquely propagating electron-acoustic instability requires a lower threshold beam speed for its excitation than does the cyclotron-sound instability, and for low to intermediate beam speeds has the higher maximum growth rate. When the plasma is sufficiently strongly magnetized that the plasma frequency of the cool electrons is less than the electron gyrofrequency, the only instability in the electron-acoustic frequency range is the strongly magnetized electron-acoustic instability. Its growth rate and real frequency exhibit a monotonic decrease with wave propagation angle and it grows at small to intermediate wave numbers where its parallel phase speed is approximately constant. The relevance of the results to the interpretation of cusp auroral hiss and auroral broadband electrostatic noise is briefly discussed

  14. Drift tube alignment and beam emittance codes in use at the SuperHILAC

    International Nuclear Information System (INIS)

    Spence, D.A.

    1974-01-01

    Two Fortran-IV codes in use at the SuperHILAC are of significant value in optimizing the geometry of the accelerator and in evaluating the performance of the heavy ion beams. The first routine described is used to determine the existing root mean square deviation of the 210 internal drift tube quadrupoles fitted to a straight line or to a second-order quadratic. It then predicts the minimum number of drift tubes, and their identities, to be moved in order to attain a user-elected margin of error fit. Brief mention is made of the pulsed-wire alignment technique for the quadrupole positioning. The second program described is part of a data system which utilizes a PDP-8/I as a control device for the manipulation of beam-scanning hardware and a CDC-6600 in an off-line interactive mode which gives the user maximum versatility in treating the raw data and displaying the results of calculations. The code portrays the transverse beam emittance figures and their transmission through the accelerator and transport lines. Also discussed are future plans which include on-line data reduction and CRT display by the PDP-8/I to enable the operators to optimize the tuning of the HILAC. (U.S.)

  15. CAB-Align: A Flexible Protein Structure Alignment Method Based on the Residue-Residue Contact Area.

    Directory of Open Access Journals (Sweden)

    Genki Terashi

    Full Text Available Proteins are flexible, and this flexibility has an essential functional role. Flexibility can be observed in loop regions, rearrangements between secondary structure elements, and conformational changes between entire domains. However, most protein structure alignment methods treat protein structures as rigid bodies. Thus, these methods fail to identify the equivalences of residue pairs in regions with flexibility. In this study, we considered that the evolutionary relationship between proteins corresponds directly to the residue-residue physical contacts rather than the three-dimensional (3D coordinates of proteins. Thus, we developed a new protein structure alignment method, contact area-based alignment (CAB-align, which uses the residue-residue contact area to identify regions of similarity. The main purpose of CAB-align is to identify homologous relationships at the residue level between related protein structures. The CAB-align procedure comprises two main steps: First, a rigid-body alignment method based on local and global 3D structure superposition is employed to generate a sufficient number of initial alignments. Then, iterative dynamic programming is executed to find the optimal alignment. We evaluated the performance and advantages of CAB-align based on four main points: (1 agreement with the gold standard alignment, (2 alignment quality based on an evolutionary relationship without 3D coordinate superposition, (3 consistency of the multiple alignments, and (4 classification agreement with the gold standard classification. Comparisons of CAB-align with other state-of-the-art protein structure alignment methods (TM-align, FATCAT, and DaliLite using our benchmark dataset showed that CAB-align performed robustly in obtaining high-quality alignments and generating consistent multiple alignments with high coverage and accuracy rates, and it performed extremely well when discriminating between homologous and nonhomologous pairs of proteins

  16. CAB-Align: A Flexible Protein Structure Alignment Method Based on the Residue-Residue Contact Area.

    Science.gov (United States)

    Terashi, Genki; Takeda-Shitaka, Mayuko

    2015-01-01

    Proteins are flexible, and this flexibility has an essential functional role. Flexibility can be observed in loop regions, rearrangements between secondary structure elements, and conformational changes between entire domains. However, most protein structure alignment methods treat protein structures as rigid bodies. Thus, these methods fail to identify the equivalences of residue pairs in regions with flexibility. In this study, we considered that the evolutionary relationship between proteins corresponds directly to the residue-residue physical contacts rather than the three-dimensional (3D) coordinates of proteins. Thus, we developed a new protein structure alignment method, contact area-based alignment (CAB-align), which uses the residue-residue contact area to identify regions of similarity. The main purpose of CAB-align is to identify homologous relationships at the residue level between related protein structures. The CAB-align procedure comprises two main steps: First, a rigid-body alignment method based on local and global 3D structure superposition is employed to generate a sufficient number of initial alignments. Then, iterative dynamic programming is executed to find the optimal alignment. We evaluated the performance and advantages of CAB-align based on four main points: (1) agreement with the gold standard alignment, (2) alignment quality based on an evolutionary relationship without 3D coordinate superposition, (3) consistency of the multiple alignments, and (4) classification agreement with the gold standard classification. Comparisons of CAB-align with other state-of-the-art protein structure alignment methods (TM-align, FATCAT, and DaliLite) using our benchmark dataset showed that CAB-align performed robustly in obtaining high-quality alignments and generating consistent multiple alignments with high coverage and accuracy rates, and it performed extremely well when discriminating between homologous and nonhomologous pairs of proteins in both

  17. High-precision laser microcutting and laser microdrilling using diffractive beam-splitting and high-precision flexible beam alignment

    Science.gov (United States)

    Zibner, F.; Fornaroli, C.; Holtkamp, J.; Shachaf, Lior; Kaplan, Natan; Gillner, A.

    2017-08-01

    High-precision laser micro machining gains more importance in industrial applications every month. Optical systems like the helical optics offer highest quality together with controllable and adjustable drilling geometry, thus as taper angle, aspect ratio and heat effected zone. The helical optics is based on a rotating Dove-prism which is mounted in a hollow shaft engine together with other optical elements like wedge prisms and plane plates. Although the achieved quality can be interpreted as extremely high the low process efficiency is a main reason that this manufacturing technology has only limited demand within the industrial market. The objective of the research studies presented in this paper is to dramatically increase process efficiency as well as process flexibility. During the last years, the average power of commercial ultra-short pulsed laser sources has increased significantly. The efficient utilization of the high average laser power in the field of material processing requires an effective distribution of the laser power onto the work piece. One approach to increase the efficiency is the application of beam splitting devices to enable parallel processing. Multi beam processing is used to parallelize the fabrication of periodic structures as most application only require a partial amount of the emitted ultra-short pulsed laser power. In order to achieve highest flexibility while using multi beam processing the single beams are diverted and re-guided in a way that enables the opportunity to process with each partial beam on locally apart probes or semimanufactures.

  18. The LACARA Vacuum Laser Accelerator Experiment: Beam Positioning and Alignment in a Strong Magnetic Field

    International Nuclear Information System (INIS)

    Shchelkunov, Sergey V.; Marshall, T. C.; Hirshfield, J. L.; Wang, Changbiao; LaPointe, M. A.

    2006-01-01

    LACARA (laser cyclotron auto-resonance accelerator) is a vacuum laser accelerator of electrons that is under construction at the Accelerator Test Facility (ATF), Brookhaven National Laboratory. It is expected that the experiment will be assembled by September 2006; this paper presents progress towards this goal. According to numerical studies, as an electron bunch moves along the LACARA solenoidal magnetic field (∼5.2 T, length ∼1 m), it will be accelerated from 50 to ∼75 MeV by interacting with a 0.8 TW Gaussian-mode circularly polarized optical pulse provided by the ATF CO2 10.6μm laser system. The LACARA laser transport optics must handle 10 J and be capable of forming a Gaussian beam inside the solenoid with a 1.4 mm waist and a Rayleigh range of 60 cm. The electron optics must transport a bunch having input emittance of 0.015 mm-mrad and 100 μm waist through the magnet. Precision alignment between the electron beam and the solenoid magnetic axis is required, and a method to achieve this is described in detail. Emittance- filtering may be necessary to yield an accelerated bunch having a narrow (∼1%) energy-spread

  19. L-GRAAL: Lagrangian graphlet-based network aligner.

    Science.gov (United States)

    Malod-Dognin, Noël; Pržulj, Nataša

    2015-07-01

    Discovering and understanding patterns in networks of protein-protein interactions (PPIs) is a central problem in systems biology. Alignments between these networks aid functional understanding as they uncover important information, such as evolutionary conserved pathways, protein complexes and functional orthologs. A few methods have been proposed for global PPI network alignments, but because of NP-completeness of underlying sub-graph isomorphism problem, producing topologically and biologically accurate alignments remains a challenge. We introduce a novel global network alignment tool, Lagrangian GRAphlet-based ALigner (L-GRAAL), which directly optimizes both the protein and the interaction functional conservations, using a novel alignment search heuristic based on integer programming and Lagrangian relaxation. We compare L-GRAAL with the state-of-the-art network aligners on the largest available PPI networks from BioGRID and observe that L-GRAAL uncovers the largest common sub-graphs between the networks, as measured by edge-correctness and symmetric sub-structures scores, which allow transferring more functional information across networks. We assess the biological quality of the protein mappings using the semantic similarity of their Gene Ontology annotations and observe that L-GRAAL best uncovers functionally conserved proteins. Furthermore, we introduce for the first time a measure of the semantic similarity of the mapped interactions and show that L-GRAAL also uncovers best functionally conserved interactions. In addition, we illustrate on the PPI networks of baker's yeast and human the ability of L-GRAAL to predict new PPIs. Finally, L-GRAAL's results are the first to show that topological information is more important than sequence information for uncovering functionally conserved interactions. L-GRAAL is coded in C++. Software is available at: http://bio-nets.doc.ic.ac.uk/L-GRAAL/. n.malod-dognin@imperial.ac.uk Supplementary data are available at

  20. Track based alignment of the Mu3e detector

    Energy Technology Data Exchange (ETDEWEB)

    Hartenstein, Ulrich [Institut fuer Kernphysik, Universitaet Mainz (Germany)

    2016-07-01

    The Mu3e experiment searches for the lepton flavor violating decay μ{sup +} → e{sup +}e{sup -}e{sup +} with a sensitivity goal for the branching fraction of better than 10{sup -16}. This process is heavily supressed in the standard model of particle physics (BR < 10{sup -50}) which makes an observation of this decay a clear indication of new physics. For track reconstruction, four barrel shaped layers consisting of about 3000 high-voltage monolithic active pixel sensors (HV-MAPS) are used. The position, orientation and possible deformations of these sensors must be known to greater precision than the assembly tolerances. A track based alignment via the General Broken Lines fit and the Millepede-II algorithm will be used to achieve this precision in the final detector. The talk discusses a study of the required alignment precision and preparations for aligning the detector using a detailed simulation.

  1. Constructive Alignment for Teaching Model-Based Design for Concurrency

    DEFF Research Database (Denmark)

    Brabrand, Claus

    2007-01-01

    "How can we make sure our students learn what we want them to?" is the number one question in teaching. This paper is intended to provide the reader with: i) a general answer to this question based on the theory of constructive alignment by John Biggs; ii) relevant insights for bringing this answer...

  2. A fast cross-validation method for alignment of electron tomography images based on Beer-Lambert law.

    Science.gov (United States)

    Yan, Rui; Edwards, Thomas J; Pankratz, Logan M; Kuhn, Richard J; Lanman, Jason K; Liu, Jun; Jiang, Wen

    2015-11-01

    In electron tomography, accurate alignment of tilt series is an essential step in attaining high-resolution 3D reconstructions. Nevertheless, quantitative assessment of alignment quality has remained a challenging issue, even though many alignment methods have been reported. Here, we report a fast and accurate method, tomoAlignEval, based on the Beer-Lambert law, for the evaluation of alignment quality. Our method is able to globally estimate the alignment accuracy by measuring the goodness of log-linear relationship of the beam intensity attenuations at different tilt angles. Extensive tests with experimental data demonstrated its robust performance with stained and cryo samples. Our method is not only significantly faster but also more sensitive than measurements of tomogram resolution using Fourier shell correlation method (FSCe/o). From these tests, we also conclude that while current alignment methods are sufficiently accurate for stained samples, inaccurate alignments remain a major limitation for high resolution cryo-electron tomography. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. NN-align. An artificial neural network-based alignment algorithm for MHC class II peptide binding prediction

    DEFF Research Database (Denmark)

    Nielsen, Morten; Lund, Ole

    2009-01-01

    this binding event. RESULTS: Here, we present a novel artificial neural network-based method, NN-align that allows for simultaneous identification of the MHC class II binding core and binding affinity. NN-align is trained using a novel training algorithm that allows for correction of bias in the training data...

  4. Propagation and stability characteristics of a 500-m-long laser-based fiducial line for high-precision alignment of long-distance linear accelerators.

    Science.gov (United States)

    Suwada, Tsuyoshi; Satoh, Masanori; Telada, Souichi; Minoshima, Kaoru

    2013-09-01

    A laser-based alignment system with a He-Ne laser has been newly developed in order to precisely align accelerator units at the KEKB injector linac. The laser beam was first implemented as a 500-m-long fiducial straight line for alignment measurements. We experimentally investigated the propagation and stability characteristics of the laser beam passing through laser pipes in vacuum. The pointing stability at the last fiducial point was successfully obtained with the transverse displacements of ±40 μm level in one standard deviation by applying a feedback control. This pointing stability corresponds to an angle of ±0.08 μrad. This report contains a detailed description of the experimental investigation for the propagation and stability characteristics of the laser beam in the laser-based alignment system for long-distance linear accelerators.

  5. Shocklets, SLAMS, and Field-Aligned Ion Beams in the Terrestrial Foreshock

    Science.gov (United States)

    Wilson, L. B.; Koval, A.; Sibeck, D. G.; Szabo, A.; Cattell, C. A.; Kasper, J. C.; Maruca, B. A.; Pulupa, M.; Salem, C. S.; Wilber, M.

    2012-01-01

    We present Wind spacecraft observations of ion distributions showing field- aligned beams (FABs) and large-amplitude magnetic fluctuations composed of a series of shocklets and short large-amplitude magnetic structures (SLAMS). The FABs are found to have T(sub k) approx 80-850 eV, V(sub b)/V(sub sw) approx 1.3-2.4, T(sub perpendicular,b)/T(sub paralell,b) approx 1-8, and n(sub b)/n(sub o) approx 0.2-11%. Saturation amplitudes for ion/ion resonant and non-resonant instabilities are too small to explain the observed SLAMS amplitudes. We show two examples where groups of SLAMS can act like a local quasi-perpendicular shock reflecting ions to produce the FABs, a scenario distinct from the more-common production at the quasi-perpendicular bow shock. The SLAMS exhibit a foot-like magnetic enhancement with a leading magnetosonic whistler train, consistent with previous observations. Strong ion and electron heating are observed within the series of shocklets and SLAMS with temperatures increasing by factors approx > 5 and approx >3, respectively. Both the core and halo electron components show strong perpendicular heating inside the feature.

  6. Effect of field-aligned-beam in parallel diffusion of energetic particles in the Earth's foreshock

    Science.gov (United States)

    Matsukiyo, S.; Nakanishi, K.; Otsuka, F.; Kis, A.; Lemperger, I.; Hada, T.

    2016-12-01

    Diffusive shock acceleration (DSA) is one of the plausible acceleration mechanisms of cosmic rays. In the standard DSA model the partial density of the accelerated particles, diffused into upstream, exponentially decreases as the distance to the shock increases. Kis et al. (GRL, 31, L20801, 2004) examined the density gradients of energetic ions upstream of the bow shock with high accuracy by using Cluster data. They estimated the diffusion coefficients of energetic ions for the event in February 18, 2003 and showed that the obtained diffusion coefficients are significantly smaller than those estimated in the past statistical study. This implies that particle acceleration at the bow shock can be more efficient than considered before. Here, we focus on the effect of the field-aligned-beam (FAB) which is often observed in the foreshock, and examine how the FAB affects the efficiency of diffusion of the energetic ions by performing test particle simulations. The upstream turbulence is given by the superposition of parallel Alfven waves with power-law energy spectrum with random phase approximation. In the spectrum we further add a peak corresponding to the waves resonantly generated by the FAB. The dependence of the diffusion coefficient on the presence of the FAB as well as total energy of the turbulence, power-law index of the turbulence, and intensity of FAB oriented waves are discussed.

  7. Electron beam based transversal profile measurements of intense ion beams

    International Nuclear Information System (INIS)

    El Moussati, Said

    2014-01-01

    A non-invasive diagnostic method for the experimental determination of the transverse profile of an intense ion beam has been developed and investigated theoretically as well as experimentally within the framework of the present work. The method is based on the deflection of electrons when passing the electromagnetic field of an ion beam. To achieve this an electron beam is employed with a specifically prepared transversal profile. This distinguish this method from similar ones which use thin electron beams for scanning the electromagnetic field [Roy et al. 2005; Blockland10]. The diagnostic method presented in this work will be subsequently called ''Electron-Beam-Imaging'' (EBI). First of all the influence of the electromagnetic field of the ion beam on the electrons has been theoretically analyzed. It was found that the magnetic field causes only a shift of the electrons along the ion beam axis, while the electric field only causes a shift in a plane transverse to the ion beam. Moreover, in the non-relativistic case the magnetic force is significantly smaller than the Coulomb one and the electrons suffer due to the magnetic field just a shift and continue to move parallel to their initial trajectory. Under the influence of the electric field, the electrons move away from the ion beam axis, their resulting trajectory shows a specific angle compared to the original direction. This deflection angle practically depends just on the electric field of the ion beam. Thus the magnetic field has been neglected when analysing the experimental data. The theoretical model provides a relationship between the deflection angle of the electrons and the charge distribution in the cross section of the ion beam. The model however only can be applied for small deflection angles. This implies a relationship between the line-charge density of the ion beam and the initial kinetic energy of the electrons. Numerical investigations have been carried out to clarify the

  8. Neural-network-directed alignment of optical systems using the laser-beam spatial filter as an example

    Science.gov (United States)

    Decker, Arthur J.; Krasowski, Michael J.; Weiland, Kenneth E.

    1993-01-01

    This report describes an effort at NASA Lewis Research Center to use artificial neural networks to automate the alignment and control of optical measurement systems. Specifically, it addresses the use of commercially available neural network software and hardware to direct alignments of the common laser-beam-smoothing spatial filter. The report presents a general approach for designing alignment records and combining these into training sets to teach optical alignment functions to neural networks and discusses the use of these training sets to train several types of neural networks. Neural network configurations used include the adaptive resonance network, the back-propagation-trained network, and the counter-propagation network. This work shows that neural networks can be used to produce robust sequencers. These sequencers can learn by example to execute the step-by-step procedures of optical alignment and also can learn adaptively to correct for environmentally induced misalignment. The long-range objective is to use neural networks to automate the alignment and operation of optical measurement systems in remote, harsh, or dangerous aerospace environments. This work also shows that when neural networks are trained by a human operator, training sets should be recorded, training should be executed, and testing should be done in a manner that does not depend on intellectual judgments of the human operator.

  9. The SPL-based Neutrino Super Beam

    CERN Document Server

    Baussan, E; Bobeth, C; Bouquerel, E; Caretta, O; Cupial, P; Davenne, T; Densham, C; Dracos, M; Fitton, M; Gaudiot, G; Kozien, M; Lacny, L; Lepers, B; Longhin, A; Loveridge, P; Osswald, F; Poussot, P; Rooney, M; Skoczen, B; Szybinski, B; Ustrzycka, A; Vassilopoulos, N; Wilcox, D; Wroblewski, A; Wurtz, J; Zeter, V; Zito, M

    2012-01-01

    The EUROnu Super Beam work package has studied a neutrino beam based on SPL at CERN and aimed at MEMPHYS, a large water Cherenkov detector, proposed for the Laboratoire Souterrain de Modane (Fr\\'ejus tunnel, France), with a baseline of 130 km. The aim of this proposed experiment is to study the CP violation in the neutrino sector. In the study reported here, we have developed the conceptual design of the neutrino beam, especially the target and the magnetic focusing device. Indeed, this beam present several unprecedented challenges, like the high primary proton beam power (4 MW), the high repetition rate (50 Hz) and the low energy of the protons (4.5 GeV). The design is completed by a study of all the main component of the system, starting from the transport system to guide the beam to the target up to the beam dump.

  10. Design and fabrication of a eccentric wheels based motorised alignment mechanism for cylindrical accelerator components

    International Nuclear Information System (INIS)

    Mundra, G.; Jain, V.; Karmarkar, Mangesh; Kotaiah, S.

    2006-01-01

    Precision alignment mechanisms with long term stability are required for accelerator components. For some of the components motorised and remotely operable alignment mechanism are required. An eccentric wheel mechanism based alignment system is very much suitable for such application. One such alignment system is designed, a prototype is machined/fabricated for SFDTL type accelerating structure and preliminary trial experiments have been done. (author)

  11. Development and Validation of a Multipoint Based Laser Alignment System for CLIC

    CERN Document Server

    Stern, G; Lackner, F; Mainaud-Durand, H; Piedigrossi, D; Sandomierski, J; Sosin, M; Geiger, A; Guillaume, S

    2013-01-01

    Alignment is one of the major challenges within CLIC study, since all accelerator components have to be aligned with accuracy up to 10 μm over sliding windows of 200 m. So far, the straight line reference concept has been based on stretched wires coupled with Wire Positioning Sensors. This concept should be validated through inter-comparison with an alternative solution. This paper proposes an alternative concept where laser beam acts as straight line reference and optical shutters coupled with cameras visualise the beam. The principle was first validated by a series of tests using low-cost components. Yet, in order to further decrease measurement uncertainty in this validation step, a high-precision automatised micrometric table and reference targets have been added to the setup. The paper presents the results obtained with this new equipment, in terms of measurement precision. In addition, the paper gives an overview of first tests done at long distance (up to 53 m), having emphasis on beam divergence

  12. Beam based measurement of beam position monitor electrode gains

    Directory of Open Access Journals (Sweden)

    D. L. Rubin

    2010-09-01

    Full Text Available Low emittance tuning at the Cornell Electron Storage Ring (CESR test accelerator depends on precision measurement of vertical dispersion and transverse coupling. The CESR beam position monitors (BPMs consist of four button electrodes, instrumented with electronics that allow acquisition of turn-by-turn data. The response to the beam will vary among the four electrodes due to differences in electronic gain and/or misalignment. This variation in the response of the BPM electrodes will couple real horizontal offset to apparent vertical position, and introduce spurious measurements of coupling and vertical dispersion. To alleviate this systematic effect, a beam based technique to measure the relative response of the four electrodes has been developed. With typical CESR parameters, simulations show that turn-by-turn BPM data can be used to determine electrode gains to within ∼0.1%.

  13. Beam based measurement of beam position monitor electrode gains

    Science.gov (United States)

    Rubin, D. L.; Billing, M.; Meller, R.; Palmer, M.; Rendina, M.; Rider, N.; Sagan, D.; Shanks, J.; Strohman, C.

    2010-09-01

    Low emittance tuning at the Cornell Electron Storage Ring (CESR) test accelerator depends on precision measurement of vertical dispersion and transverse coupling. The CESR beam position monitors (BPMs) consist of four button electrodes, instrumented with electronics that allow acquisition of turn-by-turn data. The response to the beam will vary among the four electrodes due to differences in electronic gain and/or misalignment. This variation in the response of the BPM electrodes will couple real horizontal offset to apparent vertical position, and introduce spurious measurements of coupling and vertical dispersion. To alleviate this systematic effect, a beam based technique to measure the relative response of the four electrodes has been developed. With typical CESR parameters, simulations show that turn-by-turn BPM data can be used to determine electrode gains to within ˜0.1%.

  14. A Novel Marker Based Method to Teeth Alignment in MRI

    Science.gov (United States)

    Luukinen, Jean-Marc; Aalto, Daniel; Malinen, Jarmo; Niikuni, Naoko; Saunavaara, Jani; Jääsaari, Päivi; Ojalammi, Antti; Parkkola, Riitta; Soukka, Tero; Happonen, Risto-Pekka

    2018-04-01

    Magnetic resonance imaging (MRI) can precisely capture the anatomy of the vocal tract. However, the crowns of teeth are not visible in standard MRI scans. In this study, a marker-based teeth alignment method is presented and evaluated. Ten patients undergoing orthognathic surgery were enrolled. Supraglottal airways were imaged preoperatively using structural MRI. MRI visible markers were developed, and they were attached to maxillary teeth and corresponding locations on the dental casts. Repeated measurements of intermarker distances in MRI and in a replica model was compared using linear regression analysis. Dental cast MRI and corresponding caliper measurements did not differ significantly. In contrast, the marker locations in vivo differed somewhat from the dental cast measurements likely due to marker placement inaccuracies. The markers were clearly visible in MRI and allowed for dental models to be aligned to head and neck MRI scans.

  15. Optimal alignment of mirror based pentaprisms for scanning deflectometric devices

    Energy Technology Data Exchange (ETDEWEB)

    Barber, Samuel K.; Geckeler, Ralf D.; Yashchuk, Valeriy V.; Gubarev, Mikhail V.; Buchheim, Jana; Siewert, Frank; Zeschke, Thomas

    2011-03-04

    In the recent work [Proc. of SPIE 7801, 7801-2/1-12 (2010), Opt. Eng. 50(5) (2011), in press], we have reported on improvement of the Developmental Long Trace Profiler (DLTP), a slope measuring profiler available at the Advanced Light Source Optical Metrology Laboratory, achieved by replacing the bulk pentaprism with a mirror based pentaprism (MBPP). An original experimental procedure for optimal mutual alignment of the MBPP mirrors has been suggested and verified with numerical ray tracing simulations. It has been experimentally shown that the optimally aligned MBPP allows the elimination of systematic errors introduced by inhomogeneity of the optical material and fabrication imperfections of the bulk pentaprism. In the present article, we provide the analytical derivation and verification of easily executed optimal alignment algorithms for two different designs of mirror based pentaprisms. We also provide an analytical description for the mechanism for reduction of the systematic errors introduced by a typical high quality bulk pentaprism. It is also shown that residual misalignments of an MBPP introduce entirely negligible systematic errors in surface slope measurements with scanning deflectometric devices.

  16. Fiber‐free coupling between bulk laser beams and on‐chip polymer‐based multimode waveguides

    DEFF Research Database (Denmark)

    Jensen, Thomas Glasdam; Nielsen, Lars Bue; Kutter, Jörg Peter

    2011-01-01

    light from a bulk beam to on‐chip waveguides and back into a bulk beam again. Using this setup, as much as 20% of the light coming from the source can be retrieved after passing through the on‐chip waveguides. The proposed setup is based on a pin‐aided alignment system that makes it possible to change...

  17. Developmental long trace profiler using optimally aligned mirror based pentaprism

    International Nuclear Information System (INIS)

    Barber, Samuel K.; Morrison, Gregory Y.; Yashchuk, Valeriy V.; Gubarev, Mikhail V.; Geckeler, Ralf D.; Buchheim, Jana; Siewert, Frank; Zeschke, Thomas

    2010-01-01

    A low-budget surface slope measuring instrument, the Developmental Long Trace Profiler (DLTP), was recently brought into operation at the Advanced Light Source Optical Metrology Laboratory (Nucl. Instr. and Meth. A 616, 212-223 (2010)). The instrument is based on a precisely calibrated autocollimator and a movable pentaprism. The capability of the DLTP to achieve sub-microradian surface slope metrology has been verified via cross-comparison measurements with other high-performance slope measuring instruments when measuring the same high-quality test optics. In the present work, a further improvement of the DLTP is achieved by replacing the existing bulk pentaprism with a specially designed mirror based pentaprism. A mirror based pentaprism offers the possibility to eliminate systematic errors introduced by inhomogeneity of the optical material and fabrication imperfections of a bulk pentaprism. We provide the details of the mirror based pentaprism design and describe an original experimental procedure for precision mutual alignment of the mirrors. The algorithm of the alignment procedure and its efficiency are verified with rigorous ray tracing simulations. Results of measurements of a spherically curved test mirror and a flat test mirror using the original bulk pentaprism are compared with measurements using the new mirror based pentaprism, demonstrating the improved performance.

  18. Nova laser alignment control system

    International Nuclear Information System (INIS)

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-01-01

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system

  19. Structure based alignment and clustering of proteins (STRALCP)

    Science.gov (United States)

    Zemla, Adam T.; Zhou, Carol E.; Smith, Jason R.; Lam, Marisa W.

    2013-06-18

    Disclosed are computational methods of clustering a set of protein structures based on local and pair-wise global similarity values. Pair-wise local and global similarity values are generated based on pair-wise structural alignments for each protein in the set of protein structures. Initially, the protein structures are clustered based on pair-wise local similarity values. The protein structures are then clustered based on pair-wise global similarity values. For each given cluster both a representative structure and spans of conserved residues are identified. The representative protein structure is used to assign newly-solved protein structures to a group. The spans are used to characterize conservation and assign a "structural footprint" to the cluster.

  20. Moving State Marine SINS Initial Alignment Based on High Degree CKF

    Directory of Open Access Journals (Sweden)

    Yong-Gang Zhang

    2014-01-01

    Full Text Available A new moving state marine initial alignment method of strap-down inertial navigation system (SINS is proposed based on high-degree cubature Kalman filter (CKF, which can capture higher order Taylor expansion terms of nonlinear alignment model than the existing third-degree CKF, unscented Kalman filter and central difference Kalman filter, and improve the accuracy of initial alignment under large heading misalignment angle condition. Simulation results show the efficiency and advantage of the proposed initial alignment method as compared with existing initial alignment methods for the moving state SINS initial alignment with large heading misalignment angle.

  1. Alignment analysis of urban railways based on passenger travel demand

    DEFF Research Database (Denmark)

    Andersen, Jonas Lohmann Elkjær; Landex, Alex

    2010-01-01

    Planning of urban railways like Metro and especially Light Rail Transit often result in multiple alignment alternatives from where it can be difficult to select the best one. Travel demand is a good foundation for evaluating a railway alignment for its ability to attract passengers. Therefore...... and can be applied as decision support in different stages of the urban railway alignment planning....

  2. The CMS Muon System Alignment

    CERN Document Server

    Martinez Ruiz-Del-Arbol, P

    2009-01-01

    The alignment of the muon system of CMS is performed using different techniques: photogrammetry measurements, optical alignment and alignment with tracks. For track-based alignment, several methods are employed, ranging from a hit and impact point (HIP) algorithm and a procedure exploiting chamber overlaps to a global fit method based on the Millepede approach. For start-up alignment as long as available integrated luminosity is still significantly limiting the size of the muon sample from collisions, cosmic muon and beam halo signatures play a very strong role. During the last commissioning runs in 2008 the first aligned geometries have been produced and validated with data. The CMS offline computing infrastructure has been used in order to perform improved reconstructions. We present the computational aspects related to the calculation of alignment constants at the CERN Analysis Facility (CAF), the production and population of databases and the validation and performance in the official reconstruction. Also...

  3. BEAMS: backbone extraction and merge strategy for the global many-to-many alignment of multiple PPI networks

    DEFF Research Database (Denmark)

    Alkan, Ferhat; Erten, Cesim

    2014-01-01

    MOTIVATION: Global many-to-many alignment of biological networks has been a central problem in comparative biological network studies. Given a set of biological interaction networks, the informal goal is to group together related nodes. For the case of protein-protein interaction networks...... of execution speed and memory requirements is more reasonable than the competing algorithms. AVAILABILITY AND IMPLEMENTATION: Supplementary material including code implementations in LEDA C++, experimental data and the results are available at http://webprs.khas.edu.tr/~cesim/BEAMS.tar.gz....

  4. Electronics and Algorithms for HOM Based Beam Diagnostics

    Science.gov (United States)

    Frisch, Josef; Baboi, Nicoleta; Eddy, Nathan; Nagaitsev, Sergei; Hensler, Olaf; McCormick, Douglas; May, Justin; Molloy, Stephen; Napoly, Olivier; Paparella, Rita; Petrosyan, Lyudvig; Ross, Marc; Simon, Claire; Smith, Tonee

    2006-11-01

    The signals from the Higher Order Mode (HOM) ports on superconducting cavities can be used as beam position monitors and to do survey structure alignment. A HOM-based diagnostic system has been installed to instrument both couplers on each of the 40 cryogenic accelerating structures in the DESY TTF2 Linac. The electronics uses a single stage down conversion from the 1.7 GHz HOM spectral line to a 20MHz IF which has been digitized. The electronics is based on low cost surface mount components suitable for large scale production. The analysis of the HOM data is based on Singular Value Decomposition. The response of the OM modes is calibrated using conventional BPMs.

  5. Track-Based Alignment of the Inner Detector of ATLAS

    Directory of Open Access Journals (Sweden)

    Ovcharova Ana

    2012-06-01

    Full Text Available ATLAS is a multipurpose experiment at the LHC. The tracking system of ATLAS, embedded in a 2 T solenoidal field, is composed of different technologies: silicon planar sensors (pixel and microstrips and drift-tubes. The procedure used to align the ATLAS tracker and the results of the alignment using data recorded during 2010 and 2011 using LHC proton-proton collision runs at 7 TeV are presented. Validation of the alignment is performed by measuring the alignment observables as well as many other physics observables, notably resonance invariant masses in a wide mass range (KS, J/Ψ and Z. The E/p distributions for electrons from Z → ee and W → ev are also extensively used. The results indicate that, after the alignment with real data, the attained precision of the alignment constants is approximately 5 μm. The systematic errors due to the alignment that may affect physics results are under study.

  6. Relevance-based evaluation of alignment approaches: The OAEI2007 food task revisited

    NARCIS (Netherlands)

    Hage, W.R. van; Kolb, H.; Schreiber, G.

    2008-01-01

    Current state-of-the-art ontology-alignment evaluation methods are based on the assumption that alignment relations come in two flavors: correct and incorrect. Some alignment systems find more correct mappings than others and hence, by this assumption, they perform better. In practical applications

  7. Precision alignment device

    Science.gov (United States)

    Jones, N.E.

    1988-03-10

    Apparatus for providing automatic alignment of beam devices having an associated structure for directing, collimating, focusing, reflecting, or otherwise modifying the main beam. A reference laser is attached to the structure enclosing the main beam producing apparatus and produces a reference beam substantially parallel to the main beam. Detector modules containing optical switching devices and optical detectors are positioned in the path of the reference beam and are effective to produce an electrical output indicative of the alignment of the main beam. This electrical output drives servomotor operated adjustment screws to adjust the position of elements of the structure associated with the main beam to maintain alignment of the main beam. 5 figs.

  8. Vertically Aligned Carbon Nanofiber based Biosensor Platform for Glucose Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Al Mamun, Khandaker A.; Tulip, Fahmida S.; MacArthur, Kimberly; McFarlane, Nicole; Islam, Syed K.; Hensley, Dale

    2014-03-01

    Vertically aligned carbon nanofibers (VACNFs) have recently become an important tool for biosensor design. Carbon nanofibers (CNF) have excellent conductive and structural properties with many irregularities and defect sites in addition to exposed carboxyl groups throughout their surfaces. These properties allow a better immobilization matrix compared to carbon nanotubes and offer better resolution when compared with the FET-based biosensors. VACNFs can be deterministically grown on silicon substrates allowing optimization of the structures for various biosensor applications. Two VACNF electrode architectures have been employed in this study and a comparison of their performances has been made in terms of sensitivity, sensing limitations, dynamic range, and response time. The usage of VACNF platform as a glucose sensor has been verified in this study by selecting an optimum architecture based on the VACNF forest density. Read More: http://www.worldscientific.com/doi/abs/10.1142/S0129156414500062

  9. 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....

  10. An X-ray beam position monitor based on the photoluminescence of helium gas

    Science.gov (United States)

    Revesz, Peter; White, Jeffrey A.

    2005-03-01

    A new method for white beam position monitoring for both bend magnet and wiggler synchrotron X-ray radiation has been developed. This method utilizes visible light luminescence generated as a result of ionization by the intense X-ray flux. In video beam position monitors (VBPMs), the luminescence of helium gas at atmospheric pressure is observed through a view port using a CCD camera next to the beam line. The beam position, profile, integrated intensity and FWHM are calculated from the distribution of luminescence intensity in each captured image by custom software. Misalignment of upstream apertures changes the image profile making VBPMs helpful for initial alignment of upstream beam line components. VBPMs can thus provide more information about the X-ray beam than most beam position monitors (BPMs). A beam position calibration procedure, employing a tilted plane-parallel glass plate placed in front of the camera lens, has also been developed. The accuracy of the VBPM system was measured during a bench-top experiment to be better than 1 μm. The He-luminescence-based VBPM system has been operative on three CHESS beam lines (F hard-bend and wiggler, A-line wiggler and G-line wiggler) for about a year. The beam positions are converted to analog voltages and used as feedback signals for beam stabilization. In our paper we discuss details of VBPM construction and describe further results of its performance.

  11. A rank-based sequence aligner with applications in phylogenetic analysis.

    Directory of Open Access Journals (Sweden)

    Liviu P Dinu

    Full Text Available Recent tools for aligning short DNA reads have been designed to optimize the trade-off between correctness and speed. This paper introduces a method for assigning a set of short DNA reads to a reference genome, under Local Rank Distance (LRD. The rank-based aligner proposed in this work aims to improve correctness over speed. However, some indexing strategies to speed up the aligner are also investigated. The LRD aligner is improved in terms of speed by storing [Formula: see text]-mer positions in a hash table for each read. Another improvement, that produces an approximate LRD aligner, is to consider only the positions in the reference that are likely to represent a good positional match of the read. The proposed aligner is evaluated and compared to other state of the art alignment tools in several experiments. A set of experiments are conducted to determine the precision and the recall of the proposed aligner, in the presence of contaminated reads. In another set of experiments, the proposed aligner is used to find the order, the family, or the species of a new (or unknown organism, given only a set of short Next-Generation Sequencing DNA reads. The empirical results show that the aligner proposed in this work is highly accurate from a biological point of view. Compared to the other evaluated tools, the LRD aligner has the important advantage of being very accurate even for a very low base coverage. Thus, the LRD aligner can be considered as a good alternative to standard alignment tools, especially when the accuracy of the aligner is of high importance. Source code and UNIX binaries of the aligner are freely available for future development and use at http://lrd.herokuapp.com/aligners. The software is implemented in C++ and Java, being supported on UNIX and MS Windows.

  12. Optical encoder based on a nondiffractive beam

    International Nuclear Information System (INIS)

    Lutenberg, Ariel; Perez-Quintian, Fernando; Rebollo, Maria A.

    2008-01-01

    Optical encoders are used in industrial and laboratory motion equipment to measure rotations and linear displacements. We introduce a design of an optical encoder based on a nondiffractive beam. We expect that the invariant profile and radial symmetry of the nondiffractive beam provide the design with remarkable tolerance to mechanical perturbations. We experimentally demonstrate that the proposed design generates a suitable output sinusoidal signal with low harmonic distortion. Moreover, we present a numerical model of the system based on the angular spectrum approximation whose predictions are in excellent agreement with the experimental results

  13. AlignMiner: a Web-based tool for detection of divergent regions in multiple sequence alignments of conserved sequences

    Directory of Open Access Journals (Sweden)

    Claros M Gonzalo

    2010-06-01

    Full Text Available Abstract Background Multiple sequence alignments are used to study gene or protein function, phylogenetic relations, genome evolution hypotheses and even gene polymorphisms. Virtually without exception, all available tools focus on conserved segments or residues. Small divergent regions, however, are biologically important for specific quantitative polymerase chain reaction, genotyping, molecular markers and preparation of specific antibodies, and yet have received little attention. As a consequence, they must be selected empirically by the researcher. AlignMiner has been developed to fill this gap in bioinformatic analyses. Results AlignMiner is a Web-based application for detection of conserved and divergent regions in alignments of conserved sequences, focusing particularly on divergence. It accepts alignments (protein or nucleic acid obtained using any of a variety of algorithms, which does not appear to have a significant impact on the final results. AlignMiner uses different scoring methods for assessing conserved/divergent regions, Entropy being the method that provides the highest number of regions with the greatest length, and Weighted being the most restrictive. Conserved/divergent regions can be generated either with respect to the consensus sequence or to one master sequence. The resulting data are presented in a graphical interface developed in AJAX, which provides remarkable user interaction capabilities. Users do not need to wait until execution is complete and can.even inspect their results on a different computer. Data can be downloaded onto a user disk, in standard formats. In silico and experimental proof-of-concept cases have shown that AlignMiner can be successfully used to designing specific polymerase chain reaction primers as well as potential epitopes for antibodies. Primer design is assisted by a module that deploys several oligonucleotide parameters for designing primers "on the fly". Conclusions AlignMiner can be used

  14. Real-time driver fatigue detection based on face alignment

    Science.gov (United States)

    Tao, Huanhuan; Zhang, Guiying; Zhao, Yong; Zhou, Yi

    2017-07-01

    The performance and robustness of fatigue detection largely decrease if the driver with glasses. To address this issue, this paper proposes a practical driver fatigue detection method based on face alignment at 3000 FPS algorithm. Firstly, the eye regions of the driver are localized by exploiting 6 landmarks surrounding each eye. Secondly, the HOG features of the extracted eye regions are calculated and put into SVM classifier to recognize the eye state. Finally, the value of PERCLOS is calculated to determine whether the driver is drowsy or not. An alarm will be generated if the eye is closed for a specified period of time. The accuracy and real-time on testing videos with different drivers demonstrate that the proposed algorithm is robust and obtain better accuracy for driver fatigue detection compared with some previous method.

  15. Ontology Alignment Repair through Modularization and Confidence-Based Heuristics.

    Directory of Open Access Journals (Sweden)

    Emanuel Santos

    Full Text Available Ontology Matching aims at identifying a set of semantic correspondences, called an alignment, between related ontologies. In recent years, there has been a growing interest in efficient and effective matching methods for large ontologies. However, alignments produced for large ontologies are often logically incoherent. It was only recently that the use of repair techniques to improve the coherence of ontology alignments began to be explored. This paper presents a novel modularization technique for ontology alignment repair which extracts fragments of the input ontologies that only contain the necessary classes and relations to resolve all detectable incoherences. The paper presents also an alignment repair algorithm that uses a global repair strategy to minimize both the degree of incoherence and the number of mappings removed from the alignment, while overcoming the scalability problem by employing the proposed modularization technique. Our evaluation shows that our modularization technique produces significantly small fragments of the ontologies and that our repair algorithm produces more complete alignments than other current alignment repair systems, while obtaining an equivalent degree of incoherence. Additionally, we also present a variant of our repair algorithm that makes use of the confidence values of the mappings to improve alignment repair. Our repair algorithm was implemented as part of AgreementMakerLight, a free and open-source ontology matching system.

  16. Ontology Alignment Repair through Modularization and Confidence-Based Heuristics.

    Science.gov (United States)

    Santos, Emanuel; Faria, Daniel; Pesquita, Catia; Couto, Francisco M

    2015-01-01

    Ontology Matching aims at identifying a set of semantic correspondences, called an alignment, between related ontologies. In recent years, there has been a growing interest in efficient and effective matching methods for large ontologies. However, alignments produced for large ontologies are often logically incoherent. It was only recently that the use of repair techniques to improve the coherence of ontology alignments began to be explored. This paper presents a novel modularization technique for ontology alignment repair which extracts fragments of the input ontologies that only contain the necessary classes and relations to resolve all detectable incoherences. The paper presents also an alignment repair algorithm that uses a global repair strategy to minimize both the degree of incoherence and the number of mappings removed from the alignment, while overcoming the scalability problem by employing the proposed modularization technique. Our evaluation shows that our modularization technique produces significantly small fragments of the ontologies and that our repair algorithm produces more complete alignments than other current alignment repair systems, while obtaining an equivalent degree of incoherence. Additionally, we also present a variant of our repair algorithm that makes use of the confidence values of the mappings to improve alignment repair. Our repair algorithm was implemented as part of AgreementMakerLight, a free and open-source ontology matching system.

  17. Phantom and Clinical Study of Differences in Cone Beam Computed Tomographic Registration When Aligned to Maximum and Average Intensity Projection

    Energy Technology Data Exchange (ETDEWEB)

    Shirai, Kiyonori [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Nishiyama, Kinji, E-mail: sirai-ki@mc.pref.osaka.jp [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan); Katsuda, Toshizo [Department of Radiology, National Cerebral and Cardiovascular Center, Osaka (Japan); Teshima, Teruki; Ueda, Yoshihiro; Miyazaki, Masayoshi; Tsujii, Katsutomo [Department of Radiation Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka (Japan)

    2014-01-01

    Purpose: To determine whether maximum or average intensity projection (MIP or AIP, respectively) reconstructed from 4-dimensional computed tomography (4DCT) is preferred for alignment to cone beam CT (CBCT) images in lung stereotactic body radiation therapy. Methods and Materials: Stationary CT and 4DCT images were acquired with a target phantom at the center of motion and moving along the superior–inferior (SI) direction, respectively. Motion profiles were asymmetrical waveforms with amplitudes of 10, 15, and 20 mm and a 4-second cycle. Stationary CBCT and dynamic CBCT images were acquired in the same manner as stationary CT and 4DCT images. Stationary CBCT was aligned to stationary CT, and the couch position was used as the baseline. Dynamic CBCT was aligned to the MIP and AIP of corresponding amplitudes. Registration error was defined as the SI deviation of the couch position from the baseline. In 16 patients with isolated lung lesions, free-breathing CBCT (FBCBCT) was registered to AIP and MIP (64 sessions in total), and the difference in couch shifts was calculated. Results: In the phantom study, registration errors were within 0.1 mm for AIP and 1.5 to 1.8 mm toward the inferior direction for MIP. In the patient study, the difference in the couch shifts (mean, range) was insignificant in the right-left (0.0 mm, ≤1.0 mm) and anterior–posterior (0.0 mm, ≤2.1 mm) directions. In the SI direction, however, the couch position significantly shifted in the inferior direction after MIP registration compared with after AIP registration (mean, −0.6 mm; ranging 1.7 mm to the superior side and 3.5 mm to the inferior side, P=.02). Conclusions: AIP is recommended as the reference image for registration to FBCBCT when target alignment is performed in the presence of asymmetrical respiratory motion, whereas MIP causes systematic target positioning error.

  18. Phantom and Clinical Study of Differences in Cone Beam Computed Tomographic Registration When Aligned to Maximum and Average Intensity Projection

    International Nuclear Information System (INIS)

    Shirai, Kiyonori; Nishiyama, Kinji; Katsuda, Toshizo; Teshima, Teruki; Ueda, Yoshihiro; Miyazaki, Masayoshi; Tsujii, Katsutomo

    2014-01-01

    Purpose: To determine whether maximum or average intensity projection (MIP or AIP, respectively) reconstructed from 4-dimensional computed tomography (4DCT) is preferred for alignment to cone beam CT (CBCT) images in lung stereotactic body radiation therapy. Methods and Materials: Stationary CT and 4DCT images were acquired with a target phantom at the center of motion and moving along the superior–inferior (SI) direction, respectively. Motion profiles were asymmetrical waveforms with amplitudes of 10, 15, and 20 mm and a 4-second cycle. Stationary CBCT and dynamic CBCT images were acquired in the same manner as stationary CT and 4DCT images. Stationary CBCT was aligned to stationary CT, and the couch position was used as the baseline. Dynamic CBCT was aligned to the MIP and AIP of corresponding amplitudes. Registration error was defined as the SI deviation of the couch position from the baseline. In 16 patients with isolated lung lesions, free-breathing CBCT (FBCBCT) was registered to AIP and MIP (64 sessions in total), and the difference in couch shifts was calculated. Results: In the phantom study, registration errors were within 0.1 mm for AIP and 1.5 to 1.8 mm toward the inferior direction for MIP. In the patient study, the difference in the couch shifts (mean, range) was insignificant in the right-left (0.0 mm, ≤1.0 mm) and anterior–posterior (0.0 mm, ≤2.1 mm) directions. In the SI direction, however, the couch position significantly shifted in the inferior direction after MIP registration compared with after AIP registration (mean, −0.6 mm; ranging 1.7 mm to the superior side and 3.5 mm to the inferior side, P=.02). Conclusions: AIP is recommended as the reference image for registration to FBCBCT when target alignment is performed in the presence of asymmetrical respiratory motion, whereas MIP causes systematic target positioning error

  19. Pairagon: a highly accurate, HMM-based cDNA-to-genome aligner.

    Science.gov (United States)

    Lu, David V; Brown, Randall H; Arumugam, Manimozhiyan; Brent, Michael R

    2009-07-01

    The most accurate way to determine the intron-exon structures in a genome is to align spliced cDNA sequences to the genome. Thus, cDNA-to-genome alignment programs are a key component of most annotation pipelines. The scoring system used to choose the best alignment is a primary determinant of alignment accuracy, while heuristics that prevent consideration of certain alignments are a primary determinant of runtime and memory usage. Both accuracy and speed are important considerations in choosing an alignment algorithm, but scoring systems have received much less attention than heuristics. We present Pairagon, a pair hidden Markov model based cDNA-to-genome alignment program, as the most accurate aligner for sequences with high- and low-identity levels. We conducted a series of experiments testing alignment accuracy with varying sequence identity. We first created 'perfect' simulated cDNA sequences by splicing the sequences of exons in the reference genome sequences of fly and human. The complete reference genome sequences were then mutated to various degrees using a realistic mutation simulator and the perfect cDNAs were aligned to them using Pairagon and 12 other aligners. To validate these results with natural sequences, we performed cross-species alignment using orthologous transcripts from human, mouse and rat. We found that aligner accuracy is heavily dependent on sequence identity. For sequences with 100% identity, Pairagon achieved accuracy levels of >99.6%, with one quarter of the errors of any other aligner. Furthermore, for human/mouse alignments, which are only 85% identical, Pairagon achieved 87% accuracy, higher than any other aligner. Pairagon source and executables are freely available at http://mblab.wustl.edu/software/pairagon/

  20. Electron Beam Diagnostics in Plasmas Based on Electron Beam Ionization

    Science.gov (United States)

    Leonhardt, Darrin; Leal-Quiros, Edbertho; Blackwell, David; Walton, Scott; Murphy, Donald; Fernsler, Richard; Meger, Robert

    2001-10-01

    Over the last few years, electron beam ionization has been shown to be a viable generator of high density plasmas with numerous applications in materials modification. To better understand these plasmas, we have fielded electron beam diagnostics to more clearly understand the propagation of the beam as it travels through the background gas and creates the plasma. These diagnostics vary greatly in sophistication, ranging from differentially pumped systems with energy selective elements to metal 'hockey pucks' covered with thin layers of insulation to electrically isolate the detector from the plasma but pass high energy beam electrons. Most importantly, absolute measurements of spatially resolved beam current densities are measured in a variety of pulsed and continuous beam sources. The energy distribution of the beam current(s) will be further discussed, through experiments incorporating various energy resolving elements such as simple grids and more sophisticated cylindrical lens geometries. The results are compared with other experiments of high energy electron beams through gases and appropriate disparities and caveats will be discussed. Finally, plasma parameters are correlated to the measured beam parameters for a more global picture of electron beam produced plasmas.

  1. Beam diagnostics based on virtual instrument technology for HLS

    International Nuclear Information System (INIS)

    Sun Baogen; Lu Ping; Wang Xiaohui; Wang Baoyun; Wang Junhua; Gu Liming; Fang Jia; Ma Tianji

    2009-01-01

    The paper introduce the beam diagnostics system using virtual instrument technology for Hefei Light Source (HLS), which includes a GPIB bus-based DCCT measurement system to measure the beam DC current and beam life, a VXIbus-based closed orbit measurement system to measure the beam position, a PCIbus-based beam profile measurement system to measure the beam profile and emittance, a GPIB-LAN based bunch length system using photoelectric method, and a Ethernet-based photon beam position measurement system. The software is programmed by LabVIEW, which reduces much developing work. (authors)

  2. Quality measures for HRR alignment based ISAR imaging algorithms

    CSIR Research Space (South Africa)

    Janse van Rensburg, V

    2013-05-01

    Full Text Available Some Inverse Synthetic Aperture Radar (ISAR) algorithms form the image in a two-step process of range alignment and phase conjugation. This paper discusses a comprehensive set of measures used to quantify the quality of range alignment, with the aim...

  3. Markov random field based automatic image alignment for electron tomography.

    Science.gov (United States)

    Amat, Fernando; Moussavi, Farshid; Comolli, Luis R; Elidan, Gal; Downing, Kenneth H; Horowitz, Mark

    2008-03-01

    We present a method for automatic full-precision alignment of the images in a tomographic tilt series. Full-precision automatic alignment of cryo electron microscopy images has remained a difficult challenge to date, due to the limited electron dose and low image contrast. These facts lead to poor signal to noise ratio (SNR) in the images, which causes automatic feature trackers to generate errors, even with high contrast gold particles as fiducial features. To enable fully automatic alignment for full-precision reconstructions, we frame the problem probabilistically as finding the most likely particle tracks given a set of noisy images, using contextual information to make the solution more robust to the noise in each image. To solve this maximum likelihood problem, we use Markov Random Fields (MRF) to establish the correspondence of features in alignment and robust optimization for projection model estimation. The resulting algorithm, called Robust Alignment and Projection Estimation for Tomographic Reconstruction, or RAPTOR, has not needed any manual intervention for the difficult datasets we have tried, and has provided sub-pixel alignment that is as good as the manual approach by an expert user. We are able to automatically map complete and partial marker trajectories and thus obtain highly accurate image alignment. Our method has been applied to challenging cryo electron tomographic datasets with low SNR from intact bacterial cells, as well as several plastic section and X-ray datasets.

  4. Codebook-based interference alignment for uplink MIMO interference channels

    KAUST Repository

    Lee, Hyun Ho

    2014-02-01

    In this paper, we propose a codebook-based interference alignment (IA) scheme in the constant multiple-input multipleoutput (MIMO) interference channel especially for the uplink scenario. In our proposed scheme, we assume cooperation among base stations (BSs) through reliable backhaul links so that global channel knowledge is available for all BSs, which enables BS to compute the transmit precoder and inform its quantized index to the associated user via limited rate feedback link.We present an upper bound on the rate loss of the proposed scheme and derive the scaling law of the feedback load tomaintain a constant rate loss relative to IA with perfect channel knowledge. Considering the impact of overhead due to training, cooperation, and feedback, we address the effective degrees of freedom (DOF) of the proposed scheme and derive the maximization of the effective DOF. From simulation results, we verify our analysis on the scaling law to preserve the multiplexing gain and confirm that the proposed scheme is more effective than the conventional IA scheme in terms of the effective DOF. © 2014 KICS.

  5. Aligning observed and modelled behaviour based on workflow decomposition

    Science.gov (United States)

    Wang, Lu; Du, YuYue; Liu, Wei

    2017-09-01

    When business processes are mostly supported by information systems, the availability of event logs generated from these systems, as well as the requirement of appropriate process models are increasing. Business processes can be discovered, monitored and enhanced by extracting process-related information. However, some events cannot be correctly identified because of the explosion of the amount of event logs. Therefore, a new process mining technique is proposed based on a workflow decomposition method in this paper. Petri nets (PNs) are used to describe business processes, and then conformance checking of event logs and process models is investigated. A decomposition approach is proposed to divide large process models and event logs into several separate parts that can be analysed independently; while an alignment approach based on a state equation method in PN theory enhances the performance of conformance checking. Both approaches are implemented in programmable read-only memory (ProM). The correctness and effectiveness of the proposed methods are illustrated through experiments.

  6. Principles of alignment of multi-beam lasers for thermonuclear purposes

    International Nuclear Information System (INIS)

    Basov, N.G.; Belyan, B.F.; Zhilkin, G.P.

    1978-01-01

    The problems of methods and equipment for power pulse laser adjustment, as well as the problem of adjustment automatization are considered. The adjustment of a power 12-channel ''Dolphin'' laser installation on the neodymium glass is taken as a concrete object. The adjustment objects are optical track of laser installation, guidance and laser radiation focusing system on the target, the system of target delivery to the focal volume, control system of element optical quality of laser installation and laser beams, as well as target radiation conditions in vacuum chamber. List of requirements of adjustment beams, possible sources of adjustment beams, equipment complex and laser installation adjustment methods are considered. The principles and scheme solutions of automatic adjustment of optical elements are discussed and the description of working samples of automatic joints is given. The problem of working laser beams imitation by adjusting and the possibilities of automatization of laser radiation space-angle characteristics control are considered. The control scheme of adjustment processes with computer as well as the switching on of adjustment automatic subsystem in the general automatization scheme of the ''Dolphin'' installation are discussed

  7. Engineering catalytic activity via ion beam bombardment of catalyst supports for vertically aligned carbon nanotube growth

    Science.gov (United States)

    Islam, A. E.; Nikolaev, P.; Amama, P. B.; Zakharov, D.; Sargent, G.; Saber, S.; Huffman, D.; Erford, M.; Semiatin, S. L.; Stach, E. A.; Maruyama, B.

    2015-09-01

    Carbon nanotube growth depends on the catalytic activity of metal nanoparticles on alumina or silica supports. The control on catalytic activity is generally achieved by variations in water concentration, carbon feed, and sample placement on a few types of alumina or silica catalyst supports obtained via thin film deposition. We have recently expanded the choice of catalyst supports by engineering inactive substrates like c-cut sapphire via ion beam bombardment. The deterministic control on the structure and chemistry of catalyst supports obtained by tuning the degree of beam-induced damage have enabled better regulation of the activity of Fe catalysts only in the ion beam bombarded areas and hence enabled controllable super growth of carbon nanotubes. A wide range of surface characterization techniques were used to monitor the catalytically active surface engineered via ion beam bombardment. The proposed method offers a versatile way to control carbon nanotube growth in patterned areas and also enhances the current understanding of the growth process. With the right choice of water concentration, carbon feed and sample placement, engineered catalyst supports may extend the carbon nanotube growth yield to a level that is even higher than the ones reported here, and thus offers promising applications of carbon nanotubes in electronics, heat exchanger, and energy storage.

  8. Remote sensing of local structure of the quasi-perpendicular Earth's bow shock by using field-aligned beams

    Directory of Open Access Journals (Sweden)

    B. Miao

    2009-03-01

    Full Text Available Field-aligned ion beams (FABs originate at the quasi-perpendicular Earth's bow shock and constitute an important ion population in the foreshock region. The bulk velocity of these FABs depends significantly on the shock normal angle, which is the angle between shock normal and upstream interplanetary magnetic field (IMF. This dependency may therefore be taken as an indicator of the local structure of the shock. Applying the direct reflection model to Cluster measurements, we have developed a method that uses proton FABs in the foreshock region for remote sensing of the local shock structure. The comparison of the model results with the multi-spacecraft observations of FAB events shows very good agreement in terms of wave amplitude and frequency of surface waves at the shock front.

  9. Base-By-Base: single nucleotide-level analysis of whole viral genome alignments.

    Science.gov (United States)

    Brodie, Ryan; Smith, Alex J; Roper, Rachel L; Tcherepanov, Vasily; Upton, Chris

    2004-07-14

    With ever increasing numbers of closely related virus genomes being sequenced, it has become desirable to be able to compare two genomes at a level more detailed than gene content because two strains of an organism may share the same set of predicted genes but still differ in their pathogenicity profiles. For example, detailed comparison of multiple isolates of the smallpox virus genome (each approximately 200 kb, with 200 genes) is not feasible without new bioinformatics tools. A software package, Base-By-Base, has been developed that provides visualization tools to enable researchers to 1) rapidly identify and correct alignment errors in large, multiple genome alignments; and 2) generate tabular and graphical output of differences between the genomes at the nucleotide level. Base-By-Base uses detailed annotation information about the aligned genomes and can list each predicted gene with nucleotide differences, display whether variations occur within promoter regions or coding regions and whether these changes result in amino acid substitutions. Base-By-Base can connect to our mySQL database (Virus Orthologous Clusters; VOCs) to retrieve detailed annotation information about the aligned genomes or use information from text files. Base-By-Base enables users to quickly and easily compare large viral genomes; it highlights small differences that may be responsible for important phenotypic differences such as virulence. It is available via the Internet using Java Web Start and runs on Macintosh, PC and Linux operating systems with the Java 1.4 virtual machine.

  10. A study of Hough Transform-based fingerprint alignment algorithms

    CSIR Research Space (South Africa)

    Mlambo, CS

    2014-10-01

    Full Text Available the implementation of each algorithm. The comparison is performed by considering the alignment results computed using each group of algorithms when varying number of minutiae points, rotation angle, and translation. In addition, the memory usage, computing time...

  11. Molecular bond formation in Na* + N2 energy transfer: Crossed beam study of atomic alignment and orientation

    International Nuclear Information System (INIS)

    Reiland, W.; Jamieson, G.; Tittes, U.; Hertel, I.V.

    1982-01-01

    We report the first full analysis of collisionally induced atomic alignment and orientation for a molecular collision process. In an experiment with crossed supersonic beams of N 2 and laser excited Na(3 2 Psub(3/2)) we have studied the dependence of angular and energy resolved differential quenching cross sections as a function of the linear and circular polarization of the exciting laser light. The ansisotropies observed in the linear polarization data range up to 2:1 when corrected for electron and nuclear spin relaxation. The maximum effect is found at small scattering angles and intermediate energy transfer where the cross section is also largest. The atomic alignment angle most favourable for quenching relates to the scattering angle and can be understood in a model picture in such a way that the (NaN 2 )* molecular system is formed at internuclear distances as low as R = 10a 0 . The circular asymmetry is small but with significant structure and is attributed to interaction on different potential surfaces at R > 10a 0 . Full analysis of the four measurable parameter is given in terms of the density matrix in a frame with z-axis perpendicular to collision plane which allows a clear understanding of the properties of atomic reflection symmetry and coherence of the scattering process. (orig.)

  12. Study of the alignment of X radiation beam for calibration of chambers used in radiotherapy

    International Nuclear Information System (INIS)

    Cardoso, Ricardo de Souza; Bossio, Francisco; Peixoto, Jose Guilherme Pereira

    2014-01-01

    The activities developed in radiotherapy, diagnostic radiology and radiation safety, require that the metrological parameters involving these activities have on its results a high degree of reliability, to ensure traceability. To meet the existing demand in Brazil, the National Metrology Laboratory of Ionizing Radiation - LNMRI - is deploying a new tube X-ray beams used in the calibration of the standard rooms, which serve to quality control in hospitals, clinics and industry. (author)

  13. Analysis of computational complexity for HT-based fingerprint alignment algorithms on java card environment

    CSIR Research Space (South Africa)

    Mlambo, CS

    2015-01-01

    Full Text Available In this paper, implementations of three Hough Transform based fingerprint alignment algorithms are analyzed with respect to time complexity on Java Card environment. Three algorithms are: Local Match Based Approach (LMBA), Discretized Rotation Based...

  14. LHCb: Experience with LHCb alignment software on first data

    CERN Multimedia

    Deissenroth, M

    2009-01-01

    We report results obtained with different track-based algorithms for the alignment of the LHCb detector with first data. The large-area Muon Detector and Outer Tracker have been aligned with a large sample of tracks from cosmic rays. The three silicon detectors --- VELO, TT-station and Inner Tracker --- have been aligned with beam-induced events from the LHC injection line. We compare the results from the track-based alignment with expectations from detector survey.

  15. Spreadsheet-based program for alignment of overlapping DNA sequences.

    Science.gov (United States)

    Anbazhagan, R; Gabrielson, E

    1999-06-01

    Molecular biology laboratories frequently face the challenge of aligning small overlapping DNA sequences derived from a long DNA segment. Here, we present a short program that can be used to adapt Excel spreadsheets as a tool for aligning DNA sequences, regardless of their orientation. The program runs on any Windows or Macintosh operating system computer with Excel 97 or Excel 98. The program is available for use as an Excel file, which can be downloaded from the BioTechniques Web site. Upon execution, the program opens a specially designed customized workbook and is capable of identifying overlapping regions between two sequence fragments and displaying the sequence alignment. It also performs a number of specialized functions such as recognition of restriction enzyme cutting sites and CpG island mapping without costly specialized software.

  16. NN-align. An artificial neural network-based alignment algorithm for MHC class II peptide binding prediction

    Directory of Open Access Journals (Sweden)

    Lund Ole

    2009-09-01

    Full Text Available Abstract Background The major histocompatibility complex (MHC molecule plays a central role in controlling the adaptive immune response to infections. MHC class I molecules present peptides derived from intracellular proteins to cytotoxic T cells, whereas MHC class II molecules stimulate cellular and humoral immunity through presentation of extracellularly derived peptides to helper T cells. Identification of which peptides will bind a given MHC molecule is thus of great importance for the understanding of host-pathogen interactions, and large efforts have been placed in developing algorithms capable of predicting this binding event. Results Here, we present a novel artificial neural network-based method, NN-align that allows for simultaneous identification of the MHC class II binding core and binding affinity. NN-align is trained using a novel training algorithm that allows for correction of bias in the training data due to redundant binding core representation. Incorporation of information about the residues flanking the peptide-binding core is shown to significantly improve the prediction accuracy. The method is evaluated on a large-scale benchmark consisting of six independent data sets covering 14 human MHC class II alleles, and is demonstrated to outperform other state-of-the-art MHC class II prediction methods. Conclusion The NN-align method is competitive with the state-of-the-art MHC class II peptide binding prediction algorithms. The method is publicly available at http://www.cbs.dtu.dk/services/NetMHCII-2.0.

  17. Statistical potential-based amino acid similarity matrices for aligning distantly related protein sequences.

    Science.gov (United States)

    Tan, Yen Hock; Huang, He; Kihara, Daisuke

    2006-08-15

    Aligning distantly related protein sequences is a long-standing problem in bioinformatics, and a key for successful protein structure prediction. Its importance is increasing recently in the context of structural genomics projects because more and more experimentally solved structures are available as templates for protein structure modeling. Toward this end, recent structure prediction methods employ profile-profile alignments, and various ways of aligning two profiles have been developed. More fundamentally, a better amino acid similarity matrix can improve a profile itself; thereby resulting in more accurate profile-profile alignments. Here we have developed novel amino acid similarity matrices from knowledge-based amino acid contact potentials. Contact potentials are used because the contact propensity to the other amino acids would be one of the most conserved features of each position of a protein structure. The derived amino acid similarity matrices are tested on benchmark alignments at three different levels, namely, the family, the superfamily, and the fold level. Compared to BLOSUM45 and the other existing matrices, the contact potential-based matrices perform comparably in the family level alignments, but clearly outperform in the fold level alignments. The contact potential-based matrices perform even better when suboptimal alignments are considered. Comparing the matrices themselves with each other revealed that the contact potential-based matrices are very different from BLOSUM45 and the other matrices, indicating that they are located in a different basin in the amino acid similarity matrix space.

  18. Semantics of agent-based service delegation and alignment

    NARCIS (Netherlands)

    Balsters, H; Huitema, GB; Szirbik, NB; Meersman, R; Tari, Z; Herrero, P; Mendez, G; Cavedon, L; Martin, D; Hinze, A; Buchanan, G; Perez, MS; Robles,; Humble, J; Albani, A; Dietz, JLG; Panetto, H; Scannapieco, M; Halpin, T; Spyns, P; Zaha, JM; Zimanyi, E; Stefanakis, E; Dillon, T; Feng, L; Jarrar, M; Lehmann, J; DeMoor, A; Duval, E; Aroyo, L

    2005-01-01

    In this paper we concentrate on conceptual modeling and semantics of service delegation and alignment in information systems. In delegation, a source company wishes to hand over parts of its functionality together with related responsibilities to a supplying party. From the side of the outsourcer

  19. Coarse Alignment Technology on Moving base for SINS Based on the Improved Quaternion Filter Algorithm.

    Science.gov (United States)

    Zhang, Tao; Zhu, Yongyun; Zhou, Feng; Yan, Yaxiong; Tong, Jinwu

    2017-06-17

    Initial alignment of the strapdown inertial navigation system (SINS) is intended to determine the initial attitude matrix in a short time with certain accuracy. The alignment accuracy of the quaternion filter algorithm is remarkable, but the convergence rate is slow. To solve this problem, this paper proposes an improved quaternion filter algorithm for faster initial alignment based on the error model of the quaternion filter algorithm. The improved quaternion filter algorithm constructs the K matrix based on the principle of optimal quaternion algorithm, and rebuilds the measurement model by containing acceleration and velocity errors to make the convergence rate faster. A doppler velocity log (DVL) provides the reference velocity for the improved quaternion filter alignment algorithm. In order to demonstrate the performance of the improved quaternion filter algorithm in the field, a turntable experiment and a vehicle test are carried out. The results of the experiments show that the convergence rate of the proposed improved quaternion filter is faster than that of the tradition quaternion filter algorithm. In addition, the improved quaternion filter algorithm also demonstrates advantages in terms of correctness, effectiveness, and practicability.

  20. General beam position controlling method for 3D optical systems based on the method of solving ray matrix equations

    Science.gov (United States)

    Chen, Meixiong; Yuan, Jie; Long, Xingwu; Kang, Zhenglong; Wang, Zhiguo; Li, Yingying

    2013-12-01

    A general beam position controlling method for 3D optical systems based on the method of solving ray matrix equations has been proposed in this paper. As a typical 3D optical system, nonplanar ring resonator of Zero-Lock Laser Gyroscopes has been chosen as an example to show its application. The total mismatching error induced by Faraday-wedge in nonplanar ring resonator has been defined and eliminated quite accurately with the error less than 1 μm. Compared with the method proposed in Ref. [14], the precision of the beam position controlling has been improved by two orders of magnitude. The novel method can be used to implement automatic beam position controlling in 3D optical systems with servo circuit. All those results have been confirmed by related alignment experiments. The results in this paper are important for beam controlling, ray tracing, cavity design and alignment in 3D optical systems.

  1. Implementation of EPICS based Control System for Radioisotope Beam line

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Ha; Ahn, Tae-Sung; Song, Young-Gi; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Atomic Energy Research Institute, Gyeongju (Korea, Republic of)

    2015-10-15

    Korea Mult-purpose Accelerator Complex (KOMAC) has been operating 100 MeV proton linear accelerator . For operating 100 MeV linac, various control system has been implemented such as vacuum, power supply, RCCS and etc. KOMAC is operating two beam lines so that clients can use 100 MeV proton beam for their experiment. KOMAC sends beam to beam line and target room using two dipole magnets and several quadrupole magnets. As demand for experiments and Radius Isotope using beam is increased, another beam line is under construction and RI beam line control system is need. To synchronize with KOMAC control system, RI beam line control system is based on Experimental Physics and Industrial control System (EPICS) software. The beam is transported to RI beam line to control magnet power supply and vacuum. Implementation of RI beam line control system is presented and some preliminary results are reported. The base RI beam line control system is implemented. It can control beam direction and vacuum. Comparing archived data and current data, RI beam line and control system will be improved. In the future, scroll pump and gate control system will be implemented using programmable logic controller PLC. RI beam interlock sequence will be added to KOMAC interlock system to protect linac.

  2. A new correlation based alignment technique for use in electron tomography

    International Nuclear Information System (INIS)

    Jones, S.D.; Härting, M.

    2013-01-01

    In this paper we present a new correlation based method for the alignment of a single axis tilt series. Rather than performing the pairwise correlation procedure with the central image as the starting point, the method presented here calculates the optimal starting position within the tilt series and proceeds towards both ends. The starting position is determined by maximisation of a viability function, J, which rewards cumulative series correlation and penalises both cumulative series shift and distance from the centre of the image series. - Highlights: • Pairwise correlation based alignment is investigated as a function of seed position. • It is shown that the convention of using the central image as the seed is not optimal. • A function is proposed which improves alignment by finding the optimal seed position. • The method is found to produce alignment with lower residual scores with the phantom data. • Superior alignment is produced vs the standard method with the experimental data

  3. Base-By-Base: Single nucleotide-level analysis of whole viral genome alignments

    Directory of Open Access Journals (Sweden)

    Tcherepanov Vasily

    2004-07-01

    Full Text Available Abstract Background With ever increasing numbers of closely related virus genomes being sequenced, it has become desirable to be able to compare two genomes at a level more detailed than gene content because two strains of an organism may share the same set of predicted genes but still differ in their pathogenicity profiles. For example, detailed comparison of multiple isolates of the smallpox virus genome (each approximately 200 kb, with 200 genes is not feasible without new bioinformatics tools. Results A software package, Base-By-Base, has been developed that provides visualization tools to enable researchers to 1 rapidly identify and correct alignment errors in large, multiple genome alignments; and 2 generate tabular and graphical output of differences between the genomes at the nucleotide level. Base-By-Base uses detailed annotation information about the aligned genomes and can list each predicted gene with nucleotide differences, display whether variations occur within promoter regions or coding regions and whether these changes result in amino acid substitutions. Base-By-Base can connect to our mySQL database (Virus Orthologous Clusters; VOCs to retrieve detailed annotation information about the aligned genomes or use information from text files. Conclusion Base-By-Base enables users to quickly and easily compare large viral genomes; it highlights small differences that may be responsible for important phenotypic differences such as virulence. It is available via the Internet using Java Web Start and runs on Macintosh, PC and Linux operating systems with the Java 1.4 virtual machine.

  4. ALCBEAM - Neutral beam formation and propagation code for beam-based plasma diagnostics

    Science.gov (United States)

    Bespamyatnov, I. O.; Rowan, W. L.; Liao, K. T.

    2012-03-01

    ALCBEAM is a new three-dimensional neutral beam formation and propagation code. It was developed to support the beam-based diagnostics installed on the Alcator C-Mod tokamak. The purpose of the code is to provide reliable estimates of the local beam equilibrium parameters: such as beam energy fractions, density profiles and excitation populations. The code effectively unifies the ion beam formation, extraction and neutralization processes with beam attenuation and excitation in plasma and neutral gas and beam stopping by the beam apertures. This paper describes the physical processes interpreted and utilized by the code, along with exploited computational methods. The description is concluded by an example simulation of beam penetration into plasma of Alcator C-Mod. The code is successfully being used in Alcator C-Mod tokamak and expected to be valuable in the support of beam-based diagnostics in most other tokamak environments. Program summaryProgram title: ALCBEAM Catalogue identifier: AEKU_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEKU_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 66 459 No. of bytes in distributed program, including test data, etc.: 7 841 051 Distribution format: tar.gz Programming language: IDL Computer: Workstation, PC Operating system: Linux RAM: 1 GB Classification: 19.2 Nature of problem: Neutral beams are commonly used to heat and/or diagnose high-temperature magnetically-confined laboratory plasmas. An accurate neutral beam characterization is required for beam-based measurements of plasma properties. Beam parameters such as density distribution, energy composition, and atomic excited populations of the beam atoms need to be known. Solution method: A neutral beam is initially formed as an ion beam which is extracted from

  5. Negative ion based neutral beams for plasma heating

    International Nuclear Information System (INIS)

    Prelec, K.

    1978-01-01

    Neutral beam systems based on negative ions have been considered because of a high expected power efficiency. Methods for the production, acceleration and neutralization of negative ions will be reviewed and possibilities for an application in neutral beam lines explored

  6. Alignment of Ion Accelerator for Surface Analysis using Theodolite and Laser Tracker

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Tae Sung; Seo, Dong Hyuk; Kim, Dae Il; Kim, Han Sung; Kwon, Hyeok Jung; Cho, Yong Sub [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The method of ion accelerator alignment is used two ways which are a theodolite and laser tracker. For the alignment and maintenance of the proton linear accelerator, the laser tracker is typically used at KOMAC. While the device for alignment by using laser tracker is not installed in all ion accelerator components, it was used in parallel in two methods. In this paper, alignment methods are introduced and the result and comparison of each alignment method are presented. The ion accelerator for surface analysis has aligned using theodolite and laser tracker. The two ways for alignment have advantage as well as weakness. But alignment using laser tracker is stronger than using theodolite. Because it is based on alignment and position data and it is more detailed. Also since the beam distribution is smaller than accelerator component that is direction of beam progress, main component (ex. Magnet, Chamber, Pelletron tank, etc.) alignment using laser tracker is enough to align the ion accelerator.

  7. Simultaneous AFM and fluorescence imaging: A method for aligning an AFM-tip with an excitation beam using a 2D galvanometer

    Science.gov (United States)

    Moores, A. N.; Cadby, A. J.

    2018-02-01

    Correlative fluorescence and atomic force microscopy (AFM) imaging is a highly attractive technique for use in biological imaging, enabling force and mechanical measurements of particular structures whose locations are known due to the specificity of fluorescence imaging. The ability to perform these two measurements simultaneously (rather than consecutively with post-processing correlation) is highly valuable because it would allow the mechanical properties of a structure to be tracked over time as changes in the sample occur. We present an instrument which allows simultaneous AFM and fluorescence imaging by aligning an incident fluorescence excitation beam with an AFM-tip. Alignment was performed by calibrating a 2D galvanometer present in the excitation beam path and using it to reposition the incident beam. Two programs were developed (one manual and one automated) which correlate sample features between the AFM and fluorescence images, calculating the distance required to translate the incident beam towards the AFM-tip. Using this method, we were able to obtain beam-tip alignment (and therefore field-of-view alignment) from an offset of >15 μm to within one micron in two iterations of the program. With the program running alongside data acquisition for real-time feedback between AFM and optical images, this offset was maintained over a time period of several hours. Not only does this eliminate the need to image large areas with both techniques to ensure that fields-of-view overlap, but it also raises the possibility of using this instrument for tip-enhanced fluorescence applications, a technique in which super-resolution images have previously been achieved.

  8. A user-friendly nano-CT image alignment and 3D reconstruction platform based on LabVIEW

    International Nuclear Information System (INIS)

    Wang Shenghao; Wang Zhili; Gao Kun; Wu Zhao; Zhang Kai; Zhu Peiping; Wu Ziyu

    2015-01-01

    X-ray computed tomography at the nanometer scale (nano-CT) offers a wide range of applications in scientific and industrial areas. Here we describe a reliable, user-friendly, and fast software package based on LabVIEW that may allow us to perform all procedures after the acquisition of raw projection images in order to obtain the inner structure of the investigated sample. A suitable image alignment process to address misalignment problems among image series due to mechanical manufacturing errors, thermal expansion, and other external factors has been considered, together with a novel fast parallel beam 3D reconstruction procedure that was developed ad hoc to perform the tomographic reconstruction. We have obtained remarkably improved reconstruction results at the Beijing Synchrotron Radiation Facility after the image calibration, the fundamental role of this image alignment procedure was confirmed, which minimizes the unwanted blurs and additional streaking artifacts that are always present in reconstructed slices. Moreover, this nano-CT image alignment and its associated 3D reconstruction procedure are fully based on LabVIEW routines, significantly reducing the data post-processing cycle, thus making the activity of the users faster and easier during experimental runs. (authors)

  9. Ultracompact high-efficiency polarising beam splitter based on silicon nanobrick arrays.

    Science.gov (United States)

    Zheng, Guoxing; Liu, Guogen; Kenney, Mitchell Guy; Li, Zile; He, Ping'an; Li, Song; Ren, Zhi; Deng, Qiling

    2016-03-21

    Since the transmission of anisotropic nano-structures is sensitive to the polarisation of an incident beam, a novel polarising beam splitter (PBS) based on silicon nanobrick arrays is proposed. With careful design of such structures, an incident beam with polarisation direction aligned with the long axis of the nanobrick is almost totally reflected (~98.5%), whilst that along the short axis is nearly totally transmitted (~94.3%). More importantly, by simply changing the width of the nanobrick we can shift the peak response wavelength from 1460 nm to 1625 nm, covering S, C and L bands of the fiber telecommunications windows. The silicon nanobrick-based PBS can find applications in many fields which require ultracompactness, high efficiency, and compatibility with semiconductor industry technologies.

  10. The beam-beam limit in asymmetric colliders: Optimization of the B-factory parameter base

    International Nuclear Information System (INIS)

    Tennyson, J.L.

    1990-01-01

    This paper presents a general theory of the beam-beam limit in symmetric and asymmetric lepton ring colliders. It shows how the beam-beam limit in these accelerators affects the maximum attainable luminosity and presents a specific algorithm for parameter base optimization. It is shown that the special problems inherent in asymmetric colliders derive not from the asymmetry, but from the fact that the two beams must be in different rings. Computer simulation experiments are used to demonstrate the various phenomena discussed in the theory

  11. TMRG studies on spin alignment in molecule-based ferrimagnetics [rapid communication

    Science.gov (United States)

    Liu, Q. M.; Yao, K. L.; Liu, Z. L.

    2005-05-01

    A physical picture of spin alignment in organic molecule-based ferrimagnets is presented from studying the thermal effective magnetic moment of the sublattice by use of the transfer matrix renormalization group. We conclude that the classical antiparallel spin alignment is not the most stable state. The three-spin system tends to parallel alignment when the exchange interaction between the biradical and the monoradical molecules is much weaker than that within the biradical, which can result in the decrease of the effective magnetic moment upon lowering the temperature. More importantly, we give the theoretical evidence that even the antiparallel spin alignment in the biradical monoradical alternating chain does not necessarily lead to ferrimagnetic spin ordering due to the formation of the spin singlet pairs, which suppresses the ferrimagnetic spin alignment.

  12. Initial Alignment for SINS Based on Pseudo-Earth Frame in Polar Regions.

    Science.gov (United States)

    Gao, Yanbin; Liu, Meng; Li, Guangchun; Guang, Xingxing

    2017-06-16

    An accurate initial alignment must be required for inertial navigation system (INS). The performance of initial alignment directly affects the following navigation accuracy. However, the rapid convergence of meridians and the small horizontalcomponent of rotation of Earth make the traditional alignment methods ineffective in polar regions. In this paper, from the perspective of global inertial navigation, a novel alignment algorithm based on pseudo-Earth frame and backward process is proposed to implement the initial alignment in polar regions. Considering that an accurate coarse alignment of azimuth is difficult to obtain in polar regions, the dynamic error modeling with large azimuth misalignment angle is designed. At the end of alignment phase, the strapdown attitude matrix relative to local geographic frame is obtained without influence of position errors and cumbersome computation. As a result, it would be more convenient to access the following polar navigation system. Then, it is also expected to unify the polar alignment algorithm as much as possible, thereby further unifying the form of external reference information. Finally, semi-physical static simulation and in-motion tests with large azimuth misalignment angle assisted by unscented Kalman filter (UKF) validate the effectiveness of the proposed method.

  13. A test beam upgrade based on the BEPC-LINAC

    International Nuclear Information System (INIS)

    Li Jiacai; Wu Yuanming; Cui Xiangzong; Zhang Liangsheng; Zhou Baoqing; Liu Zhengquan; Zhang Shaoping; Sun Changchun; Zhang Zhuxiang; Zhang Caidi; Zheng Linsheng; Liu Shixing; Shen Ji; Yin Zejie; Zhang Yongming; Chen Ziyu

    2004-01-01

    A total of three beam lines, E1, E2 and E3 have based on the LINAC of BEPC. The E1 beam is to be used for intense slow-positron facility. The E2 is a primary positron or electron beam with an energy of 1.3-1.5 GeV. The E3 is a secondary electron or pion test beam with a momentum can be adjustable continuously. The position accuracy of a detected particle is 0.2-0.4 mm with an event rate of 3 - 4 Hz. This beam has been successfully used for some detectors beam test. (author)

  14. 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

  15. Improving alignment in Tract-based spatial statistics: evaluation and optimization of image registration

    NARCIS (Netherlands)

    de Groot, Marius; Vernooij, Meike W.; Klein, Stefan; Ikram, M. Arfan; Vos, Frans M.; Smith, Stephen M.; Niessen, Wiro J.; Andersson, Jesper L. R.

    2013-01-01

    Anatomical alignment in neuroimaging studies is of such importance that considerable effort is put into improving the registration used to establish spatial correspondence. Tract-based spatial statistics (TBSS) is a popular method for comparing diffusion characteristics across subjects. TBSS

  16. Improving alignment in Tract-based spatial statistics : Evaluation and optimization of image registration

    NARCIS (Netherlands)

    De Groot, M.; Vernooij, M.W.; Klein, S.; Arfan Ikram, M.; Vos, F.M.; Smith, S.M.; Niessen, W.J.; Andersson, J.L.R.

    2013-01-01

    Anatomical alignment in neuroimaging studies is of such importance that considerable effort is put into improving the registration used to establish spatial correspondence. Tract-based spatial statistics (TBSS) is a popular method for comparing diffusion characteristics across subjects. TBSS

  17. Linear collider accelerator physics issues regarding alignment

    International Nuclear Information System (INIS)

    Seeman, J.T.

    1990-01-01

    The next generation of linear colliders will require more stringent alignment tolerances than those for the SLC with regard to the accelerating structures, quadrupoles, and beam position monitors. New techniques must be developed to achieve these tolerances. A combination of mechanical-electrical and beam-based methods will likely be needed

  18. ISOL based radioactive nuclear beam facilities

    International Nuclear Information System (INIS)

    Nomura, T.

    1991-07-01

    High-intensity and high-quality unstable nuclear beams can be realized by coupling an isotope separator on-line and a proper post accelerator in various primary beams. Some technical features and problems in the production of such beams are discussed. A brief description is given on 'Exotic Nuclei Arena' in Japanese Hadron Project. (author)

  19. T-BAS: Tree-Based Alignment Selector toolkit for phylogenetic-based placement, alignment downloads and metadata visualization: an example with the Pezizomycotina tree of life.

    Science.gov (United States)

    Carbone, Ignazio; White, James B; Miadlikowska, Jolanta; Arnold, A Elizabeth; Miller, Mark A; Kauff, Frank; U'Ren, Jana M; May, Georgiana; Lutzoni, François

    2017-04-15

    High-quality phylogenetic placement of sequence data has the potential to greatly accelerate studies of the diversity, systematics, ecology and functional biology of diverse groups. We developed the Tree-Based Alignment Selector (T-BAS) toolkit to allow evolutionary placement and visualization of diverse DNA sequences representing unknown taxa within a robust phylogenetic context, and to permit the downloading of highly curated, single- and multi-locus alignments for specific clades. In its initial form, T-BAS v1.0 uses a core phylogeny of 979 taxa (including 23 outgroup taxa, as well as 61 orders, 175 families and 496 genera) representing all 13 classes of largest subphylum of Fungi-Pezizomycotina (Ascomycota)-based on sequence alignments for six loci (nr5.8S, nrLSU, nrSSU, mtSSU, RPB1, RPB2 ). T-BAS v1.0 has three main uses: (i) Users may download alignments and voucher tables for members of the Pezizomycotina directly from the reference tree, facilitating systematics studies of focal clades. (ii) Users may upload sequence files with reads representing unknown taxa and place these on the phylogeny using either BLAST or phylogeny-based approaches, and then use the displayed tree to select reference taxa to include when downloading alignments. The placement of unknowns can be performed for large numbers of Sanger sequences obtained from fungal cultures and for alignable, short reads of environmental amplicons. (iii) User-customizable metadata can be visualized on the tree. T-BAS Version 1.0 is available online at http://tbas.hpc.ncsu.edu . Registration is required to access the CIPRES Science Gateway and NSF XSEDE's large computational resources. icarbon@ncsu.edu. Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  20. Alignment of CT images of skull dysmorphology using anatomy-based perpendicular axes

    International Nuclear Information System (INIS)

    Yoo, Sun K; Kim, Yong O; Kim, Hee-Joung; Kim, Nam H; Jang, Young Beom; Kim, Kee-Deog; Lee, Hye-Yeon

    2003-01-01

    Rigid body registration of 3D CT scans, based on manual identification of homologous landmarks, is useful for the visual analysis of skull dysmorphology. In this paper, a robust and simple alignment method was proposed to allow for the comparison of skull morphologies, within and between individuals with craniofacial anomalies, based on 3D CT scans, and the minimum number of anatomical landmarks, under rigidity and uniqueness constraints. Three perpendicular axes, extracted from anatomical landmarks, define the absolute coordinate system, through a rigid body transformation, to align multiple CT images for different patients and acquisition times. The accuracy of the alignment method depends on the accuracy of the localized landmarks and target points. The numerical simulation generalizes the accuracy requirements of the alignment method. Experiments using a human dried skull specimen, and ten sets of skull CT images (the pre- and post-operative CT scans of four plagiocephaly, and one fibrous dysplasia patients), demonstrated the feasibility of the technique in clinical practice

  1. Kinematic analysis and experimental verification of a eccentric wheel based precision alignment mechanism for LINAC

    International Nuclear Information System (INIS)

    Mundra, G.; Jain, V.; Singh, K.K.; Saxena, P.; Khare, R.K.; Bagre, M.

    2011-01-01

    Eccentric wheel based precision alignment system was designed for the remote motorized alignment of proposed proton injector LINAC (SFDTL). As a part of the further development for the alignment and monitoring scheme, a menu driven alignment system is being developed. The paper describes a general kinematic equation (with base line tilt correction) based on the various parameters of the mechanism like eccentricity, wheel diameter, distance between the wheels and the diameter of the cylindrical accelerator component. Based on this equation the extent of the alignment range for the 4 degree of freedom is evaluated and analysis on some of the parameters variation and the theoretical accuracy/resolution is computed. For the same a computer program is written which can compute the various points for the each discrete position of the two motor combinations. The paper also describes the experimentally evaluated values of these positions (for the full extent of area) and the matching/comparison of the two data. These data now can be used for the movement computation required for alignment of the four motors (two front and two rear motors of the support structure). (author)

  2. A Kalman Filter for SINS Self-Alignment Based on Vector Observation.

    Science.gov (United States)

    Xu, Xiang; Xu, Xiaosu; Zhang, Tao; Li, Yao; Tong, Jinwu

    2017-01-29

    In this paper, a self-alignment method for strapdown inertial navigation systems based on the q -method is studied. In addition, an improved method based on integrating gravitational apparent motion to form apparent velocity is designed, which can reduce the random noises of the observation vectors. For further analysis, a novel self-alignment method using a Kalman filter based on adaptive filter technology is proposed, which transforms the self-alignment procedure into an attitude estimation using the observation vectors. In the proposed method, a linear psuedo-measurement equation is adopted by employing the transfer method between the quaternion and the observation vectors. Analysis and simulation indicate that the accuracy of the self-alignment is improved. Meanwhile, to improve the convergence rate of the proposed method, a new method based on parameter recognition and a reconstruction algorithm for apparent gravitation is devised, which can reduce the influence of the random noises of the observation vectors. Simulations and turntable tests are carried out, and the results indicate that the proposed method can acquire sound alignment results with lower standard variances, and can obtain higher alignment accuracy and a faster convergence rate.

  3. Torsion sensing based on patterned piezoelectric beams

    Science.gov (United States)

    Cha, Youngsu; You, Hangil

    2018-03-01

    In this study, we investigated the sensing characteristics of piezoelectric beams under torsional loads. We used partially patterned piezoelectric beams to sense torsion. In particular, the piezoelectric patches are located symmetrically with respect to the line of the shear center of the beam. The patterned piezoelectric beam is modeled as a slender beam, and its electrical responses are obtained by piezoelectric electromechanical equations. To validate the modeling framework, experiments are performed using a setup that forces pure torsional deformation. Three different geometric configurations of the patterned piezoelectric layer are used for the experiments. The frequency and amplitude of the forced torsional load are systematically varied in order to study the behavior of the piezoelectric sensor. Experimental results demonstrate that two voltage outputs of the piezoelectric beam are approximately out of phase with identical amplitude. Moreover, the length of the piezoelectric layers has a significant influence on the sensing properties. Our theoretical predictions using the model support the experimental findings.

  4. SPARSE: quadratic time simultaneous alignment and folding of RNAs without sequence-based heuristics.

    Science.gov (United States)

    Will, Sebastian; Otto, Christina; Miladi, Milad; Möhl, Mathias; Backofen, Rolf

    2015-08-01

    RNA-Seq experiments have revealed a multitude of novel ncRNAs. The gold standard for their analysis based on simultaneous alignment and folding suffers from extreme time complexity of [Formula: see text]. Subsequently, numerous faster 'Sankoff-style' approaches have been suggested. Commonly, the performance of such methods relies on sequence-based heuristics that restrict the search space to optimal or near-optimal sequence alignments; however, the accuracy of sequence-based methods breaks down for RNAs with sequence identities below 60%. Alignment approaches like LocARNA that do not require sequence-based heuristics, have been limited to high complexity ([Formula: see text] quartic time). Breaking this barrier, we introduce the novel Sankoff-style algorithm 'sparsified prediction and alignment of RNAs based on their structure ensembles (SPARSE)', which runs in quadratic time without sequence-based heuristics. To achieve this low complexity, on par with sequence alignment algorithms, SPARSE features strong sparsification based on structural properties of the RNA ensembles. Following PMcomp, SPARSE gains further speed-up from lightweight energy computation. Although all existing lightweight Sankoff-style methods restrict Sankoff's original model by disallowing loop deletions and insertions, SPARSE transfers the Sankoff algorithm to the lightweight energy model completely for the first time. Compared with LocARNA, SPARSE achieves similar alignment and better folding quality in significantly less time (speedup: 3.7). At similar run-time, it aligns low sequence identity instances substantially more accurate than RAF, which uses sequence-based heuristics. © The Author 2015. Published by Oxford University Press.

  5. SPARSE: quadratic time simultaneous alignment and folding of RNAs without sequence-based heuristics

    Science.gov (United States)

    Will, Sebastian; Otto, Christina; Miladi, Milad; Möhl, Mathias; Backofen, Rolf

    2015-01-01

    Motivation: RNA-Seq experiments have revealed a multitude of novel ncRNAs. The gold standard for their analysis based on simultaneous alignment and folding suffers from extreme time complexity of O(n6). Subsequently, numerous faster ‘Sankoff-style’ approaches have been suggested. Commonly, the performance of such methods relies on sequence-based heuristics that restrict the search space to optimal or near-optimal sequence alignments; however, the accuracy of sequence-based methods breaks down for RNAs with sequence identities below 60%. Alignment approaches like LocARNA that do not require sequence-based heuristics, have been limited to high complexity (≥ quartic time). Results: Breaking this barrier, we introduce the novel Sankoff-style algorithm ‘sparsified prediction and alignment of RNAs based on their structure ensembles (SPARSE)’, which runs in quadratic time without sequence-based heuristics. To achieve this low complexity, on par with sequence alignment algorithms, SPARSE features strong sparsification based on structural properties of the RNA ensembles. Following PMcomp, SPARSE gains further speed-up from lightweight energy computation. Although all existing lightweight Sankoff-style methods restrict Sankoff’s original model by disallowing loop deletions and insertions, SPARSE transfers the Sankoff algorithm to the lightweight energy model completely for the first time. Compared with LocARNA, SPARSE achieves similar alignment and better folding quality in significantly less time (speedup: 3.7). At similar run-time, it aligns low sequence identity instances substantially more accurate than RAF, which uses sequence-based heuristics. Availability and implementation: SPARSE is freely available at http://www.bioinf.uni-freiburg.de/Software/SPARSE. Contact: backofen@informatik.uni-freiburg.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25838465

  6. Laser shaft alignment measurement model

    Science.gov (United States)

    Mo, Chang-tao; Chen, Changzheng; Hou, Xiang-lin; Zhang, Guoyu

    2007-12-01

    Laser beam's track which is on photosensitive surface of the a receiver will be closed curve, when driving shaft and the driven shaft rotate with same angular velocity and rotation direction. The coordinate of arbitrary point which is on the curve is decided by the relative position of two shafts. Basing on the viewpoint, a mathematic model of laser alignment is set up. By using a data acquisition system and a data processing model of laser alignment meter with single laser beam and a detector, and basing on the installation parameter of computer, the state parameter between two shafts can be obtained by more complicated calculation and correction. The correcting data of the four under chassis of the adjusted apparatus moving on the level and the vertical plane can be calculated. This will instruct us to move the apparatus to align the shafts.

  7. Cryo-EM image alignment based on nonuniform fast Fourier transform.

    Science.gov (United States)

    Yang, Zhengfan; Penczek, Pawel A

    2008-08-01

    In single particle analysis, two-dimensional (2-D) alignment is a fundamental step intended to put into register various particle projections of biological macromolecules collected at the electron microscope. The efficiency and quality of three-dimensional (3-D) structure reconstruction largely depends on the computational speed and alignment accuracy of this crucial step. In order to improve the performance of alignment, we introduce a new method that takes advantage of the highly accurate interpolation scheme based on the gridding method, a version of the nonuniform fast Fourier transform, and utilizes a multi-dimensional optimization algorithm for the refinement of the orientation parameters. Using simulated data, we demonstrate that by using less than half of the sample points and taking twice the runtime, our new 2-D alignment method achieves dramatically better alignment accuracy than that based on quadratic interpolation. We also apply our method to image to volume registration, the key step in the single particle EM structure refinement protocol. We find that in this case the accuracy of the method not only surpasses the accuracy of the commonly used real-space implementation, but results are achieved in much shorter time, making gridding-based alignment a perfect candidate for efficient structure determination in single particle analysis.

  8. Cryo-EM image alignment based on nonuniform fast Fourier transform

    International Nuclear Information System (INIS)

    Yang Zhengfan; Penczek, Pawel A.

    2008-01-01

    In single particle analysis, two-dimensional (2-D) alignment is a fundamental step intended to put into register various particle projections of biological macromolecules collected at the electron microscope. The efficiency and quality of three-dimensional (3-D) structure reconstruction largely depends on the computational speed and alignment accuracy of this crucial step. In order to improve the performance of alignment, we introduce a new method that takes advantage of the highly accurate interpolation scheme based on the gridding method, a version of the nonuniform fast Fourier transform, and utilizes a multi-dimensional optimization algorithm for the refinement of the orientation parameters. Using simulated data, we demonstrate that by using less than half of the sample points and taking twice the runtime, our new 2-D alignment method achieves dramatically better alignment accuracy than that based on quadratic interpolation. We also apply our method to image to volume registration, the key step in the single particle EM structure refinement protocol. We find that in this case the accuracy of the method not only surpasses the accuracy of the commonly used real-space implementation, but results are achieved in much shorter time, making gridding-based alignment a perfect candidate for efficient structure determination in single particle analysis

  9. On the origin of field-aligned beams at the quasi-perpendicular bow shock: multi-spacecraft observations by Cluster

    Directory of Open Access Journals (Sweden)

    H. Kucharek

    2004-07-01

    Full Text Available Two distinct populations of reflected and accelerated ions are known to originate from quasi-perpendicular shocks, gyrating ions and reflected ion beams. Recent observations under such bow shock conditions with Cluster have shown strong evidence that both particle distributions appear to emerge from the same reflection process. In this paper the basic production mechanism of field-aligned beams has been investigated by using CLUSTER multi-spacecraft measurements. We have analyzed several quasi-perpendicular shocks with the Cluster Ion Spectrometry experiment (CIS and followed the spatial and temporal evolution of the reflected and transmitted ion populations across the shock. These observations show that the field-aligned beams most likely result from effective scattering in pitch angle during reflection in the shock ramp. Investigating a low Mach number shock, leakage of a fraction of the thermalized ion distribution in the downstream region does not appear to be the source as the volume in phase space occupied by beam ions is empty downstream of the shock ramp.

  10. Oriented Edge-Based Feature Descriptor for Multi-Sensor Image Alignment and Enhancement

    Directory of Open Access Journals (Sweden)

    Myung-Ho Ju

    2013-10-01

    Full Text Available In this paper, we present an efficient image alignment and enhancement method for multi-sensor images. The shape of the object captured in a multi-sensor images can be determined by comparing variability of contrast using corresponding edges across multi-sensor image. Using this cue, we construct a robust feature descriptor based on the magnitudes of the oriented edges. Our proposed method enables fast image alignment by identifying matching features in multi-sensor images. We enhance the aligned multi-sensor images through the fusion of the salient regions from each image. The results of stitching the multi-sensor images and their enhancement demonstrate that our proposed method can align and enhance multi-sensor images more efficiently than previous methods.

  11. A comprehensive method for evaluating precision of transfer alignment on a moving base

    Science.gov (United States)

    Yin, Hongliang; Xu, Bo; Liu, Dezheng

    2017-09-01

    In this study, we propose the use of the Degree of Alignment (DOA) in engineering applications for evaluating the precision of and identifying the transfer alignment on a moving base. First, we derive the statistical formula on the basis of estimations. Next, we design a scheme for evaluating the transfer alignment on a moving base, for which the attitude error cannot be directly measured. Then, we build a mathematic estimation model and discuss Fixed Point Smoothing (FPS), Returns to Scale (RTS), Inverted Sequence Recursive Estimation (ISRE), and Kalman filter estimation methods, which can be used when evaluating alignment accuracy. Our theoretical calculations and simulated analyses show that the DOA reflects not only the alignment time and accuracy but also differences in the maneuver schemes, and is suitable for use as an integrated evaluation index. Furthermore, all four of these algorithms can be used to identify the transfer alignment and evaluate its accuracy. We recommend RTS in particular for engineering applications. Generalized DOAs should be calculated according to the tactical requirements.

  12. A fast inner product processor based on equal alignments

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.P.; Torng, H.C.

    1985-11-01

    Inner product computation is an important operation, invoked repeatedly in matrix multiplications. A high-speed inner product processor can be very useful (among many possible applications) in real-time signal processing. This paper presents the design of a fast inner product processor, with appreciably reduced latency and cost. The inner product processor is implemented with a tree of carry-propagate or carry-save adders; this structure is obtained with the incorporation of three innovations in the conventional multiply/add tree: The leaf-multipliers are expanded into adder subtrees, thus achieving an O(log Nb) latency, where N denotes the number of elements in a vector and b the number of bits in each element. The partial products, to be summed in producing an inner product, are reordered according to their ''minimum alignments.'' This reordering brings approximately a 20% savings in hardware-including adders and data paths. The reduction in adder widths also yields savings in carry propagation time for carry-propagate adders. For trees implemented with carry-save adders, the partial product reordering also serves to truncate the carry propagation chain in the final propagation stage by 2 log b - 1 positions, thus significantly reducing the latency further. A form of the Baugh and Wooley algorithm is adopted to implement two's complement notation with changes only in peripheral hardware.

  13. A vertically aligned carbon nanotube-based impedance sensing biosensor for rapid and high sensitive detection of cancer cells.

    Science.gov (United States)

    Abdolahad, Mohammad; Taghinejad, Mohammad; Taghinejad, Hossein; Janmaleki, Mohsen; Mohajerzadeh, Shams

    2012-03-21

    A novel vertically aligned carbon nanotube based electrical cell impedance sensing biosensor (CNT-ECIS) was demonstrated for the first time as a more rapid, sensitive and specific device for the detection of cancer cells. This biosensor is based on the fast entrapment of cancer cells on vertically aligned carbon nanotube arrays and leads to mechanical and electrical interactions between CNT tips and entrapped cell membranes, changing the impedance of the biosensor. CNT-ECIS was fabricated through a photolithography process on Ni/SiO(2)/Si layers. Carbon nanotube arrays have been grown on 9 nm thick patterned Ni microelectrodes by DC-PECVD. SW48 colon cancer cells were passed over the surface of CNT covered electrodes to be specifically entrapped on elastic nanotube beams. CNT arrays act as both adhesive and conductive agents and impedance changes occurred as fast as 30 s (for whole entrapment and signaling processes). CNT-ECIS detected the cancer cells with the concentration as low as 4000 cells cm(-2) on its surface and a sensitivity of 1.7 × 10(-3)Ω cm(2). Time and cell efficiency factor (TEF and CEF) parameters were defined which describe the sensor's rapidness and resolution, respectively. TEF and CEF of CNT-ECIS were much higher than other cell based electrical biosensors which are compared in this paper.

  14. Alignment and prediction of cis-regulatory modules based on a probabilistic model of evolution.

    Directory of Open Access Journals (Sweden)

    Xin He

    2009-03-01

    Full Text Available Cross-species comparison has emerged as a powerful paradigm for predicting cis-regulatory modules (CRMs and understanding their evolution. The comparison requires reliable sequence alignment, which remains a challenging task for less conserved noncoding sequences. Furthermore, the existing models of DNA sequence evolution generally do not explicitly treat the special properties of CRM sequences. To address these limitations, we propose a model of CRM evolution that captures different modes of evolution of functional transcription factor binding sites (TFBSs and the background sequences. A particularly novel aspect of our work is a probabilistic model of gains and losses of TFBSs, a process being recognized as an important part of regulatory sequence evolution. We present a computational framework that uses this model to solve the problems of CRM alignment and prediction. Our alignment method is similar to existing methods of statistical alignment but uses the conserved binding sites to improve alignment. Our CRM prediction method deals with the inherent uncertainties of binding site annotations and sequence alignment in a probabilistic framework. In simulated as well as real data, we demonstrate that our program is able to improve both alignment and prediction of CRM sequences over several state-of-the-art methods. Finally, we used alignments produced by our program to study binding site conservation in genome-wide binding data of key transcription factors in the Drosophila blastoderm, with two intriguing results: (i the factor-bound sequences are under strong evolutionary constraints even if their neighboring genes are not expressed in the blastoderm and (ii binding sites in distal bound sequences (relative to transcription start sites tend to be more conserved than those in proximal regions. Our approach is implemented as software, EMMA (Evolutionary Model-based cis-regulatory Module Analysis, ready to be applied in a broad biological context.

  15. An Improved Measurement Method for the Strength of Radiation of Reflective Beam in an Industrial Optical Sensor Based on Laser Displacement Meter

    OpenAIRE

    Youngchul Bae

    2016-01-01

    An optical sensor such as a laser range finder (LRF) or laser displacement meter (LDM) uses reflected and returned laser beam from a target. The optical sensor has been mainly used to measure the distance between a launch position and the target. However, optical sensor based LRF and LDM have numerous and various errors such as statistical errors, drift errors, cyclic errors, alignment errors and slope errors. Among these errors, an alignment error that contains measurement error for the stre...

  16. Three-dimensional hindfoot alignment measurements based on biplanar radiographs: comparison with standard radiographic measurements

    International Nuclear Information System (INIS)

    Sutter, Reto; Pfirrmann, Christian W.A.; Buck, Florian M.; Espinosa, Norman

    2013-01-01

    To establish a hindfoot alignment measurement technique based on low-dose biplanar radiographs and compare with hindfoot alignment measurements on long axial view radiographs, which is the current reference standard. Long axial view radiographs and low-dose biplanar radiographs of a phantom consisting of a human foot skeleton embedded in acrylic glass (phantom A) and a plastic model of a human foot in three different hindfoot positions (phantoms B1-B3) were imaged in different foot positions (20 internal to 20 external rotation). Two independent readers measured hindfoot alignment on long axial view radiographs and performed 3D hindfoot alignment measurements based on biplanar radiographs on two different occasions. Time for three-dimensional (3D) measurements was determined. Intraclass correlation coefficients (ICC) were calculated. Hindfoot alignment measurements on long axial view radiographs were characterized by a large positional variation, with a range of 14 /13 valgus to 22 /27 varus (reader 1/2 for phantom A), whereas the range of 3D hindfoot alignment measurements was 7.3 /6.0 to 9.0 /10.5 varus (reader 1/2 for phantom A), with a mean and standard deviation of 8.1 ± 0.6/8.7 ± 1.4 respectively. Interobserver agreement was high (ICC = 0.926 for phantom A, and ICC = 0.886 for phantoms B1-B3), and agreement between different readouts was high (ICC = 0.895-0.995 for reader 1, and ICC = 0.987-0.994 for reader 2) for 3D measurements. Mean duration of 3D measurements was 84 ± 15/113 ± 15 s for reader 1/2. Three-dimensional hindfoot alignment measurements based on biplanar radiographs were independent of foot positioning during image acquisition and reader independent. In this phantom study, the 3D measurements were substantially more precise than the standard radiographic measurements. (orig.)

  17. Dynamics based alignment of proteins: an alternative approach to quantify dynamic similarity

    Directory of Open Access Journals (Sweden)

    Lyngsø Rune

    2010-04-01

    Full Text Available Abstract Background The dynamic motions of many proteins are central to their function. It therefore follows that the dynamic requirements of a protein are evolutionary constrained. In order to assess and quantify this, one needs to compare the dynamic motions of different proteins. Comparing the dynamics of distinct proteins may also provide insight into how protein motions are modified by variations in sequence and, consequently, by structure. The optimal way of comparing complex molecular motions is, however, far from trivial. The majority of comparative molecular dynamics studies performed to date relied upon prior sequence or structural alignment to define which residues were equivalent in 3-dimensional space. Results Here we discuss an alternative methodology for comparative molecular dynamics that does not require any prior alignment information. We show it is possible to align proteins based solely on their dynamics and that we can use these dynamics-based alignments to quantify the dynamic similarity of proteins. Our method was tested on 10 representative members of the PDZ domain family. Conclusions As a result of creating pair-wise dynamics-based alignments of PDZ domains, we have found evolutionarily conserved patterns in their backbone dynamics. The dynamic similarity of PDZ domains is highly correlated with their structural similarity as calculated with Dali. However, significant differences in their dynamics can be detected indicating that sequence has a more refined role to play in protein dynamics than just dictating the overall fold. We suggest that the method should be generally applicable.

  18. A unified model for transfer alignment at random misalignment angles based on second-order EKF

    International Nuclear Information System (INIS)

    Cui, Xiao; Qin, Yongyuan; Yan, Gongmin; Liu, Zhenbo; Mei, Chunbo

    2017-01-01

    In the transfer alignment process of inertial navigation systems (INSs), the conventional linear error model based on the small misalignment angle assumption cannot be applied to large misalignment situations. Furthermore, the nonlinear model based on the large misalignment angle suffers from redundant computation with nonlinear filters. This paper presents a unified model for transfer alignment suitable for arbitrary misalignment angles. The alignment problem is transformed into an estimation of the relative attitude between the master INS (MINS) and the slave INS (SINS), by decomposing the attitude matrix of the latter. Based on the Rodriguez parameters, a unified alignment model in the inertial frame with the linear state-space equation and a second order nonlinear measurement equation are established, without making any assumptions about the misalignment angles. Furthermore, we employ the Taylor series expansions on the second-order nonlinear measurement equation to implement the second-order extended Kalman filter (EKF2). Monte-Carlo simulations demonstrate that the initial alignment can be fulfilled within 10 s, with higher accuracy and much smaller computational cost compared with the traditional unscented Kalman filter (UKF) at large misalignment angles. (paper)

  19. Aligning ERP systems with companies' real needs: an `Operational Model Based' method

    Science.gov (United States)

    Mamoghli, Sarra; Goepp, Virginie; Botta-Genoulaz, Valérie

    2017-02-01

    Enterprise Resource Planning (ERP) systems offer standard functionalities that have to be configured and customised by a specific company depending on its own requirements. A consistent alignment is therefore an essential success factor of ERP projects. To manage this alignment, an 'Operational Model Based' method is proposed. It is based on the design and the matching of models, and conforms to the modelling views and constructs of the ISO 19439 and 19440 enterprise-modelling standards. It is characterised by: (1) a predefined design and matching order of the models; (2) the formalisation, in terms of modelling constructs, of alignment and misalignment situations; and (3) their association with a set of decisions in order to mitigate the misalignment risk. Thus, a comprehensive understanding of the alignment management during ERP projects is given. Unlike existing methods, this one includes decisions related to the organisational changes an ERP system can induce, as well as criteria on which the best decision can be based. In this way, it provides effective support and guidance to companies implementing ERP systems, as the alignment process is detailed and structured. The method is applied on the ERP project of a Small and Medium Enterprise, showing that it can be used even in contexts where the ERP project expertise level is low.

  20. A unified model for transfer alignment at random misalignment angles based on second-order EKF

    Science.gov (United States)

    Cui, Xiao; Mei, Chunbo; Qin, Yongyuan; Yan, Gongmin; Liu, Zhenbo

    2017-04-01

    In the transfer alignment process of inertial navigation systems (INSs), the conventional linear error model based on the small misalignment angle assumption cannot be applied to large misalignment situations. Furthermore, the nonlinear model based on the large misalignment angle suffers from redundant computation with nonlinear filters. This paper presents a unified model for transfer alignment suitable for arbitrary misalignment angles. The alignment problem is transformed into an estimation of the relative attitude between the master INS (MINS) and the slave INS (SINS), by decomposing the attitude matrix of the latter. Based on the Rodriguez parameters, a unified alignment model in the inertial frame with the linear state-space equation and a second order nonlinear measurement equation are established, without making any assumptions about the misalignment angles. Furthermore, we employ the Taylor series expansions on the second-order nonlinear measurement equation to implement the second-order extended Kalman filter (EKF2). Monte-Carlo simulations demonstrate that the initial alignment can be fulfilled within 10 s, with higher accuracy and much smaller computational cost compared with the traditional unscented Kalman filter (UKF) at large misalignment angles.

  1. Video-based beam position monitoring at CHESS

    Science.gov (United States)

    Revesz, Peter; Pauling, Alan; Krawczyk, Thomas; Kelly, Kevin J.

    2012-10-01

    CHESS has pioneered the development of X-ray Video Beam Position Monitors (VBPMs). Unlike traditional photoelectron beam position monitors that rely on photoelectrons generated by the fringe edges of the X-ray beam, with VBPMs we collect information from the whole cross-section of the X-ray beam. VBPMs can also give real-time shape/size information. We have developed three types of VBPMs: (1) VBPMs based on helium luminescence from the intense white X-ray beam. In this case the CCD camera is viewing the luminescence from the side. (2) VBPMs based on luminescence of a thin (~50 micron) CVD diamond sheet as the white beam passes through it. The CCD camera is placed outside the beam line vacuum and views the diamond fluorescence through a viewport. (3) Scatter-based VBPMs. In this case the white X-ray beam passes through a thin graphite filter or Be window. The scattered X-rays create an image of the beam's footprint on an X-ray sensitive fluorescent screen using a slit placed outside the beam line vacuum. For all VBPMs we use relatively inexpensive 1.3 Mega-pixel CCD cameras connected via USB to a Windows host for image acquisition and analysis. The VBPM host computers are networked and provide live images of the beam and streams of data about the beam position, profile and intensity to CHESS's signal logging system and to the CHESS operator. The operational use of VBPMs showed great advantage over the traditional BPMs by providing direct visual input for the CHESS operator. The VBPM precision in most cases is on the order of ~0.1 micron. On the down side, the data acquisition frequency (50-1000ms) is inferior to the photoelectron based BPMs. In the future with the use of more expensive fast cameras we will be able create VBPMs working in the few hundreds Hz scale.

  2. Excimer laser beam profile recording based on electrochemical etched polycarbonate

    International Nuclear Information System (INIS)

    Parvin, P.; Jaleh, B.; Zangeneh, H.R.; Zamanipour, Z.; Davoud-Abadi, Gh.R.

    2008-01-01

    There is no polymeric detector used to register the beam profile of UV lasers. Here, a method is proposed for the measurement of intensive UV beam pattern of the excimer lasers based on the photoablated polycarbonate detector after coherent UV exposure and the subsequent electrochemical etching. UV laser induced defects in the form of self-microstructuring on polycarbonate are developed to replicate the spatial intensity distribution as a beam profiler

  3. Excimer laser beam profile recording based on electrochemical etched polycarbonate

    Energy Technology Data Exchange (ETDEWEB)

    Parvin, P. [Physics Department, Amirkabir University of Technology, P.O. Box 15875-4413, Hafez Ave, Tehran (Iran, Islamic Republic of); Laser Research Center, AEOI, P.O. Box 1165-8486, Tehran (Iran, Islamic Republic of)], E-mail: parvin@aut.ac.ir; Jaleh, B. [Physics Department, Bu-Ali Sina University, Postal Code 65174, Hamedan (Iran, Islamic Republic of); Zangeneh, H.R. [Physics Department, Amirkabir University of Technology, P.O. Box 15875-4413, Hafez Ave, Tehran (Iran, Islamic Republic of); Zamanipour, Z. [Laser Research Center, AEOI, P.O. Box 1165-8486, Tehran (Iran, Islamic Republic of); Davoud-Abadi, Gh.R. [Physics Department, Amirkabir University of Technology, P.O. Box 15875-4413, Hafez Ave, Tehran (Iran, Islamic Republic of)

    2008-08-15

    There is no polymeric detector used to register the beam profile of UV lasers. Here, a method is proposed for the measurement of intensive UV beam pattern of the excimer lasers based on the photoablated polycarbonate detector after coherent UV exposure and the subsequent electrochemical etching. UV laser induced defects in the form of self-microstructuring on polycarbonate are developed to replicate the spatial intensity distribution as a beam profiler.

  4. Study and application of micrometric alignment on the prototype girders of the CLIC Two-Beam Module

    CERN Document Server

    Gazis, Nikolaos; Mainaud-Durand, Hélène; Samochkine, Alexandre; Anastasopoulos, Michail

    2011-01-01

    The Compact LInear Collider (CLIC), currently under study at CERN, aims at the development of a Multi-TeV e+ e- collider. The micro-precision CLIC RF-structures will have an accelerating gradient of 100 MV/m and will be mounted and aligned on specially developed supporting girders. The girder fabrication constraints are dictated by stringent physics requirements. The micrometric pre-alignment over several kilometers of girders, allow for the CLIC structures to fulfill their acceleration and collision functionality. Study of such girders and their sophisticated alignment method, is a challenging case involving dedicated mechanical design as well as prototype production and experimental testing.

  5. Applications of power beaming from space-based nuclear power stations. [Laser beaming to airplanes; microwave beaming to ground

    Energy Technology Data Exchange (ETDEWEB)

    Powell, J.R.; Botts, T.E.; Hertzberg, A.

    1981-01-01

    Power beaming from space-based reactor systems is examined using an advanced compact, lightweight Rotating Bed Reactor (RBR). Closed Brayton power conversion efficiencies in the range of 30 to 40% can be achieved with turbines, with reactor exit temperatures on the order of 2000/sup 0/K and a liquid drop radiator to reject heat at temperatures of approx. 500/sup 0/K. Higher RBR coolant temperatures (up to approx. 3000/sup 0/K) are possible, but gains in power conversion efficiency are minimal, due to lower expander efficiency (e.g., a MHD generator). Two power beaming applications are examined - laser beaming to airplanes and microwave beaming to fixed ground receivers. Use of the RBR greatly reduces system weight and cost, as compared to solar power sources. Payback times are a few years at present prices for power and airplane fuel.

  6. Image-based quantification of fiber alignment within electrospun tissue engineering scaffolds is related to mechanical anisotropy.

    Science.gov (United States)

    Fee, Timothy; Downs, Crawford; Eberhardt, Alan; Zhou, Yong; Berry, Joel

    2016-07-01

    It is well documented that electrospun tissue engineering scaffolds can be fabricated with variable degrees of fiber alignment to produce scaffolds with anisotropic mechanical properties. Several attempts have been made to quantify the degree of fiber alignment within an electrospun scaffold using image-based methods. However, these methods are limited by the inability to produce a quantitative measure of alignment that can be used to make comparisons across publications. Therefore, we have developed a new approach to quantifying the alignment present within a scaffold from scanning electron microscopic (SEM) images. The alignment is determined by using the Sobel approximation of the image gradient to determine the distribution of gradient angles with an image. This data was fit to a Von Mises distribution to find the dispersion parameter κ, which was used as a quantitative measure of fiber alignment. We fabricated four groups of electrospun polycaprolactone (PCL) + Gelatin scaffolds with alignments ranging from κ = 1.9 (aligned) to κ = 0.25 (random) and tested our alignment quantification method on these scaffolds. It was found that our alignment quantification method could distinguish between scaffolds of different alignments more accurately than two other published methods. Additionally, the alignment parameter κ was found to be a good predictor the mechanical anisotropy of our electrospun scaffolds. The ability to quantify fiber alignment within and make direct comparisons of scaffold fiber alignment across publications can reduce ambiguity between published results where cells are cultured on "highly aligned" fibrous scaffolds. This could have important implications for characterizing mechanics and cellular behavior on aligned tissue engineering scaffolds. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1680-1686, 2016. © 2016 Wiley Periodicals, Inc.

  7. Improved accuracy of multiple ncRNA alignment by incorporating structural information into a MAFFT-based framework

    Directory of Open Access Journals (Sweden)

    Toh Hiroyuki

    2008-04-01

    Full Text Available Abstract Background Structural alignment of RNAs is becoming important, since the discovery of functional non-coding RNAs (ncRNAs. Recent studies, mainly based on various approximations of the Sankoff algorithm, have resulted in considerable improvement in the accuracy of pairwise structural alignment. In contrast, for the cases with more than two sequences, the practical merit of structural alignment remains unclear as compared to traditional sequence-based methods, although the importance of multiple structural alignment is widely recognized. Results We took a different approach from a straightforward extension of the Sankoff algorithm to the multiple alignments from the viewpoints of accuracy and time complexity. As a new option of the MAFFT alignment program, we developed a multiple RNA alignment framework, X-INS-i, which builds a multiple alignment with an iterative method incorporating structural information through two components: (1 pairwise structural alignments by an external pairwise alignment method such as SCARNA or LaRA and (2 a new objective function, Four-way Consistency, derived from the base-pairing probability of every sub-aligned group at every multiple alignment stage. Conclusion The BRAliBASE benchmark showed that X-INS-i outperforms other methods currently available in the sum-of-pairs score (SPS criterion. As a basis for predicting common secondary structure, the accuracy of the present method is comparable to or rather higher than those of the current leading methods such as RNA Sampler. The X-INS-i framework can be used for building a multiple RNA alignment from any combination of algorithms for pairwise RNA alignment and base-pairing probability. The source code is available at the webpage found in the Availability and requirements section.

  8. Coordination Analysis Using Global Structural Constraints and Alignment-based Local Features

    Science.gov (United States)

    Hara, Kazuo; Shimbo, Masashi; Matsumoto, Yuji

    We propose a hybrid approach to coordinate structure analysis that combines a simple grammar to ensure consistent global structure of coordinations in a sentence, and features based on sequence alignment to capture local symmetry of conjuncts. The weight of the alignment-based features, which in turn determines the score of coordinate structures, is optimized by perceptron training on a given corpus. A bottom-up chart parsing algorithm efficiently finds the best scoring structure, taking both nested or non-overlapping flat coordinations into account. We demonstrate that our approach outperforms existing parsers in coordination scope detection on the Genia corpus.

  9. Simulation based analysis of laser beam brazing

    Science.gov (United States)

    Dobler, Michael; Wiethop, Philipp; Schmid, Daniel; Schmidt, Michael

    2016-03-01

    Laser beam brazing is a well-established joining technology in car body manufacturing with main applications in the joining of divided tailgates and the joining of roof and side panels. A key advantage of laser brazed joints is the seam's visual quality which satisfies highest requirements. However, the laser beam brazing process is very complex and process dynamics are only partially understood. In order to gain deeper knowledge of the laser beam brazing process, to determine optimal process parameters and to test process variants, a transient three-dimensional simulation model of laser beam brazing is developed. This model takes into account energy input, heat transfer as well as fluid and wetting dynamics that lead to the formation of the brazing seam. A validation of the simulation model is performed by metallographic analysis and thermocouple measurements for different parameter sets of the brazing process. These results show that the multi-physical simulation model not only can be used to gain insight into the laser brazing process but also offers the possibility of process optimization in industrial applications. The model's capabilities in determining optimal process parameters are exemplarily shown for the laser power. Small deviations in the energy input can affect the brazing results significantly. Therefore, the simulation model is used to analyze the effect of the lateral laser beam position on the energy input and the resulting brazing seam.

  10. GPU-based cone beam computed tomography.

    Science.gov (United States)

    Noël, Peter B; Walczak, Alan M; Xu, Jinhui; Corso, Jason J; Hoffmann, Kenneth R; Schafer, Sebastian

    2010-06-01

    The use of cone beam computed tomography (CBCT) is growing in the clinical arena due to its ability to provide 3D information during interventions, its high diagnostic quality (sub-millimeter resolution), and its short scanning times (60 s). In many situations, the short scanning time of CBCT is followed by a time-consuming 3D reconstruction. The standard reconstruction algorithm for CBCT data is the filtered backprojection, which for a volume of size 256(3) takes up to 25 min on a standard system. Recent developments in the area of Graphic Processing Units (GPUs) make it possible to have access to high-performance computing solutions at a low cost, allowing their use in many scientific problems. We have implemented an algorithm for 3D reconstruction of CBCT data using the Compute Unified Device Architecture (CUDA) provided by NVIDIA (NVIDIA Corporation, Santa Clara, California), which was executed on a NVIDIA GeForce GTX 280. Our implementation results in improved reconstruction times from minutes, and perhaps hours, to a matter of seconds, while also giving the clinician the ability to view 3D volumetric data at higher resolutions. We evaluated our implementation on ten clinical data sets and one phantom data set to observe if differences occur between CPU and GPU-based reconstructions. By using our approach, the computation time for 256(3) is reduced from 25 min on the CPU to 3.2 s on the GPU. The GPU reconstruction time for 512(3) volumes is 8.5 s. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

  11. K2 and K2*: efficient alignment-free sequence similarity measurement based on Kendall statistics.

    Science.gov (United States)

    Lin, Jie; Adjeroh, Donald A; Jiang, Bing-Hua; Jiang, Yue

    2018-05-15

    Alignment-free sequence comparison methods can compute the pairwise similarity between a huge number of sequences much faster than sequence-alignment based methods. We propose a new non-parametric alignment-free sequence comparison method, called K2, based on the Kendall statistics. Comparing to the other state-of-the-art alignment-free comparison methods, K2 demonstrates competitive performance in generating the phylogenetic tree, in evaluating functionally related regulatory sequences, and in computing the edit distance (similarity/dissimilarity) between sequences. Furthermore, the K2 approach is much faster than the other methods. An improved method, K2*, is also proposed, which is able to determine the appropriate algorithmic parameter (length) automatically, without first considering different values. Comparative analysis with the state-of-the-art alignment-free sequence similarity methods demonstrates the superiority of the proposed approaches, especially with increasing sequence length, or increasing dataset sizes. The K2 and K2* approaches are implemented in the R language as a package and is freely available for open access (http://community.wvu.edu/daadjeroh/projects/K2/K2_1.0.tar.gz). yueljiang@163.com. Supplementary data are available at Bioinformatics online.

  12. pyPaSWAS: Python-based multi-core CPU and GPU sequence alignment.

    Science.gov (United States)

    Warris, Sven; Timal, N Roshan N; Kempenaar, Marcel; Poortinga, Arne M; van de Geest, Henri; Varbanescu, Ana L; Nap, Jan-Peter

    2018-01-01

    Our previously published CUDA-only application PaSWAS for Smith-Waterman (SW) sequence alignment of any type of sequence on NVIDIA-based GPUs is platform-specific and therefore adopted less than could be. The OpenCL language is supported more widely and allows use on a variety of hardware platforms. Moreover, there is a need to promote the adoption of parallel computing in bioinformatics by making its use and extension more simple through more and better application of high-level languages commonly used in bioinformatics, such as Python. The novel application pyPaSWAS presents the parallel SW sequence alignment code fully packed in Python. It is a generic SW implementation running on several hardware platforms with multi-core systems and/or GPUs that provides accurate sequence alignments that also can be inspected for alignment details. Additionally, pyPaSWAS support the affine gap penalty. Python libraries are used for automated system configuration, I/O and logging. This way, the Python environment will stimulate further extension and use of pyPaSWAS. pyPaSWAS presents an easy Python-based environment for accurate and retrievable parallel SW sequence alignments on GPUs and multi-core systems. The strategy of integrating Python with high-performance parallel compute languages to create a developer- and user-friendly environment should be considered for other computationally intensive bioinformatics algorithms.

  13. Parametric Design and Mechanical Analysis of Beams based on SINOVATION

    Science.gov (United States)

    Xu, Z. G.; Shen, W. D.; Yang, D. Y.; Liu, W. M.

    2017-07-01

    In engineering practice, engineer needs to carry out complicated calculation when the loads on the beam are complex. The processes of analysis and calculation take a lot of time and the results are unreliable. So VS2005 and ADK are used to develop a software for beams design based on the 3D CAD software SINOVATION with C ++ programming language. The software can realize the mechanical analysis and parameterized design of various types of beams and output the report of design in HTML format. Efficiency and reliability of design of beams are improved.

  14. Centroid stabilization for laser alignment to corner cubes: designing a matched filter

    Energy Technology Data Exchange (ETDEWEB)

    Awwal, Abdul A. S.; Bliss, Erlan; Brunton, Gordon; Kamm, Victoria Miller; Leach, Richard R.; Lowe-Webb, Roger; Roberts, Randy; Wilhelmsen, Karl

    2016-11-08

    Automation of image-based alignment of National Ignition Facility high energy laser beams is providing the capability of executing multiple target shots per day. One important alignment is beam centration through the second and third harmonic generating crystals in the final optics assembly (FOA), which employs two retroreflecting corner cubes as centering references for each beam. Beam-to-beam variations and systematic beam changes over time in the FOA corner cube images can lead to a reduction in accuracy as well as increased convergence durations for the template-based position detector. A systematic approach is described that maintains FOA corner cube templates and guarantees stable position estimation.

  15. Arc-based smoothing of ion beam intensity on targets

    International Nuclear Information System (INIS)

    Friedman, Alex

    2012-01-01

    By manipulating a set of ion beams upstream of a target, it is possible to arrange for a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy (“heavy-ion fusion”). Here, we consider an approach to such smoothing that is based on rapidly “wobbling” each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this is sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. It is found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.

  16. Microcontroller based interface unit for Indus-2 beam scraper

    International Nuclear Information System (INIS)

    Puntambekar, T.A.; Holikatti, A.C.; Banerji, Anil; Kotaiah, S.

    2005-01-01

    In this paper we present the design and development of a microcontroller based interface unit for Indus-2 beam scraper, which is a destructive type of diagnostic device. The design of the interface unit has been aimed at a complete remote operation of the beam scraper from the control room. Safety interlock issues have also been presented. (author)

  17. Study and development of a laser based alignment system for the compact linear collider

    CERN Document Server

    AUTHOR|(CDS)2083149

    The first objective of the PhD thesis is to develop a new type of positioning sensor to align components at micrometre level over 200 m with respect to a laser beam as straight line reference. The second objective is to estimate the measurement accuracy of the total alignment system over 200 m. The context of the PhD thesis is the Compact Linear Collider project, which is a study for a future particle accelerator. The proposed positioning sensor is made of a camera and an open/close shutter. The sensor can measure the position of the laser beam with respect to its own coordinate system. To do a measurement, the shutter closes, a laser spot appears on it, the camera captures a picture of the laser spot and the coordinates of the laser spot centre are reconstructed in the sensor coordinate system with image processing. Such a measurement requires reference targets on the positioning sensor. To reach the rst objective of the PhD thesis, we used laser theory...

  18. Automatic learning-based beam angle selection for thoracic IMRT

    International Nuclear Information System (INIS)

    Amit, Guy; Marshall, Andrea; Purdie, Thomas G.; Jaffray, David A.; Levinshtein, Alex; Hope, Andrew J.; Lindsay, Patricia; Pekar, Vladimir

    2015-01-01

    Purpose: The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process, which requires the planner to iterate between choosing beam angles, specifying dose–volume objectives and executing IMRT optimization. In thorax treatment planning, where there are no class solutions for beam placement, beam angle selection is performed manually, based on the planner’s clinical experience. The purpose of this work is to propose and study a computationally efficient framework that utilizes machine learning to automatically select treatment beam angles. Such a framework may be helpful for reducing the overall planning workload. Methods: The authors introduce an automated beam selection method, based on learning the relationships between beam angles and anatomical features. Using a large set of clinically approved IMRT plans, a random forest regression algorithm is trained to map a multitude of anatomical features into an individual beam score. An optimization scheme is then built to select and adjust the beam angles, considering the learned interbeam dependencies. The validity and quality of the automatically selected beams evaluated using the manually selected beams from the corresponding clinical plans as the ground truth. Results: The analysis included 149 clinically approved thoracic IMRT plans. For a randomly selected test subset of 27 plans, IMRT plans were generated using automatically selected beams and compared to the clinical plans. The comparison of the predicted and the clinical beam angles demonstrated a good average correspondence between the two (angular distance 16.8° ± 10°, correlation 0.75 ± 0.2). The dose distributions of the semiautomatic and clinical plans were equivalent in terms of primary target volume

  19. In-plane aligned YBCO film on textured YSZ buffer layer deposited on NiCr alloy tape by laser ablation with only O+ ion beam assistance

    International Nuclear Information System (INIS)

    Xin Tang Huang

    2000-01-01

    High critical current density and in-plane aligned YBa 2 Cu 3 O 7-x (YBCO) film on a textured yttria-stabilized zirconia (YSZ) buffer layer deposited on NiCr alloy (Hastelloy c-275) tape by laser ablation with only O + ion beam assistance was fabricated. The values of the x-ray phi-scan full width at half-maximum (FWHM) for YSZ(202) and YBCO(103) are 18 deg. and 11 deg., respectively. The critical current density of YBCO film is 7.9 x 105 A cm -2 at liquid nitrogen temperature and zero field, and its critical temperature is 90 K. (author)

  20. Alignment of global supply networks based on strategic groups of supply chains

    Directory of Open Access Journals (Sweden)

    Nikos G. Moraitakis

    2017-09-01

    Full Text Available Background: From a supply chain perspective, often big differences exist between global raw material suppliers’ approaches to supply their respective local markets. The progressing complexity of large centrally managed global supply networks and their often-unknown upstream ramifications increase the likelihood of undetected bottlenecks and inefficiencies. It is therefore necessary to develop an approach to strategically master the upstream complexity of such networks from a holistic supply chain perspective in order to align regional competitive priorities and supply chain structures. The objective of this research is hence to develop an approach for the supply-chain-based alignment of complex global supply networks. Method: We review existing literature from the fields of supply chain and network management, strategic sourcing, and strategic management. Based on the literature review and theoretical and practical considerations we deduce a conceptual approach to consider upstream supply chain structures in supply network alignment initiatives. Results: On the basis of these considerations and current empirical literature we transfer strategic group theory to the supply network management context. The proposed approach introduces strategic groups of supply chains as a segmentation criterion for complex global supply networks which enables the network-wide alignment of competitive priorities. Conclusion: Supply-chain-based segmentation of global supply network structures can effectively reduce the complexity, firms face when aiming to strategically align their supply chains on a holistic level. The results of this research are applicable for certain types of global supply networks and can be used for network alignment and strategy development. The approach can furthermore generate insights useable for negotiation support with suppliers.

  1. Agent Based Model in SAS Environment for Rail Transit System Alignment Determination

    Directory of Open Access Journals (Sweden)

    I Made Indradjaja Brunner

    2018-04-01

    Full Text Available Transit system had been proposed for the urban area of Honolulu. One consideration to be determined is the alignment of the transit system. Decision to set the transit alignment will have influences on which areas will be served, who will be benefiting, as well as who will be impacted. Inputs for the decision usually conducted through public meetings, where community members are shown numbers of maps with pre-set routes. That approach could lead to a rather subjective decision by the community members. This paper attempts to discuss the utilization of grid map in determining the best alignment for rail transit system in Honolulu, Hawaii. It tries to use a more objective approach using various data derived from thematic maps. Overlaid maps are aggregated into a uniform 0.1-square mile vector based grid map system in GIS environment. The large dataset in the GIS environment is analyzed and manipulated using SAS software. The SAS procedure is applied to select the location of the alignment using a rational and deterministic approach. Grid cells that are superior compared to the others are selected based on several predefined criteria. Location of the dominant cells indicates possible transit alignment. The SAS procedure is designed to allow a transient vector called the GUIDE (Grid Unit with Intelligent Directional Expertise agent to analyze several cells at its vicinity and to move towards a cell with the highest value. Each time the agent landed on a cell, it left a mark. The chain of those marks shows location for the transit alignment. This study shows that the combination of ArcGIS and SAS allows a robust analysis of spatial data and manipulation of its datasets, which can be used to run a simulation mimicking the Agent-Based Modelling. This study also opens up further study possibilities by increasing number of factors analyzed by the agent, as well as creating a composite value of multi-factors.

  2. Incremental Ontology-Based Extraction and Alignment in Semi-structured Documents

    Science.gov (United States)

    Thiam, Mouhamadou; Bennacer, Nacéra; Pernelle, Nathalie; Lô, Moussa

    SHIRIis an ontology-based system for integration of semi-structured documents related to a specific domain. The system’s purpose is to allow users to access to relevant parts of documents as answers to their queries. SHIRI uses RDF/OWL for representation of resources and SPARQL for their querying. It relies on an automatic, unsupervised and ontology-driven approach for extraction, alignment and semantic annotation of tagged elements of documents. In this paper, we focus on the Extract-Align algorithm which exploits a set of named entity and term patterns to extract term candidates to be aligned with the ontology. It proceeds in an incremental manner in order to populate the ontology with terms describing instances of the domain and to reduce the access to extern resources such as Web. We experiment it on a HTML corpus related to call for papers in computer science and the results that we obtain are very promising. These results show how the incremental behaviour of Extract-Align algorithm enriches the ontology and the number of terms (or named entities) aligned directly with the ontology increases.

  3. Genetic Process Mining: Alignment-based Process Model Mutation

    NARCIS (Netherlands)

    Eck, van M.L.; Buijs, J.C.A.M.; Dongen, van B.F.; Fournier, F.; Mendling, J.

    2015-01-01

    The Evolutionary Tree Miner (ETM) is a genetic process discovery algorithm that enables the user to guide the discovery process based on preferences with respect to four process model quality dimensions: replay fitness, precision, generalization and simplicity. Traditionally, the ETM algorithm uses

  4. A prototype distributed object-oriented architecture for image-based automatic laser alignment

    International Nuclear Information System (INIS)

    Stout, E.A.; Kamm, V.J.M.; Spann, J.M.; Van Arsdall, P.J.

    1996-01-01

    Designing a computer control system for the National Ignition Facility (NIF) is a complex undertaking because of the system's large size and its distributed nature. The controls team is addressing that complexity by adopting the object-oriented programming paradigm, designing reusable software frameworks, and using the Common Object Request Broker Architecture (CORBA) for distribution. A prototype system for image-based automatic laser alignment has been developed to evaluate and gain experience with CORBA and OOP in a small distributed system. The prototype is also important in evaluating alignment concepts, image processing techniques, speed and accuracy of automatic alignment objectives for the NIF, and control hardware for aligment devices. The prototype system has met its inital objectives and provides a basis for continued development

  5. Rapid Transfer Alignment of MEMS SINS Based on Adaptive Incremental Kalman Filter.

    Science.gov (United States)

    Chu, Hairong; Sun, Tingting; Zhang, Baiqiang; Zhang, Hongwei; Chen, Yang

    2017-01-14

    In airborne MEMS SINS transfer alignment, the error of MEMS IMU is highly environment-dependent and the parameters of the system model are also uncertain, which may lead to large error and bad convergence of the Kalman filter. In order to solve this problem, an improved adaptive incremental Kalman filter (AIKF) algorithm is proposed. First, the model of SINS transfer alignment is defined based on the "Velocity and Attitude" matching method. Then the detailed algorithm progress of AIKF and its recurrence formulas are presented. The performance and calculation amount of AKF and AIKF are also compared. Finally, a simulation test is designed to verify the accuracy and the rapidity of the AIKF algorithm by comparing it with KF and AKF. The results show that the AIKF algorithm has better estimation accuracy and shorter convergence time, especially for the bias of the gyroscope and the accelerometer, which can meet the accuracy and rapidity requirement of transfer alignment.

  6. Rapid Transfer Alignment of MEMS SINS Based on Adaptive Incremental Kalman Filter

    Directory of Open Access Journals (Sweden)

    Hairong Chu

    2017-01-01

    Full Text Available In airborne MEMS SINS transfer alignment, the error of MEMS IMU is highly environment-dependent and the parameters of the system model are also uncertain, which may lead to large error and bad convergence of the Kalman filter. In order to solve this problem, an improved adaptive incremental Kalman filter (AIKF algorithm is proposed. First, the model of SINS transfer alignment is defined based on the “Velocity and Attitude” matching method. Then the detailed algorithm progress of AIKF and its recurrence formulas are presented. The performance and calculation amount of AKF and AIKF are also compared. Finally, a simulation test is designed to verify the accuracy and the rapidity of the AIKF algorithm by comparing it with KF and AKF. The results show that the AIKF algorithm has better estimation accuracy and shorter convergence time, especially for the bias of the gyroscope and the accelerometer, which can meet the accuracy and rapidity requirement of transfer alignment.

  7. An Electron Beam Profile Instrument Based on FBGs

    Directory of Open Access Journals (Sweden)

    Dan Sporea

    2014-08-01

    Full Text Available Along with the dose rate and the total irradiation dose measurements, the knowledge of the beam localization and the beam profile/energy distribution in the beam are parameters of interest for charged particle accelerator installations when they are used in scientific investigations, industrial applications or medical treatments. The transverse profile of the beam, its position, its centroid location, and its focus or flatness depend on the instrument operating conditions or on the beam exit setup. Proof-of-concept of a new type of charged particle beam diagnostics based on fiber Bragg gratings (FBGs was demonstrated. Its operating principle relies on the measurement of the peak wavelength changes for an array of FBG sensors as function of the temperature following the exposure to an electron beam. Periodically, the sensor irradiation is stopped and the FBG are force cooled to a reference temperature with which the temperature influencing each sensor during beam exposure is compared. Commercially available FBGs, and FBGs written in radiation resistant optical fibers, were tested under electron beam irradiation in order to study their possible use in this application.

  8. Two-Stream Transformer Networks for Video-based Face Alignment.

    Science.gov (United States)

    Liu, Hao; Lu, Jiwen; Feng, Jianjiang; Zhou, Jie

    2017-08-01

    In this paper, we propose a two-stream transformer networks (TSTN) approach for video-based face alignment. Unlike conventional image-based face alignment approaches which cannot explicitly model the temporal dependency in videos and motivated by the fact that consistent movements of facial landmarks usually occur across consecutive frames, our TSTN aims to capture the complementary information of both the spatial appearance on still frames and the temporal consistency information across frames. To achieve this, we develop a two-stream architecture, which decomposes the video-based face alignment into spatial and temporal streams accordingly. Specifically, the spatial stream aims to transform the facial image to the landmark positions by preserving the holistic facial shape structure. Accordingly, the temporal stream encodes the video input as active appearance codes, where the temporal consistency information across frames is captured to help shape refinements. Experimental results on the benchmarking video-based face alignment datasets show very competitive performance of our method in comparisons to the state-of-the-arts.

  9. pyPaSWAS : Python-based multi-core CPU and GPU sequence alignment

    NARCIS (Netherlands)

    Warris, Sven; Timal, N Roshan N; Kempenaar, Marcel; Poortinga, Arne M; van de Geest, Henri; Varbanescu, Ana L; Nap, Jan-Peter

    2018-01-01

    BACKGROUND: Our previously published CUDA-only application PaSWAS for Smith-Waterman (SW) sequence alignment of any type of sequence on NVIDIA-based GPUs is platform-specific and therefore adopted less than could be. The OpenCL language is supported more widely and allows use on a variety of

  10. Beam Based RF Voltage Measurements and Longitudinal Beam Tomography at the Fermilab Booster

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C. M. [Fermilab; Bhat, S. [Fermilab

    2017-10-19

    Increasing proton beam power on neutrino production targets is one of the major goals of the Fermilab long term accelerator programs. In this effort, the Fermilab 8 GeV Booster synchrotron plays a critical role for at least the next two decades. Therefore, understanding the Booster in great detail is important as we continue to improve its performance. For example, it is important to know accurately the available RF power in the Booster by carrying out beam-based measurements in order to specify the needed upgrades to the Booster RF system. Since the Booster magnetic field is changing continuously measuring/calibrating the RF voltage is not a trivial task. Here, we present a beam based method for the RF voltage measurements. Data analysis is carried out using computer programs developed in Python and MATLAB. The method presented here is applicable to any RCS which do not have flat-bottom and flat-top in the acceleration magnetic ramps. We have also carried out longitudinal beam tomography at injection and extraction energies with the data used for RF voltage measurements. Beam based RF voltage measurements and beam tomography were never done before for the Fermilab Booster. The results from these investigations will be very useful in future intensity upgrades.

  11. First Experiences of Beam Presence Detection Based on Dedicated Beam Position Monitors

    CERN Document Server

    Jalal, A; Gasior, M; Todd, B

    2011-01-01

    High intensity particle beam injection into the LHC is only permitted when a low intensity pilot beam is already circulating in the LHC. This requirement addresses some of the risks associated with high intensity injection, and is enforced by a so-called Beam Presence Flag (BPF) system which is part of the interlock chain between the LHC and its injector complex. For the 2010 LHC run, the detection of the presence of this pilot beam was implemented using the LHC Fast Beam Current Transformer (FBCT) system. However, the primary function of the FBCTs, that is reliable measurement of beam currents, did not allow the BPF system to satisfy all quality requirements of the LHC Machine Protection System (MPS). Safety requirements associated with high intensity injections triggered the development of a dedicated system, based on Beam Position Monitors (BPM). This system was meant to work first in parallel with the FBCT BPF system and eventually replace it. At the end of 2010 and in 2011, this new BP...

  12. Reactor - and accelerator-based filtered beams

    International Nuclear Information System (INIS)

    Mill, A.J.; Harvey, J.R.

    1980-01-01

    The neutrons produced in high flux nuclear reactors and in accelerator, induced fission and spallation reactions, represent the most intense sources of neutrons available for research. However, the neutrons from these sources are not monoenergetic, covering the broad range extending from 10 -3 eV up to 10 7 eV or so. In order to make quantitative measurements of the effects of neutrons and their dependence on neutron energy it is desirable to have mono-energetic neutron sources. The paper describes briefly methods of obtaining mono-energetic neutrons and different methods of filtration. This is followed by more detailed discussion of neutron window filters and a summary of the filtered beam facilities using this technique. The review concludes with a discussion of the main applications of filtered beams and their present and future importance

  13. Graphene as transmissive electrodes and aligning layers for liquid-crystal-based electro-optic devices.

    Science.gov (United States)

    Basu, Rajratan; Shalov, Samuel A

    2017-07-01

    In a conventional liquid crystal (LC) cell, polyimide layers are used to align the LC homogeneously in the cell, and transmissive indium tin oxide (ITO) electrodes are used to apply the electric field to reorient the LC along the field. It is experimentally presented here that monolayer graphene films on the two glass substrates can function concurrently as the LC aligning layers and the transparent electrodes to fabricate an LC cell, without using the conventional polyimide and ITO substrates. This replacement can effectively decrease the thickness of all the alignment layers and electrodes from about 100 nm to less than 1 nm. The interaction between LC and graphene through π-π electron stacking imposes a planar alignment on the LC in the graphene-based cell-which is verified using a crossed polarized microscope. The graphene-based LC cell exhibits an excellent nematic director reorientation process from planar to homeotropic configuration through the application of an electric field-which is probed by dielectric and electro-optic measurements. Finally, it is shown that the electro-optic switching is significantly faster in the graphene-based LC cell than in a conventional ITO-polyimide LC cell.

  14. Skeleton-based human action recognition using multiple sequence alignment

    Science.gov (United States)

    Ding, Wenwen; Liu, Kai; Cheng, Fei; Zhang, Jin; Li, YunSong

    2015-05-01

    Human action recognition and analysis is an active research topic in computer vision for many years. This paper presents a method to represent human actions based on trajectories consisting of 3D joint positions. This method first decompose action into a sequence of meaningful atomic actions (actionlets), and then label actionlets with English alphabets according to the Davies-Bouldin index value. Therefore, an action can be represented using a sequence of actionlet symbols, which will preserve the temporal order of occurrence of each of the actionlets. Finally, we employ sequence comparison to classify multiple actions through using string matching algorithms (Needleman-Wunsch). The effectiveness of the proposed method is evaluated on datasets captured by commodity depth cameras. Experiments of the proposed method on three challenging 3D action datasets show promising results.

  15. Performance and perspectives of the diamond based Beam Condition Monitor for beam loss monitoring at CMS

    CERN Document Server

    AUTHOR|(CDS)2080862

    2015-01-01

    At CMS, a beam loss monitoring system is operated to protect the silicon detectors from high particle rates, arising from intense beam loss events. As detectors, poly-crystalline CVD diamond sensors are placed around the beam pipe at several locations inside CMS. In case of extremely high detector currents, the LHC beams are automatically extracted from the LHC rings.Diamond is the detector material of choice due to its radiation hardness. Predictions of the detector lifetime were made based on FLUKA monte-carlo simulations and irradiation test results from the RD42 collaboration, which attested no significant radiation damage over several years.During the LHC operational Run1 (2010 â?? 2013), the detector efficiencies were monitored. A signal decrease of about 50 times stronger than expectations was observed in the in-situ radiation environment. Electric field deformations due to charge carriers, trapped in radiation induced lattice defects, are responsible for this signal decrease. This so-called polarizat...

  16. Beam-based calibration system of BPM offset on BEPC

    International Nuclear Information System (INIS)

    Hu Chunliang

    2004-01-01

    The ever-increasing demand for better performance from circular accelerators requires improved methods to calibrate beam position monitors (BPM). A beam based calibration system has been established to locate the centers of the BPM with respect to the magnetic center of quadrupole magnets. Additional windings are applied to the quadrupole magnets to make the quadrupole magnetic strength individually adjustable and the number of the power supply of all 32 additional windings is only one. Software system has been finished to automatically measure the offsets of BPMs. The effect of the beam-based calibration system shows that the calibration of BPM has been more quickly and accurately

  17. 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

  18. 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.

  19. Performance based design of reinforced concrete beams under impact

    Directory of Open Access Journals (Sweden)

    S. Tachibana

    2010-06-01

    Full Text Available The purpose of this research is to collect fundamental data and to establish a performance-based design method for reinforced concrete beams under perpendicular impact load.

    Series of low speed impact experiments using reinforced concrete beams were performed varying span length, cross section and main reinforcement.

    The experimental results are evaluated focusing on the impact load characteristics and the impact behaviours of reinforced concrete beams. Various characteristic values and their relationships are investigated such as the collision energy, the impact force duration, the energy absorbed by the beams and the beam response values. Also the bending performance of the reinforced concrete beams against perpendicular impact is evaluated.

    An equation is proposed to estimate the maximum displacement of the beam based on the collision energy and the static ultimate bending strength. The validity of the proposed equation is confirmed by comparison with experimental results obtained by other researchers as well as numerical results obtained by FEM simulations. The proposed equation allows for a performance based design of the structure accounting for the actual deformation due to the expected impact action.

  20. Proton-beam writing channel based on an electrostatic accelerator

    Science.gov (United States)

    Lapin, A. S.; Rebrov, V. A.; Kolin'ko, S. V.; Salivon, V. F.; Ponomarev, A. G.

    2016-09-01

    We have described the structure of the proton-beam writing channel as a continuation of a nuclear scanning microprobe channel. The problem of the accuracy of positioning a probe by constructing a new high-frequency electrostatic scanning system has been solved. Special attention has been paid to designing the probe-forming system and its various configurations have been considered. The probe-forming system that best corresponds to the conditions of the lithographic process has been found based on solving the problem of optimizing proton beam formation. A system for controlling beam scanning using multifunctional module of integrated programmable logic systems has been developed.

  1. Synergistic Instance-Level Subspace Alignment for Fine-Grained Sketch-Based Image Retrieval.

    Science.gov (United States)

    Li, Ke; Pang, Kaiyue; Song, Yi-Zhe; Hospedales, Timothy M; Xiang, Tao; Zhang, Honggang

    2017-08-25

    We study the problem of fine-grained sketch-based image retrieval. By performing instance-level (rather than category-level) retrieval, it embodies a timely and practical application, particularly with the ubiquitous availability of touchscreens. Three factors contribute to the challenging nature of the problem: (i) free-hand sketches are inherently abstract and iconic, making visual comparisons with photos difficult, (ii) sketches and photos are in two different visual domains, i.e. black and white lines vs. color pixels, and (iii) fine-grained distinctions are especially challenging when executed across domain and abstraction-level. To address these challenges, we propose to bridge the image-sketch gap both at the high-level via parts and attributes, as well as at the low-level, via introducing a new domain alignment method. More specifically, (i) we contribute a dataset with 304 photos and 912 sketches, where each sketch and image is annotated with its semantic parts and associated part-level attributes. With the help of this dataset, we investigate (ii) how strongly-supervised deformable part-based models can be learned that subsequently enable automatic detection of part-level attributes, and provide pose-aligned sketch-image comparisons. To reduce the sketch-image gap when comparing low-level features, we also (iii) propose a novel method for instance-level domain-alignment, that exploits both subspace and instance-level cues to better align the domains. Finally (iv) these are combined in a matching framework integrating aligned low-level features, mid-level geometric structure and high-level semantic attributes. Extensive experiments conducted on our new dataset demonstrate effectiveness of the proposed method.

  2. First experiences of beam presence detection based on dedicated beam position monitors

    International Nuclear Information System (INIS)

    Jalal, A.; Gabourin, S.; Gasior, M.; Todd, B.

    2012-01-01

    High intensity particle beam injection into the LHC is only permitted when a low intensity pilot beam is already circulating in the LHC. This requirement addresses some of the risks associated with high intensity injection, and is enforced by a so-called Beam Presence Flag (BPF) system which is part of the interlock chain between the LHC and its injector complex. For the 2010 LHC run, the detection of the presence of this pilot beam was implemented using the LHC Fast Beam Current Transformer (FBCT) system. However, the primary function of the FBCTs, that is reliable measurement of beam currents, did not allow the BPF system to satisfy all quality requirements of the LHC Machine Protection System (MPS). Safety requirements associated with high intensity injections triggered the development of a dedicated system, based on Beam Position Monitors (BPM). This system was meant to work first in parallel with the FBCT BPF system and eventually replace it. At the end of 2010 and in 2011, this new BPF implementation based on BPMs was designed, built, tested and deployed. This paper reviews both the FBCT and BPM implementation of the BPF system, outlining the changes during the transition period. The paper briefly describes the testing methods, focuses on the results obtained from the tests performed during the end of 2010 LHC run and shows the changes made for the BPM BPF system deployment in LHC in 2011. Whilst the system has been proved to work with a threshold of 6*10 8 charges, it has been implemented with a threshold of 2*10 9 charges to protect the LHC. (authors)

  3. Extended particle-based simulation for magnetic-aligned compaction of hard magnetic particles

    Energy Technology Data Exchange (ETDEWEB)

    Soda, Rikio; Takagi, Kenta; Ozaki, Kimihiro, E-mail: r-soda@aist.go.jp

    2015-12-15

    In order to understand the magnetic-aligned compaction process, we develop a three-dimensional (3D) discrete element method for simulating the motion of hard magnetic particles subjected to strong compression and magnetic fields. The proposed simulation model also considers the exact magnetic force involved via the calculation of the magnetic moment. First, to validate the simulation model, single-action compaction in the absence of a magnetic field was calculated. The calculated compaction curves are in good quantitative agreement with experimental ones. Based on this simulation model, the alignment behavior of Nd–Fe–B particles during compression under the application of a static magnetic field. The developed simulation model enables the visualization of particle behavior including the misorientation of the magnetization easy axis, which provided the quantitative relationships between applied pressure and particle misorientation. - Highlights: • A practical 3D DEM simulation technique for magnetic-aligned compaction was developed. • An extended simulation model was introduced for hard magnetic particles. • Magnetic-aligned compaction was simulated using the developed simulation model.

  4. Track based alignment of the CMS silicon tracker and its implication on physics performance

    International Nuclear Information System (INIS)

    Draeger, Jula

    2011-08-01

    In order to fully exploit the discovery potential of the CMS detector for new physics beyond the Standard Model at the high luminosity and centre-of-mass energy provided by the Large Hadron Collider, a careful calibration of the detector and profound understanding of its impact on physics performance are necessary to provide realistic uncertainties for the measurements of physics processes. This thesis describes the track-based alignment of the inner tracking system of CMS with the Millepede II algorithm. Using the combined information of tracks from cosmic rays and collisions taken in 2010, a remarkable local alignment precision has been reached that meets the design specification for most regions of the detector and takes into account instabilities of the detector geometry over time. In addition, the impact of the alignment of b tagging or the Z boson resonance are investigated. The latter is studied to investigate the impact of correlated detector distortions which hardly influence the overall solution of the minimisation problem but introduce biases in the track parameters and thus the derived physics quantities. The determination and constraint of these weak modes present the future challenge of the alignment task at CMS. (orig.)

  5. MISTICA: Minimum Spanning Tree-Based Coarse Image Alignment for Microscopy Image Sequences.

    Science.gov (United States)

    Ray, Nilanjan; McArdle, Sara; Ley, Klaus; Acton, Scott T

    2016-11-01

    Registration of an in vivo microscopy image sequence is necessary in many significant studies, including studies of atherosclerosis in large arteries and the heart. Significant cardiac and respiratory motion of the living subject, occasional spells of focal plane changes, drift in the field of view, and long image sequences are the principal roadblocks. The first step in such a registration process is the removal of translational and rotational motion. Next, a deformable registration can be performed. The focus of our study here is to remove the translation and/or rigid body motion that we refer to here as coarse alignment. The existing techniques for coarse alignment are unable to accommodate long sequences often consisting of periods of poor quality images (as quantified by a suitable perceptual measure). Many existing methods require the user to select an anchor image to which other images are registered. We propose a novel method for coarse image sequence alignment based on minimum weighted spanning trees (MISTICA) that overcomes these difficulties. The principal idea behind MISTICA is to reorder the images in shorter sequences, to demote nonconforming or poor quality images in the registration process, and to mitigate the error propagation. The anchor image is selected automatically making MISTICA completely automated. MISTICA is computationally efficient. It has a single tuning parameter that determines graph width, which can also be eliminated by the way of additional computation. MISTICA outperforms existing alignment methods when applied to microscopy image sequences of mouse arteries.

  6. Accurate and robust brain image alignment using boundary-based registration.

    Science.gov (United States)

    Greve, Douglas N; Fischl, Bruce

    2009-10-15

    The fine spatial scales of the structures in the human brain represent an enormous challenge to the successful integration of information from different images for both within- and between-subject analysis. While many algorithms to register image pairs from the same subject exist, visual inspection shows that their accuracy and robustness to be suspect, particularly when there are strong intensity gradients and/or only part of the brain is imaged. This paper introduces a new algorithm called Boundary-Based Registration, or BBR. The novelty of BBR is that it treats the two images very differently. The reference image must be of sufficient resolution and quality to extract surfaces that separate tissue types. The input image is then aligned to the reference by maximizing the intensity gradient across tissue boundaries. Several lower quality images can be aligned through their alignment with the reference. Visual inspection and fMRI results show that BBR is more accurate than correlation ratio or normalized mutual information and is considerably more robust to even strong intensity inhomogeneities. BBR also excels at aligning partial-brain images to whole-brain images, a domain in which existing registration algorithms frequently fail. Even in the limit of registering a single slice, we show the BBR results to be robust and accurate.

  7. Track based alignment of the CMS silicon tracker and its implication on physics performance

    Energy Technology Data Exchange (ETDEWEB)

    Draeger, Jula

    2011-08-15

    In order to fully exploit the discovery potential of the CMS detector for new physics beyond the Standard Model at the high luminosity and centre-of-mass energy provided by the Large Hadron Collider, a careful calibration of the detector and profound understanding of its impact on physics performance are necessary to provide realistic uncertainties for the measurements of physics processes. This thesis describes the track-based alignment of the inner tracking system of CMS with the Millepede II algorithm. Using the combined information of tracks from cosmic rays and collisions taken in 2010, a remarkable local alignment precision has been reached that meets the design specification for most regions of the detector and takes into account instabilities of the detector geometry over time. In addition, the impact of the alignment of b tagging or the Z boson resonance are investigated. The latter is studied to investigate the impact of correlated detector distortions which hardly influence the overall solution of the minimisation problem but introduce biases in the track parameters and thus the derived physics quantities. The determination and constraint of these weak modes present the future challenge of the alignment task at CMS. (orig.)

  8. Ultrasound beam characteristics of a symmetric nodal origami based array

    Science.gov (United States)

    Bilgunde, Prathamesh N.; Bond, Leonard J.

    2018-04-01

    Origami-the ancient art of paper folding-is being explored in acoustics for effective focusing of sound. In this short communication, we present a numerical investigation of beam characteristics for an origami based ultrasound array. A spatial re-configuration of array elements is performed based upon the symmetric nodal origami. The effect of fold angle on the ultrasound beam is evaluated using frequency domain and transient finite element analysis. It was found that increase in the fold angle reduces near field length by 58% and also doubles the beam intensity as compared to the linear array. Transient analysis also indicated 80% reduction in the -6dB beam width, which can improve the lateral resolution of phased array. Such a spatially re-configurable array could potentially be used in the future to reduce the cost of electronics in the phased array instrumentation.

  9. MATLAB based beam orbit correction system of HLS storage ring

    International Nuclear Information System (INIS)

    Ding Shichuan; Liu Gongfa; Xuan Ke; Li Weimin; Wang Lin; Wang Jigang; Li Chuan; Bao Xun; Guo Weiqun

    2006-01-01

    The distortion of closed orbit usually causes much side effect which is harmful to synchrotron radiation source such as HLS, so it is necessary to correct the distortion of closed orbit. In this paper, the correction principle, development procedure and test of MATLAB based on beam orbit correction system of HLS storage ring are described. The correction system is consisted of the beam orbit measure system, corrector magnet system and the control system, and the beam orbit correction code based on MATLAB is working on the operation interface. The data of the beam orbit are analyzed and calculated firstly, and then the orbit is corrected by changing corrector strength via control system. The test shows that the distortion of closed orbit is from max 4.468 mm before correction to max 0.299 mm after correction as well as SDEV is from 2.986 mm to 0.087 mm. So the correction system reaches the design goal. (authors)

  10. Beam Dynamics Simulation for the CTF3 Drive Beam Accelerator

    CERN Document Server

    Schulte, Daniel

    2000-01-01

    A new CLIC Test Facility (CTF3) at CERN will serve to study the drive beam generation for the Compact Linear Collider (CLIC). CTF3 has to accelerate a 3.5 A electron beam in almost fully-loaded structures. The pulse contains more than 2000 bunches, one in every second RF bucket, and has a length of more than one microsecond. Different options for the lattice of the drive-beam accelerator are presented, based on FODO-cells and triplets as well as solenoids. The transverse stability is simulated, including the effects of beam jitter, alignment and beam-based correction.

  11. TotalReCaller: improved accuracy and performance via integrated alignment and base-calling.

    Science.gov (United States)

    Menges, Fabian; Narzisi, Giuseppe; Mishra, Bud

    2011-09-01

    Currently, re-sequencing approaches use multiple modules serially to interpret raw sequencing data from next-generation sequencing platforms, while remaining oblivious to the genomic information until the final alignment step. Such approaches fail to exploit the full information from both raw sequencing data and the reference genome that can yield better quality sequence reads, SNP-calls, variant detection, as well as an alignment at the best possible location in the reference genome. Thus, there is a need for novel reference-guided bioinformatics algorithms for interpreting analog signals representing sequences of the bases ({A, C, G, T}), while simultaneously aligning possible sequence reads to a source reference genome whenever available. Here, we propose a new base-calling algorithm, TotalReCaller, to achieve improved performance. A linear error model for the raw intensity data and Burrows-Wheeler transform (BWT) based alignment are combined utilizing a Bayesian score function, which is then globally optimized over all possible genomic locations using an efficient branch-and-bound approach. The algorithm has been implemented in soft- and hardware [field-programmable gate array (FPGA)] to achieve real-time performance. Empirical results on real high-throughput Illumina data were used to evaluate TotalReCaller's performance relative to its peers-Bustard, BayesCall, Ibis and Rolexa-based on several criteria, particularly those important in clinical and scientific applications. Namely, it was evaluated for (i) its base-calling speed and throughput, (ii) its read accuracy and (iii) its specificity and sensitivity in variant calling. A software implementation of TotalReCaller as well as additional information, is available at: http://bioinformatics.nyu.edu/wordpress/projects/totalrecaller/ fabian.menges@nyu.edu.

  12. Observations of the spatial and temporal structure of field-aligned beam and gyrating ring distributions at the quasi-perpendicular bow shock with Cluster CIS

    Directory of Open Access Journals (Sweden)

    E. Möbius

    2001-09-01

    Full Text Available During the early orbit phase, the Cluster spacecraft have repeatedly crossed the perpendicular Earth’s bow shock and provided the first multi-spacecraft measurements. We have analyzed data from the Cluster Ion Spectrometry experiment (CIS, which observes the 3D-ion distribution function of the major species in the energy range of 5 eV to 40 keV with a 4 s resolution. Beams of reflected ions were observed simultaneously at all spacecraft locations and could be tracked from upstream to the shock itself. They were found to originate from the same distribution of ions that constitutes the reflected gyrating ions, which form a ring distribution in the velocity space immediately upstream and downstream of the shock. This observation suggests a common origin of ring and beam populations at quasi-perpendicular shocks in the form of specular reflection and immediate pitch angle scattering. Generally, the spatial evolution across the shock is very similar on all spacecraft, but phased in time according to their relative location. However, a distinct temporal structure of the ion fluxes in the field-aligned beam is observed that varies simultaneously on all spacecraft. This is likely to reflect the variations in the reflection and scattering efficiencies.Key words. Interplanetary physics (planetary bow shocks; energetic particles; instruments and techniques

  13. Alignment Condition-Based Robust Adaptive Iterative Learning Control of Uncertain Robot System

    Directory of Open Access Journals (Sweden)

    Guofeng Tong

    2014-04-01

    Full Text Available This paper proposes an adaptive iterative learning control strategy integrated with saturation-based robust control for uncertain robot system in presence of modelling uncertainties, unknown parameter, and external disturbance under alignment condition. An important merit is that it achieves adaptive switching of gain matrix both in conventional PD-type feedforward control and robust adaptive control in the iteration domain simultaneously. The analysis of convergence of proposed control law is based on Lyapunov's direct method under alignment initial condition. Simulation results demonstrate the faster learning rate and better robust performance with proposed algorithm by comparing with other existing robust controllers. The actual experiment on three-DOF robot manipulator shows its better practical effectiveness.

  14. Landmark matching based retinal image alignment by enforcing sparsity in correspondence matrix.

    Science.gov (United States)

    Zheng, Yuanjie; Daniel, Ebenezer; Hunter, Allan A; Xiao, Rui; Gao, Jianbin; Li, Hongsheng; Maguire, Maureen G; Brainard, David H; Gee, James C

    2014-08-01

    Retinal image alignment is fundamental to many applications in diagnosis of eye diseases. In this paper, we address the problem of landmark matching based retinal image alignment. We propose a novel landmark matching formulation by enforcing sparsity in the correspondence matrix and offer its solutions based on linear programming. The proposed formulation not only enables a joint estimation of the landmark correspondences and a predefined transformation model but also combines the benefits of the softassign strategy (Chui and Rangarajan, 2003) and the combinatorial optimization of linear programming. We also introduced a set of reinforced self-similarities descriptors which can better characterize local photometric and geometric properties of the retinal image. Theoretical analysis and experimental results with both fundus color images and angiogram images show the superior performances of our algorithms to several state-of-the-art techniques. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Are institutional missions aligned with journal-based or document-based disciplinary structures?

    Energy Technology Data Exchange (ETDEWEB)

    Klavans, R.; Boyack, K.W.

    2016-07-01

    Missions represent the underlying purpose of an institution. These missions can be focused (finding a cure for cancer) or diverse (providing all health services to a local population). They might be aimed at basic research (finding new sub-atomic particles) or very applied (forecasting tomorrow’s weather). Missions can be extremely practical (building i-phones) or abstract (creating maps of scientific inquiry). Our primary focus is on those institutions that are also contributing to society’s knowledge about scientific and technical phenomena. The publications of these institutions are, to some degree, an implicit statement of their mission. Institutions focusing on a cure for cancer will publish articles associated with cancer, while hospitals will publish in a diverse set of medical specialties. Institutions focused on subatomic particles publish in specialized physics journals. While the publication profile of an institution is obviously not the same as an institution’s mission, it is typically consistent with its mission. In this study we analyze the publication profiles of over 4400 institutions using Scopus data to determine if their institutional missions are best explained using a journal-based classification system or a document-based classification system. The structure of this article is as follows. The background section places this work in the context of two streams of research – the accuracies of different document classification systems, and the effect of different national contexts (specifically wealth, health and democracy) on science systems and their impact. We then describe our data and methods before addressing two questions: Do the missions of certain types of institutions align with journal-based or article-based disciplines, and does this vary with national context (wealth, health and democracy). We conclude with a discussion of limitations and possible areas for further investigation. (Author)

  16. The AAG's ALIGNED Toolkit: A Place-based Approach to Fostering Diversity in the Geosciences

    Science.gov (United States)

    Rodrigue, C. M.

    2012-12-01

    Where do we look to attract a more diverse group of students to academic programs in geography and the geosciences? What do we do once we find them? This presentation introduces the ALIGNED Toolkit developed by the Association of American Geographers, with funding from the NSF's Opportunities to Enhance Diversity in the Geosciences (OEDG) Program. ALIGNED (Addressing Locally-tailored Information Infrastructure and Geoscience Needs for Enhancing Diversity) seeks to align the needs of university departments and underrepresented students by drawing upon the intellectual wealth of geography and spatial science to provide better informed, knowledge-based action to enhance diversity in higher education and the geoscience workforce. The project seeks to inform and transform the ways in which departments and programs envision and realize their own goals to enhance diversity, promote inclusion, and broaden participation. We also seek to provide the data, information, knowledge, and best practices needed in order to enhance the recruitment and retention of underrepresented students. The ALIGNED Toolkit is currently in a beta release, available to 13 pilot departments and 50 testing departments of geography/geosciences. It consolidates a variety of data from departments, the U.S. Census Bureau, and the U.S. Department of Education's National Center for Education Statistics to provide interactive, GIS-based visualizations across multiple scales. It also incorporates a place-based, geographic perspective to support departments in their efforts to enhance diversity. A member of ALIGNED's senior personnel, who is also a representative of one of the pilot departments, will provide an overview and preview of the tool while sharing her department's experiences in progressing toward its diversity goals. A brief discussion on how geoscience departments might benefit from the ALIGNED approach and resources will follow. Undergraduate advisors, graduate program directors, department

  17. An embeddable optical strain gauge based on a buckled beam.

    Science.gov (United States)

    Du, Yang; Chen, Yizheng; Zhu, Chen; Zhuang, Yiyang; Huang, Jie

    2017-11-01

    We report, for the first time, a low cost, compact, and novel mechanically designed extrinsic Fabry-Perot interferometer (EFPI)-based optical fiber sensor with a strain amplification mechanism for strain measurement. The fundamental design principle includes a buckled beam with a coated gold layer, mounted on two grips. A Fabry-Perot cavity is produced between the buckled beam and the endface of a single mode fiber (SMF). A ceramic ferrule is applied for supporting and orienting the SMF. The principal sensor elements are packaged and protected by two designed metal shells. The midpoint of the buckled beam will experience a deflection vertically when the beam is subjected to a horizontally/axially compressive displacement. It has been found that the vertical deflection of the beam at midpoint can be 6-17 times larger than the horizontal/axial displacement, which forms the basis of a strain amplification mechanism. The user-configurable buckling beam geometry-based strain amplification mechanism enables the strain sensor to achieve a wide range of strain measurement sensitivities. The designed EFPI was used to monitor shrinkage of a square brick of mortar. The strain was measured during the drying/curing stage. We envision that it could be a good strain sensor to be embedded in civil materials/structures under a harsh environment for a prolonged period of time.

  18. An embeddable optical strain gauge based on a buckled beam

    Science.gov (United States)

    Du, Yang; Chen, Yizheng; Zhu, Chen; Zhuang, Yiyang; Huang, Jie

    2017-11-01

    We report, for the first time, a low cost, compact, and novel mechanically designed extrinsic Fabry-Perot interferometer (EFPI)-based optical fiber sensor with a strain amplification mechanism for strain measurement. The fundamental design principle includes a buckled beam with a coated gold layer, mounted on two grips. A Fabry-Perot cavity is produced between the buckled beam and the endface of a single mode fiber (SMF). A ceramic ferrule is applied for supporting and orienting the SMF. The principal sensor elements are packaged and protected by two designed metal shells. The midpoint of the buckled beam will experience a deflection vertically when the beam is subjected to a horizontally/axially compressive displacement. It has been found that the vertical deflection of the beam at midpoint can be 6-17 times larger than the horizontal/axial displacement, which forms the basis of a strain amplification mechanism. The user-configurable buckling beam geometry-based strain amplification mechanism enables the strain sensor to achieve a wide range of strain measurement sensitivities. The designed EFPI was used to monitor shrinkage of a square brick of mortar. The strain was measured during the drying/curing stage. We envision that it could be a good strain sensor to be embedded in civil materials/structures under a harsh environment for a prolonged period of time.

  19. Image guidance during head-and-neck cancer radiation therapy: analysis of alignment trends with in-room cone-beam computed tomography scans.

    Science.gov (United States)

    Zumsteg, Zachary; DeMarco, John; Lee, Steve P; Steinberg, Michael L; Lin, Chun Shu; McBride, William; Lin, Kevin; Wang, Pin-Chieh; Kupelian, Patrick; Lee, Percy

    2012-06-01

    On-board cone-beam computed tomography (CBCT) is currently available for alignment of patients with head-and-neck cancer before radiotherapy. However, daily CBCT is time intensive and increases the overall radiation dose. We assessed the feasibility of using the average couch shifts from the first several CBCTs to estimate and correct for the presumed systematic setup error. 56 patients with head-and-neck cancer who received daily CBCT before intensity-modulated radiation therapy had recorded shift values in the medial-lateral, superior-inferior, and anterior-posterior dimensions. The average displacements in each direction were calculated for each patient based on the first five or 10 CBCT shifts and were presumed to represent the systematic setup error. The residual error after this correction was determined by subtracting the calculated shifts from the shifts obtained using daily CBCT. The magnitude of the average daily residual three-dimensional (3D) error was 4.8 ± 1.4 mm, 3.9 ± 1.3 mm, and 3.7 ± 1.1 mm for uncorrected, five CBCT corrected, and 10 CBCT corrected protocols, respectively. With no image guidance, 40.8% of fractions would have been >5 mm off target. Using the first five CBCT shifts to correct subsequent fractions, this percentage decreased to 19.0% of all fractions delivered and decreased the percentage of patients with average daily 3D errors >5 mm from 35.7% to 14.3% vs. no image guidance. Using an average of the first 10 CBCT shifts did not significantly improve this outcome. Using the first five CBCT shift measurements as an estimation of the systematic setup error improves daily setup accuracy for a subset of patients with head-and-neck cancer receiving intensity-modulated radiation therapy and primarily benefited those with large 3D correction vectors (>5 mm). Daily CBCT is still necessary until methods are developed that more accurately determine which patients may benefit from alternative imaging strategies. Copyright © 2012 Elsevier

  20. Beam electron microprobe

    CERN Document Server

    Stoller, D; Muterspaugh, M W; Pollock, R E

    1999-01-01

    A beam profile monitor based on the deflection of a probe electron beam by the electric field of a stored, electron-cooled proton beam is described and first results are presented. Electrons were transported parallel to the proton beam by a uniform longitudinal magnetic field. The probe beam may be slowly scanned across the stored beam to determine its intensity, position, and size. Alternatively, it may be scanned rapidly over a narrow range within the interior of the stored beam for continuous observation of the changing central density during cooling. Examples of a two dimensional charge density profile obtained from a raster scan and of a cooling alignment study illustrate the scope of measurements made possible by this device.

  1. Remote sensing of local structure of the quasi-perpendicular Earth's bow shock by using field-aligned beams

    Directory of Open Access Journals (Sweden)

    B. Miao

    2009-03-01

    Full Text Available Field-aligned ion beams (FABs originate at the quasi-perpendicular Earth's bow shock and constitute an important ion population in the foreshock region. The bulk velocity of these FABs depends significantly on the shock normal angle, which is the angle between shock normal and upstream interplanetary magnetic field (IMF. This dependency may therefore be taken as an indicator of the local structure of the shock. Applying the direct reflection model to Cluster measurements, we have developed a method that uses proton FABs in the foreshock region for remote sensing of the local shock structure. The comparison of the model results with the multi-spacecraft observations of FAB events shows very good agreement in terms of wave amplitude and frequency of surface waves at the shock front.

  2. Curve aligning approach for gait authentication based on a wearable accelerometer

    International Nuclear Information System (INIS)

    Sun, Hu; Yuao, Tao

    2012-01-01

    Gait authentication based on a wearable accelerometer is a novel biometric which can be used for identity identification, medical rehabilitation and early detection of neurological disorders. The method for matching gait patterns tells heavily on authentication performances. In this paper, curve aligning is introduced as a new method for matching gait patterns and it is compared with correlation and dynamic time warping (DTW). A support vector machine (SVM) is proposed to fuse pattern-matching methods in a decision level. Accelerations collected from ankles of 22 walking subjects are processed for authentications in our experiments. The fusion of curve aligning with backward–forward accelerations and DTW with vertical accelerations promotes authentication performances substantially and consistently. This fusion algorithm is tested repeatedly. Its mean and standard deviation of equal error rates are 0.794% and 0.696%, respectively, whereas among all presented non-fusion algorithms, the best one shows an EER of 3.03%. (paper)

  3. High-performance supercapacitors based on vertically aligned carbon nanotubes and nonaqueous electrolytes

    Science.gov (United States)

    Kim, Byungwoo; Chung, Haegeun; Kim, Woong

    2012-04-01

    We demonstrate the high performance of supercapacitors fabricated with vertically aligned carbon nanotubes and nonaqueous electrolytes such as ionic liquids and conventional organic electrolytes. Specific capacitance, maximum power and energy density of the supercapacitor measured in ionic liquid were ˜75 F g-1, ˜987 kW kg-1 and ˜27 W h kg-1, respectively. The high power performance was consistently indicated by a fast relaxation time constant of 0.2 s. In addition, electrochemical oxidation of the carbon nanotubes improved the specific capacitance (˜158 F g-1) and energy density (˜53 W h kg-1). Both high power and energy density could be attributed to the fast ion transport realized by the alignment of carbon nanotubes and the wide operational voltage defined by the ionic liquid. The demonstrated carbon-nanotube- and nonaqueous-electrolyte-based supercapacitors show great potential for the development of high-performance energy storage devices.

  4. Application of a clustering-based peak alignment algorithm to analyze various DNA fingerprinting data.

    Science.gov (United States)

    Ishii, Satoshi; Kadota, Koji; Senoo, Keishi

    2009-09-01

    DNA fingerprinting analysis such as amplified ribosomal DNA restriction analysis (ARDRA), repetitive extragenic palindromic PCR (rep-PCR), ribosomal intergenic spacer analysis (RISA), and denaturing gradient gel electrophoresis (DGGE) are frequently used in various fields of microbiology. The major difficulty in DNA fingerprinting data analysis is the alignment of multiple peak sets. We report here an R program for a clustering-based peak alignment algorithm, and its application to analyze various DNA fingerprinting data, such as ARDRA, rep-PCR, RISA, and DGGE data. The results obtained by our clustering algorithm and by BioNumerics software showed high similarity. Since several R packages have been established to statistically analyze various biological data, the distance matrix obtained by our R program can be used for subsequent statistical analyses, some of which were not previously performed but are useful in DNA fingerprinting studies.

  5. High-performance supercapacitors based on vertically aligned carbon nanotubes and nonaqueous electrolytes.

    Science.gov (United States)

    Kim, Byungwoo; Chung, Haegeun; Kim, Woong

    2012-04-20

    We demonstrate the high performance of supercapacitors fabricated with vertically aligned carbon nanotubes and nonaqueous electrolytes such as ionic liquids and conventional organic electrolytes. Specific capacitance, maximum power and energy density of the supercapacitor measured in ionic liquid were ~75 F g(-1), ~987 kW kg(-1) and ~27 W h kg(-1), respectively. The high power performance was consistently indicated by a fast relaxation time constant of 0.2 s. In addition, electrochemical oxidation of the carbon nanotubes improved the specific capacitance (~158 F g(-1)) and energy density (~53 W h kg(-1)). Both high power and energy density could be attributed to the fast ion transport realized by the alignment of carbon nanotubes and the wide operational voltage defined by the ionic liquid. The demonstrated carbon-nanotube- and nonaqueous-electrolyte-based supercapacitors show great potential for the development of high-performance energy storage devices. © 2012 IOP Publishing Ltd

  6. Value-based insurance design: aligning incentives and evidence in pulmonary medicine.

    Science.gov (United States)

    Fendrick, A Mark; Zank, Daniel C

    2013-11-01

    When consumers are required to pay the same out-of-pocket amount for pulmonary services for which clinical benefits depend on patient characteristics, clinical indication, and provider choice, there is an enormous potential for both underutilization and overutilization. Unlike most current one-size-fits-all health plan designs, value-based insurance design (V-BID) explicitly acknowledges clinical heterogeneity across the continuum of care. By adding clinical nuance to benefit design, V-BID seeks to align consumer and provider incentives with value, encouraging the use of high-value services and discouraging the use of low-value interventions. This article describes the concept of V-BID; creates a framework for its development in pulmonary medicine; and outlines how this concept aligns with research, care delivery, and payment reform initiatives.

  7. Parallel algorithms for large-scale biological sequence alignment on Xeon-Phi based clusters.

    Science.gov (United States)

    Lan, Haidong; Chan, Yuandong; Xu, Kai; Schmidt, Bertil; Peng, Shaoliang; Liu, Weiguo

    2016-07-19

    Computing alignments between two or more sequences are common operations frequently performed in computational molecular biology. The continuing growth of biological sequence databases establishes the need for their efficient parallel implementation on modern accelerators. This paper presents new approaches to high performance biological sequence database scanning with the Smith-Waterman algorithm and the first stage of progressive multiple sequence alignment based on the ClustalW heuristic on a Xeon Phi-based compute cluster. Our approach uses a three-level parallelization scheme to take full advantage of the compute power available on this type of architecture; i.e. cluster-level data parallelism, thread-level coarse-grained parallelism, and vector-level fine-grained parallelism. Furthermore, we re-organize the sequence datasets and use Xeon Phi shuffle operations to improve I/O efficiency. Evaluations show that our method achieves a peak overall performance up to 220 GCUPS for scanning real protein sequence databanks on a single node consisting of two Intel E5-2620 CPUs and two Intel Xeon Phi 7110P cards. It also exhibits good scalability in terms of sequence length and size, and number of compute nodes for both database scanning and multiple sequence alignment. Furthermore, the achieved performance is highly competitive in comparison to optimized Xeon Phi and GPU implementations. Our implementation is available at https://github.com/turbo0628/LSDBS-mpi .

  8. Application of diamond based beam loss monitors at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Maria

    2013-04-15

    the LHC, especially near each quadrupole and next to collimators. Ionization chambers have a time resolution of 40 s that is a half LHC turn and in case of a large beam loss, they request a beam dump. Another type of beam loss monitors are diamond sensors because of a time resolution of about one nanosecond and high radiation hardness. One diamond detector system is located in the cleaning region of the LHC and is able to detect various types of beam losses. Another diamond detector system (BCM1F) is installed inside the CMS detector to protect the CMS from adverse beam conditions. BCM1F monitors also the luminosity during collisions and delivers important beam parameters. Additional condition monitors, based on the BCM1F system, are located next to CMS, near to LHCb and ALICE to measure large beam losses in the LHC ring. The process of a beam loss due to dust particles is explained, and additional simulations were done to understand these process in more detail. The result of the simulation are also given. Beam loss data recorded by the diamond sensors in the cleaning region and the BCM1F diamonds are presented.

  9. Application of diamond based beam loss monitors at LHC

    International Nuclear Information System (INIS)

    Hempel, Maria

    2013-04-01

    collimators. Ionization chambers have a time resolution of 40 s that is a half LHC turn and in case of a large beam loss, they request a beam dump. Another type of beam loss monitors are diamond sensors because of a time resolution of about one nanosecond and high radiation hardness. One diamond detector system is located in the cleaning region of the LHC and is able to detect various types of beam losses. Another diamond detector system (BCM1F) is installed inside the CMS detector to protect the CMS from adverse beam conditions. BCM1F monitors also the luminosity during collisions and delivers important beam parameters. Additional condition monitors, based on the BCM1F system, are located next to CMS, near to LHCb and ALICE to measure large beam losses in the LHC ring. The process of a beam loss due to dust particles is explained, and additional simulations were done to understand these process in more detail. The result of the simulation are also given. Beam loss data recorded by the diamond sensors in the cleaning region and the BCM1F diamonds are presented.

  10. High-accuracy alignment based on atmospherical dispersion - technological approaches and solutions for the dual-wavelength transmitter

    International Nuclear Information System (INIS)

    Burkhard, Boeckem

    1999-01-01

    In the course of the progressive developments of sophisticated geodetic systems utilizing electromagnetic waves in the visible or near IR-range a more detailed knowledge of the propagation medium and coevally solutions of atmospherically induced limitations will become important. An alignment system based on atmospherical dispersion, called a dispersometer, is a metrological solution to the atmospherically induced limitations, in optical alignment and direction observations of high accuracy. In the dispersometer we are using the dual-wavelength method for dispersive air to obtain refraction compensated angle measurements, the detrimental impact of atmospheric turbulence notwithstanding. The principle of the dual-wavelength method utilizes atmospherical dispersion, i.e. the wavelength dependence of the refractive index. The difference angle between two light beams of different wavelengths, which is called the dispersion angle Δβ, is to first approximation proportional to the refraction angle: β IR ν(β blue - β IR ) = ν Δβ, this equation implies that the dispersion angle has to be measured at least 42 times more accurate than the desired accuracy of the refraction angle for the wavelengths used in the present dispersometer. This required accuracy constitutes one major difficulty for the instrumental performance in applying the dispersion effect. However, the dual-wavelength method can only be successfully used in an optimized transmitter-receiver combination. Beyond the above mentioned resolution requirement for the detector, major difficulties in instrumental realization arise in the availability of a suitable dual-wavelength laser light source, laser light modulation with a very high extinction ratio and coaxial emittance of mono-mode radiation at both wavelengths. Therefore, this paper focuses on the solutions of the dual-wavelength transmitter introducing a new hardware approach and a complete re-design of the in [1] proposed conception of the dual

  11. High-resolution accelerator alignment using x-ray optics

    Directory of Open Access Journals (Sweden)

    Bingxin Yang

    2006-03-01

    Full Text Available We propose a novel alignment technique utilizing the x-ray beam of an undulator in conjunction with pinholes and position-sensitive detectors for positioning components of the accelerator, undulator, and beam line in an x-ray free-electron laser. Two retractable pinholes at each end of the undulator define a stable and reproducible x-ray beam axis (XBA. Targets are precisely positioned on the XBA using a pinhole camera technique. Position-sensitive detectors responding to both x-ray and electron beams enable direct transfer of the position setting from the XBA to the electron beam. This system has the potential to deliver superior alignment accuracy (1–3   μm for target pinholes in the transverse directions over a long distance (200 m or longer. It can be used to define the beam axis of the electron-beam–based alignment, enabling high reproducibility of the latter. This x-ray–based concept should complement the electron-beam–based alignment and the existing survey methods to raise the alignment accuracy of long accelerators to an unprecedented level. Further improvement of the transverse accuracy using x-ray zone plates will be discussed. We also propose a concurrent measurement scheme during accelerator operation to allow real-time feedback for transverse position correction.

  12. Alignment of CEBAF cryomodules

    International Nuclear Information System (INIS)

    Schneider, W.J.; Bisognano, J.J.; Fischer, J.

    1993-06-01

    CEBAF, the Continuous Electron Beam Accelerator Facility, when completed, will house a 4 GeV recirculating accelerator. Each of the accelerator's two linacs contains 160 superconducting radio frequency (SRF) 1497 MHz niobium cavities in 20 cryomodules. Alignments of the cavities within the cryomodule with respect to beam axis is critical to achieving the optimum accelerator performance. This paper discusses the rationale for the current specification on cavity mechanical alignment: 2 mrad (rms) applied to the 0.5 m active length cavities. We describe the tooling that was developed to achieve the tolerance at the time of cavity pair assembly, to preserve and integrate alignment during cryomodule assembly, and to translate alignment to appropriate installation in the beam line

  13. Design of a neutrino source based on beta beams

    Directory of Open Access Journals (Sweden)

    E. Wildner

    2014-07-01

    Full Text Available “Beta beams” produce collimated pure electron (antineutrino beams by accelerating beta active ions to high energies and having them decay in a racetrack shaped storage ring of 7 km circumference, the decay ring. EUROnu beta beams are based on CERN infrastructures and existing machines. Using existing machines may be an advantage for the cost evaluation, but will also constrain the physics performance. The isotope pair of choice for the beta beam is ^{6}He and ^{18}Ne. However, before the EUROnu studies one of the required isotopes, ^{18}Ne, could not be produced in rates that satisfy the needs for physics of the beta beam. Therefore, studies of alternative beta emitters, ^{8}Li and ^{8}B, with properties interesting for a beta beam have been proposed and have been studied within EUROnu. These alternative isotopes could be produced by using a small storage ring, in which the beam traverses a target, creating the ^{8}Li and ^{8}B isotopes. This production ring, the injection linac and the target system have been evaluated. Measurements of the cross section of the reactions to produce the beta beam isotopes show interesting results. A device to collect the produced isotopes from the target has been developed and tested. However, the yields of ^{8}Li and ^{8}B, using the production ring for production of ^{8}Li and ^{8}B, is not yet, according to simulations, giving the rates of isotopes that would be needed. Therefore, a new method of producing the ^{18}Ne isotope has been developed and tested giving good production rates. A 60 GHz ECRIS prototype, the first in the world, was developed and tested for ion production with contributions from EUROnu. The decay ring lattices for the ^{8}Li and ^{8}B have been developed and the lattice for ^{6}He and ^{18}Ne has been optimized to ensure the high intensity ion beam stability.

  14. Accelerator Based Neutron Beams for Neutron Capture Therapy

    International Nuclear Information System (INIS)

    Yanch, Jacquelyn C.

    2003-01-01

    The DOE-funded accelerator BNCT program at the Massachusetts Institute of Technology has resulted in the only operating accelerator-based epithermal neutron beam facility capable of generating significant dose rates in the world. With five separate beamlines and two different epithermal neutron beam assemblies installed, we are currently capable of treating patients with rheumatoid arthritis in less than 15 minutes (knee joints) or 4 minutes (finger joints) or irradiating patients with shallow brain tumors to a healthy tissue dose of 12.6 Gy in 3.6 hours. The accelerator, designed by Newton scientific Incorporated, is located in dedicated laboratory space that MIT renovated specifically for this project. The Laboratory for Accelerator Beam Applications consists of an accelerator room, a control room, a shielded radiation vault, and additional laboratory space nearby. In addition to the design, construction and characterization of the tandem electrostatic accelerator, this program also resulted in other significant accomplishments. Assemblies for generating epithermal neutron beams were designed, constructed and experimentally evaluated using mixed-field dosimetry techniques. Strategies for target construction and target cooling were implemented and tested. We demonstrated that the method of submerged jet impingement using water as the coolant is capable of handling power densities of up to 6 x 10(sup 7) W/m(sup 2) with heat transfer coefficients of 10(sup 6)W/m(sup 2)-K. Experiments with the liquid metal gallium demonstrated its superiority compared with water with little effect on the neutronic properties of the epithermal beam. Monoenergetic proton beams generated using the accelerator were used to evaluate proton RBE as a function of LET and demonstrated a maximum RBE at approximately 30-40 keV/um, a finding consistent with results published by other researchers. We also developed an experimental approach to biological intercomparison of epithermal beams and

  15. Sequence comparison alignment-free approach based on suffix tree and L-words frequency.

    Science.gov (United States)

    Soares, Inês; Goios, Ana; Amorim, António

    2012-01-01

    The vast majority of methods available for sequence comparison rely on a first sequence alignment step, which requires a number of assumptions on evolutionary history and is sometimes very difficult or impossible to perform due to the abundance of gaps (insertions/deletions). In such cases, an alternative alignment-free method would prove valuable. Our method starts by a computation of a generalized suffix tree of all sequences, which is completed in linear time. Using this tree, the frequency of all possible words with a preset length L-L-words--in each sequence is rapidly calculated. Based on the L-words frequency profile of each sequence, a pairwise standard Euclidean distance is then computed producing a symmetric genetic distance matrix, which can be used to generate a neighbor joining dendrogram or a multidimensional scaling graph. We present an improvement to word counting alignment-free approaches for sequence comparison, by determining a single optimal word length and combining suffix tree structures to the word counting tasks. Our approach is, thus, a fast and simple application that proved to be efficient and powerful when applied to mitochondrial genomes. The algorithm was implemented in Python language and is freely available on the web.

  16. Sequence Comparison Alignment-Free Approach Based on Suffix Tree and L-Words Frequency

    Directory of Open Access Journals (Sweden)

    Inês Soares

    2012-01-01

    Full Text Available The vast majority of methods available for sequence comparison rely on a first sequence alignment step, which requires a number of assumptions on evolutionary history and is sometimes very difficult or impossible to perform due to the abundance of gaps (insertions/deletions. In such cases, an alternative alignment-free method would prove valuable. Our method starts by a computation of a generalized suffix tree of all sequences, which is completed in linear time. Using this tree, the frequency of all possible words with a preset length L—L-words—in each sequence is rapidly calculated. Based on the L-words frequency profile of each sequence, a pairwise standard Euclidean distance is then computed producing a symmetric genetic distance matrix, which can be used to generate a neighbor joining dendrogram or a multidimensional scaling graph. We present an improvement to word counting alignment-free approaches for sequence comparison, by determining a single optimal word length and combining suffix tree structures to the word counting tasks. Our approach is, thus, a fast and simple application that proved to be efficient and powerful when applied to mitochondrial genomes. The algorithm was implemented in Python language and is freely available on the web.

  17. Nanostructured pillars based on vertically aligned carbon nanotubes as the stationary phase in micro-CEC.

    Science.gov (United States)

    Wu, Ren-Guei; Yang, Chung-Shi; Wang, Pen-Cheng; Tseng, Fan-Gang

    2009-06-01

    We present a micro-CEC chip carrying out a highly efficient separation of dsDNA fragments through vertically aligned multi-wall carbon nanotubes (MWCNTs) in a microchannel. The vertically aligned MWCNTs were grown directly in the microchannel to form straight nanopillar arrays as ordered and directional chromatographic supports. 1-Pyrenedodecanoic acid was employed for the surface modification of the MWCNTs' stationary phase to adsorb analytes by hydrophobic interactions. This device was used for separating dsDNA fragments of three different lengths (254, 360, and 572 bp), and fluorescence detection was employed to verify the electrokinetic transport in the MWCNT array. The micro-CEC separation of the three compounds was achieved in less than 300 s at a field strength of 66 V/cm due to superior laminar flow patterns and a lower flow resistance resulting from the vertically aligned MWCNTs being used as the stationary phase medium. In addition, a fivefold reduction of band broadening was obtained when the analyte was separated by the chromatographic MWCNT array channel instead of the CE channel. From all of the results, we suggest that an in situ grown and directional MWCNT array can potentially be useful for preparing more diversified forms of stationary phases for vertically efficient chip-based electrochromatography.

  18. High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures

    Science.gov (United States)

    Gupta, Bipin Kumar; Kedawat, Garima; Gangwar, Amit Kumar; Nagpal, Kanika; Kashyap, Pradeep Kumar; Srivastava, Shubhda; Singh, Satbir; Kumar, Pawan; Suryawanshi, Sachin R.; Seo, Deok Min; Tripathi, Prashant; More, Mahendra A.; Srivastava, O. N.; Hahm, Myung Gwan; Late, Dattatray J.

    2018-01-01

    The vertical aligned carbon nanotubes (CNTs)-based pillar architectures were created on laminated silicon oxide/silicon (SiO2/Si) wafer substrate at 775 °C by using water-assisted chemical vapor deposition under low pressure process condition. The lamination was carried out by aluminum (Al, 10.0 nm thickness) as a barrier layer and iron (Fe, 1.5 nm thickness) as a catalyst precursor layer sequentially on a silicon wafer substrate. Scanning electron microscope (SEM) images show that synthesized CNTs are vertically aligned and uniformly distributed with a high density. The CNTs have approximately 2-30 walls with an inner diameter of 3-8 nm. Raman spectrum analysis shows G-band at 1580 cm-1 and D-band at 1340 cm-1. The G-band is higher than D-band, which indicates that CNTs are highly graphitized. The field emission analysis of the CNTs revealed high field emission current density (4mA/cm2 at 1.2V/μm), low turn-on field (0.6 V/μm) and field enhancement factor (6917) with better stability and longer lifetime. Emitter morphology resulting in improved promising field emission performances, which is a crucial factor for the fabrication of pillared shaped vertical aligned CNTs bundles as practical electron sources.

  19. High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures

    Directory of Open Access Journals (Sweden)

    Bipin Kumar Gupta

    2018-01-01

    Full Text Available The vertical aligned carbon nanotubes (CNTs-based pillar architectures were created on laminated silicon oxide/silicon (SiO2/Si wafer substrate at 775 °C by using water-assisted chemical vapor deposition under low pressure process condition. The lamination was carried out by aluminum (Al, 10.0 nm thickness as a barrier layer and iron (Fe, 1.5 nm thickness as a catalyst precursor layer sequentially on a silicon wafer substrate. Scanning electron microscope (SEM images show that synthesized CNTs are vertically aligned and uniformly distributed with a high density. The CNTs have approximately 2–30 walls with an inner diameter of 3–8 nm. Raman spectrum analysis shows G-band at 1580 cm−1 and D-band at 1340 cm−1. The G-band is higher than D-band, which indicates that CNTs are highly graphitized. The field emission analysis of the CNTs revealed high field emission current density (4mA/cm2 at 1.2V/μm, low turn-on field (0.6 V/μm and field enhancement factor (6917 with better stability and longer lifetime. Emitter morphology resulting in improved promising field emission performances, which is a crucial factor for the fabrication of pillared shaped vertical aligned CNTs bundles as practical electron sources.

  20. Experimental demonstration of dielectric structure based two beam acceleration

    International Nuclear Information System (INIS)

    Gai, W.; Conde, M. E.; Konecny, R.; Power, J. G.; Schoessow, P.; Sun, X.; Zou, P.

    2000-01-01

    We report on the experimental results of the dielectric based two beam accelerator (step-up transformer). By using a single high charge beam, we have generated and extracted a high power RF pulse from a 7.8 GHz primary dielectric structure and then subsequently transferred to a second accelerating structure with higher dielectric constant and smaller transverse dimensions. We have measured the energy change of a second (witness) beam passing through the acceleration stage. The measured gradient is >4 times the deceleration gradient. The detailed experiment of set-up and results of the measurements are dimmed. Future plans for the development of a 100 MeV demonstration accelerator based on this technique is presented

  1. Experimental demonstration of dielectric structure based two beam acceleration.

    Energy Technology Data Exchange (ETDEWEB)

    Gai, W.; Conde, M. E.; Konecny, R.; Power, J. G.; Schoessow, P.; Sun, X.; Zou, P.

    2000-11-28

    We report on the experimental results of the dielectric based two beam accelerator (step-up transformer). By using a single high charge beam, we have generated and extracted a high power RF pulse from a 7.8 GHz primary dielectric structure and then subsequently transferred to a second accelerating structure with higher dielectric constant and smaller transverse dimensions. We have measured the energy change of a second (witness) beam passing through the acceleration stage. The measured gradient is >4 times the deceleration gradient. The detailed experiment of set-up and results of the measurements are dimmed. Future plans for the development of a 100 MeV demonstration accelerator based on this technique is presented.

  2. A Method for SINS Alignment with Large Initial Misalignment Angles Based on Kalman Filter with Parameters Resetting

    Directory of Open Access Journals (Sweden)

    Xixiang Liu

    2014-01-01

    Full Text Available In the initial alignment process of strapdown inertial navigation system (SINS, large initial misalignment angles always bring nonlinear problem, which causes alignment failure when the classical linear error model and standard Kalman filter are used. In this paper, the problem of large misalignment angles in SINS initial alignment is investigated, and the key reason for alignment failure is given as the state covariance from Kalman filter cannot represent the true one during the steady filtering process. According to the analysis, an alignment method for SINS based on multiresetting the state covariance matrix of Kalman filter is designed to deal with large initial misalignment angles, in which classical linear error model and standard Kalman filter are used, but the state covariance matrix should be multireset before the steady process until large misalignment angles are decreased to small ones. The performance of the proposed method is evaluated by simulation and car test, and the results indicate that the proposed method can fulfill initial alignment with large misalignment angles effectively and the alignment accuracy of the proposed method is as precise as that of alignment with small misalignment angles.

  3. Toward a view-oriented approach for aligning RDF-based biomedical repositories.

    Science.gov (United States)

    Anguita, A; García-Remesal, M; de la Iglesia, D; Graf, N; Maojo, V

    2015-01-01

    This article is part of the Focus Theme of METHODS of Information in Medicine on "Managing Interoperability and Complexity in Health Systems". The need for complementary access to multiple RDF databases has fostered new lines of research, but also entailed new challenges due to data representation disparities. While several approaches for RDF-based database integration have been proposed, those focused on schema alignment have become the most widely adopted. All state-of-the-art solutions for aligning RDF-based sources resort to a simple technique inherited from legacy relational database integration methods. This technique - known as element-to-element (e2e) mappings - is based on establishing 1:1 mappings between single primitive elements - e.g. concepts, attributes, relationships, etc. - belonging to the source and target schemas. However, due to the intrinsic nature of RDF - a representation language based on defining tuples -, one may find RDF elements whose semantics vary dramatically when combined into a view involving other RDF elements - i.e. they depend on their context. The latter cannot be adequately represented in the target schema by resorting to the traditional e2e approach. These approaches fail to properly address this issue without explicitly modifying the target ontology, thus lacking the required expressiveness for properly reflecting the intended semantics in the alignment information. To enhance existing RDF schema alignment techniques by providing a mechanism to properly represent elements with context-dependent semantics, thus enabling users to perform more expressive alignments, including scenarios that cannot be adequately addressed by the existing approaches. Instead of establishing 1:1 correspondences between single primitive elements of the schemas, we propose adopting a view-based approach. The latter is targeted at establishing mapping relationships between RDF subgraphs - that can be regarded as the equivalent of views in traditional

  4. Application of ion beams for polymeric carbon based biomaterials

    International Nuclear Information System (INIS)

    Evelyn, A.L.

    2001-01-01

    Ion beams have been shown to be quite suitable for the modification and analysis of carbon based biomaterials. Glassy polymeric carbon (GPC), made from cured phenolic resins, has a high chemical inertness that makes it useful as a biomaterial in medicine for drug delivery systems and for the manufacture of heart valves and other prosthetic devices. Low and high-energy ion beams have been used, with both partially and fully cured phenolic resins, to enhance biological cell/tissue growth on, and to increase tissue adhesion to GPC surfaces. Samples bombarded with energetic ion beams in the keV to MeV range exhibited increased surface roughness, measured using optical microscopy and atomic force microscopy. Ion beams were also used to perform nuclear reaction analyses of GPC encapsulated drugs for use in internal drug delivery systems. The results from the high energy bombardment were more dramatic and are shown in this paper. The interaction of energetic ions has demonstrated the useful application of ion beams to enhance the properties of carbon-based biomaterials

  5. Plasma based Ar+ beam assisted poly(dimethylsiloxane) surface modification

    International Nuclear Information System (INIS)

    Vladkova, T.G.; Keranov, I.L.; Dineff, P.D.; Youroukov, S.Y.; Avramova, I.A.; Krasteva, N.; Altankov, G.P.

    2005-01-01

    Plasma based Ar + beam performed in RF (13.56 MHz) low-pressure (200 mTorr) glow discharge (at 100 W, 1200 W and 2500 W) with a serial capacitance was employed for surface modification of poly(dimethylsiloxane) (PDMS) aimed at improvement of its interactions with living cells. The presence of a serial capacitance ensures arise of an ion-flow inside the plasma volume directed toward the treated sample and the vary of the discharge power ensures varied density of the ion-flow. XPS analysis was performed to study the changes in the surface chemical composition of the modified samples and the corresponding changes in the surface energy were monitored by contact angle measurements. We found that plasma based Ar + beam transforms the initially hydrophobic PDMS surface into a hydrophilic one mainly due to a raising of the polar component of the surface tension, this effect being most probably due to an enrichment of the modified surface layer with permanent dipoles of a [SiO x ]-based network and elimination of the original methyl groups. The initial adhesion of human fibroblast cells was studied on the described above plasma based Ar + beam modified and acrylic acid (AA) grafted or not fibronectin (FN) pre-coated or bare surfaces. The cell response seems to be related with the peculiar structure and wettability of the modified PDMS surface layer after plasma based Ar + beam treatment followed or not by AA grafting

  6. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G. Gomez and J. Pivarski

    2011-01-01

    Alignment efforts in the first few months of 2011 have shifted away from providing alignment constants (now a well established procedure) and focussed on some critical remaining issues. The single most important task left was to understand the systematic differences observed between the track-based (TB) and hardware-based (HW) barrel alignments: a systematic difference in r-φ and in z, which grew as a function of z, and which amounted to ~4-5 mm differences going from one end of the barrel to the other. This difference is now understood to be caused by the tracker alignment. The systematic differences disappear when the track-based barrel alignment is performed using the new “twist-free” tracker alignment. This removes the largest remaining source of systematic uncertainty. Since the barrel alignment is based on hardware, it does not suffer from the tracker twist. However, untwisting the tracker causes endcap disks (which are aligned ...

  7. Optical beam classification using deep learning: a comparison with rule- and feature-based classification

    Science.gov (United States)

    Alom, Md. Zahangir; Awwal, Abdul A. S.; Lowe-Webb, Roger; Taha, Tarek M.

    2017-08-01

    Deep-learning methods are gaining popularity because of their state-of-the-art performance in image classification tasks. In this paper, we explore classification of laser-beam images from the National Ignition Facility (NIF) using a novel deeplearning approach. NIF is the world's largest, most energetic laser. It has nearly 40,000 optics that precisely guide, reflect, amplify, and focus 192 laser beams onto a fusion target. NIF utilizes four petawatt lasers called the Advanced Radiographic Capability (ARC) to produce backlighting X-ray illumination to capture implosion dynamics of NIF experiments with picosecond temporal resolution. In the current operational configuration, four independent short-pulse ARC beams are created and combined in a split-beam configuration in each of two NIF apertures at the entry of the pre-amplifier. The subaperture beams then propagate through the NIF beampath up to the ARC compressor. Each ARC beamlet is separately compressed with a dedicated set of four gratings and recombined as sub-apertures for transport to the parabola vessel, where the beams are focused using parabolic mirrors and pointed to the target. Small angular errors in the compressor gratings can cause the sub-aperture beams to diverge from one another and prevent accurate alignment through the transport section between the compressor and parabolic mirrors. This is an off-normal condition that must be detected and corrected. The goal of the off-normal check is to determine whether the ARC beamlets are sufficiently overlapped into a merged single spot or diverged into two distinct spots. Thus, the objective of the current work is three-fold: developing a simple algorithm to perform off-normal classification, exploring the use of Convolutional Neural Network (CNN) for the same task, and understanding the inter-relationship of the two approaches. The CNN recognition results are compared with other machine-learning approaches, such as Deep Neural Network (DNN) and Support

  8. An ion beam analysis software based on ImageJ

    International Nuclear Information System (INIS)

    Udalagama, C.; Chen, X.; Bettiol, A.A.; Watt, F.

    2013-01-01

    The suit of techniques (RBS, STIM, ERDS, PIXE, IL, IF,…) available in ion beam analysis yields a variety of rich information. Typically, after the initial challenge of acquiring data we are then faced with the task of having to extract relevant information or to present the data in a format with the greatest impact. This process sometimes requires developing new software tools. When faced with such situations the usual practice at the Centre for Ion Beam Applications (CIBA) in Singapore has been to use our computational expertise to develop ad hoc software tools as and when we need them. It then became apparent that the whole ion beam community can benefit from such tools; specifically from a common software toolset that can be developed and maintained by everyone with freedom to use and allowance to modify. In addition to the benefits of readymade tools and sharing the onus of development, this also opens up the possibility for collaborators to access and analyse ion beam data without having to depend on an ion beam lab. This has the virtue of making the ion beam techniques more accessible to a broader scientific community. We have identified ImageJ as an appropriate software base to develop such a common toolset. In addition to being in the public domain and been setup for collaborative tool development, ImageJ is accompanied by hundreds of modules (plugins) that allow great breadth in analysis. The present work is the first step towards integrating ion beam analysis into ImageJ. Some of the features of the current version of the ImageJ ‘ion beam’ plugin are: (1) reading list mode or event-by-event files, (2) energy gates/sorts, (3) sort stacks, (4) colour function, (5) real time map updating, (6) real time colour updating and (7) median and average map creation

  9. An ion beam analysis software based on ImageJ

    Energy Technology Data Exchange (ETDEWEB)

    Udalagama, C., E-mail: chammika@nus.edu.sg [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117 542 (Singapore); Chen, X.; Bettiol, A.A.; Watt, F. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117 542 (Singapore)

    2013-07-01

    The suit of techniques (RBS, STIM, ERDS, PIXE, IL, IF,…) available in ion beam analysis yields a variety of rich information. Typically, after the initial challenge of acquiring data we are then faced with the task of having to extract relevant information or to present the data in a format with the greatest impact. This process sometimes requires developing new software tools. When faced with such situations the usual practice at the Centre for Ion Beam Applications (CIBA) in Singapore has been to use our computational expertise to develop ad hoc software tools as and when we need them. It then became apparent that the whole ion beam community can benefit from such tools; specifically from a common software toolset that can be developed and maintained by everyone with freedom to use and allowance to modify. In addition to the benefits of readymade tools and sharing the onus of development, this also opens up the possibility for collaborators to access and analyse ion beam data without having to depend on an ion beam lab. This has the virtue of making the ion beam techniques more accessible to a broader scientific community. We have identified ImageJ as an appropriate software base to develop such a common toolset. In addition to being in the public domain and been setup for collaborative tool development, ImageJ is accompanied by hundreds of modules (plugins) that allow great breadth in analysis. The present work is the first step towards integrating ion beam analysis into ImageJ. Some of the features of the current version of the ImageJ ‘ion beam’ plugin are: (1) reading list mode or event-by-event files, (2) energy gates/sorts, (3) sort stacks, (4) colour function, (5) real time map updating, (6) real time colour updating and (7) median and average map creation.

  10. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G.Gomez.

    Since June of 2009, the muon alignment group has focused on providing new alignment constants and on finalizing the hardware alignment reconstruction. Alignment constants for DTs and CSCs were provided for CRAFT09 data reprocessing. For DT chambers, the track-based alignment was repeated using CRAFT09 cosmic ray muons and validated using segment extrapolation and split cosmic tools. One difference with respect to the previous alignment is that only five degrees of freedom were aligned, leaving the rotation around the local x-axis to be better determined by the hardware system. Similarly, DT chambers poorly aligned by tracks (due to limited statistics) were aligned by a combination of photogrammetry and hardware-based alignment. For the CSC chambers, the hardware system provided alignment in global z and rotations about local x. Entire muon endcap rings were further corrected in the transverse plane (global x and y) by the track-based alignment. Single chamber track-based alignment suffers from poor statistic...

  11. National negative-ion-based neutral-beam development plan

    International Nuclear Information System (INIS)

    Cooper, W.S.; Pyle, R.V.

    1983-08-01

    The plan covers facilities required, program milestones, and decision points. It includes identification of applications, experiments, theoretical research areas, development of specific technologies and reactor development and demonstration facilities required to bring about the successful application of negative-ion-based neutral beams. Particular emphasis is placed on those activities leading to use on existing plasma confinement experiments or their upgrades

  12. Network secure communications based on beam halo-chaos

    International Nuclear Information System (INIS)

    Liu Qiang; Fang Jinqing; Li Yong

    2010-01-01

    Based on beam halo-chaos synchronization in the beam transport network (line)with small-world effect, using three synchronization methods:the driver-response synchronization, small-world topology coupling synchronization and multi-local small-world topology coupling synchronization, three kinds of secure communication projects were designed respectively, and were studied numerically by the Simulink tool of the Matlab software. Numerical experimental results demonstrate that encryption and decryption of the original signal are realized successfully. It provides effective theoretical foundation and reference for the next engineering design and network experiment. (authors)

  13. Equipment response spectra for base-isolated shear beam structures

    International Nuclear Information System (INIS)

    Ahmadi, G.; Su, L.

    1992-01-01

    Equipment response spectra in base-isolated structure under seismic ground excitations are studied. The equipment is treated as a single-degree-of-freedom system attached to a nonuniform elastic beam structural model. Several leading base isolation systems, including the laminated rubber bearing, the resilient-friction base isolator with and without a sliding upper plate, and the EDF system are considered. Deflection and acceleration response spectra for the equipment and the shear beam structure subject to a sinusoidal and the accelerogram of the N00W component of El Centro 1940 earthquake are evaluated. Primary-secondary interaction effects are included in the analysis. Several numerical parametric studies are carried out and the effectiveness of different base isolation systems in protecting the nonstructural components is studied. It is shown that use of properly designed base isolation systems provides considerable protection for secondary systems, as well as, the structure against severe seismic loadings. (orig.)

  14. Sound beam manipulation based on temperature gradients

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Feng [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); School of Physics & Electronic Engineering, Changshu Institute of Technology, Changshu 215500 (China); Quan, Li; Liu, Xiaozhou, E-mail: xzliu@nju.edu.cn; Gong, Xiufen [Key Laboratory of Modern Acoustics, Institute of Acoustics and School of Physics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-10-28

    Previous research with temperature gradients has shown the feasibility of controlling airborne sound propagation. Here, we present a temperature gradients based airborne sound manipulation schemes: a cylindrical acoustic omnidirectional absorber (AOA). The proposed AOA has high absorption performance which can almost completely absorb the incident wave. Geometric acoustics is used to obtain the refractive index distributions with different radii, which is then utilized to deduce the desired temperature gradients. Since resonant units are not applied in the scheme, its working bandwidth is expected to be broadband. The scheme is temperature-tuned and easy to realize, which is of potential interest to fields such as noise control or acoustic cloaking.

  15. Pairagon: a highly accurate, HMM-based cDNA-to-genome aligner

    DEFF Research Database (Denmark)

    Lu, David V; Brown, Randall H; Arumugam, Manimozhiyan

    2009-01-01

    MOTIVATION: The most accurate way to determine the intron-exon structures in a genome is to align spliced cDNA sequences to the genome. Thus, cDNA-to-genome alignment programs are a key component of most annotation pipelines. The scoring system used to choose the best alignment is a primary...... determinant of alignment accuracy, while heuristics that prevent consideration of certain alignments are a primary determinant of runtime and memory usage. Both accuracy and speed are important considerations in choosing an alignment algorithm, but scoring systems have received much less attention than...

  16. Tutorial on beam-based feedback systems for linacs

    International Nuclear Information System (INIS)

    Hendrickson, L.; Allison, S.; Gromme, T.; Grossberg, P.; Himel, T.; Krauter, K.; MacKenzie, R.; Ross, M.; Sass, R.; Shoaee, H.

    1994-08-01

    A generalized fast feedback system stabilizes beams in the SLC. It performs measurements and modifies actuator settings to control beam states such as position, angle, energy and intensity on a pulse to pulse basis. An adaptive cascade feature allows communication between a series of linac loops, avoiding overcorrection problems. The system is based on the state space formalism of digital control theory. Due to the database-driven design, new loops are added without requiring software modifications. Recent enhancements support the monitoring and control of nonlinear states such as beam phase using excitation techniques. In over three years of operation, the feedback system has grown from its original eight loops to more than fifty loops, and it has been invaluable in stabilizing the machine

  17. Clinical results of proton beam therapy for skull base chordoma

    International Nuclear Information System (INIS)

    Igaki, Hiroshi; Tokuuye, Koichi; Okumura, Toshiyuki; Sugahara, Shinji; Kagei, Kenji; Hata, Masaharu; Ohara, Kiyoshi; Hashimoto, Takayuki; Tsuboi, Koji; Takano, Shingo; Matsumura, Akira; Akine, Yasuyuki

    2004-01-01

    Purpose: To evaluate clinical results of proton beam therapy for patients with skull base chordoma. Methods and materials: Thirteen patients with skull base chordoma who were treated with proton beams with or without X-rays at the University of Tsukuba between 1989 and 2000 were retrospectively reviewed. A median total tumor dose of 72.0 Gy (range, 63.0-95.0 Gy) was delivered. The patients were followed for a median period of 69.3 months (range, 14.6-123.4 months). Results: The 5-year local control rate was 46.0%. Cause-specific, overall, and disease-free survival rates at 5 years were 72.2%, 66.7%, and 42.2%, respectively. The local control rate was higher, without statistical significance, for those with preoperative tumors <30 mL. Partial or subtotal tumor removal did not yield better local control rates than for patients who underwent biopsy only as the latest surgery. Conclusion: Proton beam therapy is effective for patients with skull base chordoma, especially for those with small tumors. For a patient with a tumor of <30 mL with no prior treatment, biopsy without tumor removal seems to be appropriate before proton beam therapy

  18. Unusual photoluminescence properties of vertically aligned InN nanorods grown by plasma-assisted molecular-beam epitaxy

    International Nuclear Information System (INIS)

    Shen, C.H.; Chen, H.Y.; Lin, H.W.; Wu, C.Y.; Gwo, S.; Klochikhin, A.A.; Davydov, V.Yu.

    2007-01-01

    We report the unusual photoluminescence (PL) properties of vertically aligned InN nanorod arrays grown on Si(111) with a Si 3 N 4 buffer layer. The optimum growth conditions of InN nanorods are obtained by controlling the III/V ratio and the growth temperature. Structural characterization by X-ray diffraction and scanning electron microscopy indicates that individual nanorods are wurtzite InN single crystals with the growth direction along the c-axis. Near-infrared PL from InN nanorods is clearly observed at room temperature. However, in comparison to the PL from InN epitaxial films, the PL from InN nanorods is significantly lower in efficiency and exhibit anomalous temperature dependence. We propose that these unusual PL properties are results of considerable structural disorder (especially for the low-temperature grown InN nanorods) and strong surface electron accumulation effect. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. SDT: a virus classification tool based on pairwise sequence alignment and identity calculation.

    Directory of Open Access Journals (Sweden)

    Brejnev Muhizi Muhire

    Full Text Available The perpetually increasing rate at which viral full-genome sequences are being determined is creating a pressing demand for computational tools that will aid the objective classification of these genome sequences. Taxonomic classification approaches that are based on pairwise genetic identity measures are potentially highly automatable and are progressively gaining favour with the International Committee on Taxonomy of Viruses (ICTV. There are, however, various issues with the calculation of such measures that could potentially undermine the accuracy and consistency with which they can be applied to virus classification. Firstly, pairwise sequence identities computed based on multiple sequence alignments rather than on multiple independent pairwise alignments can lead to the deflation of identity scores with increasing dataset sizes. Also, when gap-characters need to be introduced during sequence alignments to account for insertions and deletions, methodological variations in the way that these characters are introduced and handled during pairwise genetic identity calculations can cause high degrees of inconsistency in the way that different methods classify the same sets of sequences. Here we present Sequence Demarcation Tool (SDT, a free user-friendly computer program that aims to provide a robust and highly reproducible means of objectively using pairwise genetic identity calculations to classify any set of nucleotide or amino acid sequences. SDT can produce publication quality pairwise identity plots and colour-coded distance matrices to further aid the classification of sequences according to ICTV approved taxonomic demarcation criteria. Besides a graphical interface version of the program for Windows computers, command-line versions of the program are available for a variety of different operating systems (including a parallel version for cluster computing platforms.

  20. Bidirectional composition on lie groups for gradient-based image alignment.

    Science.gov (United States)

    Mégret, Rémi; Authesserre, Jean-Baptiste; Berthoumieu, Yannick

    2010-09-01

    In this paper, a new formulation based on bidirectional composition on Lie groups (BCL) for parametric gradient-based image alignment is presented. Contrary to the conventional approaches, the BCL method takes advantage of the gradients of both template and current image without combining them a priori. Based on this bidirectional formulation, two methods are proposed and their relationship with state-of-the-art gradient based approaches is fully discussed. The first one, i.e., the BCL method, relies on the compositional framework to provide the minimization of the compensated error with respect to an augmented parameter vector. The second one, the projected BCL (PBCL), corresponds to a close approximation of the BCL approach. A comparative study is carried out dealing with computational complexity, convergence rate and frequence of convergence. Numerical experiments using a conventional benchmark show the performance improvement especially for asymmetric levels of noise, which is also discussed from a theoretical point of view.

  1. Reliability of lower limb alignment measures using an established landmark-based method with a customized computer software program

    Science.gov (United States)

    Sled, Elizabeth A.; Sheehy, Lisa M.; Felson, David T.; Costigan, Patrick A.; Lam, Miu; Cooke, T. Derek V.

    2010-01-01

    The objective of the study was to evaluate the reliability of frontal plane lower limb alignment measures using a landmark-based method by (1) comparing inter- and intra-reader reliability between measurements of alignment obtained manually with those using a computer program, and (2) determining inter- and intra-reader reliability of computer-assisted alignment measures from full-limb radiographs. An established method for measuring alignment was used, involving selection of 10 femoral and tibial bone landmarks. 1) To compare manual and computer methods, we used digital images and matching paper copies of five alignment patterns simulating healthy and malaligned limbs drawn using AutoCAD. Seven readers were trained in each system. Paper copies were measured manually and repeat measurements were performed daily for 3 days, followed by a similar routine with the digital images using the computer. 2) To examine the reliability of computer-assisted measures from full-limb radiographs, 100 images (200 limbs) were selected as a random sample from 1,500 full-limb digital radiographs which were part of the Multicenter Osteoarthritis (MOST) Study. Three trained readers used the software program to measure alignment twice from the batch of 100 images, with two or more weeks between batch handling. Manual and computer measures of alignment showed excellent agreement (intraclass correlations [ICCs] 0.977 – 0.999 for computer analysis; 0.820 – 0.995 for manual measures). The computer program applied to full-limb radiographs produced alignment measurements with high inter- and intra-reader reliability (ICCs 0.839 – 0.998). In conclusion, alignment measures using a bone landmark-based approach and a computer program were highly reliable between multiple readers. PMID:19882339

  2. A MEMORY EFFICIENT HARDWARE BASED PATTERN MATCHING AND PROTEIN ALIGNMENT SCHEMES FOR HIGHLY COMPLEX DATABASES

    OpenAIRE

    Bennet, M.Anto; Sankaranarayanan, S.; Deepika, M.; Nanthini, N.; Bhuvaneshwari, S.; Priyanka, M.

    2017-01-01

    Protein sequence alignment to find correlation between different species, or genetic mutations etc. is the most computational intensive task when performing protein comparison. To speed-up the alignment, Systolic Arrays (SAs) have been used. In order to avoid the internal-loop problem which reduces the performance, pipeline interleaving strategy has been presented. This strategy is applied to an SA for Smith Waterman (SW) algorithm which is an alignment algorithm to locally align two proteins...

  3. A value-based maturity model for IT alignment in networked businesses

    NARCIS (Netherlands)

    Santana Tapia, R.G.

    Business-IT alignment can be achieved at various levels of maturity. Supposing that an organization has tried to achieve business-IT alignment, a question to face is: how is that organization going to know the level of maturity of its alignment situation in order to plan future ways of action? That

  4. Development of a nuclear data base for relativistic ion beams

    International Nuclear Information System (INIS)

    Townsend, L.W.; Wong, M.; Schimmerling, W.; Wilson, J.W.

    1987-01-01

    The primary limitation on the development of heavy ion beam transport methods is the lack of an accurate nuclear data base. Because of the large number of ion/target combinations, the complexity of the reaction products, and the broad range of energies required, it is unlikely that the data base will ever be compiled from experiments alone. For the last 15 years, relativistic heavy-ion accelerators have been available, but the experimental data base remains inadequate. However, theoretical models of heavy-ion reactions are being derived to provide cross section data for beam transport problems. A concurrent experimental program to provide sufficient experimental data to validate the model is also in progress. Model development and experimental results for model validation are discussed. The need for additional nuclear fragmentation data is identified

  5. Dimensionality Reduction for Hyperspectral Data Based on Class-Aware Tensor Neighborhood Graph and Patch Alignment.

    Science.gov (United States)

    Gao, Yang; Wang, Xuesong; Cheng, Yuhu; Wang, Z Jane

    2015-08-01

    To take full advantage of hyperspectral information, to avoid data redundancy and to address the curse of dimensionality concern, dimensionality reduction (DR) becomes particularly important to analyze hyperspectral data. Exploring the tensor characteristic of hyperspectral data, a DR algorithm based on class-aware tensor neighborhood graph and patch alignment is proposed here. First, hyperspectral data are represented in the tensor form through a window field to keep the spatial information of each pixel. Second, using a tensor distance criterion, a class-aware tensor neighborhood graph containing discriminating information is obtained. In the third step, employing the patch alignment framework extended to the tensor space, we can obtain global optimal spectral-spatial information. Finally, the solution of the tensor subspace is calculated using an iterative method and low-dimensional projection matrixes for hyperspectral data are obtained accordingly. The proposed method effectively explores the spectral and spatial information in hyperspectral data simultaneously. Experimental results on 3 real hyperspectral datasets show that, compared with some popular vector- and tensor-based DR algorithms, the proposed method can yield better performance with less tensor training samples required.

  6. Phase Retrieval Using a Genetic Algorithm on the Systematic Image-Based Optical Alignment Testbed

    Science.gov (United States)

    Taylor, Jaime R.

    2003-01-01

    NASA s Marshall Space Flight Center s Systematic Image-Based Optical Alignment (SIBOA) Testbed was developed to test phase retrieval algorithms and hardware techniques. Individuals working with the facility developed the idea of implementing phase retrieval by breaking the determination of the tip/tilt of each mirror apart from the piston motion (or translation) of each mirror. Presented in this report is an algorithm that determines the optimal phase correction associated only with the piston motion of the mirrors. A description of the Phase Retrieval problem is first presented. The Systematic Image-Based Optical Alignment (SIBOA) Testbeb is then described. A Discrete Fourier Transform (DFT) is necessary to transfer the incoming wavefront (or estimate of phase error) into the spatial frequency domain to compare it with the image. A method for reducing the DFT to seven scalar/matrix multiplications is presented. A genetic algorithm is then used to search for the phase error. The results of this new algorithm on a test problem are presented.

  7. Evaluation of GMI and PMI diffeomorphic‐based demons algorithms for aligning PET and CT Images

    Science.gov (United States)

    Yang, Juan; Zhang, You; Yin, Yong

    2015-01-01

    Fusion of anatomic information in computed tomography (CT) and functional information in F18‐FDG positron emission tomography (PET) is crucial for accurate differentiation of tumor from benign masses, designing radiotherapy treatment plan and staging of cancer. Although current PET and CT images can be acquired from combined F18‐FDG PET/CT scanner, the two acquisitions are scanned separately and take a long time, which may induce potential positional errors in global and local caused by respiratory motion or organ peristalsis. So registration (alignment) of whole‐body PET and CT images is a prerequisite for their meaningful fusion. The purpose of this study was to assess the performance of two multimodal registration algorithms for aligning PET and CT images. The proposed gradient of mutual information (GMI)‐based demons algorithm, which incorporated the GMI between two images as an external force to facilitate the alignment, was compared with the point‐wise mutual information (PMI) diffeomorphic‐based demons algorithm whose external force was modified by replacing the image intensity difference in diffeomorphic demons algorithm with the PMI to make it appropriate for multimodal image registration. Eight patients with esophageal cancer(s) were enrolled in this IRB‐approved study. Whole‐body PET and CT images were acquired from a combined F18‐FDG PET/CT scanner for each patient. The modified Hausdorff distance (dMH) was used to evaluate the registration accuracy of the two algorithms. Of all patients, the mean values and standard deviations (SDs) of dMH were 6.65 (± 1.90) voxels and 6.01 (± 1.90) after the GMI‐based demons and the PMI diffeomorphic‐based demons registration algorithms respectively. Preliminary results on oncological patients showed that the respiratory motion and organ peristalsis in PET/CT esophageal images could not be neglected, although a combined F18‐FDG PET/CT scanner was used for image acquisition. The PMI

  8. Evaluation of GMI and PMI diffeomorphic-based demons algorithms for aligning PET and CT Images.

    Science.gov (United States)

    Yang, Juan; Wang, Hongjun; Zhang, You; Yin, Yong

    2015-07-08

    Fusion of anatomic information in computed tomography (CT) and functional information in 18F-FDG positron emission tomography (PET) is crucial for accurate differentiation of tumor from benign masses, designing radiotherapy treatment plan and staging of cancer. Although current PET and CT images can be acquired from combined 18F-FDG PET/CT scanner, the two acquisitions are scanned separately and take a long time, which may induce potential positional errors in global and local caused by respiratory motion or organ peristalsis. So registration (alignment) of whole-body PET and CT images is a prerequisite for their meaningful fusion. The purpose of this study was to assess the performance of two multimodal registration algorithms for aligning PET and CT images. The proposed gradient of mutual information (GMI)-based demons algorithm, which incorporated the GMI between two images as an external force to facilitate the alignment, was compared with the point-wise mutual information (PMI) diffeomorphic-based demons algorithm whose external force was modified by replacing the image intensity difference in diffeomorphic demons algorithm with the PMI to make it appropriate for multimodal image registration. Eight patients with esophageal cancer(s) were enrolled in this IRB-approved study. Whole-body PET and CT images were acquired from a combined 18F-FDG PET/CT scanner for each patient. The modified Hausdorff distance (d(MH)) was used to evaluate the registration accuracy of the two algorithms. Of all patients, the mean values and standard deviations (SDs) of d(MH) were 6.65 (± 1.90) voxels and 6.01 (± 1.90) after the GMI-based demons and the PMI diffeomorphic-based demons registration algorithms respectively. Preliminary results on oncological patients showed that the respiratory motion and organ peristalsis in PET/CT esophageal images could not be neglected, although a combined 18F-FDG PET/CT scanner was used for image acquisition. The PMI diffeomorphic-based demons

  9. Numerical Upscaling of Solute Transport in Fractured Porous Media Based on Flow Aligned Blocks

    Science.gov (United States)

    Leube, P.; Nowak, W.; Sanchez-Vila, X.

    2013-12-01

    High-contrast or fractured-porous media (FPM) pose one of the largest unresolved challenges for simulating large hydrogeological systems. The high contrast in advective transport between fast conduits and low-permeability rock matrix, including complex mass transfer processes, leads to the typical complex characteristics of early bulk arrivals and long tailings. Adequate direct representation of FPM requires enormous numerical resolutions. For large scales, e.g. the catchment scale, and when allowing for uncertainty in the fracture network architecture or in matrix properties, computational costs quickly reach an intractable level. In such cases, multi-scale simulation techniques have become useful tools. They allow decreasing the complexity of models by aggregating and transferring their parameters to coarser scales and so drastically reduce the computational costs. However, these advantages come at a loss of detail and accuracy. In this work, we develop and test a new multi-scale or upscaled modeling approach based on block upscaling. The novelty is that individual blocks are defined by and aligned with the local flow coordinates. We choose a multi-rate mass transfer (MRMT) model to represent the remaining sub-block non-Fickian behavior within these blocks on the coarse scale. To make the scale transition simple and to save computational costs, we capture sub-block features by temporal moments (TM) of block-wise particle arrival times to be matched with the MRMT model. By predicting spatial mass distributions of injected tracers in a synthetic test scenario, our coarse-scale solution matches reasonably well with the corresponding fine-scale reference solution. For predicting higher TM-orders (such as arrival time and effective dispersion), the prediction accuracy steadily decreases. This is compensated to some extent by the MRMT model. If the MRMT model becomes too complex, it loses its effect. We also found that prediction accuracy is sensitive to the choice of

  10. Damage identification in beams by a response surface based technique

    Directory of Open Access Journals (Sweden)

    Teidj S.

    2014-01-01

    Full Text Available In this work, identification of damage in uniform homogeneous metallic beams was considered through the propagation of non dispersive elastic torsional waves. The proposed damage detection procedure consisted of the following sequence. Giving a localized torque excitation, having the form of a short half-sine pulse, the first step was calculating the transient solution of the resulting torsional wave. This torque could be generated in practice by means of asymmetric laser irradiation of the beam surface. Then, a localized defect assumed to be characterized by an abrupt reduction of beam section area with a given height and extent was placed at a known location of the beam. Next, the response in terms of transverse section rotation rate was obtained for a point situated afterwards the defect, where the sensor was positioned. This last could utilize in practice the concept of laser vibrometry. A parametric study has been conducted after that by using a full factorial design of experiments table and numerical simulations based on a finite difference characteristic scheme. This has enabled the derivation of a response surface model that was shown to represent adequately the response of the system in terms of the following factors: defect extent and severity. The final step was performing the inverse problem solution in order to identify the defect characteristics by using measurement.

  11. High-speed all-optical DNA local sequence alignment based on a three-dimensional artificial neural network.

    Science.gov (United States)

    Maleki, Ehsan; Babashah, Hossein; Koohi, Somayyeh; Kavehvash, Zahra

    2017-07-01

    This paper presents an optical processing approach for exploring a large number of genome sequences. Specifically, we propose an optical correlator for global alignment and an extended moiré matching technique for local analysis of spatially coded DNA, whose output is fed to a novel three-dimensional artificial neural network for local DNA alignment. All-optical implementation of the proposed 3D artificial neural network is developed and its accuracy is verified in Zemax. Thanks to its parallel processing capability, the proposed structure performs local alignment of 4 million sequences of 150 base pairs in a few seconds, which is much faster than its electrical counterparts, such as the basic local alignment search tool.

  12. Laser diagnostics for picosecond e-beams

    International Nuclear Information System (INIS)

    Pogorelsky, I.; Ben-Zvi, I.

    1992-01-01

    We propose a novel approach to picosecond e-bunch/laser pulse synchronization and spatial alignment based upon refraction and reflection of a laser beam on a plasma column created by relativistic electrons traveling through a gas or solid optical material. The technique may be used in laser accelerators and for general subpicosecond e-beam diagnostics

  13. An Improved Measurement Method for the Strength of Radiation of Reflective Beam in an Industrial Optical Sensor Based on Laser Displacement Meter

    Directory of Open Access Journals (Sweden)

    Youngchul Bae

    2016-05-01

    Full Text Available An optical sensor such as a laser range finder (LRF or laser displacement meter (LDM uses reflected and returned laser beam from a target. The optical sensor has been mainly used to measure the distance between a launch position and the target. However, optical sensor based LRF and LDM have numerous and various errors such as statistical errors, drift errors, cyclic errors, alignment errors and slope errors. Among these errors, an alignment error that contains measurement error for the strength of radiation of returned laser beam from the target is the most serious error in industrial optical sensors. It is caused by the dependence of the measurement offset upon the strength of radiation of returned beam incident upon the focusing lens from the target. In this paper, in order to solve these problems, we propose a novel method for the measurement of the output of direct current (DC voltage that is proportional to the strength of radiation of returned laser beam in the received avalanche photo diode (APD circuit. We implemented a measuring circuit that is able to provide an exact measurement of reflected laser beam. By using the proposed method, we can measure the intensity or strength of radiation of laser beam in real time and with a high degree of precision.

  14. An Improved Measurement Method for the Strength of Radiation of Reflective Beam in an Industrial Optical Sensor Based on Laser Displacement Meter.

    Science.gov (United States)

    Bae, Youngchul

    2016-05-23

    An optical sensor such as a laser range finder (LRF) or laser displacement meter (LDM) uses reflected and returned laser beam from a target. The optical sensor has been mainly used to measure the distance between a launch position and the target. However, optical sensor based LRF and LDM have numerous and various errors such as statistical errors, drift errors, cyclic errors, alignment errors and slope errors. Among these errors, an alignment error that contains measurement error for the strength of radiation of returned laser beam from the target is the most serious error in industrial optical sensors. It is caused by the dependence of the measurement offset upon the strength of radiation of returned beam incident upon the focusing lens from the target. In this paper, in order to solve these problems, we propose a novel method for the measurement of the output of direct current (DC) voltage that is proportional to the strength of radiation of returned laser beam in the received avalanche photo diode (APD) circuit. We implemented a measuring circuit that is able to provide an exact measurement of reflected laser beam. By using the proposed method, we can measure the intensity or strength of radiation of laser beam in real time and with a high degree of precision.

  15. High-performance supercapacitors based on vertically aligned carbon nanotubes and nonaqueous electrolytes

    International Nuclear Information System (INIS)

    Kim, Byungwoo; Kim, Woong; Chung, Haegeun

    2012-01-01

    We demonstrate the high performance of supercapacitors fabricated with vertically aligned carbon nanotubes and nonaqueous electrolytes such as ionic liquids and conventional organic electrolytes. Specific capacitance, maximum power and energy density of the supercapacitor measured in ionic liquid were ∼75 F g −1 , ∼987 kW kg −1 and ∼27 W h kg −1 , respectively. The high power performance was consistently indicated by a fast relaxation time constant of 0.2 s. In addition, electrochemical oxidation of the carbon nanotubes improved the specific capacitance (∼158 F g −1 ) and energy density (∼53 W h kg −1 ). Both high power and energy density could be attributed to the fast ion transport realized by the alignment of carbon nanotubes and the wide operational voltage defined by the ionic liquid. The demonstrated carbon-nanotube- and nonaqueous-electrolyte-based supercapacitors show great potential for the development of high-performance energy storage devices. (paper)

  16. Electrochemical Capacitors Based on Aligned Carbon Nanotubes Directly Synthesized on Tantalum Substrates

    International Nuclear Information System (INIS)

    Kim, Byung Woo; Chung, Hae Geun; Kim, Woong; Min, Byoung Koun; Kim, Hong Gon

    2010-01-01

    We demonstrate that vertically aligned carbon nanotubes can be synthesized directly on tantalum substrate via waterassisted chemical vapor deposition and evaluate their properties as electrochemical capacitors. The mean diameter of the carbon nanotubes was 7.1 ± 1.5 nm, and 70% of them had double walls. The intensity ratio of G-band to D-band in Raman spectra was as high as 5, indicating good quality of the carbon nanotubes. Owing to the alignment and low equivalent series resistance, the carbon nanotube based supercapacitors showed good rate performance. Rectangular shape of cyclic voltammogram was maintained even at the scan rate of > 1 V/s in 1 M sulfuric acid aqueous solution. Specific capacitance was well-retained (∼94%) even when the discharging current density dramatically increased up to 145 A/g. Consequently, specific power as high as 60 kW/kg was obtained from as-grown carbon nanotubes in aqueous solution. Maximum specific energy of ∼20 Wh/kg was obtained when carbon nanotubes were electrochemically oxidized and operated in organic solution. Demonstration of direct synthesis of carbon nanotubes on tantalum current collectors and their applications as supercapacitors could be an invaluable basis for fabrication of high performance carbon nanotube supercapacitors

  17. Aligned carbon nanotube based ultrasonic microtransducers for durability monitoring in civil engineering.

    Science.gov (United States)

    Lebental, B; Chainais, P; Chenevier, P; Chevalier, N; Delevoye, E; Fabbri, J-M; Nicoletti, S; Renaux, P; Ghis, A

    2011-09-30

    Structural health monitoring of porous materials such as concrete is becoming a major component in our resource-limited economy, as it conditions durable exploitation of existing facilities. Durability in porous materials depends on nanoscale features which need to be monitored in situ with nanometric resolution. To address this problem, we put forward an approach based on the development of a new nanosensor, namely a capacitive micrometric ultrasonic transducer whose vibrating membrane is made of aligned single-walled carbon nanotubes (SWNT). Such sensors are meant to be embedded in large numbers within a porous material in order to provide information on its durability by monitoring in situ neighboring individual micropores. In the present paper, we report on the feasibility of the key building block of the proposed sensor: we have fabricated well-aligned, ultra-thin, dense SWNT membranes that show above-nanometer amplitudes of vibration over a large range of frequencies spanning from 100 kHz to 5 MHz.

  18. Beam-Based Diagnostics of RF-Breakdown in the Two-Beam Test-Stand in CTF3

    CERN Document Server

    Johnson, M

    2007-01-01

    The general outline of a beam-based diagnostic method of RF-breakdown, using BPMs, at the two-beam test-stand in CTF3 is discussed. The basic components of the set-up and their functions in the diagnostic are described. Estimations of the expected error in the measured parameters are performed.

  19. A scintillating fibre-based profiler for low intensity ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Finocchiaro, P. [Istituto Nazionale di Fisica Nucleare, Catania (Italy); Amato, A. [Istituto Nazionale di Fisica Nucleare, Catania (Italy); Ciavola, G. [Istituto Nazionale di Fisica Nucleare, Catania (Italy); Cuttone, G. [Istituto Nazionale di Fisica Nucleare, Catania (Italy); Gu, M. [Istituto Nazionale di Fisica Nucleare, Catania (Italy); Raia, G. [Istituto Nazionale di Fisica Nucleare, Catania (Italy); Rovelli, A. [Istituto Nazionale di Fisica Nucleare, Catania (Italy)

    1997-01-11

    In the framework of the EXCYT radioactive ion beam facility, now under development at LNS Catania, we have developed a new beam profile monitor based on a scintillating fibre and a photodetector. Its sensitivity allows the detection of single beam particles in pulse mode, thus representing a useful tool for diagnostics of low and very low intensity beams. (orig.).

  20. A scintillating fibre-based profiler for low intensity ion beams

    International Nuclear Information System (INIS)

    Finocchiaro, P.; Amato, A.; Ciavola, G.; Cuttone, G.; Gu, M.; Raia, G.; Rovelli, A.

    1997-01-01

    In the framework of the EXCYT radioactive ion beam facility, now under development at LNS Catania, we have developed a new beam profile monitor based on a scintillating fibre and a photodetector. Its sensitivity allows the detection of single beam particles in pulse mode, thus representing a useful tool for diagnostics of low and very low intensity beams. (orig.)

  1. Beam-based Feedback Simulations for the NLC Linac

    International Nuclear Information System (INIS)

    Hendrickson, Linda

    2000-01-01

    Extensive beam-based feedback systems are planned as an integral part of the Next Linear Collider (NLC) control system. Wakefield effects are a significant influence on the feedback design, imposing both architectural and algorithmic constraints. Studies are in progress to assure the optimal selection of devices and to refine and confirm the algorithms for the system design. The authors show the results of initial simulations, along with evaluations of system response for various conditions of ground motion and other operational disturbances

  2. Can a semi-automated surface matching and principal axis-based algorithm accurately quantify femoral shaft fracture alignment in six degrees of freedom?

    Science.gov (United States)

    Crookshank, Meghan C; Beek, Maarten; Singh, Devin; Schemitsch, Emil H; Whyne, Cari M

    2013-07-01

    Accurate alignment of femoral shaft fractures treated with intramedullary nailing remains a challenge for orthopaedic surgeons. The aim of this study is to develop and validate a cone-beam CT-based, semi-automated algorithm to quantify the malalignment in six degrees of freedom (6DOF) using a surface matching and principal axes-based approach. Complex comminuted diaphyseal fractures were created in nine cadaveric femora and cone-beam CT images were acquired (27 cases total). Scans were cropped and segmented using intensity-based thresholding, producing superior, inferior and comminution volumes. Cylinders were fit to estimate the long axes of the superior and inferior fragments. The angle and distance between the two cylindrical axes were calculated to determine flexion/extension and varus/valgus angulation and medial/lateral and anterior/posterior translations, respectively. Both surfaces were unwrapped about the cylindrical axes. Three methods of matching the unwrapped surface for determination of periaxial rotation were compared based on minimizing the distance between features. The calculated corrections were compared to the input malalignment conditions. All 6DOF were calculated to within current clinical tolerances for all but two cases. This algorithm yielded accurate quantification of malalignment of femoral shaft fractures for fracture gaps up to 60 mm, based on a single CBCT image of the fractured limb. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  3. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G.Gomez

    2010-01-01

    The main developments in muon alignment since March 2010 have been the production, approval and deployment of alignment constants for the ICHEP data reprocessing. In the barrel, a new geometry, combining information from both hardware and track-based alignment systems, has been developed for the first time. The hardware alignment provides an initial DT geometry, which is then anchored as a rigid solid, using the link alignment system, to a reference frame common to the tracker. The “GlobalPositionRecords” for both the Tracker and Muon systems are being used for the first time, and the initial tracker-muon relative positioning, based on the link alignment, yields good results within the photogrammetry uncertainties of the Tracker and alignment ring positions. For the first time, the optical and track-based alignments show good agreement between them; the optical alignment being refined by the track-based alignment. The resulting geometry is the most complete to date, aligning all 250 DTs, ...

  4. A beam monitor based on MPGD detectors for hadron therapy

    Directory of Open Access Journals (Sweden)

    Altieri P. R.

    2018-01-01

    Full Text Available Remarkable scientific and technological progress during the last years has led to the construction of accelerator based facilities dedicated to hadron therapy. This kind of technology requires precise and continuous control of position, intensity and shape of the ions or protons used to irradiate cancers. Patient safety, accelerator operation and dose delivery should be optimized by a real time monitoring of beam intensity and profile during the treatment, by using non-destructive, high spatial resolution detectors. In the framework of AMIDERHA (AMIDERHA - Enhanced Radiotherapy with HAdron project funded by the Ministero dell’Istruzione, dell’Università e della Ricerca (Italian Ministry of Education and Research the authors are studying and developing an innovative beam monitor based on Micro Pattern Gaseous Detectors (MPDGs characterized by a high spatial resolution and rate capability. The Monte Carlo simulation of the beam monitor prototype was carried out to optimize the geometrical set up and to predict the behavior of the detector. A first prototype has been constructed and successfully tested using 55Fe, 90Sr and also an X-ray tube. Preliminary results on both simulations and tests will be presented.

  5. GEM-based thermal neutron beam monitors for spallation sources

    International Nuclear Information System (INIS)

    Croci, G.; Claps, G.; Caniello, R.; Cazzaniga, C.; Grosso, G.; Murtas, F.; Tardocchi, M.; Vassallo, E.; Gorini, G.; Horstmann, C.; Kampmann, R.; Nowak, G.; Stoermer, M.

    2013-01-01

    The development of new large area and high flux thermal neutron detectors for future neutron spallation sources, like the European Spallation Source (ESS) is motivated by the problem of 3 He shortage. In the framework of the development of ESS, GEM (Gas Electron Multiplier) is one of the detector technologies that are being explored as thermal neutron sensors. A first prototype of GEM-based thermal neutron beam monitor (bGEM) has been built during 2012. The bGEM is a triple GEM gaseous detector equipped with an aluminum cathode coated by 1μm thick B 4 C layer used to convert thermal neutrons to charged particles through the 10 B(n, 7 Li)α nuclear reaction. This paper describes the results obtained by testing a bGEM detector at the ISIS spallation source on the VESUVIO beamline. Beam profiles (FWHM x =31 mm and FWHM y =36 mm), bGEM thermal neutron counting efficiency (≈1%), detector stability (3.45%) and the time-of-flight spectrum of the beam were successfully measured. This prototype represents the first step towards the development of thermal neutrons detectors with efficiency larger than 50% as alternatives to 3 He-based gaseous detectors

  6. An Elaboration of a Strategic Alignment Model of University Information Systems based on SAM Model

    Directory of Open Access Journals (Sweden)

    S. Ahriz

    2018-02-01

    Full Text Available Information system is a guarantee of the universities' ability to anticipate the essential functions to their development and durability. The alignment of information system, one of the pillars of IT governance, has become a necessity. In this paper, we consider the problem of strategic alignment model implementation in Moroccan universities. Literature revealed that few studies have examined strategic alignment in the public sector, particularly in higher education institutions. Hence we opted for an exploratory approach that aims to better understanding the strategic alignment and to evaluate the degree of its use within Moroccan universities. The data gained primarily through interviews with top managers and IT managers reveal that the alignment is not formalized and that it would be appropriate to implement an alignment model. It is found that the implementation of our proposed model can help managers to maximize returns of IT investment and to increase their efficiency.

  7. Linear Fresnel zone plate based two-state alignment system for 0.25 micron x-ray lithography

    International Nuclear Information System (INIS)

    Chen, G.

    1993-01-01

    X-ray lithography has proven to be a cost effective and promising technique for fabricating Integrated Circuits (ICs) with minimum feature sizes of less than 0.25 μm. Since IC fabrication is a multilevel process, to preserve the functionality of devices, circuit patterns printed at each lithography level must match existing patterns on the wafer with an accuracy of less than 1/3 ∼ 1/5 of the minimum feature size. An alignment system is used to position the mask relative to the wafer so that mask circuit patterns can be printed on the wafer at the designed position. As the minimum printed feature size shrinks, the overlay requirements of a lithography tool become more stringent. A stepper for 0.25 μm feature device fabrication requires an overlay accuracy of 0.075 μm, of which only 0.05 μm (mean + 3σ) is allocated to its alignment system. This thesis presents the development of a linear Fresnel zone late based two-state alignment (TSA) method for a 0.25 μm x-ray lithography tool. The authors first analyze the overlay requirement in a lithography process and the error allocation to the alignment system for a 0.25 μ feature x-ray lithography tool. They then describe the principle of the two-state alignment, its computer simulation and the optimal alignment mark design. They carried out an optical bench test for the one-axes alignment setup and experimentally evaluated the performance of the system. They developed a three-axes TSA system and integrated the system with the ES-3 x-ray beamline to construct the CXrL aligner, an experimental x-ray exposure system in CXrL. They measured the alignment accuracy of the exposure system to be better than 0.035 μm (3σ) on both metal and dielectric alignment mark substrates. They also studied the effect of processing coatings on the alignment signal with different wafer mark substrates. They successfully printed the 0.5 μm gate level patterns for the first NMOS test chip at CXrL

  8. GPU-based fast pencil beam algorithm for proton therapy

    International Nuclear Information System (INIS)

    Fujimoto, Rintaro; Nagamine, Yoshihiko; Kurihara, Tsuneya

    2011-01-01

    Performance of a treatment planning system is an essential factor in making sophisticated plans. The dose calculation is a major time-consuming process in planning operations. The standard algorithm for proton dose calculations is the pencil beam algorithm which produces relatively accurate results, but is time consuming. In order to shorten the computational time, we have developed a GPU (graphics processing unit)-based pencil beam algorithm. We have implemented this algorithm and calculated dose distributions in the case of a water phantom. The results were compared to those obtained by a traditional method with respect to the computational time and discrepancy between the two methods. The new algorithm shows 5-20 times faster performance using the NVIDIA GeForce GTX 480 card in comparison with the Intel Core-i7 920 processor. The maximum discrepancy of the dose distribution is within 0.2%. Our results show that GPUs are effective for proton dose calculations.

  9. An energy-based beam hardening model in tomography

    International Nuclear Information System (INIS)

    Casteele, E van de; Dyck, D van; Sijbers, J; Raman, E

    2002-01-01

    As a consequence of the polychromatic x-ray source, used in micro-computer tomography (μCT) and in medical CT, the attenuation is no longer a linear function of absorber thickness. If this nonlinear beam hardening effect is not compensated, the reconstructed images will be corrupted by cupping artefacts. In this paper, a bimodal energy model for the detected energy spectrum is presented, which can be used for reduction of artefacts caused by beam hardening in well-specified conditions. Based on the combination of the spectrum of the source and the detector efficiency, the assumption is made that there are two dominant energies which can describe the system. The validity of the proposed model is examined by fitting the model to the experimental datapoints obtained on a microtomograph for different materials and source voltages

  10. Bright single photon source based on self-aligned quantum dot–cavity systems

    DEFF Research Database (Denmark)

    Maier, Sebastian; Gold, Peter; Forchel, Alfred

    2014-01-01

    We report on a quasi-planar quantum-dot-based single-photon source that shows an unprecedented high extraction efficiency of 42% without complex photonic resonator geometries or post-growth nanofabrication. This very high efficiency originates from the coupling of the photons emitted by a quantum...... dot to a Gaussian shaped nanohill defect that naturally arises during epitaxial growth in a self-aligned manner. We investigate the morphology of these defects and characterize the photonic operation mechanism. Our results show that these naturally arising coupled quantum dot-defects provide a new...... avenue for efficient (up to 42% demonstrated) and pure (g2(0) value of 0.023) single-photon emission....

  11. Genetic Algorithm Phase Retrieval for the Systematic Image-Based Optical Alignment Testbed

    Science.gov (United States)

    Taylor, Jaime; Rakoczy, John; Steincamp, James

    2003-01-01

    Phase retrieval requires calculation of the real-valued phase of the pupil fimction from the image intensity distribution and characteristics of an optical system. Genetic 'algorithms were used to solve two one-dimensional phase retrieval problem. A GA successfully estimated the coefficients of a polynomial expansion of the phase when the number of coefficients was correctly specified. A GA also successfully estimated the multiple p h e s of a segmented optical system analogous to the seven-mirror Systematic Image-Based Optical Alignment (SIBOA) testbed located at NASA s Marshall Space Flight Center. The SIBOA testbed was developed to investigate phase retrieval techniques. Tiphilt and piston motions of the mirrors accomplish phase corrections. A constant phase over each mirror can be achieved by an independent tip/tilt correction: the phase Conection term can then be factored out of the Discrete Fourier Tranform (DFT), greatly reducing computations.

  12. Alternate transmission relaying based on interference alignment in 3-relay half-duplex MIMO systems

    KAUST Repository

    Park, Seongho; Park, Kihong; Ko, Youngchai; Alouini, Mohamed-Slim

    2012-01-01

    In a half-duplex relaying, the capacity pre-log factor 1/2 is a major drawback in spectral efficiency. This paper proposes a linear precoding/decoding scheme and an alternate relaying protocol in a dual-hop half-duplex system where three relays help the communication between the source and the destination. In our proposed scheme, we consider a phase incoherent method in relays in which the source alternately transmits message signals to the different relays. In addition, we propose a linear interference alignment scheme which can suppress the inter-relay interference resulting from the phase incoherence of relaying. Based on our analysis of degrees of freedom and our simulation results, we show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying. © 2012 IEEE.

  13. Alternate transmission relaying based on interference alignment in 3-relay half-duplex MIMO systems

    KAUST Repository

    Park, Seongho

    2012-09-01

    In a half-duplex relaying, the capacity pre-log factor 1/2 is a major drawback in spectral efficiency. This paper proposes a linear precoding/decoding scheme and an alternate relaying protocol in a dual-hop half-duplex system where three relays help the communication between the source and the destination. In our proposed scheme, we consider a phase incoherent method in relays in which the source alternately transmits message signals to the different relays. In addition, we propose a linear interference alignment scheme which can suppress the inter-relay interference resulting from the phase incoherence of relaying. Based on our analysis of degrees of freedom and our simulation results, we show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying. © 2012 IEEE.

  14. A hybrid cloud read aligner based on MinHash and kmer voting that preserves privacy

    Science.gov (United States)

    Popic, Victoria; Batzoglou, Serafim

    2017-05-01

    Low-cost clouds can alleviate the compute and storage burden of the genome sequencing data explosion. However, moving personal genome data analysis to the cloud can raise serious privacy concerns. Here, we devise a method named Balaur, a privacy preserving read mapper for hybrid clouds based on locality sensitive hashing and kmer voting. Balaur can securely outsource a substantial fraction of the computation to the public cloud, while being highly competitive in accuracy and speed with non-private state-of-the-art read aligners on short read data. We also show that the method is significantly faster than the state of the art in long read mapping. Therefore, Balaur can enable institutions handling massive genomic data sets to shift part of their analysis to the cloud without sacrificing accuracy or exposing sensitive information to an untrusted third party.

  15. Simulation based assembly and alignment process ability analysis for line replaceable units of the high power solid state laser facility

    International Nuclear Information System (INIS)

    Wang, Junfeng; Lu, Cong; Li, Shiqi

    2016-01-01

    Highlights: • Discrete event simulation is applied to analyze the assembly and alignment process ability of LRUs in SG-III facility. • The overall assembly and alignment process of LRUs with specific characteristics is described. • An extended-directed graph is proposed to express the assembly and alignment process of LRUs. • Different scenarios have been simulated to evaluate assembling process ability of LRUs and decision making is supported to ensure the construction millstone. - Abstract: Line replaceable units (LRUs) are important components of the very large high power solid state laser facilities. The assembly and alignment process ability of LRUs will impact the construction milestone of facilities. This paper describes the use of discrete event simulation method for assembly and alignment process analysis of LRUs in such facilities. The overall assembly and alignment process for LRUs is presented based on the layout of the optics assembly laboratory and the process characteristics are analyzed. An extended-directed graph is proposed to express the assembly and alignment process of LRUs. Taking the LRUs of disk amplifier system in Shen Guang-III (SG-III) facility as the example, some process simulation models are built based on the Quest simulation platform. The constraints, such as duration, equipment, technician and part supply, are considered in the simulation models. Different simulation scenarios have been carried out to evaluate the assembling process ability of LRUs. The simulation method can provide a valuable decision making and process optimization tool for the optics assembly laboratory layout and the process working out of such facilities.

  16. Simulation based assembly and alignment process ability analysis for line replaceable units of the high power solid state laser facility

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junfeng; Lu, Cong; Li, Shiqi, E-mail: sqli@hust.edu.cn

    2016-11-15

    Highlights: • Discrete event simulation is applied to analyze the assembly and alignment process ability of LRUs in SG-III facility. • The overall assembly and alignment process of LRUs with specific characteristics is described. • An extended-directed graph is proposed to express the assembly and alignment process of LRUs. • Different scenarios have been simulated to evaluate assembling process ability of LRUs and decision making is supported to ensure the construction millstone. - Abstract: Line replaceable units (LRUs) are important components of the very large high power solid state laser facilities. The assembly and alignment process ability of LRUs will impact the construction milestone of facilities. This paper describes the use of discrete event simulation method for assembly and alignment process analysis of LRUs in such facilities. The overall assembly and alignment process for LRUs is presented based on the layout of the optics assembly laboratory and the process characteristics are analyzed. An extended-directed graph is proposed to express the assembly and alignment process of LRUs. Taking the LRUs of disk amplifier system in Shen Guang-III (SG-III) facility as the example, some process simulation models are built based on the Quest simulation platform. The constraints, such as duration, equipment, technician and part supply, are considered in the simulation models. Different simulation scenarios have been carried out to evaluate the assembling process ability of LRUs. The simulation method can provide a valuable decision making and process optimization tool for the optics assembly laboratory layout and the process working out of such facilities.

  17. Development of a diplexer based on dielectric beam splitters

    International Nuclear Information System (INIS)

    D'Arcangelo, O.; Alessi, E.; Bin, W.; Bruschi, A.; Moro, A.; Muzzini, V.

    2011-01-01

    Controllable power combination and distribution of multiple sources into multiple transmission lines may increase efficiency and flexibility of ECRH systems. A new quasi-optical version of diplexer based on a resonating system, coupling two transmission lines, is under development at IFP-CNR. Two dielectric beam splitters work as input/output ports for the diplexer, which can be thought as a Fabry-Perot resonator. A third beam splitter can be inserted in the middle of the resonator. In this case the diplexer looks like a pair of mirrored resonators coupled by through the central splitter. Each beam splitter is made of a water-free silica layer, three quarter of wavelength thick at 140 GHz. The simulated performances were tested as a function of the frequency on the two splitters simpler model. Preliminary results confirm qualitatively theoretical predictions as well as the good channel separation obtainable with the three splitters version. Present work describes the system realization together with the low power tests performed.

  18. Optical encoder based on a nondiffractive beam III

    Energy Technology Data Exchange (ETDEWEB)

    Lutenberg, Ariel; Perez-Quintian, Fernando

    2009-09-20

    In two preceding works (Appl. Opt.47, 2201-2206, 2008APOPAI0003-693510.1364/AO.47.002201; Appl. Opt.48, 414-424, 2009APOPAI0003-693510.1364/AO.48.000414) we introduced the design of an optical encoder based on a nondiffractive beam and studied the dependence of its performance on its parameters (e.g., grating pitch, photodetector size). In those works we proposed different optimization criteria and concluded that the proposed design provides an output sinusoidal signal with high contrast and very low harmonic distortion, while having remarkable tolerance to variations in its parameters and to mechanical perturbations. In this work we (1) study how to improve the system performance by means of selecting appropriate photodetector geometry, (2) study the system performance for different nondiffractive beam geometries, and (3) quantify the output signal tolerance to vertical and lateral misalignment between the centers of the nondiffractive beam and the photodetector. As a consequence, we obtain new sets of optimal parameters that significantly improve the system performance and enhance its tolerance to mechanical perturbations and fabrication errors.

  19. Microcontroller based two axis microtron beam extraction system

    International Nuclear Information System (INIS)

    Ashoka, H.; Jathar, M.; Meshram, V.; Rao, Nageswara

    2009-01-01

    Microtron is an electron accelerator which is used to accelerate the electron beam. The Microtron consists of electro magnet with two poles separated by yoke for completion of path for magnetic flux lines. A compact Microtron capable of accelerating electrons up to 12 MeV has been developed in RRCAT. The beam from the Microtron has to be extracted from various orbits depending upon the user requirement (X-Y stage is built with an accuracy of 100 μm). This paper describes the design and development of microcontroller based two axis beam extraction system for Microtron, with a resolution of 50 μm to position the extraction tube with respect to selected orbit. Two axis motion controller is developed using current controlled micro-stepping driver mechanism, which uses Bipolar Chopper Drive for driving stepper motors. Each phase has 2A continuous driving capability. The system is provided with user selectable controls like speed, steps, direction, and mode. This system is provided with RS-232 interface, to accept commands from PC. This system also has local keyboard and LCD interface to use in Stand-alone mode (local Mode). (author)

  20. Evaporation-based method for preparing gelatin foams with aligned tubular pore structures

    International Nuclear Information System (INIS)

    Frazier, Shane D.; Srubar, Wil V.

    2016-01-01

    Gelatin-based foams with aligned tubular pore structures were prepared via liquid-to-gas vaporization of tightly bound water in dehydrated gelatin hydrogels. This study elucidates the mechanism of the foaming process by investigating the secondary (i.e., helical) structure, molecular interactions, and water content of gelatin films before and after foaming using X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. Experimental data from gelatin samples prepared at various gelatin-to-water concentrations (5–30 wt.%) substantiate that resulting foam structures are similar in pore diameter (approximately 350 μm), shape, and density (0.05–0.22 g/cm"3) to those fabricated using conventional methods (e.g., freeze-drying). Helical structures were identified in the films but were not evident in the foamed samples after vaporization (~ 150 °C), suggesting that the primary foaming mechanism is governed by the vaporization of water that is tightly bound in secondary structures (i.e., helices, β-turns, β-sheets) that are present in dehydrated gelatin films. FTIR and TGA data show that the foaming process leads to more disorder and reduced hydrogen bonding to hydroxyl groups in gelatin and that no thermal degradation of gelatin occurs before or after foaming. - Highlights: • A new method is presented for fabricating gelatin foams with aligned, tubular pores. • Gelatin hydrogels were dehydrated then heated to 150 °C to induce foaming. • Vaporization of tightly (vs. loosely) bound water is the primary foaming mechanism • Foaming induced no thermal degradation but caused disorder in secondary structures • Foam microstructures are similar to those prepared using conventional methods.

  1. Evaporation-based method for preparing gelatin foams with aligned tubular pore structures

    Energy Technology Data Exchange (ETDEWEB)

    Frazier, Shane D.; Srubar, Wil V., E-mail: wsrubar@colorado.edu

    2016-05-01

    Gelatin-based foams with aligned tubular pore structures were prepared via liquid-to-gas vaporization of tightly bound water in dehydrated gelatin hydrogels. This study elucidates the mechanism of the foaming process by investigating the secondary (i.e., helical) structure, molecular interactions, and water content of gelatin films before and after foaming using X-ray diffraction, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. Experimental data from gelatin samples prepared at various gelatin-to-water concentrations (5–30 wt.%) substantiate that resulting foam structures are similar in pore diameter (approximately 350 μm), shape, and density (0.05–0.22 g/cm{sup 3}) to those fabricated using conventional methods (e.g., freeze-drying). Helical structures were identified in the films but were not evident in the foamed samples after vaporization (~ 150 °C), suggesting that the primary foaming mechanism is governed by the vaporization of water that is tightly bound in secondary structures (i.e., helices, β-turns, β-sheets) that are present in dehydrated gelatin films. FTIR and TGA data show that the foaming process leads to more disorder and reduced hydrogen bonding to hydroxyl groups in gelatin and that no thermal degradation of gelatin occurs before or after foaming. - Highlights: • A new method is presented for fabricating gelatin foams with aligned, tubular pores. • Gelatin hydrogels were dehydrated then heated to 150 °C to induce foaming. • Vaporization of tightly (vs. loosely) bound water is the primary foaming mechanism • Foaming induced no thermal degradation but caused disorder in secondary structures • Foam microstructures are similar to those prepared using conventional methods.

  2. Business-IT alignment in PSS value networks : a capability-based framework

    NARCIS (Netherlands)

    Bagheri, S.; Kusters, R.J.; Trienekens, J.J.M.; Camarinha-Matos, L.M.; Afsarmanesh, H.

    2014-01-01

    Advanced information technology (IT) is regarded as a foundation for the operation of product-service system (PSS) value networks. This requires alignment between IT and PSS business strategy. Business‐IT alignment (BIA) in a value network can raise the ability of partners to collaborate effectively

  3. Value-Based Business-IT Alignment in Networked Constellations of Enterprises

    NARCIS (Netherlands)

    Gordijn, Jaap; van Eck, Pascal; Cox, K.; Dubois, E.; Pigneur, Y.; Bleistein, S.J.; Verner, J.; Davis, A.M.; Wieringa, Roelf J.

    Business-ICT alignment is the problem of matching ICTservices with the requirements of the business. In businesses of any significant size, business-ICT alignment is a hard problem, which is currently not solved completely. With the advent of networked constellations of enterprises, the problem gets

  4. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    Z. Szillasi and G. Gomez.

    2013-01-01

    When CMS is opened up, major components of the Link and Barrel Alignment systems will be removed. This operation, besides allowing for maintenance of the detector underneath, is needed for making interventions that will reinforce the alignment measurements and make the operation of the alignment system more reliable. For that purpose and also for their general maintenance and recalibration, the alignment components will be transferred to the Alignment Lab situated in the ISR area. For the track-based alignment, attention is focused on the determination of systematic uncertainties, which have become dominant, since now there is a large statistics of muon tracks. This will allow for an improved Monte Carlo misalignment scenario and updated alignment position errors, crucial for high-momentum muon analysis such as Z′ searches.

  5. Focused Ion Beam Nanopatterning for Carbon Nanotube Ropes Based Sensor

    Directory of Open Access Journals (Sweden)

    Vera LA FERRARA

    2007-11-01

    Full Text Available Focused Ion Beam (FIB technology has been used to realize electrode patterns for contacting Single Walled Carbon Nanotubes (SWCNTs ropes for chemical gas sensor applications. Two types of transducers, based on a single rope and on bundles, have been realized starting from silicon/Si3N4 substrate. Electrical behaviour, at room temperature, in toxic gas environments, has been investigated and compared to evaluate contribution of a single rope based sensor respect to bundles one. For all the devices, upon exposure to NO2 and NH3, the conductance has been found to increase or decrease respectively. Conductance signal is stronger for sensor based on bundles, but it also evident that response time in NO2 is faster for device based on a single rope. FIB technology offers, then, the possibility to contact easily a single sensitive nanowire, as carbon nanotube rope.

  6. 3D dictionary learning based iterative cone beam CT reconstruction

    Directory of Open Access Journals (Sweden)

    Ti Bai

    2014-03-01

    Full Text Available Purpose: This work is to develop a 3D dictionary learning based cone beam CT (CBCT reconstruction algorithm on graphic processing units (GPU to improve the quality of sparse-view CBCT reconstruction with high efficiency. Methods: A 3D dictionary containing 256 small volumes (atoms of 3 × 3 × 3 was trained from a large number of blocks extracted from a high quality volume image. On the basis, we utilized cholesky decomposition based orthogonal matching pursuit algorithm to find the sparse representation of each block. To accelerate the time-consuming sparse coding in the 3D case, we implemented the sparse coding in a parallel fashion by taking advantage of the tremendous computational power of GPU. Conjugate gradient least square algorithm was adopted to minimize the data fidelity term. Evaluations are performed based on a head-neck patient case. FDK reconstruction with full dataset of 364 projections is used as the reference. We compared the proposed 3D dictionary learning based method with tight frame (TF by performing reconstructions on a subset data of 121 projections. Results: Compared to TF based CBCT reconstruction that shows good overall performance, our experiments indicated that 3D dictionary learning based CBCT reconstruction is able to recover finer structures, remove more streaking artifacts and also induce less blocky artifacts. Conclusion: 3D dictionary learning based CBCT reconstruction algorithm is able to sense the structural information while suppress the noise, and hence to achieve high quality reconstruction under the case of sparse view. The GPU realization of the whole algorithm offers a significant efficiency enhancement, making this algorithm more feasible for potential clinical application.-------------------------------Cite this article as: Bai T, Yan H, Shi F, Jia X, Lou Y, Xu Q, Jiang S, Mou X. 3D dictionary learning based iterative cone beam CT reconstruction. Int J Cancer Ther Oncol 2014; 2(2:020240. DOI: 10

  7. Dosimetric performance evaluation regarding proton beam incident angles of a lithium-based AB-BNCT design

    International Nuclear Information System (INIS)

    Lee, Pei-Yi; Jiang, Shiang-Huei; Liu, Yuan-Hao

    2014-01-01

    The 7 Li(p,xn) 7 Be nuclear reaction, based on the low-energy protons, could produce soft neutrons for accelerator-based boron neutron capture therapy (AB-BNCT). Based on the fact that the induced neutron field is relatively divergent, the relationship between the incident angle of proton beam and the neutron beam quality was evaluated in this study. To provide an intense epithermal neutron beam, a beam-shaping assembly (BSA) was designed. And a modified Snyder head phantom was used in the calculations for evaluating the dosimetric performance. From the calculated results, the intensity of epithermal neutrons increased with the increase in proton incident angle. Hence, either the irradiation time or the required proton current can be reduced. When the incident angle of 2.5-MeV proton beam is 120 deg., the required proton current is ∼13.3 mA for an irradiation time of half an hour. The results of this study show that the BSA designs can generate neutron beams with good intensity and penetrability. Using a 20-mA, 2.5-MeV proton beam as the source, the required irradiation time, to induce 60 RBE-Gy of maximum tumour dose, is less than half an hour in any proton beam alignments. On the premise that the dosimetric performances are similar, the intensity of epithermal neutrons can be increased by using non-collinear (e.g. 90 deg., 120 deg.) incident protons. Thus, either the irradiation time or the required proton current can be reduced. The use of 120 deg. BSA model shows the possibility to reduce the required proton current to ∼13.3 mA when the goal of irradiation time is 30 min. The decrease of required proton beam current certainly will make the use of lithium target much easier. In June 2013, a 5-MeV, 30-mA radio frequency quadruple (RFQ) accelerator for BNCT was built at INFN-LNL (Legnaro National Laboratories, Italy), which shows a possibility to build a suitable RFQ accelerator for the authors' design. In addition, a 2.5-MeV, 30-mA Tandem accelerator was

  8. Real time radiation dosimeters based on vertically aligned multiwall carbon nanotubes and graphene.

    Science.gov (United States)

    Funaro, Maria; Sarno, Maria; Ciambelli, Paolo; Altavilla, Claudia; Proto, Antonio

    2013-02-22

    Measurements of the absorbed dose and quality assurance programs play an important role in radiotherapy. Ionization chambers (CIs) are considered the most important dosimeters for their high accuracy, practicality and reliability, allowing absolute dose measurements. However, they have a relative large physical size, which limits their spatial resolution, and require a high bias voltage to achieve an acceptable collection of charges, excluding their use for in vivo dosimetry. In this paper, we propose new real time radiation detectors with electrodes based on graphene or vertically aligned multiwall carbon nanotubes (MWCNTs). We have investigated their charge collection efficiency and compared their performance with electrodes made of a conventional material. Moreover, in order to highlight the effect of nanocarbons, reference radiation detectors were also tested. The proposed dosimeters display an excellent linear response to dose and collect more charge than reference ones at a standard bias voltage, permitting the construction of miniaturized CIs. Moreover, an MWCNT based CI gives the best charge collection efficiency and it enables working also to lower bias voltages and zero volts, allowing in vivo applications. Graphene based CIs show better performance with respect to reference dosimeters at a standard bias voltage. However, at decreasing bias voltage the charge collection efficiency becomes worse if compared to a reference detector, likely due to graphene's semiconducting behavior.

  9. Cone-beam and fan-beam image reconstruction algorithms based on spherical and circular harmonics

    International Nuclear Information System (INIS)

    Zeng, Gengsheng L; Gullberg, Grant T

    2004-01-01

    A cone-beam image reconstruction algorithm using spherical harmonic expansions is proposed. The reconstruction algorithm is in the form of a summation of inner products of two discrete arrays of spherical harmonic expansion coefficients at each cone-beam point of acquisition. This form is different from the common filtered backprojection algorithm and the direct Fourier reconstruction algorithm. There is no re-sampling of the data, and spherical harmonic expansions are used instead of Fourier expansions. As a special case, a new fan-beam image reconstruction algorithm is also derived in terms of a circular harmonic expansion. Computer simulation results for both cone-beam and fan-beam algorithms are presented for circular planar orbit acquisitions. The algorithms give accurate reconstructions; however, the implementation of the cone-beam reconstruction algorithm is computationally intensive. A relatively efficient algorithm is proposed for reconstructing the central slice of the image when a circular scanning orbit is used

  10. A laser beam quality definition based on induced temperature rise.

    Science.gov (United States)

    Miller, Harold C

    2012-12-17

    Laser beam quality metrics like M(2) can be used to describe the spot sizes and propagation behavior of a wide variety of non-ideal laser beams. However, for beams that have been diffracted by limiting apertures in the near-field, or those with unusual near-field profiles, the conventional metrics can lead to an inconsistent or incomplete description of far-field performance. This paper motivates an alternative laser beam quality definition that can be used with any beam. The approach uses a consideration of the intrinsic ability of a laser beam profile to heat a material. Comparisons are made with conventional beam quality metrics. An analysis on an asymmetric Gaussian beam is used to establish a connection with the invariant beam propagation ratio.

  11. High performance flexible pH sensor based on carboxyl-functionalized and DEP aligned SWNTs

    International Nuclear Information System (INIS)

    Liu, Lu; Shao, Jinyou; Li, Xiangming; Zhao, Qiang; Nie, Bangbang; Xu, Chuan; Ding, Haitao

    2016-01-01

    Highlights: • The flexible chemiresistive pH sensor based on two-terminal microsensors eliminating the need for a reference electrode, is simple in structure and can be fabricated on a variety of substrates such as PET, PI and PVC. • SWNTs as an ideal one dimensional material are carboxyl-functionalized to make the pH sensor show high sensitivity and outstanding flexibility for practical applications. • DEP technique is used to manipulate and position SWNTs into appropriate locations and desired formations to improve the metal-nanotube interface and highly rapid detection of pH value, resulting in better overall device performance. • Mechanical bendability of the pH sensor, which arises from the combination of flexible PET substrates and SWNTs, offer a significant improvement for applications that are difficult or impossible to achieve with traditional sensors on rigid substrates. - Abstract: The detection and control of the pH is very important in many biomedical and chemical reaction processes. A miniaturized flexible pH sensor that is light weight, robust, and conformable is very important in many applications, such as multifunctional lab-on-a-chip systems or wearable biomedical devices. In this work, we demonstrate a flexible chemiresistive pH sensor based on dielectrophoresis (DEP) aligned carboxyl-functionalized single-walled carbon nanotubes (SWNTs). Decorated carboxyl groups can react with hydrogen (H"+) and hydroxide (OH"−) ions, enabling the sensor to be capable of sensing the pH. DEP is used to deposit well-organized and highly aligned SWNTs in desired locations, which improves the metal-nanotube interface and highly rapid detection of the pH, resulting in better overall device performance. When pH buffer solutions are dropped onto such SWNTs, the H"+ and OH"− ions caninteract with the carboxyl groups and affect the generation of holes and electrons in the SWNTs, leading to resistance variations in the SWNTs. The results shows that the

  12. High performance flexible pH sensor based on carboxyl-functionalized and DEP aligned SWNTs

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lu; Shao, Jinyou, E-mail: jyshao@mail.xjtu.edu.cn; Li, Xiangming; Zhao, Qiang; Nie, Bangbang; Xu, Chuan; Ding, Haitao

    2016-11-15

    Highlights: • The flexible chemiresistive pH sensor based on two-terminal microsensors eliminating the need for a reference electrode, is simple in structure and can be fabricated on a variety of substrates such as PET, PI and PVC. • SWNTs as an ideal one dimensional material are carboxyl-functionalized to make the pH sensor show high sensitivity and outstanding flexibility for practical applications. • DEP technique is used to manipulate and position SWNTs into appropriate locations and desired formations to improve the metal-nanotube interface and highly rapid detection of pH value, resulting in better overall device performance. • Mechanical bendability of the pH sensor, which arises from the combination of flexible PET substrates and SWNTs, offer a significant improvement for applications that are difficult or impossible to achieve with traditional sensors on rigid substrates. - Abstract: The detection and control of the pH is very important in many biomedical and chemical reaction processes. A miniaturized flexible pH sensor that is light weight, robust, and conformable is very important in many applications, such as multifunctional lab-on-a-chip systems or wearable biomedical devices. In this work, we demonstrate a flexible chemiresistive pH sensor based on dielectrophoresis (DEP) aligned carboxyl-functionalized single-walled carbon nanotubes (SWNTs). Decorated carboxyl groups can react with hydrogen (H{sup +}) and hydroxide (OH{sup −}) ions, enabling the sensor to be capable of sensing the pH. DEP is used to deposit well-organized and highly aligned SWNTs in desired locations, which improves the metal-nanotube interface and highly rapid detection of the pH, resulting in better overall device performance. When pH buffer solutions are dropped onto such SWNTs, the H{sup +} and OH{sup −} ions caninteract with the carboxyl groups and affect the generation of holes and electrons in the SWNTs, leading to resistance variations in the SWNTs. The results

  13. Novel methods in track-based alignment to correct for time-dependent distortions of the ATLAS Inner Detector

    CERN Document Server

    Estrada Pastor, Oscar; The ATLAS collaboration

    2017-01-01

    ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system and the quality of its offline alignment. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). Offline track alignment of the ATLAS tracking system has to deal with about 700,000 degrees of freedom (DoF) defining its geometrical parameters, representing a considerable numerical challenge in terms of both CPU time and precision. An outline of the track based alignment approach and its implementation within the ATLAS software will be presented. Special attention will be paid to describe the techniques allowing to pinpoint and eliminate track parameters biases due to alignment. During Run-II, ATLAS Inner Detector Alignment framework has been adapted and upgraded to correct very short time sc...

  14. A three-dimensional vertically aligned functionalized multilayer graphene architecture: an approach for graphene-based thermal interfacial materials.

    Science.gov (United States)

    Liang, Qizhen; Yao, Xuxia; Wang, Wei; Liu, Yan; Wong, Ching Ping

    2011-03-22

    Thermally conductive functionalized multilayer graphene sheets (fMGs) are efficiently aligned in large-scale by a vacuum filtration method at room temperature, as evidenced by SEM images and polarized Raman spectroscopy. A remarkably strong anisotropy in properties of aligned fMGs is observed. High electrical (∼386 S cm(-1)) and thermal conductivity (∼112 W m(-1) K(-1) at 25 °C) and ultralow coefficient of thermal expansion (∼-0.71 ppm K(-1)) in the in-plane direction of A-fMGs are obtained without any reduction process. Aligned fMGs are vertically assembled between contacted silicon/silicon surfaces with pure indium as a metallic medium. Thus-constructed three-dimensional vertically aligned fMG thermal interfacial material (VA-fMG TIM) architecture has significantly higher equivalent thermal conductivity (75.5 W m(-1) K(-1)) and lower contact thermal resistance (5.1 mm2 K W(-1)), compared with their counterpart from A-fMGs that are recumbent between silicon surfaces. This finding provides a throughout approach for a graphene-based TIM assembly as well as knowledge of vertically aligned graphene architectures, which may not only facilitate graphene's application in current demanding thermal management but also promote its widespread applications in electrodes of energy storage devices, conductive polymeric composites, etc.

  15. Image-based overlay and alignment metrology through optically opaque media with sub-surface probe microscopy

    Science.gov (United States)

    van Es, Maarten H.; Mohtashami, Abbas; Piras, Daniele; Sadeghian, Hamed

    2018-03-01

    Nondestructive subsurface nanoimaging through optically opaque media is considered to be extremely challenging and is essential for several semiconductor metrology applications including overlay and alignment and buried void and defect characterization. The current key challenge in overlay and alignment is the measurement of targets that are covered by optically opaque layers. Moreover, with the device dimensions moving to the smaller nodes and the issue of the so-called loading effect causing offsets between between targets and product features, it is increasingly desirable to perform alignment and overlay on product features or so-called on-cell overlay, which requires higher lateral resolution than optical methods can provide. Our recently developed technique known as SubSurface Ultrasonic Resonance Force Microscopy (SSURFM) has shown the capability for high-resolution imaging of structures below a surface based on (visco-)elasticity of the constituent materials and as such is a promising technique to perform overlay and alignment with high resolution in upcoming production nodes. In this paper, we describe the developed SSURFM technique and the experimental results on imaging buried features through various layers and the ability to detect objects with resolution below 10 nm. In summary, the experimental results show that the SSURFM is a potential solution for on-cell overlay and alignment as well as detecting buried defects or voids and generally metrology through optically opaque layers.

  16. Rapid shear alignment of sub-10 nm cylinder-forming block copolymer films based on thermal expansion mismatch

    Science.gov (United States)

    Nicaise, Samuel M.; Gadelrab, Karim R.; G, Amir Tavakkoli K.; Ross, Caroline A.; Alexander-Katz, Alfredo; Berggren, Karl K.

    2018-01-01

    Directed self-assembly of block copolymers (BCPs) provided by shear-stress can produce aligned sub-10 nm structures over large areas for applications in integrated circuits, next-generation data storage, and plasmonic structures. In this work, we present a fast, versatile BCP shear-alignment process based on coefficient of thermal expansion mismatch of the BCP film, a rigid top coat and a substrate. Monolayer and bilayer cylindrical microdomains of poly(styrene-b-dimethylsiloxane) aligned preferentially in-plane and orthogonal to naturally-forming or engineered cracks in the top coat film, allowing for orientation control over 1 cm2 substrates. Annealing temperatures, up to 275 °C, provided low-defect alignment up to 2 mm away from cracks for rapid (<1 min) annealing times. Finite-element simulations of the stress as a function of annealing time, annealing temperature, and distance from cracks showed that shear stress during the cooling phase of the thermal annealing was critical for the observed microdomain alignment.

  17. Highly efficient growth of vertically aligned carbon nanotubes on Fe-Ni based metal alloy foils for supercapacitors

    Science.gov (United States)

    Amalina Raja Seman, Raja Noor; Asyadi Azam, Mohd; Ambri Mohamed, Mohd

    2016-12-01

    Supercapacitors are highly promising energy devices with superior charge storage performance and a long lifecycle. Construction of the supercapacitor cell, especially electrode fabrication, is critical to ensure good performance in applications. This work demonstrates direct growth of vertically aligned carbon nanotubes (CNTs) on Fe-Ni based metal alloy foils, namely SUS 310S, Inconel 600 and YEF 50, and their use in symmetric vertically aligned CNT supercapacitor electrodes. Alumina and cobalt thin film catalysts were deposited onto the foils, and then CNT growth was performed using alcohol catalytic chemical vapour deposition. By this method, vertically aligned CNTs were successfully grown and used directly as a binder-free supercapacitor electrode to deliver excellent electrochemical performance. The device showed relatively good specific capacitance, a superior rate capability and excellent cycle stability, maintaining about 96% capacitance up to 1000 cycles.

  18. AlignerBoost: A Generalized Software Toolkit for Boosting Next-Gen Sequencing Mapping Accuracy Using a Bayesian-Based Mapping Quality Framework.

    Directory of Open Access Journals (Sweden)

    Qi Zheng

    2016-10-01

    Full Text Available Accurate mapping of next-generation sequencing (NGS reads to reference genomes is crucial for almost all NGS applications and downstream analyses. Various repetitive elements in human and other higher eukaryotic genomes contribute in large part to ambiguously (non-uniquely mapped reads. Most available NGS aligners attempt to address this by either removing all non-uniquely mapping reads, or reporting one random or "best" hit based on simple heuristics. Accurate estimation of the mapping quality of NGS reads is therefore critical albeit completely lacking at present. Here we developed a generalized software toolkit "AlignerBoost", which utilizes a Bayesian-based framework to accurately estimate mapping quality of ambiguously mapped NGS reads. We tested AlignerBoost with both simulated and real DNA-seq and RNA-seq datasets at various thresholds. In most cases, but especially for reads falling within repetitive regions, AlignerBoost dramatically increases the mapping precision of modern NGS aligners without significantly compromising the sensitivity even without mapping quality filters. When using higher mapping quality cutoffs, AlignerBoost achieves a much lower false mapping rate while exhibiting comparable or higher sensitivity compared to the aligner default modes, therefore significantly boosting the detection power of NGS aligners even using extreme thresholds. AlignerBoost is also SNP-aware, and higher quality alignments can be achieved if provided with known SNPs. AlignerBoost's algorithm is computationally efficient, and can process one million alignments within 30 seconds on a typical desktop computer. AlignerBoost is implemented as a uniform Java application and is freely available at https://github.com/Grice-Lab/AlignerBoost.

  19. AlignerBoost: A Generalized Software Toolkit for Boosting Next-Gen Sequencing Mapping Accuracy Using a Bayesian-Based Mapping Quality Framework.

    Science.gov (United States)

    Zheng, Qi; Grice, Elizabeth A

    2016-10-01

    Accurate mapping of next-generation sequencing (NGS) reads to reference genomes is crucial for almost all NGS applications and downstream analyses. Various repetitive elements in human and other higher eukaryotic genomes contribute in large part to ambiguously (non-uniquely) mapped reads. Most available NGS aligners attempt to address this by either removing all non-uniquely mapping reads, or reporting one random or "best" hit based on simple heuristics. Accurate estimation of the mapping quality of NGS reads is therefore critical albeit completely lacking at present. Here we developed a generalized software toolkit "AlignerBoost", which utilizes a Bayesian-based framework to accurately estimate mapping quality of ambiguously mapped NGS reads. We tested AlignerBoost with both simulated and real DNA-seq and RNA-seq datasets at various thresholds. In most cases, but especially for reads falling within repetitive regions, AlignerBoost dramatically increases the mapping precision of modern NGS aligners without significantly compromising the sensitivity even without mapping quality filters. When using higher mapping quality cutoffs, AlignerBoost achieves a much lower false mapping rate while exhibiting comparable or higher sensitivity compared to the aligner default modes, therefore significantly boosting the detection power of NGS aligners even using extreme thresholds. AlignerBoost is also SNP-aware, and higher quality alignments can be achieved if provided with known SNPs. AlignerBoost's algorithm is computationally efficient, and can process one million alignments within 30 seconds on a typical desktop computer. AlignerBoost is implemented as a uniform Java application and is freely available at https://github.com/Grice-Lab/AlignerBoost.

  20. Validation of the CLIC alignment strategy on short range

    CERN Document Server

    Mainaud Durand, H; Griffet, S; Kemppinen, J; Rude, V; Sosin, M

    2012-01-01

    The pre-alignment of CLIC consists of aligning the components of linacs and beam delivery systems (BDS) in the most accurate possible way, so that a first pilot beam can circulate and allow the implementation of the beam based alignment. Taking into account the precision and accuracy needed: 10 µm rms over sliding windows of 200m, this pre-alignment must be active and it can be divided into two parts: the determination of a straight reference over 20 km, thanks to a metrological network and the determination of the component positions with respect to this reference, and their adjustment. The second part is the object of the paper, describing the steps of the proposed strategy: firstly the fiducialisation of the different components of CLIC; secondly, the alignment of these components on common supports and thirdly the active alignment of these supports using sensors and actuators. These steps have been validated on a test setup over a length of 4m, and the obtained results are analysed.

  1. Vacuum mechatronic laser alignment system on the Nova laser

    International Nuclear Information System (INIS)

    Holliday, M.; Wong, K.; Shelton, R.

    1991-11-01

    The experiments conducted on NOVA are done to investigate inertially confined laser fusion reactions. To this end, the ten beams of the laser are aligned to within 30mm. The target chamber employs a vacuum mechatronic based reticle/target positioning system to accomplish this. It is a five degree-of-freedom chamber resident system, known as the Alignment Aids Positioner or AAP. The AAP aids in beam and diagnostic alignment by accurately positioning a reticle at target chamber center to with 7mm. The AAP system increases target positioning and alignment flexibility and accuracy through the use of a computer controlled multi degree-of-freedom stage assembly. This device uses microstepping DC stepper motors with encoders to achieve closed loop control in a 10 -6 torr vacuum. The AAP has two positioning regimes to move the alignment reticle and do beam alignment. One is course positioning in the Y-Z plane that moves a high resolution stage assembly to target chamber center. The other regime is high resolution movement in the X,Y,Z and q directions. 5 refs., 9 figs

  2. The backward phase flow and FBI-transform-based Eulerian Gaussian beams for the Schroedinger equation

    International Nuclear Information System (INIS)

    Leung Shingyu; Qian Jianliang

    2010-01-01

    We propose the backward phase flow method to implement the Fourier-Bros-Iagolnitzer (FBI)-transform-based Eulerian Gaussian beam method for solving the Schroedinger equation in the semi-classical regime. The idea of Eulerian Gaussian beams has been first proposed in . In this paper we aim at two crucial computational issues of the Eulerian Gaussian beam method: how to carry out long-time beam propagation and how to compute beam ingredients rapidly in phase space. By virtue of the FBI transform, we address the first issue by introducing the reinitialization strategy into the Eulerian Gaussian beam framework. Essentially we reinitialize beam propagation by applying the FBI transform to wavefields at intermediate time steps when the beams become too wide. To address the second issue, inspired by the original phase flow method, we propose the backward phase flow method which allows us to compute beam ingredients rapidly. Numerical examples demonstrate the efficiency and accuracy of the proposed algorithms.

  3. Adaptive radiotherapy based on contrast enhanced cone beam CT imaging

    International Nuclear Information System (INIS)

    Soevik, Aaste; Skogmo, Hege K.; Roedal, Jan; Lervaag, Christoffer; Eilertsen, Karsten; Malinen, Eirik

    2010-01-01

    Cone beam CT (CBCT) imaging has become an integral part of radiation therapy, with images typically used for offline or online patient setup corrections based on bony anatomy co-registration. Ideally, the co-registration should be based on tumor localization. However, soft tissue contrast in CBCT images may be limited. In the present work, contrast enhanced CBCT (CECBCT) images were used for tumor visualization and treatment adaptation. Material and methods. A spontaneous canine maxillary tumor was subjected to repeated cone beam CT imaging during fractionated radiotherapy (10 fractions in total). At five of the treatment fractions, CECBCT images, employing an iodinated contrast agent, were acquired, as well as pre-contrast CBCT images. The tumor was clearly visible in post-contrast minus pre-contrast subtraction images, and these contrast images were used to delineate gross tumor volumes. IMRT dose plans were subsequently generated. Four different strategies were explored: 1) fully adapted planning based on each CECBCT image series, 2) planning based on images acquired at the first treatment fraction and patient repositioning following bony anatomy co-registration, 3) as for 2), but with patient repositioning based on co-registering contrast images, and 4) a strategy with no patient repositioning or treatment adaptation. The equivalent uniform dose (EUD) and tumor control probability (TCP) calculations to estimate treatment outcome for each strategy. Results. Similar translation vectors were found when bony anatomy and contrast enhancement co-registration were compared. Strategy 1 gave EUDs closest to the prescription dose and the highest TCP. Strategies 2 and 3 gave EUDs and TCPs close to that of strategy 1, with strategy 3 being slightly better than strategy 2. Even greater benefits from strategies 1 and 3 are expected with increasing tumor movement or deformation during treatment. The non-adaptive strategy 4 was clearly inferior to all three adaptive strategies

  4. Development and preliminary evaluation of a new anatomically based prosthetic alignment method for below-knee prosthesis.

    Science.gov (United States)

    Tafti, Nahid; Karimlou, Masoud; Mardani, Mohammad Ali; Jafarpisheh, Amir Salar; Aminian, Gholam Reza; Safari, Reza

    2018-04-20

    The objectives of current study were to a) assess similarities and relationships between anatomical landmark-based angles and distances of lower limbs in unilateral transtibial amputees and b) develop and evaluate a new anatomically based static prosthetic alignment method. First sub-study assessed the anthropometrical differences and relationships between the lower limbs in the photographs taken from amputees. Data were analysed via paired t-test and regression analysis. Results show no significant differences in frontal and transverse planes. In the sagittal plane, the anthropometric parameters of the amputated limb were significantly correlated to the corresponding variables of the sound limb. The results served as bases for the development of a new prosthetic alignment method. The method was evaluated on a single subject study. Prosthetic alignment carried out by an experienced prosthetist was compared with such alignment adjusted by an inexperienced prosthetist but with the use of the developed method. In sagittal and frontal planes, the socket angle was tuned with respect to the shin angle, and the position of the prosthetic foot was tuned in relation to the pelvic landmarks. Further study is needed to assess the proposed method on a larger sample of amputees and prosthetists.

  5. Ultracompact photonic crystal polarization beam splitter based on multimode interference.

    Science.gov (United States)

    Lu, Ming-Feng; Liao, Shan-Mei; Huang, Yang-Tung

    2010-02-01

    We propose a theoretical design for a compact photonic crystal (PC) polarization beam splitter (PBS) based on the multimode interference (MMI) effect. The size of a conventional MMI device designed by the self-imaging principle is not compact enough; therefore, we design a compact PC PBS based on the difference of the interference effect between TE and TM modes. Within the MMI coupler, the dependence of interference of modes on propagation distance is weak for a TE wave and strong for a TM wave; as a result, the length of the MMI section can be only seven lattice constants. Simulation results show that the insertion losses are 0.32 and 0.89 dB, and the extinction ratios are 14.4 and 17.5 dB for Port 1 (TE mode) and Port 2 (TM mode), respectively.

  6. Simultaneous Wireless Information and Power Transfer for MIMO Interference Channel Networks Based on Interference Alignment

    Directory of Open Access Journals (Sweden)

    Anming Dong

    2017-09-01

    Full Text Available This paper considers power splitting (PS-based simultaneous wireless information and power transfer (SWIPT for multiple-input multiple-output (MIMO interference channel networks where multiple transceiver pairs share the same frequency spectrum. As the PS model is adopted, an individual receiver splits the received signal into two parts for information decoding (ID and energy harvesting (EH, respectively. Aiming to minimize the total transmit power, transmit precoders, receive filters and PS ratios are jointly designed under a predefined signal-to-interference-plus-noise ratio (SINR and EH constraints. The formulated joint transceiver design and power splitting problem is non-convex and thus difficult to solve directly. In order to effectively obtain its solution, the feasibility conditions of the formulated non-convex problem are first analyzed. Based on the analysis, an iterative algorithm is proposed by alternatively optimizing the transmitters together with the power splitting factors and the receivers based on semidefinite programming (SDP relaxation. Moreover, considering the prohibitive computational cost of the SDP for practical applications, a low-complexity suboptimal scheme is proposed by separately designing interference-suppressing transceivers based on interference alignment (IA and optimizing the transmit power allocation together with splitting factors. The transmit power allocation and receive power splitting problem is then recast as a convex optimization problem and solved efficiently. To further reduce the computational complexity, a low-complexity scheme is proposed by calculating the transmit power allocation and receive PS ratios in closed-form. Simulation results show the effectiveness of the proposed schemes in achieving SWIPT for MIMO interference channel (IC networks.

  7. An OMG model-based approach for aligning information systems requirements and architectures with business

    OpenAIRE

    Salgado, Carlos Eduardo Rodrigues Teixeira

    2017-01-01

    Tese de Doutoramento (Programa Doutoral em Tecnologias e Sistemas de Informação) The challenges involved in developing information systems (which are able to adapt to rapidly changing business and technological conditions) are directly related to the importance of their alignment with the business counterpart. These challenges comprise issues that cross management and information systems domains, relating and aligning them in order to attain superior performance for the organiz...

  8. Alignment control of GEO 600

    International Nuclear Information System (INIS)

    Grote, H; Heinzel, G; Freise, A; Gossler, S; Willke, B; Lueck, H; Ward, H; Casey, M M; Strain, K A; Robertson, D I; Hough, J; Danzmannx, K

    2004-01-01

    We give an overview of the automatic mirror alignment system of the gravitational wave detector GEO 600. In order to achieve the required sensitivity of the Michelson interferometer, the axes of interfering beams have to be superimposed with a residual angle of the order 10 -8 rad. The beam spots have to be centred on the mirrors to minimize coupling of alignment noise into longitudinal signals. We present the actual control topology and results from the system in operation, which controls all alignment degrees of the power-recycled Michelson. With this system continuous lock stretches of more than 121 h duration were achieved

  9. Improving alignment in Tract-based spatial statistics: evaluation and optimization of image registration.

    Science.gov (United States)

    de Groot, Marius; Vernooij, Meike W; Klein, Stefan; Ikram, M Arfan; Vos, Frans M; Smith, Stephen M; Niessen, Wiro J; Andersson, Jesper L R

    2013-08-01

    Anatomical alignment in neuroimaging studies is of such importance that considerable effort is put into improving the registration used to establish spatial correspondence. Tract-based spatial statistics (TBSS) is a popular method for comparing diffusion characteristics across subjects. TBSS establishes spatial correspondence using a combination of nonlinear registration and a "skeleton projection" that may break topological consistency of the transformed brain images. We therefore investigated feasibility of replacing the two-stage registration-projection procedure in TBSS with a single, regularized, high-dimensional registration. To optimize registration parameters and to evaluate registration performance in diffusion MRI, we designed an evaluation framework that uses native space probabilistic tractography for 23 white matter tracts, and quantifies tract similarity across subjects in standard space. We optimized parameters for two registration algorithms on two diffusion datasets of different quality. We investigated reproducibility of the evaluation framework, and of the optimized registration algorithms. Next, we compared registration performance of the regularized registration methods and TBSS. Finally, feasibility and effect of incorporating the improved registration in TBSS were evaluated in an example study. The evaluation framework was highly reproducible for both algorithms (R(2) 0.993; 0.931). The optimal registration parameters depended on the quality of the dataset in a graded and predictable manner. At optimal parameters, both algorithms outperformed the registration of TBSS, showing feasibility of adopting such approaches in TBSS. This was further confirmed in the example experiment. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Sketch-based 3D modeling by aligning outlines of an image

    Directory of Open Access Journals (Sweden)

    Chunxiao Li

    2016-07-01

    Full Text Available In this paper we present an efficient technique for sketch-based 3D modeling using automatically extracted image features. Creating a 3D model often requires a drawing of irregular shapes composed of curved lines as a starting point but it is difficult to hand-draw such lines without introducing awkward bumps and edges along the lines. We propose an automatic alignment of a user׳s hand-drawn sketch lines to the contour lines of an image, facilitating a considerable level of ease with which the user can carelessly continue sketching while the system intelligently snaps the sketch lines to a background image contour, no longer requiring the strenuous effort and stress of trying to make a perfect line during the modeling task. This interactive technique seamlessly combines the efficiency and perception of the human user with the accuracy of computational power, applied to the domain of 3D modeling where the utmost precision of on-screen drawing has been one of the hurdles of the task hitherto considered a job requiring a highly skilled and careful manipulation by the user. We provide several examples to demonstrate the accuracy and efficiency of the method with which complex shapes were achieved easily and quickly in the interactive outline drawing task.

  11. Beam Diagnostics for Laser Undulator Based on Compton Backward Scattering

    CERN Document Server

    Kuroda, R

    2005-01-01

    A compact soft X-ray source is required in various research fields such as material and biological science. The laser undulator based on Compton backward scattering has been developed as a compact soft X-ray source for the biological observation at Waseda University. It is performed in a water window region (250eV - 500 eV) using the interaction between 1047 nm Nd:YLF laser (10ps FWHM) and about 5 MeV high quality electron beam (10ps FWHM) generated from rf gun system. The range of X-ray energy in the water window region has K-shell absorption edges of Oxygen, Carbon and Nitrogen, which mainly constitute of living body. Since the absorption coefficient of water is much smaller than the protein's coefficient in this range, a dehydration of the specimens is not necessary. To generate the soft X-ray pulse stably, the electron beam diagnostics have been developed such as the emittance measurement using double slit scan technique, the bunch length measurement using two frequency analysis technique. In this confere...

  12. Beam closed orbit feedback based on PID control

    International Nuclear Information System (INIS)

    Xuan Ke; Wang Lin; Liu Gongfa; Li Weimin; Li Chuan; Wang Jigang; Bao Xun; Xu Hongliang

    2013-01-01

    The algorithm in the feedback system has important influence on the performance of the beam orbit. Good feedback algorithm can greatly improve the beam orbit stability. In this paper, the theory of beam closed orbit correction, the principle of PID control and the beam closed orbit feedback correction using PID control were introduced. The simulation results were given. Compared with least-square method, the PID feedback algorithm makes the steady-state error smaller and more accurate, and enhances the beam orbit stability. (authors)

  13. 3D QSAR models built on structure-based alignments of Abl tyrosine kinase inhibitors.

    Science.gov (United States)

    Falchi, Federico; Manetti, Fabrizio; Carraro, Fabio; Naldini, Antonella; Maga, Giovanni; Crespan, Emmanuele; Schenone, Silvia; Bruno, Olga; Brullo, Chiara; Botta, Maurizio

    2009-06-01

    Quality QSAR: A combination of docking calculations and a statistical approach toward Abl inhibitors resulted in a 3D QSAR model, the analysis of which led to the identification of ligand portions important for affinity. New compounds designed on the basis of the model were found to have very good affinity for the target, providing further validation of the model itself.The X-ray crystallographic coordinates of the Abl tyrosine kinase domain in its active, inactive, and Src-like inactive conformations were used as targets to simulate the binding mode of a large series of pyrazolo[3,4-d]pyrimidines (known Abl inhibitors) by means of GOLD software. Receptor-based alignments provided by molecular docking calculations were submitted to a GRID-GOLPE protocol to generate 3D QSAR models. Analysis of the results showed that the models based on the inactive and Src-like inactive conformations had very poor statistical parameters, whereas the sole model based on the active conformation of Abl was characterized by significant internal and external predictive ability. Subsequent analysis of GOLPE PLS pseudo-coefficient contour plots of this model gave us a better understanding of the relationships between structure and affinity, providing suggestions for the next optimization process. On the basis of these results, new compounds were designed according to the hydrophobic and hydrogen bond donor and acceptor contours, and were found to have improved enzymatic and cellular activity with respect to parent compounds. Additional biological assays confirmed the important role of the selected compounds as inhibitors of cell proliferation in leukemia cells.

  14. Laser beam shaping design based on micromirror array

    Science.gov (United States)

    Fang, Han; Su, Bida; Liu, Jiaguo; Fan, Xiaoli; Jing, Wang

    2017-10-01

    In the practical application of the laser, it is necessary to use the laser beam shaping technology to shape the output beam of laser device to the uniform light intensity distribution. The shaping divergent optical system of compound eye integrator way is composed of beam expanding mirror group and lens array. Its working principle is to expand the output laser to a certain size of caliber, and then divide the beam with lens array into multiple sub beam, where the lens unit of lens array can control the divergence angle of sub beam through the design of focal length, with mutual superposition of the sub beam in far field, to make up for the nonuniformity of beam, so that the radiant exitance on the radiated surface may become uniform. In this paper, we use a reflective microlens array to realize the laser beam shaping. By through of the practical optical path model established, the ray tracing is carried out and the simulation results for single-mode Gaussian beam with noise circumstance is provided. The analysis results show that the laser beam shaping under different inputs can be effectively realized by use of microlens array. All the energy is within the signal window, with a high energy efficiency of more than 90%; The measured surface has a better uniformity, and the uniformity is better than 99.5% at 150m.

  15. Performance of positive ion based high power ion source of EAST neutral beam injector

    International Nuclear Information System (INIS)

    Hu, Chundong; Xie, Yahong; Xie, Yuanlai; Liu, Sheng; Xu, Yongjian; Liang, Lizhen; Jiang, Caichao; Li, Jun; Liu, Zhimin

    2016-01-01

    The positive ion based source with a hot cathode based arc chamber and a tetrode accelerator was employed for a neutral beam injector on the experimental advanced superconducting tokamak (EAST). Four ion sources were developed and each ion source has produced 4 MW @ 80 keV hydrogen beam on the test bed. 100 s long pulse operation with modulated beam has also been tested on the test bed. The accelerator was upgraded from circular shaped to diamond shaped in the latest two ion sources. In the latest campaign of EAST experiment, four ion sources injected more than 4 MW deuterium beam with beam energy of 60 keV into EAST

  16. Embedded design based virtual instrument program for positron beam automation

    International Nuclear Information System (INIS)

    Jayapandian, J.; Gururaj, K.; Abhaya, S.; Parimala, J.; Amarendra, G.

    2008-01-01

    Automation of positron beam experiment with a single chip embedded design using a programmable system on chip (PSoC) which provides easy interfacing of the high-voltage DC power supply is reported. Virtual Instrument (VI) control program written in Visual Basic 6.0 ensures the following functions (i) adjusting of sample high voltage by interacting with the programmed PSoC hardware, (ii) control of personal computer (PC) based multi channel analyzer (MCA) card for energy spectroscopy, (iii) analysis of the obtained spectrum to extract the relevant line shape parameters, (iv) plotting of relevant parameters and (v) saving the file in the appropriate format. The present study highlights the hardware features of the PSoC hardware module as well as the control of MCA and other units through programming in Visual Basic

  17. Monte Carlo simulation of beam characteristics from small fields based on TrueBeam flattening-filter-free mode

    International Nuclear Information System (INIS)

    Feng, Zhongsu; Yue, Haizhen; Zhang, Yibao; Wu, Hao; Cheng, Jinsheng; Su, Xu

    2016-01-01

    Through the Monte Carlo (MC) simulation of 6 and 10 MV flattening-filter-free (FFF) beams from Varian TrueBeam accelerator, this study aims to find the best incident electron distribution for further studying the small field characteristics of these beams. By incorporating the training materials of Varian on the geometry and material parameters of TrueBeam Linac head, the 6 and 10 MV FFF beams were modelled using the BEAMnrc and DOSXYZnrc codes, where the percentage depth doses (PDDs) and the off-axis ratios (OARs) curves of fields ranging from 4 × 4 to 40 × 40 cm 2 were simulated for both energies by adjusting the incident beam energy, radial intensity distribution and angular spread, respectively. The beam quality and relative output factor (ROF) were calculated. The simulations and measurements were compared using Gamma analysis method provided by Verisoft program (PTW, Freiburg, Germany), based on which the optimal MC model input parameters were selected and were further used to investigate the beam characteristics of small fields. The Full Width Half Maximum (FWHM), mono-energetic energy and angular spread of the resultant incident Gaussian radial intensity electron distribution were 0.75 mm, 6.1 MeV and 0.9° for the nominal 6 MV FFF beam, and 0.7 mm, 10.8 MeV and 0.3° for the nominal 10 MV FFF beam respectively. The simulation was mostly comparable to the measurement. Gamma criteria of 1 mm/1 % (local dose) can be met by all PDDs of fields larger than 1 × 1 cm 2 , and by all OARs of no larger than 20 × 20 cm 2 , otherwise criteria of 1 mm/2 % can be fulfilled. Our MC simulated ROFs agreed well with the measured ROFs of various field sizes (the discrepancies were less than 1 %), except for the 1 × 1 cm 2 field. The MC simulation agrees well with the measurement and the proposed model parameters can be clinically used for further dosimetric studies of 6 and 10 MV FFF beams

  18. Electron beam based transversal profile measurements of intense ion beams; Elektronenstrahl-Diagnostik zur Bestimmung vom transversalen Profil intensiver Ionenstrahlen

    Energy Technology Data Exchange (ETDEWEB)

    El Moussati, Said

    2014-11-03

    A non-invasive diagnostic method for the experimental determination of the transverse profile of an intense ion beam has been developed and investigated theoretically as well as experimentally within the framework of the present work. The method is based on the deflection of electrons when passing the electromagnetic field of an ion beam. To achieve this an electron beam is employed with a specifically prepared transversal profile. This distinguish this method from similar ones which use thin electron beams for scanning the electromagnetic field [Roy et al. 2005; Blockland10]. The diagnostic method presented in this work will be subsequently called ''Electron-Beam-Imaging'' (EBI). First of all the influence of the electromagnetic field of the ion beam on the electrons has been theoretically analyzed. It was found that the magnetic field causes only a shift of the electrons along the ion beam axis, while the electric field only causes a shift in a plane transverse to the ion beam. Moreover, in the non-relativistic case the magnetic force is significantly smaller than the Coulomb one and the electrons suffer due to the magnetic field just a shift and continue to move parallel to their initial trajectory. Under the influence of the electric field, the electrons move away from the ion beam axis, their resulting trajectory shows a specific angle compared to the original direction. This deflection angle practically depends just on the electric field of the ion beam. Thus the magnetic field has been neglected when analysing the experimental data. The theoretical model provides a relationship between the deflection angle of the electrons and the charge distribution in the cross section of the ion beam. The model however only can be applied for small deflection angles. This implies a relationship between the line-charge density of the ion beam and the initial kinetic energy of the electrons. Numerical investigations have been carried out to clarify the

  19. Proposal for an alignment method of the CLIC linear accelerator - From geodesic networks to the active pre-alignment

    International Nuclear Information System (INIS)

    Touze, T.

    2011-01-01

    The compact linear collider (CLIC) is the particle accelerator project proposed by the european organization for nuclear research (CERN) for high energy physics after the large hadron collider (LHC). Because of the nano-metric scale of the CLIC leptons beams, the emittance growth budget is very tight. It induces alignment tolerances on the positions of the CLIC components that have never been achieved before. The last step of the CLIC alignment will be done according to the beam itself. It falls within the competence of the physicists. However, in order to implement the beam-based feedback, a challenging pre-alignment is required: 10 μm at 3σ along a 200 m sliding window. For such a precision, the proposed solution must be compatible with a feedback between the measurement and repositioning systems. The CLIC pre-alignment will have to be active. This thesis does not demonstrate the feasibility of the CLIC active pre-alignment but shows the way to the last developments that have to be done for that purpose. A method is proposed. Based on the management of the Helmert transformations between Euclidean coordinate systems, from the geodetic networks to the metrological measurements, this method is likely to solve the CLIC pre-alignment problem. Large scale facilities have been built and Monte-Carlo simulations have been made in order to validate the mathematical modeling of the measurement systems and of the alignment references. When this is done, it will be possible to extrapolate the modeling to the entire CLIC length. It will be the last step towards the demonstration of the CLIC pre-alignment feasibility. (author)

  20. 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.

  1. Novel methods in track-based alignment to correct for time-dependent distortions of the ATLAS Inner Detector

    CERN Document Server

    Estrada Pastor, Oscar; The ATLAS collaboration

    2017-01-01

    ATLAS is a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution and unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system and the quality of its alignment. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). The offline track alignment of the ATLAS tracking system has to deal with about 700,000 degrees of freedom (DoF) defining its geometrical parameters, representing a considerable numerical challenge in terms of both CPU time and precision. An outline of the track based alignment approach and its implementation within the ATLAS software is presented. Special attention is paid to describe the techniques allowing to pinpoint and eliminate track parameters biases. During Run-II, ATLAS Inner Detector Alignment framework has been adapted and upgraded to correct very short time scale movements of the sub-det...

  2. Radioactive nuclear beam facilities based on projectile fragmentation

    International Nuclear Information System (INIS)

    Sherrill, B.M.

    1992-01-01

    The production of radioactive beams using direct separation techniques is discussed. The reaction mechanisms which can be used to produce radioactive beams with these techniques can be broadly divided into three groups, projectile fragmentation, nucleon transfer, and Coulomb disassociation. Radioactive nuclei produced in these ways have large forward momenta with relatively sharp angular distributions peaked near zero degrees which are suitable for collection with magnetic devices. Secondary beam intensities of up to a few percent of the primary beam intensity are possible, although depending on the production mechanism the beam emittance may be poor. Further beam purification can be achieved using atomic processes with profiled energy degraders. The features of the production reaction mechanism, separation techniques, and a review of world wide efforts are presented. The advantages and disadvantages of the method are presented, with discussion of techniques to overcome some of the disadvantages. (Author)

  3. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G. Gomez

    2011-01-01

    A new set of muon alignment constants was approved in August. The relative position between muon chambers is essentially unchanged, indicating good detector stability. The main changes concern the global positioning of the barrel and of the endcap rings to match the new Tracker geometry. Detailed studies of the differences between track-based and optical alignment of DTs have proven to be a valuable tool for constraining Tracker alignment weak modes, and this information is now being used as part of the alignment procedure. In addition to the “split-cosmic” analysis used to investigate the muon momentum resolution at high momentum, a new procedure based on reconstructing the invariant mass of di-muons from boosted Zs is under development. Both procedures show an improvement in the momentum precision of Global Muons with respect to Tracker-only Muons. Recent developments in track-based alignment include a better treatment of the tails of residual distributions and accounting for correla...

  4. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G.Gomez

    2011-01-01

    The Muon Alignment work now focuses on producing a new track-based alignment with higher track statistics, making systematic studies between the results of the hardware and track-based alignment methods and aligning the barrel using standalone muon tracks. Currently, the muon track reconstruction software uses a hardware-based alignment in the barrel (DT) and a track-based alignment in the endcaps (CSC). An important task is to assess the muon momentum resolution that can be achieved using the current muon alignment, especially for highly energetic muons. For this purpose, cosmic ray muons are used, since the rate of high-energy muons from collisions is very low and the event statistics are still limited. Cosmics have the advantage of higher statistics in the pT region above 100 GeV/c, but they have the disadvantage of having a mostly vertical topology, resulting in a very few global endcap muons. Only the barrel alignment has therefore been tested so far. Cosmic muons traversing CMS from top to bottom are s...

  5. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    Gervasio Gomez

    The main progress of the muon alignment group since March has been in the refinement of both the track-based alignment for the DTs and the hardware-based alignment for the CSCs. For DT track-based alignment, there has been significant improvement in the internal alignment of the superlayers inside the DTs. In particular, the distance between superlayers is now corrected, eliminating the residual dependence on track impact angles, and good agreement is found between survey and track-based corrections. The new internal geometry has been approved to be included in the forthcoming reprocessing of CRAFT samples. The alignment of DTs with respect to the tracker using global tracks has also improved significantly, since the algorithms use the latest B-field mapping, better run selection criteria, optimized momentum cuts, and an alignment is now obtained for all six degrees of freedom (three spatial coordinates and three rotations) of the aligned DTs. This work is ongoing and at a stage where we are trying to unders...

  6. Note: A simple image processing based fiducial auto-alignment method for sample registration.

    Science.gov (United States)

    Robertson, Wesley D; Porto, Lucas R; Ip, Candice J X; Nantel, Megan K T; Tellkamp, Friedjof; Lu, Yinfei; Miller, R J Dwayne

    2015-08-01

    A simple method for the location and auto-alignment of sample fiducials for sample registration using widely available MATLAB/LabVIEW software is demonstrated. The method is robust, easily implemented, and applicable to a wide variety of experiment types for improved reproducibility and increased setup speed. The software uses image processing to locate and measure the diameter and center point of circular fiducials for distance self-calibration and iterative alignment and can be used with most imaging systems. The method is demonstrated to be fast and reliable in locating and aligning sample fiducials, provided here by a nanofabricated array, with accuracy within the optical resolution of the imaging system. The software was further demonstrated to register, load, and sample the dynamically wetted array.

  7. Selection of coplanar or noncoplanar beams using three-dimensional optimization based on maximum beam separation and minimized nontarget irradiation

    International Nuclear Information System (INIS)

    Das, Shiva K.; Marks, Lawrence B.

    1997-01-01

    Purpose: The design of an appropriate set of multiple fixed fields to achieve a steep dose gradient at the tumor edge, with minimal normal tissue exposure, is a very difficult problem, since a virtually infinite number of possible beam orientations exists. In practice we have selected beams in an iterative and often time-consuming process. This work proposes an optimization method, based on geometric and dose elements, to effectively arrive at a set of beam orientations. Methods and Materials: Beams are selected by minimizing a goal function including an angle function (beam separation for steep dose gradient at target edge) and a length function (related to normal tissue dose volume histogram). The relative importance of these two factors may be adjusted depending on the clinic situation. The model is flexible and can include case specific practical anatomic and physical considerations. Results: In extremely simple situations, the goal function yields results consistent with well-known analytical solutions. When applied to more complex clinical situations, it provides clinically reasonable solutions similar to those empirically developed by the clinician. The optimization process takes approximately 25 min on a UNIX workstation. Conclusion: The optimization scheme provides a practical means for rapidly designing multiple field coplanar or noncoplanar treatments. It overcomes limitations in human three-dimensional visualization such as trying to visualize beam directions and keeping track of the hinge angle between beams while accounting for anatomic/machine constraints. In practice, it has been used as a starting point for physicians to make modifications, based on their clinical judgment

  8. CloudAligner: A fast and full-featured MapReduce based tool for sequence mapping

    Directory of Open Access Journals (Sweden)

    Shi Weisong

    2011-06-01

    Full Text Available Abstract Background Research in genetics has developed rapidly recently due to the aid of next generation sequencing (NGS. However, massively-parallel NGS produces enormous amounts of data, which leads to storage, compatibility, scalability, and performance issues. The Cloud Computing and MapReduce framework, which utilizes hundreds or thousands of shared computers to map sequencing reads quickly and efficiently to reference genome sequences, appears to be a very promising solution for these issues. Consequently, it has been adopted by many organizations recently, and the initial results are very promising. However, since these are only initial steps toward this trend, the developed software does not provide adequate primary functions like bisulfite, pair-end mapping, etc., in on-site software such as RMAP or BS Seeker. In addition, existing MapReduce-based applications were not designed to process the long reads produced by the most recent second-generation and third-generation NGS instruments and, therefore, are inefficient. Last, it is difficult for a majority of biologists untrained in programming skills to use these tools because most were developed on Linux with a command line interface. Results To urge the trend of using Cloud technologies in genomics and prepare for advances in second- and third-generation DNA sequencing, we have built a Hadoop MapReduce-based application, CloudAligner, which achieves higher performance, covers most primary features, is more accurate, and has a user-friendly interface. It was also designed to be able to deal with long sequences. The performance gain of CloudAligner over Cloud-based counterparts (35 to 80% mainly comes from the omission of the reduce phase. In comparison to local-based approaches, the performance gain of CloudAligner is from the partition and parallel processing of the huge reference genome as well as the reads. The source code of CloudAligner is available at http

  9. CloudAligner: A fast and full-featured MapReduce based tool for sequence mapping.

    Science.gov (United States)

    Nguyen, Tung; Shi, Weisong; Ruden, Douglas

    2011-06-06

    Research in genetics has developed rapidly recently due to the aid of next generation sequencing (NGS). However, massively-parallel NGS produces enormous amounts of data, which leads to storage, compatibility, scalability, and performance issues. The Cloud Computing and MapReduce framework, which utilizes hundreds or thousands of shared computers to map sequencing reads quickly and efficiently to reference genome sequences, appears to be a very promising solution for these issues. Consequently, it has been adopted by many organizations recently, and the initial results are very promising. However, since these are only initial steps toward this trend, the developed software does not provide adequate primary functions like bisulfite, pair-end mapping, etc., in on-site software such as RMAP or BS Seeker. In addition, existing MapReduce-based applications were not designed to process the long reads produced by the most recent second-generation and third-generation NGS instruments and, therefore, are inefficient. Last, it is difficult for a majority of biologists untrained in programming skills to use these tools because most were developed on Linux with a command line interface. To urge the trend of using Cloud technologies in genomics and prepare for advances in second- and third-generation DNA sequencing, we have built a Hadoop MapReduce-based application, CloudAligner, which achieves higher performance, covers most primary features, is more accurate, and has a user-friendly interface. It was also designed to be able to deal with long sequences. The performance gain of CloudAligner over Cloud-based counterparts (35 to 80%) mainly comes from the omission of the reduce phase. In comparison to local-based approaches, the performance gain of CloudAligner is from the partition and parallel processing of the huge reference genome as well as the reads. The source code of CloudAligner is available at http://cloudaligner.sourceforge.net/ and its web version is at http

  10. Simulation of beamline alignment operations

    International Nuclear Information System (INIS)

    Annese, C; Miller, M G.

    1999-01-01

    The CORBA-based Simulator was a Laboratory Directed Research and Development (LDRD) project that applied simulation techniques to explore critical questions about distributed control systems. The simulator project used a three-prong approach that studied object-oriented distribution tools, computer network modeling, and simulation of key control system scenarios. The National Ignition Facility's (NIF) optical alignment system was modeled to study control system operations. The alignment of NIF's 192 beamlines is a large complex operation involving more than 100 computer systems and 8000 mechanized devices. The alignment process is defined by a detailed set of procedures; however, many of the steps are deterministic. The alignment steps for a poorly aligned component are similar to that of a nearly aligned component; however, additional operations/iterations are required to complete the process. Thus, the same alignment operations will require variable amounts of time to perform depending on the current alignment condition as well as other factors. Simulation of the alignment process is necessary to understand beamline alignment time requirements and how shared resources such as the Output Sensor and Target Alignment Sensor effect alignment efficiency. The simulation has provided alignment time estimates and other results based on documented alignment procedures and alignment experience gained in the laboratory. Computer communication time, mechanical hardware actuation times, image processing algorithm execution times, etc. have been experimentally determined and incorporated into the model. Previous analysis of alignment operations utilized average implementation times for all alignment operations. Resource sharing becomes rather simple to model when only average values are used. The time required to actually implement the many individual alignment operations will be quite dynamic. The simulation model estimates the time to complete an operation using

  11. Accelerator development for a radioactive beam facility based on ATLAS

    International Nuclear Information System (INIS)

    Shepard, K. W.

    1998-01-01

    The existing superconducting linac ATLAS is in many respects an ideal secondary beam accelerator for an ISOL (Isotope separator on-line) type radioactive beam facility. Such a facility would require the addition of two major accelerator elements: a low charge state injector for the existing heavy ion linac, and a primary beam accelerator providing 220 MV of acceleration for protons and light ions. Development work for both of these elements, including the option of superconducting cavities for the primary beam accelerator is discussed

  12. Accelerator development for a radioactive beam facility based on ATLAS.

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K. W.

    1998-01-08

    The existing superconducting linac ATLAS is in many respects an ideal secondary beam accelerator for an ISOL (Isotope separator on-line) type radioactive beam facility. Such a facility would require the addition of two major accelerator elements: a low charge state injector for the existing heavy ion linac, and a primary beam accelerator providing 220 MV of acceleration for protons and light ions. Development work for both of these elements, including the option of superconducting cavities for the primary beam accelerator is discussed.

  13. Application of vertex and mass constraints in track-based alignment

    International Nuclear Information System (INIS)

    Amoraal, J.; Blouw, J.; Blusk, S.; Borghi, S.; Cattaneo, M.; Chiapolini, N.; Conti, G.; Deissenroth, M.; Dupertuis, F.; Eijk, R. van der; Fave, V.; Gersabeck, M.; Hicheur, A.; Hulsbergen, W.; Hutchcroft, D.; Kozlinskiy, A.; Lambert, R.W.

    2013-01-01

    The software alignment of planar tracking detectors using samples of charged particle trajectories may lead to global detector distortions that affect vertex and momentum resolution. We present an alignment procedure that constrains such distortions by making use of samples of decay vertices reconstructed from two or more trajectories and putting constraints on their invariant mass. We illustrate the method by using a sample of invariant-mass constrained vertices from D 0 →K − π + decays to remove a curvature bias in the LHCb spectrometer

  14. Embedded-Based Graphics Processing Unit Cluster Platform for Multiple Sequence Alignments

    Directory of Open Access Journals (Sweden)

    Jyh-Da Wei

    2017-08-01

    Full Text Available High-end graphics processing units (GPUs, such as NVIDIA Tesla/Fermi/Kepler series cards with thousands of cores per chip, are widely applied to high-performance computing fields in a decade. These desktop GPU cards should be installed in personal computers/servers with desktop CPUs, and the cost and power consumption of constructing a GPU cluster platform are very high. In recent years, NVIDIA releases an embedded board, called Jetson Tegra K1 (TK1, which contains 4 ARM Cortex-A15 CPUs and 192 Compute Unified Device Architecture cores (belong to Kepler GPUs. Jetson Tegra K1 has several advantages, such as the low cost, low power consumption, and high applicability, and it has been applied into several specific applications. In our previous work, a bioinformatics platform with a single TK1 (STK platform was constructed, and this previous work is also used to prove that the Web and mobile services can be implemented in the STK platform with a good cost-performance ratio by comparing a STK platform with the desktop CPU and GPU. In this work, an embedded-based GPU cluster platform will be constructed with multiple TK1s (MTK platform. Complex system installation and setup are necessary procedures at first. Then, 2 job assignment modes are designed for the MTK platform to provide services for users. Finally, ClustalW v2.0.11 and ClustalWtk will be ported to the MTK platform. The experimental results showed that the speedup ratios achieved 5.5 and 4.8 times for ClustalW v2.0.11 and ClustalWtk, respectively, by comparing 6 TK1s with a single TK1. The MTK platform is proven to be useful for multiple sequence alignments.

  15. Embedded-Based Graphics Processing Unit Cluster Platform for Multiple Sequence Alignments.

    Science.gov (United States)

    Wei, Jyh-Da; Cheng, Hui-Jun; Lin, Chun-Yuan; Ye, Jin; Yeh, Kuan-Yu

    2017-01-01

    High-end graphics processing units (GPUs), such as NVIDIA Tesla/Fermi/Kepler series cards with thousands of cores per chip, are widely applied to high-performance computing fields in a decade. These desktop GPU cards should be installed in personal computers/servers with desktop CPUs, and the cost and power consumption of constructing a GPU cluster platform are very high. In recent years, NVIDIA releases an embedded board, called Jetson Tegra K1 (TK1), which contains 4 ARM Cortex-A15 CPUs and 192 Compute Unified Device Architecture cores (belong to Kepler GPUs). Jetson Tegra K1 has several advantages, such as the low cost, low power consumption, and high applicability, and it has been applied into several specific applications. In our previous work, a bioinformatics platform with a single TK1 (STK platform) was constructed, and this previous work is also used to prove that the Web and mobile services can be implemented in the STK platform with a good cost-performance ratio by comparing a STK platform with the desktop CPU and GPU. In this work, an embedded-based GPU cluster platform will be constructed with multiple TK1s (MTK platform). Complex system installation and setup are necessary procedures at first. Then, 2 job assignment modes are designed for the MTK platform to provide services for users. Finally, ClustalW v2.0.11 and ClustalWtk will be ported to the MTK platform. The experimental results showed that the speedup ratios achieved 5.5 and 4.8 times for ClustalW v2.0.11 and ClustalWtk, respectively, by comparing 6 TK1s with a single TK1. The MTK platform is proven to be useful for multiple sequence alignments.

  16. Tidal alignment of galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš

    2015-08-01

    We develop an analytic model for galaxy intrinsic alignments (IA) based on the theory of tidal alignment. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed alignment of luminous red galaxies with the linear model as well as the frequently used "nonlinear alignment model," finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the "GI" term) can be effectively separated into source alignment and source clustering, and we accurately model the observed alignment down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average alignment of galaxies with density tracers no longer follows the tidal alignment prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal alignment in the context of cosmic shear measurements.

  17. Automatic Angular alignment of LHC Collimators

    CERN Document Server

    Azzopardi, Gabriella; Salvachua Ferrando, Belen Maria; Mereghetti, Alessio; Bruce, Roderik; Redaelli, Stefano; CERN. Geneva. ATS Department

    2017-01-01

    The LHC is equipped with a complex collimation system to protect sensitive equipment from unavoidable beam losses. Collimators are positioned close to the beam using an alignment procedure. Until now they have always been aligned assuming no tilt between the collimator and the beam, however, tank misalignments or beam envelope angles at large-divergence locations could introduce a tilt limiting the collimation performance. Three different algorithms were implemented to automatically align a chosen collimator at various angles. The implementation was tested on a number of collimators during this MD and no human intervention was required.

  18. Proton beam micromachining on strippable aqueous base developable negative resist

    International Nuclear Information System (INIS)

    Rajta, I.; Uzonyi, I.; Baradacs, E.; Chatzichristidi, M.; Raptis, I.; Valamontes, E.S.

    2004-01-01

    Complete text of publication follows. Proton Beam Micromachining (PBM, also known as P-beam writing), a novel direct- write process for the production of 3D microstructures, can be used to make multilevel structures in a single layer of resist by varying the ion energy. The interaction between the bombarding ions and the target material is mainly ionization, and very few ions suffer high angle nuclear collisions, therefore structures made with PBM have smooth near vertical side walls. The most commony applied resists in PBM are the positive, conventional, polymethyl methacrylate (PMMA); and the negative, chemically amplified, SU-8 (Micro Chem Corp). SU-8 is an epoxy based resist suitable also for LIGA and UV-LIGA processes, it offers good sensitivity, good process latitude, very high aspect ratio and therefore it dominates in the high aspect ratio micromachining applications. SU-8 requires 30 nC/mm 2 fluence for PBM irradiations at 2 MeV protons. Its crosslinking chemistry is based on the eight epoxy rings in the polymer chain, which provide a very dense three dimensional network in the presence of suitably activated photo acid generators (PAGs) which is very difficult to be stripped away after development. Thus, stripping has to be assisted with plasma processes or with special liquid removers. Moreover, the SU-8 developer is organic, propylene glycol methyl ether acetate (PGMEA), and thus environmentally non-friendly. To overcome the SU-8 stripping limitations, design of a negative resist system where solubility change is not based solely on cross- linking but also on the differentiation of hydrophilicity between exposed and non-exposed areas is desirable. A new resist formulation, fulfilling the above specifications has been developed recently [1]. This formulation is based on a specific grade epoxy novolac (EP) polymer, a partially hydrogenated poly-4-hydroxy styrene (PHS) polymer, and an onium salt as photoacid generator (PAG), and has been successfully

  19. Semantic similarity-based alignment between clinical archetypes and SNOMED CT: an application to observations.

    Science.gov (United States)

    Meizoso García, María; Iglesias Allones, José Luis; Martínez Hernández, Diego; Taboada Iglesias, María Jesús

    2012-08-01

    One of the main challenges of eHealth is semantic interoperability of health systems. But, this will only be possible if the capture, representation and access of patient data is standardized. Clinical data models, such as OpenEHR Archetypes, define data structures that are agreed by experts to ensure the accuracy of health information. In addition, they provide an option to normalize clinical data by means of binding terms used in the model definition to standard medical vocabularies. Nevertheless, the effort needed to establish the association between archetype terms and standard terminology concepts is considerable. Therefore, the purpose of this study is to provide an automated approach to bind OpenEHR archetypes terms to the external terminology SNOMED CT, with the capability to do it at a semantic level. This research uses lexical techniques and external terminological tools in combination with context-based techniques, which use information about structural and semantic proximity to identify similarities between terms and so, to find alignments between them. The proposed approach exploits both the structural context of archetypes and the terminology context, in which concepts are logically defined through the relationships (hierarchical and definitional) to other concepts. A set of 25 OBSERVATION archetypes with 477 bound terms was used to test the method. Of these, 342 terms (74.6%) were linked with 96.1% precision, 71.7% recall and 1.23 SNOMED CT concepts on average for each mapping. It has been detected that about one third of the archetype clinical information is grouped logically. Context-based techniques take advantage of this to increase the recall and to validate a 30.4% of the bindings produced by lexical techniques. This research shows that it is possible to automatically map archetype terms to a standard terminology with a high precision and recall, with the help of appropriate contextual and semantic information of both models. Moreover, the

  20. A Case Study of the Alignment between Curriculum and Assessment in the New York State Earth Science Standards-Based System

    Science.gov (United States)

    Contino, Julie

    2013-01-01

    In a standards-based system, it is important for all components of the system to align in order to achieve the intended goals. No Child Left Behind law mandates that assessments be fully aligned with state standards, be valid, reliable and fair, be reported to all stakeholders, and provide evidence that all students in the state are meeting the…

  1. Reputation-based ontology alignment for autonomy and interoperability in distributed access control

    NARCIS (Netherlands)

    Trivellato, Daniel; Spiessens, Fred; Zannone, Nicola; Etalle, Sandro

    2009-01-01

    Vocabulary alignment is a main challenge in distributedaccess control as peers should understand each other’spolicies unambiguously. Ontologies enable mutual understanding among peers by providing a precise semantics to concepts and relationships in a domain. However, due to the distributed nature

  2. ECR ion source based low energy ion beam facility

    Indian Academy of Sciences (India)

    Mass analyzed highly charged ion beams of energy ranging from a few keV to a few MeV plays an important role in various aspects of research in modern physics. In this paper a unique low energy ion beam facility (LEIBF) set up at Nuclear Science Centre (NSC) for providing low and medium energy multiply charged ion ...

  3. Development of a beam test telescope based on the Alibava readout system

    International Nuclear Information System (INIS)

    Marco-Hernandez, R

    2011-01-01

    A telescope for a beam test have been developed as a result of a collaboration among the University of Liverpool, Centro Nacional de Microelectronica (CNM) of Barcelona and Instituto de Fisica Corpuscular (IFIC) of Valencia. This system is intended to carry out both analogue charge collection and spatial resolution measurements with different types of microstrip or pixel silicon detectors in a beam test environment. The telescope has four XY measurement as well as trigger planes (XYT board) and it can accommodate up to twelve devices under test (DUT board). The DUT board uses two Beetle ASICs for the readout of chilled silicon detectors. The board could operate in a self-triggering mode. The board features a temperature sensor and it can be mounted on a rotary stage. A peltier element is used for cooling the DUT. Each XYT board measures the track space points using two silicon strip detectors connected to two Beetle ASICs. It can also trigger on the particle tracks in the beam test. The board includes a CPLD which allows for the synchronization of the trigger signal to a common clock frequency, delaying and implementing coincidence with other XYT boards. An Alibava mother board is used to read out and to control each XYT/DUT board from a common trigger signal and a common clock signal. The Alibava board has a TDC on board to have a time stamp of each trigger. The data collected by each Alibava board is sent to a master card by means of a local data/address bus following a custom digital protocol. The master board distributes the trigger, clock and reset signals. It also merges the data streams from up to sixteen Alibava boards. The board has also a test channel for testing in a standard mode a XYT or DUT board. This board is implemented with a Xilinx development board and a custom patch board. The master board is connected with the DAQ software via 100M Ethernet. Track based alignment software has also been developed for the data obtained with the DAQ software.

  4. Development of a beam test telescope based on the Alibava readout system

    Science.gov (United States)

    Marco-Hernández, R.

    2011-01-01

    A telescope for a beam test have been developed as a result of a collaboration among the University of Liverpool, Centro Nacional de Microelectrónica (CNM) of Barcelona and Instituto de Física Corpuscular (IFIC) of Valencia. This system is intended to carry out both analogue charge collection and spatial resolution measurements with different types of microstrip or pixel silicon detectors in a beam test environment. The telescope has four XY measurement as well as trigger planes (XYT board) and it can accommodate up to twelve devices under test (DUT board). The DUT board uses two Beetle ASICs for the readout of chilled silicon detectors. The board could operate in a self-triggering mode. The board features a temperature sensor and it can be mounted on a rotary stage. A peltier element is used for cooling the DUT. Each XYT board measures the track space points using two silicon strip detectors connected to two Beetle ASICs. It can also trigger on the particle tracks in the beam test. The board includes a CPLD which allows for the synchronization of the trigger signal to a common clock frequency, delaying and implementing coincidence with other XYT boards. An Alibava mother board is used to read out and to control each XYT/DUT board from a common trigger signal and a common clock signal. The Alibava board has a TDC on board to have a time stamp of each trigger. The data collected by each Alibava board is sent to a master card by means of a local data/address bus following a custom digital protocol. The master board distributes the trigger, clock and reset signals. It also merges the data streams from up to sixteen Alibava boards. The board has also a test channel for testing in a standard mode a XYT or DUT board. This board is implemented with a Xilinx development board and a custom patch board. The master board is connected with the DAQ software via 100M Ethernet. Track based alignment software has also been developed for the data obtained with the DAQ software.

  5. Development of a beam test telescope based on the Alibava readout system

    Energy Technology Data Exchange (ETDEWEB)

    Marco-Hernandez, R, E-mail: rmarco@ific.uv.es [Intituto de Fisica Corpuscular (CSIC-UV), Edificicio Institutos de Investigacion, PolIgono de La Coma, s/n. E-46980 Paterna (Valencia) (Spain)

    2011-01-15

    A telescope for a beam test have been developed as a result of a collaboration among the University of Liverpool, Centro Nacional de Microelectronica (CNM) of Barcelona and Instituto de Fisica Corpuscular (IFIC) of Valencia. This system is intended to carry out both analogue charge collection and spatial resolution measurements with different types of microstrip or pixel silicon detectors in a beam test environment. The telescope has four XY measurement as well as trigger planes (XYT board) and it can accommodate up to twelve devices under test (DUT board). The DUT board uses two Beetle ASICs for the readout of chilled silicon detectors. The board could operate in a self-triggering mode. The board features a temperature sensor and it can be mounted on a rotary stage. A peltier element is used for cooling the DUT. Each XYT board measures the track space points using two silicon strip detectors connected to two Beetle ASICs. It can also trigger on the particle tracks in the beam test. The board includes a CPLD which allows for the synchronization of the trigger signal to a common clock frequency, delaying and implementing coincidence with other XYT boards. An Alibava mother board is used to read out and to control each XYT/DUT board from a common trigger signal and a common clock signal. The Alibava board has a TDC on board to have a time stamp of each trigger. The data collected by each Alibava board is sent to a master card by means of a local data/address bus following a custom digital protocol. The master board distributes the trigger, clock and reset signals. It also merges the data streams from up to sixteen Alibava boards. The board has also a test channel for testing in a standard mode a XYT or DUT board. This board is implemented with a Xilinx development board and a custom patch board. The master board is connected with the DAQ software via 100M Ethernet. Track based alignment software has also been developed for the data obtained with the DAQ software.

  6. Improving mass measurement accuracy in mass spectrometry based proteomics by combining open source tools for chromatographic alignment and internal calibration.

    Science.gov (United States)

    Palmblad, Magnus; van der Burgt, Yuri E M; Dalebout, Hans; Derks, Rico J E; Schoenmaker, Bart; Deelder, André M

    2009-05-02

    Accurate mass determination enhances peptide identification in mass spectrometry based proteomics. We here describe the combination of two previously published open source software tools to improve mass measurement accuracy in Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). The first program, msalign, aligns one MS/MS dataset with one FTICRMS dataset. The second software, recal2, uses peptides identified from the MS/MS data for automated internal calibration of the FTICR spectra, resulting in sub-ppm mass measurement errors.

  7. Prestress Force Identification for Externally Prestressed Concrete Beam Based on Frequency Equation and Measured Frequencies

    Directory of Open Access Journals (Sweden)

    Luning Shi

    2014-01-01

    Full Text Available A prestress force identification method for externally prestressed concrete uniform beam based on the frequency equation and the measured frequencies is developed. For the purpose of the prestress force identification accuracy, we first look for the appropriate method to solve the free vibration equation of externally prestressed concrete beam and then combine the measured frequencies with frequency equation to identify the prestress force. To obtain the exact solution of the free vibration equation of multispan externally prestressed concrete beam, an analytical model of externally prestressed concrete beam is set up based on the Bernoulli-Euler beam theory and the function relation between prestress variation and vibration displacement is built. The multispan externally prestressed concrete beam is taken as the multiple single-span beams which must meet the bending moment and rotation angle boundary conditions, the free vibration equation is solved using sublevel simultaneous method and the semi-analytical solution of the free vibration equation which considered the influence of prestress on section rigidity and beam length is obtained. Taking simply supported concrete beam and two-span concrete beam with external tendons as examples, frequency function curves are obtained with the measured frequencies into it and the prestress force can be identified using the abscissa of the crosspoint of frequency functions. Identification value of the prestress force is in good agreement with the test results. The method can accurately identify prestress force of externally prestressed concrete beam and trace the trend of effective prestress force.

  8. Broadband and high-efficiency vortex beam generator based on a hybrid helix array.

    Science.gov (United States)

    Fang, Chaoqun; Wu, Chao; Gong, Zhijie; Zhao, Song; Sun, Anqi; Wei, Zeyong; Li, Hongqiang

    2018-04-01

    The vortex beam which carries the orbital angular momentum has versatile applications, such as high-resolution imaging, optical communications, and particle manipulation. Generating vortex beams with the Pancharatnam-Berry (PB) phase has drawn considerable attention for its unique spin-to-orbital conversion features. Despite the PB phase being frequency independent, an optical element with broadband high-efficiency circular polarization conversion feature is still needed for the broadband high-efficiency vortex beam generation. In this work, a broadband and high-efficiency vortex beam generator based on the PB phase is built with a hybrid helix array. Such devices can generate vortex beams with arbitrary topological charge. Moreover, vortex beams with opposite topological charge can be generated with an opposite handedness incident beam that propagates backward. The measured efficiency of our device is above 65% for a wide frequency range, with the relative bandwidth of 46.5%.

  9. Development of a Laser-based Emittance Monitor for Negative Hydrogen Beams

    CERN Document Server

    AUTHOR|(CDS)2078368; Schmauss, Bernhard; Gibson, Stephen; Boorman, Gary; Bosco, Alessio

    High energy particle accelerators are designed to collide charged particle beams and thus study the collision products. Maximising the collision rate, to generate sufficient statistics for precise measurements of rare processes, is one of the key parameters for optimising the overall collider performance. The CERN Large Hadron Collider (LHC) Injectors Upgrade (LIU) includes the construction of LINAC4, a completely new machine working as a first linear acceleration stage for the LHC beam. By accelerating a negative hydrogen beam (H-) instead of protons, it aims to double the beam brightness via a more efficient transfer to the first circular accelerator and subsequently boost the LHC collision rate. To achieve this, a precise knowledge of the transverse beam characteristics in terms of beam emittance is essential. This thesis work covers the development of a laser-based monitor meant to measure non-destructively the LINAC4 beam transverse profile and emittance. This included the implementation of dif...

  10. Development and Optimisation of the SPS and LHC beam diagnostics based on Synchrotron Radiation monitors

    CERN Document Server

    AUTHOR|(CDS)2081364; Roncarolo, Federico

    Measuring the beam transverse emittance is fundamental in every accelerator, in particular for colliders, where its precise determination is essential to maximize the luminosity and thus the performance of the colliding beams.
 Synchrotron Radiation (SR) is a versatile tool for non-destructive beam diagnostics, since its characteristics are closely related to those of the source beam. At CERN, being the only available diagnostics at high beam intensity and energy, SR monitors are exploited as the proton beam size monitor of the two higher energy machines, the Super Proton Synchrotron (SPS) and the Large Hadron Collider (LHC). The thesis work documented in this report focused on the design, development, characterization and optimization of these beam size monitors. Such studies were based on a comprehensive set of theoretical calculations, numerical simulations and experiments. A powerful simulation tool has been developed combining conventional softwares for SR simulation and optics design, thus allowing t...

  11. 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.)

  12. The ATLAS beam pick-up based timing system

    International Nuclear Information System (INIS)

    Ohm, C.; Pauly, T.

    2010-01-01

    The ATLAS BPTX stations are composed of electrostatic button pick-up detectors, located 175 m away along the beam pipe on both sides of ATLAS. The pick-ups are installed as a part of the LHC beam instrumentation and used by ATLAS for timing purposes. The usage of the BPTX signals in ATLAS is twofold: they are used both in the trigger system and for LHC beam monitoring. The BPTX signals are discriminated with a constant-fraction discriminator to provide a Level-1 trigger when a bunch passes through ATLAS. Furthermore, the BPTX detectors are used by a stand-alone monitoring system for the LHC bunches and timing signals. The BPTX monitoring system measures the phase between collisions and clock with a precision better than 100 ps in order to guarantee a stable phase relationship for optimal signal sampling in the sub-detector front-end electronics. In addition to monitoring this phase, the properties of the individual bunches are measured and the structure of the beams is determined. On September 10, 2008, the first LHC beams reached the ATLAS experiment. During this period with beam, the ATLAS BPTX system was used extensively to time in the read-out of the sub-detectors. In this paper, we present the performance of the BPTX system and its measurements of the first LHC beams.

  13. Sagnac Interferometer Based Generation of Controllable Cylindrical Vector Beams

    Directory of Open Access Journals (Sweden)

    Cristian Acevedo

    2016-01-01

    Full Text Available We report on a novel experimental geometry to generate cylindrical vector beams in a very robust manner. Continuous control of beams’ properties is obtained using an optically addressable spatial light modulator incorporated into a Sagnac interferometer. Forked computer-generated holograms allow introducing different topological charges while orthogonally polarized beams within the interferometer permit encoding the spatial distribution of polarization. We also demonstrate the generation of complex waveforms obtained by combining two orthogonal beams having both radial modulations and azimuthal dislocations.

  14. SU-E-J-181: Effect of Prostate Motion On Combined Brachytherapy and External Beam Dose Based On Daily Motion of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Narayana, V; McLaughlin, P [Providence Cancer Center, Southfield, MI (United States); University of Michigan, Ann Arbor, MI (United States); Ealbaj, J [University of Michigan, Ann Arbor, MI (United States)

    2015-06-15

    Purpose: In this study, the adequacy of target expansions on the combined external beam and implant dose was examined based on the measured daily motion of the prostate. Methods: Thirty patients received an I–125 prostate implant prescribed to dose of 90Gy. This was followed by external beam to deliver a dose of 90Gyeq (external beam equivalent) to the prostate over 25 to 30 fractions. An ideal IMRT plan was developed by optimizing the external beam dose based on the delivered implant dose. The implant dose was converted to an equivalent external beam dose using the linear quadratic model. Patients were set up on the treatment table by daily orthogonal imaging and aligning the marker seeds in the prostate. Orthogonal images were obtained at the end of treatment to assess prostate intrafraction motion. Based on the observed motion of the markers between the initial and final images, 5 individual plans showing the actual dose delivered to the patient were calculated. A final true dose distribution was established based on summing the implant dose and the 5 external beam plans. Dose to the prostate, seminal vesicles, lymphnodes and normal tissues, rectal wall, urethra and lower sphincter were calculated and compared to ideal. On 18 patients who were sexually active, dose to the corpus cavernosum and internal pudendal artery was also calculated. Results: The average prostate motion in 3 orthogonal directions was less than 1 mm with a standard deviation of less than +2 mm. Dose and volume parameters showed that there was no decrease in dose to the targets and a marginal decrease in dose to in normal tissues. Conclusion: Dose delivered by seed implant moves with the prostate, decreasing the impact of intrafractions dose movement on actual dose delivered. Combined brachytherapy and external beam dose delivered to the prostate was not sensitive to prostate motion.

  15. Information Technology Project Portfolio and Strategy Alignment Assessment Based on Data Envelopment Analysis

    Directory of Open Access Journals (Sweden)

    Marisa Analía Sánchez

    2012-11-01

    Full Text Available Recent researches have shown that companies face considerable difficulties in assessing the strategy value contribution of Information Technology (IT investments. One of the major obstacles to achieving strategy alignment is that organizations find extremely difficult to link and quantify the IT investments benefits with strategic goals. The aim of this paper is to define an approach to assess portfolio-strategy alignment. To this end a formal specification of Kaplan and Norton Strategy Map is developed utilizing Unified Modeling Language (UML. The approach uses the Strategy Map as a framework for defining the portfolio value contribution and Data Envelopment Analysis (DEA is used as the methodology for measuring efficiency of project portfolios.DOI:10.5585/gep.v3i2.66

  16. Performance and track-based alignment of the Phase-1 upgraded CMS pixel detector

    CERN Document Server

    Botta, Valeria

    2017-01-01

    The Compact Muon Solenoid (CMS) detector is a multi-purpose detector constructed in order to study high-energy particle collisions at the Large Hadron Collider (LHC) at CERN. The all-silicon design of the tracking system of the CMS experiment provided excellent resolution for charged tracks and an efficient tagging of jets during Run 1 and Run 2 of the LHC. After the pixel detector of the CMS experiment was upgraded and installed during the shutdown in the beginning of 2017, the positions and orientations of the tracker modules needed to be determined with a precision of several micrometers. The alignment also needs to be quickly recalculated each time the state of the CMS magnet is changed between 0 T and 3.8 T. The latest results of the CMS tracker performance in the 2017 run are presented, with a special focus on alignment and resolution performance using several million reconstructed tracks from cosmic rays and collision data.

  17. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G. Gomez

    Since December, the muon alignment community has focused on analyzing the data recorded so far in order to produce new DT and CSC Alignment Records for the second reprocessing of CRAFT data. Two independent algorithms were developed which align the DT chambers using global tracks, thus providing, for the first time, a relative alignment of the barrel with respect to the tracker. These results are an important ingredient for the second CRAFT reprocessing and allow, for example, a more detailed study of any possible mis-modelling of the magnetic field in the muon spectrometer. Both algorithms are constructed in such a way that the resulting alignment constants are not affected, to first order, by any such mis-modelling. The CSC chambers have not yet been included in this global track-based alignment due to a lack of statistics, since only a few cosmics go through the tracker and the CSCs. A strategy exists to align the CSCs using the barrel as a reference until collision tracks become available. Aligning the ...

  18. Study of biomaterials by ion-beam based methods

    International Nuclear Information System (INIS)

    Racolta, Petru; Craciun, Liviu; Cincu, Emanuela; Voiculescu, Dana; Muresan, Ofelia; Serban, Alin; Filip, Andrei Ilie; Bunea, Danil; Antoniac, Vasile; Tudor, Tiberiu Laurian; Visan, Teodor; Visan, Sanda; Ibris, Neluta

    2002-01-01

    The extension lifetime of prosthetic devices, dental materials and orthodontic devices is one main goal of the international medical supply community. In the frame of an interdisciplinary national project, IFIN-HH has started experimentation on some alternative procedures to study the wear/corrosion phenomena of biological materials by using ion-beam based techniques. Since joint prostheses are mechanical bearings there are concerns over friction and wear just as there are with any bearing. These concerns date back to the early introduction of total hip prostheses and were shown to be justified by the early failures due to wear. Subsequently, changes in materials and designs reduced the incidence of wear failure to a low level at which failures due to other mechanisms became dominant. Interest turned to preventing femoral component fracture, reducing the rates of infection, and reducing the rates of loosening. Attention to wear as a mechanism of failure has recently increased. The failure rate for joint replacement at the hip or knee has been progressively reduced. The biologic effects of wear debris have been recognized; wearing out of the prosthesis is no longer a prerequisite for an adverse outcome. There is an active search for new materials with increased wear resistance. In the case of metallic component from hip, knee prostheses and dental alloys, we present the optimum nuclear reactions according with the main parameters of our U-120 Cyclotron (p, d, E max = 13 MeV and α particle, E max = 26 MeV). In the case of polymers, one of an articulating couple of the prosthetic devices, direct activation causes severe changes in its surface morphology and its structure (formation of defects and free radicals). We have developed an indirect activation mode using the principle of recoil ion implantation, applied to 56 Co radioactive ions generated by proton particle beams on a Fe target (thickness ∼ 10 mm). A thin target of elementary composition A is bombarded by

  19. Morphing Downwind-Aligned Rotor Concept Based on a 13-MW Wind Turbine

    Energy Technology Data Exchange (ETDEWEB)

    Ichter, Brian; Steele, Adam; Loth, Eric; Moriarty, Patrick; Selig, Michael

    2016-04-01

    To alleviate the mass-scaling issues associated with conventional upwind rotors of extreme-scale wind turbines (>/=10 MW), a morphing downwind-aligned rotor (MoDaR) concept is proposed herein. The concept employs a downwind rotor with blades whose elements are stiff (no intentional flexibility) but with hub-joints that can be unlocked to allow for moment-free downwind alignment. Aligning the combination of gravitational, centrifugal and thrust forces along the blade path reduces downwind cantilever loads, resulting in primarily tensile loading. For control simplicity, the blade curvature can be fixed with a single morphing degree of freedom using a near-hub joint for coning angle: 22 degrees at rated conditions. The conventional baseline was set as the 13.2-MW Sandia 100-m all glass blade in a three-bladed upwind configuration. To quantify potential mass savings, a downwind load-aligning, two-bladed rotor was designed. Because of the reduced number of blades, the MoDaR concept had a favorable 33% mass reduction. The blade reduction and coning led to a reduction in rated power, but morphing increased energy capture at lower speeds such that both the MoDaR and conventional rotors have the same average power: 5.4 MW. A finite element analysis showed that quasi-steady structural stresses could be reduced, over a range of operating wind speeds and azimuthal angles, despite the increases in loading per blade. However, the concept feasibility requires additional investigation of the mass, cost and complexity of the morphing hinge, the impact of unsteady aeroelastic influence because of turbulence and off-design conditions, along with system-level Levelized Cost of Energy analysis.

  20. Business Process as a Service Model Based Business and IT Cloud Alignment as a Cloud Offering

    OpenAIRE

    Robert Woitsch; Wilfrid Utz

    2015-01-01

    Cloud computing proved to offer flexible IT solutions. Although large enterprises may benefit from this technology, SMEs are falling behind in cloud usage due to missing ITcompetence and hence lose the ability to efficiently adapt their IT to their business needs. This paper introduces the project idea of the H2020 project CloudSocket, by elaborating the idea of Business Processes as a Service (BPaaS), where concept models and semantics are applied to align business processes with Cloud deplo...

  1. Model Based Business and IT Cloud Alignment as a Cloud Offering

    OpenAIRE

    Robert Woitsch; Wilfrid Utz

    2015-01-01

    Cloud computing proved to offer flexible IT solutions. Although large enterprises may benefit from this technology by educating their IT departments, SMEs are dramatically falling behind in cloud usage and hence lose the ability to efficiently adapt their IT to their business needs. This paper introduces the project idea of the H2020 project CloudSocket, by elaborating the idea of Business Processes as a Service, where concept models and semantics are applied to align business pro...

  2. Negative-ion-based neutral beams for fusion

    International Nuclear Information System (INIS)

    Cooper, W.S.; Anderson, O.A.; Chan, C.F.

    1987-10-01

    To maximize the usefulness of an engineering test reactor (e.g., ITER, TIBER), it is highly desirable that it operate under steady-state conditions. The most attractive option for maintaining the circulating current needed in the center of the plasma is the injection of powerful beams of neutral deuterium atoms. The beam simultaneously heats the plasma. At the energies required, in excess of 500 keV, such beams can be made by accelerating D - ions and then removing the electron. Sources are being developed that generate the D - ions in the volume of a specially constructed plasma discharge, without the addition of cesium. These sources must operate with minimum gas flow, to avoid stripping the D - beam, and with minimum electron output. We are designing at LBL highly efficient electrostatic accelerators that combine electric strong-focusing with dc acceleration and offer the possibility of varying the beam energy at constant current while minimizing breakdown. Some form of rf acceleration may also be required. To minimize irradiation of the ion sources and accelerators, the D - beam can be transported through a maze in the neutron shielding. The D - ions can be converted to neutrals in a gas or plasma target, but advances in laser and mirror technology may make possible very efficient photodetachment systems by the time an ETR becomes operational. 9 refs., 4 figs

  3. SU-E-T-403: Evaluation of the Beam Performance of a Varian TrueBeam Linear Accelerator Under External Device-Based Gated Delivery Conditions

    International Nuclear Information System (INIS)

    Kobulnicky, K; Pawlak, D; Purwar, A

    2015-01-01

    Purpose: To examine the beam performance of a Varian TrueBeam linear accelerator under external device-based gated delivery conditions. Methods: Six gating cycles were used to evaluate the gating performance of a standard production TrueBeam system that was not specially tuned in any way. The system was equipped with a factory installed external gating interface (EXGI). An in-house EXGI tester box was used to simulate the input gating signals. The gating cycles were selected based on long beam-on and short beam-off times, short beam-on and long beam-off times, or equal beam on and off times to check linac performance. The beam latencies were measured as the time difference between the logic high gating signal and the first or last target pulses with an oscilloscope. Tissue-Phantom Ratio, beam flatness, and dose distributions from 5 different plans were measured using the 6 different gating durations and the un-gated irradiation. A PTW 729 2-D array was used to compare 5 plans versus the un-gated delivery with a 1%/1mm gamma index passing criteria. Results: The beam latencies of the linac were based off of 20 samples for beam-on and beam-off, for each gating cycle. The average beam-on delays were measured to be between 57 and 66msec, with a maximum of 88 msec. The beam off latencies averaged between 19 and 26msec, with a maximum of 48 msec. TPR20,10 measurements showed beam energy stability within 0.5% of the un-gated delivery. Beam flatness was better than 2.5% for all gated cycles. All but two deliveries, the open field with 4 seconds on, 1 second off, and a five field IMRT plan with 0.5 seconds on, 2.5 seconds off, had >90% passing rate. Conclusion: TrueBeam demonstrates excellent beam stability with minimal beam latencies under external device-based gated operations. Dosimetric measurements show minimal variation in beam energy, flatness, and plan delivery. Authors are employees of Varian Medical Systems, Inc

  4. SU-E-T-403: Evaluation of the Beam Performance of a Varian TrueBeam Linear Accelerator Under External Device-Based Gated Delivery Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kobulnicky, K; Pawlak, D; Purwar, A [Varian Medical Systems, Inc., Palo Alto, CA (United States)

    2015-06-15

    Purpose: To examine the beam performance of a Varian TrueBeam linear accelerator under external device-based gated delivery conditions. Methods: Six gating cycles were used to evaluate the gating performance of a standard production TrueBeam system that was not specially tuned in any way. The system was equipped with a factory installed external gating interface (EXGI). An in-house EXGI tester box was used to simulate the input gating signals. The gating cycles were selected based on long beam-on and short beam-off times, short beam-on and long beam-off times, or equal beam on and off times to check linac performance. The beam latencies were measured as the time difference between the logic high gating signal and the first or last target pulses with an oscilloscope. Tissue-Phantom Ratio, beam flatness, and dose distributions from 5 different plans were measured using the 6 different gating durations and the un-gated irradiation. A PTW 729 2-D array was used to compare 5 plans versus the un-gated delivery with a 1%/1mm gamma index passing criteria. Results: The beam latencies of the linac were based off of 20 samples for beam-on and beam-off, for each gating cycle. The average beam-on delays were measured to be between 57 and 66msec, with a maximum of 88 msec. The beam off latencies averaged between 19 and 26msec, with a maximum of 48 msec. TPR20,10 measurements showed beam energy stability within 0.5% of the un-gated delivery. Beam flatness was better than 2.5% for all gated cycles. All but two deliveries, the open field with 4 seconds on, 1 second off, and a five field IMRT plan with 0.5 seconds on, 2.5 seconds off, had >90% passing rate. Conclusion: TrueBeam demonstrates excellent beam stability with minimal beam latencies under external device-based gated operations. Dosimetric measurements show minimal variation in beam energy, flatness, and plan delivery. Authors are employees of Varian Medical Systems, Inc.

  5. A self-calibrating ion beam profiler based on a CsI scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Finocchiaro, P. E-mail: finocchiaro@lns.infn.it; Ciavola, G.; Cosentino, L.; Gu, M.; Raia, G.; Rovelli, A

    1999-11-21

    We report on the test results obtained with a prototype beam profiler based on a thin slit and a CsI scintillator, read out by means of a compact photomultiplier. Such a device has proven to be suitable to perform ion beam diagnostics at low and very low intensities. In particular, our device is suitable for being used in the energy and intensity ranges expected at the EXCYT radioactive ion beam facility, that is currently under development at LNS Catania.

  6. A self-calibrating ion beam profiler based on a CsI scintillator

    International Nuclear Information System (INIS)

    Finocchiaro, P.; Ciavola, G.; Cosentino, L.; Gu, M.; Raia, G.; Rovelli, A.

    1999-01-01

    We report on the test results obtained with a prototype beam profiler based on a thin slit and a CsI scintillator, read out by means of a compact photomultiplier. Such a device has proven to be suitable to perform ion beam diagnostics at low and very low intensities. In particular, our device is suitable for being used in the energy and intensity ranges expected at the EXCYT radioactive ion beam facility, that is currently under development at LNS Catania

  7. Development of a computerized tomographic system based on the FAN-BEAM technique

    International Nuclear Information System (INIS)

    Junqueira, M.M.; Santos, C.A.C.; Borges, J.C.

    1986-01-01

    The Nuclear Instrumentation Laboratory, at COPPE/UFRJ, concentrates its researches in the development of computerized tomographic systems, looking for applications in industrial and medical non destructive analysing techniques. In this work we have projected and constructed a tomographic prototype, based on the FAN-BEAM technique for irradiating the object under analysis. An algorithm previously developed to analyse parallel beams, was modified and adapted to the FAN-BEAM geometry. (Author) [pt

  8. SPES: A new cyclotron-based facility for research and applications with high-intensity beams

    Science.gov (United States)

    Maggiore, M.; Campo, D.; Antonini, P.; Lombardi, A.; Manzolaro, M.; Andrighetto, A.; Monetti, A.; Scarpa, D.; Esposito, J.; Silvestrin, L.

    2017-06-01

    In 2016, Laboratori Nazionali di Legnaro (Italy) started the commissioning of a new accelerator facility based on a high-power cyclotron able to deliver proton beams up to 70 MeV of energy and 700 μA current. Such a machine is the core of the Selective Production of Exotic Species (SPES) project whose main goal is to provide exotics beam for nuclear and astrophysics research and to deliver high-intensity proton beams for medical applications and neutrons generator.

  9. Improving the quality of biomarker candidates in untargeted metabolomics via peak table-based alignment of comprehensive two-dimensional gas chromatography-mass spectrometry data

    Science.gov (United States)

    Bean, Heather D.; Hill, Jane E.; Dimandja, Jean-Marie D.

    2015-01-01

    The potential of high-resolution analytical technologies like GC×GC/TOF MS in untargeted metabolomics and biomarker discovery has been limited by the development of fully automated software that can efficiently align and extract information from multiple chromatographic data sets. In this work we report the first investigation on a peak-by-peak basis of the chromatographic factors that impact GC×GC data alignment. A representative set of 16 compounds of different chromatographic characteristics were followed through the alignment of 63 GC×GC chromatograms. We found that varying the mass spectral match parameter had a significant influence on the alignment for poorly- resolved peaks, especially those at the extremes of the detector linear range, and no influence on well- chromatographed peaks. Therefore, optimized chromatography is required for proper GC×GC data alignment. Based on these observations, a workflow is presented for the conservative selection of biomarker candidates from untargeted metabolomics analyses. PMID:25857541

  10. High-performance Supercapacitors Based on Electrochemical-induced Vertical-aligned Carbon Nanotubes and Polyaniline Nanocomposite Electrodes

    Science.gov (United States)

    Wu, Guan; Tan, Pengfeng; Wang, Dongxing; Li, Zhe; Peng, Lu; Hu, Ying; Wang, Caifeng; Zhu, Wei; Chen, Su; Chen, Wei

    2017-03-01

    Supercapacitors, which store electrical energy through reversible ion on the surface of conductive electrodes have gained enormous attention for variously portable energy storage devices. Since the capacitive performance is mainly determined by the structural and electrochemical properties of electrodes, the electrodes become more crucial to higher performance. However, due to the disordered microstructure and low electrochemical activity of electrode for ion tortuous migration and accumulation, the supercapacitors present relatively low capacitance and energy density. Here we report a high-performance supercapacitor based on polyaniline/vertical-aligned carbon nanotubes (PANI/VA-CNTs) nanocomposite electrodes where the vertical-aligned-structure is formed by the electrochemical-induction (0.75 V). The supercapacitor displays large specific capacitance of 403.3 F g-1, which is 6 times higher than disordered CNTs in HClO4 electrolyte. Additionally, the supercapacitor can also present high specific capacitance (314.6 F g-1), excellent cycling stability (90.2% retention after 3000 cycles at 4 A g-1) and high energy density (98.1 Wh kg-1) in EMIBF4 organic electrolyte. The key to high-performance lies in the vertical-aligned-structure providing direct path channel for ion faster diffusion and high electrochemical capacitance of polyaniline for ion more accommodation.

  11. High-performance Supercapacitors Based on Electrochemical-induced Vertical-aligned Carbon Nanotubes and Polyaniline Nanocomposite Electrodes.

    Science.gov (United States)

    Wu, Guan; Tan, Pengfeng; Wang, Dongxing; Li, Zhe; Peng, Lu; Hu, Ying; Wang, Caifeng; Zhu, Wei; Chen, Su; Chen, Wei

    2017-03-08

    Supercapacitors, which store electrical energy through reversible ion on the surface of conductive electrodes have gained enormous attention for variously portable energy storage devices. Since the capacitive performance is mainly determined by the structural and electrochemical properties of electrodes, the electrodes become more crucial to higher performance. However, due to the disordered microstructure and low electrochemical activity of electrode for ion tortuous migration and accumulation, the supercapacitors present relatively low capacitance and energy density. Here we report a high-performance supercapacitor based on polyaniline/vertical-aligned carbon nanotubes (PANI/VA-CNTs) nanocomposite electrodes where the vertical-aligned-structure is formed by the electrochemical-induction (0.75 V). The supercapacitor displays large specific capacitance of 403.3 F g -1 , which is 6 times higher than disordered CNTs in HClO 4 electrolyte. Additionally, the supercapacitor can also present high specific capacitance (314.6 F g -1 ), excellent cycling stability (90.2% retention after 3000 cycles at 4 A g -1 ) and high energy density (98.1 Wh kg -1 ) in EMIBF 4 organic electrolyte. The key to high-performance lies in the vertical-aligned-structure providing direct path channel for ion faster diffusion and high electrochemical capacitance of polyaniline for ion more accommodation.

  12. Software-based data path for raster-scanned multi-beam mask lithography

    Science.gov (United States)

    Rajagopalan, Archana; Agarwal, Ankita; Buck, Peter; Geller, Paul; Hamaker, H. Christopher; Rao, Nagswara

    2016-10-01

    According to the 2013 SEMATECH Mask Industry Survey,i roughly half of all photomasks are produced using laser mask pattern generator ("LMPG") lithography. LMPG lithography can be used for all layers at mature technology nodes, and for many non-critical and semi-critical masks at advanced nodes. The extensive use of multi-patterning at the 14-nm node significantly increases the number of critical mask layers, and the transition in wafer lithography from positive tone resist to negative tone resist at the 14-nm design node enables the switch from advanced binary masks back to attenuated phase shifting masks that require second level writes to remove unwanted chrome. LMPG lithography is typically used for second level writes due to its high productivity, absence of charging effects, and versatile non-actinic alignment capability. As multi-patterning use expands from double to triple patterning and beyond, the number of LMPG second level writes increases correspondingly. The desire to reserve the limited capacity of advanced electron beam writers for use when essential is another factor driving the demand for LMPG capacity. The increasing demand for cost-effective productivity has kept most of the laser mask writers ever manufactured running in production, sometimes long past their projected lifespan, and new writers continue to be built based on hardware developed some years ago.ii The data path is a case in point. While state-ofthe- art when first introduced, hardware-based data path systems are difficult to modify or add new features to meet the changing requirements of the market. As data volumes increase, design styles change, and new uses are found for laser writers, it is useful to consider a replacement for this critical subsystem. The availability of low-cost, high-performance, distributed computer systems combined with highly scalable EDA software lends itself well to creating an advanced data path system. EDA software, in routine production today, scales

  13. Optimal design of a beam-based dynamic vibration absorber using fixed-points theory

    Science.gov (United States)

    Hua, Yingyu; Wong, Waion; Cheng, Li

    2018-05-01

    The addition of a dynamic vibration absorber (DVA) to a vibrating structure could provide an economic solution for vibration suppressions if the absorber is properly designed and located onto the structure. A common design of the DVA is a sprung mass because of its simple structure and low cost. However, the vibration suppression performance of this kind of DVA is limited by the ratio between the absorber mass and the mass of the primary structure. In this paper, a beam-based DVA (beam DVA) is proposed and optimized for minimizing the resonant vibration of a general structure. The vibration suppression performance of the proposed beam DVA depends on the mass ratio, the flexural rigidity and length of the beam. In comparison with the traditional sprung mass DVA, the proposed beam DVA shows more flexibility in vibration control design because it has more design parameters. With proper design, the beam DVA's vibration suppression capability can outperform that of the traditional DVA under the same mass constraint. The general approach is illustrated using a benchmark cantilever beam as an example. The receptance theory is introduced to model the compound system consisting of the host beam and the attached beam-based DVA. The model is validated through comparisons with the results from Abaqus as well as the Transfer Matrix method (TMM) method. Fixed-points theory is then employed to derive the analytical expressions for the optimum tuning ratio and damping ratio of the proposed beam absorber. A design guideline is then presented to choose the parameters of the beam absorber. Comparisons are finally presented between the beam absorber and the traditional DVA in terms of the vibration suppression effect. It is shown that the proposed beam absorber can outperform the traditional DVA by following this proposed guideline.

  14. Formatt: Correcting protein multiple structural alignments by incorporating sequence alignment

    Directory of Open Access Journals (Sweden)

    Daniels Noah M

    2012-10-01

    Full Text Available Abstract Background The quality of multiple protein structure alignments are usually computed and assessed based on geometric functions of the coordinates of the backbone atoms from the protein chains. These purely geometric methods do not utilize directly protein sequence similarity, and in fact, determining the proper way to incorporate sequence similarity measures into the construction and assessment of protein multiple structure alignments has proved surprisingly difficult. Results We present Formatt, a multiple structure alignment based on the Matt purely geometric multiple structure alignment program, that also takes into account sequence similarity when constructing alignments. We show that Formatt outperforms Matt and other popular structure alignment programs on the popular HOMSTRAD benchmark. For the SABMark twilight zone benchmark set that captures more remote homology, Formatt and Matt outperform other programs; depending on choice of embedded sequence aligner, Formatt produces either better sequence and structural alignments with a smaller core size than Matt, or similarly sized alignments with better sequence similarity, for a small cost in average RMSD. Conclusions Considering sequence information as well as purely geometric information seems to improve quality of multiple structure alignments, though defining what constitutes the best alignment when sequence and structural measures would suggest different alignments remains a difficult open question.

  15. Performance Analysis of a Threshold-Based Parallel Multiple Beam Selection Scheme for WDM FSO Systems

    KAUST Repository

    Nam, Sung Sik; Alouini, Mohamed-Slim; Ko, Young-Chai

    2018-01-01

    In this paper, we statistically analyze the performance of a threshold-based parallel multiple beam selection scheme for a free-space optical (FSO) based system with wavelength division multiplexing (WDM) in cases where a pointing error has occurred

  16. Beyond Alignment

    DEFF Research Database (Denmark)

    Beyond Alignment: Applying Systems Thinking to Architecting Enterprises is a comprehensive reader about how enterprises can apply systems thinking in their enterprise architecture practice, for business transformation and for strategic execution. The book's contributors find that systems thinking...

  17. Study of a high power hydrogen beam diagnostic based on secondary electron emission

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, UNIPD, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Department of Management and Engineering, University di Padova strad. S. Nicola 3, 36100 Vicenza (Italy); Panasenkov, A. [NRC, Kurchatov Institute, 1, Kurchatov Sq, Moscow 123182 (Russian Federation); Veltri, P. [Consorzio RFX (CNR, ENEA, INFN, UNIPD, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); INFN-LNL, viale dell’Università n. 2, 35020 Legnaro (Italy); Serianni, G.; Pasqualotto, R. [Consorzio RFX (CNR, ENEA, INFN, UNIPD, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy)

    2016-11-15

    In high power neutral beams for fusion, beam uniformity is an important figure of merit. Knowing the transverse power profile is essential during the initial phases of beam source operation, such as those expected for the ITER heating neutral beam (HNB) test facility. To measure it a diagnostic technique is proposed, based on the collection of secondary electrons generated by beam-surface and beam-gas interactions, by an array of positively biased collectors placed behind the calorimeter tubes. This measurement showed in the IREK test stand good proportionality to the primary beam current. To investigate the diagnostic performances in different conditions, we developed a numerical model of secondary electron emission, induced by beam particle impact on the copper tubes, and reproducing the cascade of secondary emission caused by successive electron impacts. The model is first validated against IREK measurements. It is then applied to the HNB case, to assess the locality of the measurement, the proportionality to the beam current density, and the influence of beam plasma.

  18. Surface-conduction electron-emitter characteristics and fabrication based on vertically aligned carbon nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Yi-Ting [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei 10607, Taiwan (China); Li, Kuan-Wei [Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei 10607, Taiwan (China); Honda, Shin-ichi [Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Lin, Pao-Hung; Huang, Ying-Sheng [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei 10607, Taiwan (China); Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei 10607, Taiwan (China); Lee, Kuei-Yi, E-mail: kylee@mail.ntust.edu.tw [Graduate Institute of Electro-Optical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei 10607, Taiwan (China); Department of Electronic and Computer Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Road, Taipei 10607, Taiwan (China)

    2017-06-01

    Graphical abstract: The pattern design provides a new structure of surface-conduction electron-emitter display (SED). Delta-star shaped vertically aligned CNT (VACNT) arrays with 20o tips can simultaneously provide three emitters to bombard the sides of equilateral triangles pattern of VACNT, which produces numerous secondary electrons and enhance the SED efficiency. - Highlights: • The carbon nanotube (CNT) has replaced palladium oxide (PdO) as the electrode material for surface-conduction electron-emitter (SCE) applications. • The vertically aligned CNT (VACNT) arrays with 20° tips of the delta-star arrangement are used as cathodes that easily emit electrons. The cathode pattern simultaneously provides three emitters to bombard the sides of equilateral triangles pattern of VACNT. • The VACNT arrays were covered with magnesium oxide (MgO) nanostructures to promote the surface-conduction electron-emitter display (SED) efficiency (η). • The η was stably maintained in the 75–85% range. The proposed design provides a facile new method for developing SED applications. - Abstract: The carbon nanotube (CNT) has replaced palladium oxide (PdO) as the electrode material for surface-conduction electron-emitter (SCE) applications. Vertically aligned CNT arrays with a delta-star arrangement were patterned and synthesized onto a quartz substrate using photolithography and thermal chemical vapor deposition. Delta-star shaped VACNT arrays with 20° tips are used as cathodes that easily emit electrons because of their high electrical field gradient. In order to improve the field emission and secondary electrons (SEs) in SCE applications, magnesium oxide (MgO) nanostructures were coated onto the VACNT arrays to promote the surface-conduction electron-emitter display (SED) efficiency (η). According to the definition of η in SCE applications, in this study, the η was stably maintained in the 75–85% range. The proposed design provides a facile new method for

  19. Development and Testing of Atomic Beam-Based Plasma Edge Diagnostics in the CIEMAT Fusion Devices

    International Nuclear Information System (INIS)

    Tafalla, D.; Tabares, F.L.; Ortiz, P.; Herrero, V.J.; Tanarro, I.

    1998-01-01

    In this report the development of plasma edge diagnostic based on atomic beam techniques fir their application in the CIEMAT fusion devices is described. The characterisation of the beams in laboratory experiments at the CSIC, together with first results in the Torsatron TJ-II are reported. Two types of beam diagnostics have been developed: a thermal (effusive) Li and a supersonic, pulsed He beams. This work has been carried out in collaboration between the institutions mentioned above under partial financial support by EURATOM. (Author) 17 refs

  20. Fen+ beam profile diagnostics based on Al2O3: Cr scintillating screen

    International Nuclear Information System (INIS)

    He Tie; Lei Jiarong; Liu Meng; An Li; Wang Xinhua; Zheng Pu

    2013-01-01

    Some techniques of beam profile measurements such as wire rotating scan, Faraday cups array and infrared imaging were investigated. A measurement device was built based on scintillating screen to cater for the demand of accelerator beam profile diagnostics. The device was bombarded under several tens to hundred nanoampere Fe n+ (n=5-12) ion beam. The Fe n+ ion beam experiment shows that the imaging saturation is mainly caused by light intensity rather than scintillating screen. A way to solve the saturation problem with a specially developed lens was mentioned. The grayscale of beam profile imaging is approximately linear with respect to the beam intensity, and the reason for formation of this relationship was analyzed. (authors)

  1. Reference dosimetry of proton pencil beams based on dose-area product: a proof of concept.

    Science.gov (United States)

    Gomà, Carles; Safai, Sairos; Vörös, Sándor

    2017-06-21

    This paper describes a novel approach to the reference dosimetry of proton pencil beams based on dose-area product ([Formula: see text]). It depicts the calibration of a large-diameter plane-parallel ionization chamber in terms of dose-area product in a 60 Co beam, the Monte Carlo calculation of beam quality correction factors-in terms of dose-area product-in proton beams, the Monte Carlo calculation of nuclear halo correction factors, and the experimental determination of [Formula: see text] of a single proton pencil beam. This new approach to reference dosimetry proves to be feasible, as it yields [Formula: see text] values in agreement with the standard and well-established approach of determining the absorbed dose to water at the centre of a broad homogeneous field generated by the superposition of regularly-spaced proton pencil beams.

  2. Multi-beam synchronous measurement based on PSD phase detection using frequency-domain multiplexing

    Science.gov (United States)

    Duan, Ying; Qin, Lan; Xue, Lian; Xi, Feng; Mao, Jiubing

    2013-10-01

    According to the principle of centroid measurement, position-sensitive detectors (PSD) are commonly used for micro displacement detection. However, single-beam detection method cannot satisfy such tasks as multi-dimension position measurement, three dimension vision reconstruction, and robot precision positioning, which require synchronous measurement of multiple light beams. Consequently, we designed PSD phase detection method using frequency-domain multiplexing for synchronous detection of multiple modulated light beams. Compared to previous PSD amplitude detection method, the phase detection method using FDM has advantages of simplified measuring system, low cost, high capability of resistance to light interference as well as improved resolution. The feasibility of multi-beam synchronous measurement based on PSD phase detection using FDM was validated by multi-beam measuring experiments. The maximum non-linearity error of the multi-beam synchronous measurement is 6.62%.

  3. Finite element analysis of rotating beams physics based interpolation

    CERN Document Server

    Ganguli, Ranjan

    2017-01-01

    This book addresses the solution of rotating beam free-vibration problems using the finite element method. It provides an introduction to the governing equation of a rotating beam, before outlining the solution procedures using Rayleigh-Ritz, Galerkin and finite element methods. The possibility of improving the convergence of finite element methods through a judicious selection of interpolation functions, which are closer to the problem physics, is also addressed. The book offers a valuable guide for students and researchers working on rotating beam problems – important engineering structures used in helicopter rotors, wind turbines, gas turbines, steam turbines and propellers – and their applications. It can also be used as a textbook for specialized graduate and professional courses on advanced applications of finite element analysis.

  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. A DSP based data acquisition module for colliding beam accelerators

    International Nuclear Information System (INIS)

    Mead, J.A.; Shea, T.J.

    1995-10-01

    In 1999, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory will accelerate and store two beams of gold ions. The ions will then collide head on at a total energy of nearly 40 trillion electron volts. Attaining these conditions necessitates real-time monitoring of beam parameters and for this purpose a flexible data acquisition platform has been developed. By incorporating a floating point digital signal processor (DSP) and standard input/output modules, this system can acquire and process data from a variety of beam diagnostic devices. The DSP performs real time corrections, filtering, and data buffering to greatly reduce control system computation and bandwidth requirements. We will describe the existing hardware and software while emphasizing the compromises required to achieve a flexible yet cost effective system. Applications in several instrumentation systems currently construction will also be presented

  6. Dose-volume based ranking of incident beam direction and its utility in facilitating IMRT beam placement

    International Nuclear Information System (INIS)

    Schreibmann, Eduard; Xing Lei

    2005-01-01

    Purpose: Beam orientation optimization in intensity-modulated radiation therapy (IMRT) is computationally intensive, and various single beam ranking techniques have been proposed to reduce the search space. Up to this point, none of the existing ranking techniques considers the clinically important dose-volume effects of the involved structures, which may lead to clinically irrelevant angular ranking. The purpose of this work is to develop a clinically sensible angular ranking model with incorporation of dose-volume effects and to show its utility for IMRT beam placement. Methods and Materials: The general consideration in constructing this angular ranking function is that a beamlet/beam is preferable if it can deliver a higher dose to the target without exceeding the tolerance of the sensitive structures located on the path of the beamlet/beam. In the previously proposed dose-based approach, the beamlets are treated independently and, to compute the maximally deliverable dose to the target volume, the intensity of each beamlet is pushed to its maximum intensity without considering the values of other beamlets. When volumetric structures are involved, the complication arises from the fact that there are numerous dose distributions corresponding to the same dose-volume tolerance. In this situation, the beamlets are not independent and an optimization algorithm is required to find the intensity profile that delivers the maximum target dose while satisfying the volumetric constraints. In this study, the behavior of a volumetric organ was modeled by using the equivalent uniform dose (EUD). A constrained sequential quadratic programming algorithm (CFSQP) was used to find the beam profile that delivers the maximum dose to the target volume without violating the EUD constraint or constraints. To assess the utility of the proposed technique, we planned a head-and-neck and abdominal case with and without the guidance of the angular ranking information. The qualities of the

  7. NOVA integrated alignment/diagnostic sensors

    International Nuclear Information System (INIS)

    1978-01-01

    Under Contract 3772003 to the Lawrence Livermore Laboratory, Aerojet ElectroSystems Company has investigated a number of alignment system design topics for the NOVA and SHIVA upgrade lasers. Prior reports dealt with the Main Beam Alignment System, and with Multipass Amplifier Alignment Concepts. This report, which completes the contract, examines ways in which the Return Beam Diagnostic (RBD) package and Incident Beam Diagnostic (IBD) packages may be reconfigured to a more integrated package. In particular, the report shows that the RBD optics may be directly integrated in the Pointing Focus and Centering (PFC) sensor, and that the IBD optics may use the same basic common configuration as the PFC/RBD package

  8. Ice and Atoms: experiments with laboratory-based positron beams

    International Nuclear Information System (INIS)

    Coleman, P G

    2011-01-01

    This short review presents results of new positron and positronium (Ps) experiments in condensed matter and atomic physics, as an illustration of the satisfying variety of scientific endeavours involving positron beams which can be pursued with relatively simple apparatus in a university laboratory environment. The first of these two studies - on ice films - is an example of how positrons and Ps can provide new insights into an important system which has been widely interrogated by other techniques. The second is an example of how simple positron beam systems can still provide interesting information - here on a current interesting fundamental problem in positron atomic physics.

  9. Photovoltaic-Concentrator Based Power Beaming For Space Elevator Application

    International Nuclear Information System (INIS)

    Becker, Daniel E.; Chiang, Richard; Keys, Catherine C.; Lyjak, Andrew W.; Starch, Michael D.; Nees, John A.

    2010-01-01

    The MClimber team, at the Student Space Systems Fabrication Laboratory of the University of Michigan, has developed a prototype robotic climber for competition in the NASA sponsored Power Beaming Challenge. This paper describes the development of the system that utilizes a simple telescope to deliver an 8 kW beam to a photovoltaic panel in order to power a one kilometer climb. Its unique approach utilizes a precision GPS signal to track the panel. Fundamental systems of the project were implemented using a design strategy focusing on robustness and modularity. Development of this design and its results are presented.

  10. Considerations involved in the design of negative-ion-based neutral beam systems

    International Nuclear Information System (INIS)

    Cooper, W.S.

    1983-11-01

    We consider the requirements and constraints for negative-ion-based neutral beam injection systems, and show how these are reflected in design considerations. We will attempt to develop a set of guidelines for users and developers to use to see how well (in a qualitative sense, at least) a particular neutral beam system fits a particular proposed need

  11. SLC beam line error analysis using a model-based expert system

    International Nuclear Information System (INIS)

    Lee, M.; Kleban, S.

    1988-02-01

    Commissioning particle beam line is usually a very time-consuming and labor-intensive task for accelerator physicists. To aid in commissioning, we developed a model-based expert system that identifies error-free regions, as well as localizing beam line errors. This paper will give examples of the use of our system for the SLC commissioning. 8 refs., 5 figs

  12. Compact high-efficiency vortex beam emitter based on a silicon photonics micro-ring

    DEFF Research Database (Denmark)

    Li, Shimao; Ding, Yunhong; Guan, Xiaowei

    2018-01-01

    Photonic integrated devices that emit vortex beam carrying orbital angular momentum are becoming key components for multiple applications. Here we propose and demonstrate a high-efficiency vortex beam emitter based on a silicon micro-ring resonator integrated with a metal mirror. Such a compact...

  13. Cost-effective parallel optical interconnection module based on fully passive-alignment process

    Science.gov (United States)

    Son, Dong Hoon; Heo, Young Soon; Park, Hyoung-Jun; Kang, Hyun Seo; Kim, Sung Chang

    2017-11-01

    In optical interconnection technology, high-speed and large data transitions with low error rate and cost reduction are key issues for the upcoming 8K media era. The researchers present notable types of optical manufacturing structures of a four-channel parallel optical module by fully passive alignment, which are able to reduce manufacturing time and cost. Each of the components, such as vertical-cavity surface laser/positive-intrinsic negative-photodiode array, microlens array, fiber array, and receiver (RX)/transmitter (TX) integrated circuit, is integrated successfully using flip-chip bonding, die bonding, and passive alignment with a microscope. Clear eye diagrams are obtained by 25.78-Gb/s (for TX) and 25.7-Gb/s (for RX) nonreturn-to-zero signals of pseudorandom binary sequence with a pattern length of 231 to 1. The measured responsivity and minimum sensitivity of the RX are about 0.5 A/W and ≤-6.5 dBm at a bit error rate (BER) of 10-12, respectively. The optical power margin at a BER of 10-12 is 7.5 dB, and cross talk by the adjacent channel is ≤1 dB.

  14. An empirical test of the treatment of indels during optimization alignment based on the phylogeny of the genus Secale (Poaceae)

    DEFF Research Database (Denmark)

    Petersen, Gitte; Seberg, Ole; Aagesen, Lone

    2004-01-01

    The ability of the program POY, implementing optimization alignment, to deal with major indels is explored and discussed in connection with a phylogenetic analysis of the genus Secale based on partial Adhl sequences. The Adhl sequences used span exon 2-4. Nearly all variation is found in intron 2...... recovers both genera as monophyletic when knowledge of the duplication is incorporated in the analysis. The phylogenetic relationships within Secale are not clearly resolved. Subspecific taxa of Secale strictum have identical sequences and they are confined to a monophyletic group. However, the two...

  15. Reconstruction of laser beam wavefronts based on mode analysis

    CSIR Research Space (South Africa)

    Schulze, C

    2013-07-01

    Full Text Available . Experimental setup for measuring the far field of differ- ently aberrated Gaussian beams. He–Ne, helium–neon laser; L 1–3 , lenses; M, mirror; SLM 1 , spatial light modulator; CCD, camera. Fig. 8. Theoretical and measured far fields FFth and FFm of a...

  16. CMS Muon Alignment: System Description and first results

    CERN Document Server

    Sobron, M

    2008-01-01

    The CMS detector has been instrumented with a precise and complex opto-mechanical alignment subsystem that provides a common reference frame between Tracker and Muon detection systems by means of a net of laser beams. The system allows a continuous and accurate monitoring of the muon chambers positions with respect to the Tracker body. Preliminary results of operation during the test of the CMS 4T solenoid magnet, performed in 2006, are presented. These measurements complement the information provided by the use of survey techniques and the results of alignment algorithms based on muon tracks crossing the detector.

  17. Propagation of rotational Risley-prism-array-based Gaussian beams in turbulent atmosphere

    Science.gov (United States)

    Chen, Feng; Ma, Haotong; Dong, Li; Ren, Ge; Qi, Bo; Tan, Yufeng

    2018-03-01

    Limited by the size and weight of prism and optical assembling, Rotational Risley-prism-array system is a simple but effective way to realize high power and superior beam quality of deflecting laser output. In this paper, the propagation of the rotational Risley-prism-array-based Gaussian beam array in atmospheric turbulence is studied in detail. An analytical expression for the average intensity distribution at the receiving plane is derived based on nonparaxial ray tracing method and extended Huygens-Fresnel principle. Power in the diffraction-limited bucket is chosen to evaluate beam quality. The effect of deviation angle, propagation distance and intensity of turbulence on beam quality is studied in detail by quantitative simulation. It reveals that with the propagation distance increasing, the intensity distribution gradually evolves from multiple-petal-like shape into the pattern that contains one main-lobe in the center with multiple side-lobes in weak turbulence. The beam quality of rotational Risley-prism-array-based Gaussian beam array with lower deviation angle is better than its counterpart with higher deviation angle when propagating in weak and medium turbulent (i.e. Cn2 beam quality of higher deviation angle arrays degrades faster as the intensity of turbulence gets stronger. In the case of propagating in strong turbulence, the long propagation distance (i.e. z > 10km ) and deviation angle have no influence on beam quality.

  18. Study of device mass production capability of the character projection based electron beam direct writing process technology toward 14 nm node and beyond

    Science.gov (United States)

    Kojima, Yoshinori; Takahashi, Yasushi; Takakuwa, Masaki; Ohshio, Shuzo; Sugatani, Shinji; Tujimura, Ryo; Takita, Hiroshi; Ogino, Kozo; Hoshino, Hiromi; Ito, Yoshio; Miyajima, Masaaki; Kon, Jun-ichi

    2012-03-01

    Techniques to appropriately control the key factors for a character projection (CP) based electron beam direct writing (EBDW) technology for mass production are shown and discussed. In order to achieve accurate CD control, the CP technique using the master CP is adopted. Another CP technique, the Packed CP, is used to obtain suitable shot count. For the alignment on the some critical layers which have the normally an even surface, the alignment methodology differ from photolithography is required. The process that etches the SiO2 material in the shallow trench isolation is added and then the alignment marks can be detected using electron beam even at the gate layer, which is normally on an even surface. The proximity effect correction using the simplified electron energy flux model and the hybrid exposure are used to obtain enough process margins. As a result, the sufficient CD accuracy, overlay accuracy, and yield are obtained on the 65 nm node device. The condition in our system is checked using self-diagnosis on a regular basis, and scheduled maintenances have been properly performed. Due to the proper system control, more than 10,000 production wafers have been successfully exposed so far without any major system downtime. It is shown that those techniques can be adapted to the 32 nm node production with slight modifications. For the 14 nm node and beyond, however, the drastic increment of the shot count becomes more of a concern. The Multi column cell (MCC) exposure method, the key concept of which is the parallelization of the electron beam columns with a CP, can overcome this concern. It is expected that by using the MCC exposure system, those techniques will be applicable to the rapid establishment for the 14 nm node technology.

  19. Flexible Semitransparent Energy Harvester with High Pressure Sensitivity and Power Density Based on Laterally Aligned PZT Single-Crystal Nanowires.

    Science.gov (United States)

    Zhao, Quan-Liang; He, Guang-Ping; Di, Jie-Jian; Song, Wei-Li; Hou, Zhi-Ling; Tan, Pei-Pei; Wang, Da-Wei; Cao, Mao-Sheng

    2017-07-26

    A flexible semitransparent energy harvester is assembled based on laterally aligned Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) single-crystal nanowires (NWs). Such a harvester presents the highest open-circuit voltage and a stable area power density of up to 10 V and 0.27 μW/cm 2 , respectively. A high pressure sensitivity of 0.14 V/kPa is obtained in the dynamic pressure sensing, much larger than the values reported in other energy harvesters based on piezoelectric single-crystal NWs. Furthermore, theoretical and finite element analyses also confirm that the piezoelectric voltage constant g 33 of PZT NWs is competitive to the lead-based bulk single crystals and ceramics, and the enhanced pressure sensitivity and power density are substantially linked to the flexible structure with laterally aligned PZT NWs. The energy harvester in this work holds great potential in flexible and transparent sensing and self-powered systems.

  20. Optimizing multiple sequence alignments using a genetic algorithm based on three objectives: structural information, non-gaps percentage and totally conserved columns.

    Science.gov (United States)

    Ortuño, Francisco M; Valenzuela, Olga; Rojas, Fernando; Pomares, Hector; Florido, Javier P; Urquiza, Jose M; Rojas, Ignacio

    2013-09-01

    Multiple sequence alignments (MSAs) are widely used approaches in bioinformatics to carry out other tasks such as structure predictions, biological function analyses or phylogenetic modeling. However, current tools usually provide partially optimal alignments, as each one is focused on specific biological features. Thus, the same set of sequences can produce different alignments, above all when sequences are less similar. Consequently, researchers and biologists do not agree about which is the most suitable way to evaluate MSAs. Recent evaluations tend to use more complex scores including further biological features. Among them, 3D structures are increasingly being used to evaluate alignments. Because structures are more conserved in proteins than sequences, scores with structural information are better suited to evaluate more distant relationships between sequences. The proposed multiobjective algorithm, based on the non-dominated sorting genetic algorithm, aims to jointly optimize three objectives: STRIKE score, non-gaps percentage and totally conserved columns. It was significantly assessed on the BAliBASE benchmark according to the Kruskal-Wallis test (P algorithm also outperforms other aligners, such as ClustalW, Multiple Sequence Alignment Genetic Algorithm (MSA-GA), PRRP, DIALIGN, Hidden Markov Model Training (HMMT), Pattern-Induced Multi-sequence Alignment (PIMA), MULTIALIGN, Sequence Alignment Genetic Algorithm (SAGA), PILEUP, Rubber Band Technique Genetic Algorithm (RBT-GA) and Vertical Decomposition Genetic Algorithm (VDGA), according to the Wilcoxon signed-rank test (P 0.05) with the advantage of being able to use less structures. Structural information is included within the objective function to evaluate more accurately the obtained alignments. The source code is available at http://www.ugr.es/~fortuno/MOSAStrE/MO-SAStrE.zip.

  1. Beta Beams: an accelerator based facility to explore Neutrino oscillation physics

    CERN Document Server

    Wildner, E; Hansen, C; De Melo Mendonca, T; Stora, T; Payet, J; Chance, A; Zorin, V; Izotov, I; Rasin, S; Sidorov, A; Skalyga, V; De Angelis, G; Prete, G; Cinausero, M; Kravchuk, VL; Gramegna, F; Marchi, T; Collazuol, G; De Rosa, G; Delbar, T; Loiselet, M; Keutgen, T; Mitrofanov, S; Lamy, T; Latrasse, L; Marie-Jeanne, M; Sortais, P; Thuillier, T; Debray, F; Trophime, C; Hass, M; Hirsh, T; Berkovits, D; Stahl, A

    2011-01-01

    The discovery that the neutrino changes flavor as it travels through space has implications for the Standard Model of particle physics (SM)[1]. To know the contribution of neutrinos to the SM, needs precise measurements of the parameters governing the neutrino oscillations. This will require a high intensity beam-based neutrino oscillation facility. The EURONu Design Study will review three currently accepted methods of realizing this facility (the so-called Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make a decision on the layout and construction of the future European neutrino oscillation facility. ”Beta Beams” produce collimated pure electron neutrino and antineutrino beams by accelerating beta active ions to high energies and letting them decay in a race-track shaped storage ring. EURONu Beta Beams are based on CERNs infrastructure and the fact that some of the already ...

  2. Aligning molecules with intense nonresonant laser fields

    DEFF Research Database (Denmark)

    Larsen, J.J.; Safvan, C.P.; Sakai, H.

    1999-01-01

    Molecules in a seeded supersonic beam are aligned by the interaction between an intense nonresonant linearly polarized laser field and the molecular polarizability. We demonstrate the general applicability of the scheme by aligning I2, ICl, CS2, CH3I, and C6H5I molecules. The alignment is probed...... by mass selective two dimensional imaging of the photofragment ions produced by femtosecond laser pulses. Calculations on the degree of alignment of I2 are in good agreement with the experiments. We discuss some future applications of laser aligned molecules....

  3. Modified alignment CGHs for aspheric surface test

    Science.gov (United States)

    Song, Jae-Bong; Yang, Ho-Soon; Rhee, Hyug-Gyo; Lee, Yun-Woo

    2009-08-01

    Computer Generated Holograms (CGH) for optical test are commonly consisted of one main pattern for testing aspheric surface and some alignment patterns for aligning the interferometer, CGH, and the test optics. To align the CGH plate and the test optics, we designed the alignment CGHs modified from the cat's eye alignment method, which are consisted of a couple of CGH patterns. The incident beam passed through the one part of the alignment CGH pattern is focused onto the one radius position of the test aspheric surface, and is reflected to the other part, and vice versa. This method has several merits compared to the conventional cat's eye alignment method. First, this method can be used in testing optics with a center hole, and the center part of CGH plate can be assigned to the alignment pattern. Second, the alignment pattern becomes a concentric circular arc pattern. The whole CGH patterns including the main pattern and alignment patterns are consisted of only concentric circular fringes. This concentric circular pattern can be easily made by the polar coordinated writer with circular scanning. The required diffraction angle becomes relatively small, so the 1st order diffraction beams instead of the 3rd order diffraction beam can be used as alignment beams, and the visibility can be improved. This alignment method also is more sensitive to the tilt and the lateral shift of the test aspheric surface. Using this alignment pattern, a 200 mm diameter F/0.5 aspheric mirror and a 600 mm diameter F/0.9 mirror were tested.

  4. Highly Stretchable Supercapacitors Based on Aligned Carbon Nanotube/Molybdenum Disulfide Composites.

    Science.gov (United States)

    Lv, Tian; Yao, Yao; Li, Ning; Chen, Tao

    2016-08-01

    Stretchable supercapacitors that can sustain their performance under unpredictable tensile force are important elements for practical applications of various portable and wearable electronics. However, the stretchability of most reported supercapacitors was often lower than 100 % because of the limitation of the electrodes used. Herein we developed all-solid-state supercapacitors with a stretchability as high as 240 % by using aligned carbon nanotube composites with compact structure as electrodes. By combined with pseudocapacitive molybdenum disulfide nanosheets, the newly developed supercapacitor showed a specific capacitance of 13.16 F cm(-3) , and also showed excellent cycling retention (98 %) after 10 000 charge-discharge cycles. This work also presents a general and effective approach in developing high-performance electrodes for flexible and stretchable electronics. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Tree Alignment Based on Needleman-Wunsch Algorithm for Sensor Selection in Smart Homes.

    Science.gov (United States)

    Chua, Sook-Ling; Foo, Lee Kien

    2017-08-18

    Activity recognition in smart homes aims to infer the particular activities of the inhabitant, the aim being to monitor their activities and identify any abnormalities, especially for those living alone. In order for a smart home to support its inhabitant, the recognition system needs to learn from observations acquired through sensors. One question that often arises is which sensors are useful and how many sensors are required to accurately recognise the inhabitant's activities? Many wrapper methods have been proposed and remain one of the popular evaluators for sensor selection due to its superior accuracy performance. However, they are prohibitively slow during the evaluation process and may run into the risk of overfitting due to the extent of the search. Motivated by this characteristic, this paper attempts to reduce the cost of the evaluation process and overfitting through tree alignment. The performance of our method is evaluated on two public datasets obtained in two distinct smart home environments.

  6. Alignment and integration of complex networks by hypergraph-based spectral clustering

    Science.gov (United States)

    Michoel, Tom; Nachtergaele, Bruno

    2012-11-01

    Complex networks possess a rich, multiscale structure reflecting the dynamical and functional organization of the systems they model. Often there is a need to analyze multiple networks simultaneously, to model a system by more than one type of interaction, or to go beyond simple pairwise interactions, but currently there is a lack of theoretical and computational methods to address these problems. Here we introduce a framework for clustering and community detection in such systems using hypergraph representations. Our main result is a generalization of the Perron-Frobenius theorem from which we derive spectral clustering algorithms for directed and undirected hypergraphs. We illustrate our approach with applications for local and global alignment of protein-protein interaction networks between multiple species, for tripartite community detection in folksonomies, and for detecting clusters of overlapping regulatory pathways in directed networks.

  7. In-plane aligned YBCO tape on textured YSZ buffer layer deposited on stainless steel substrate by laser ablation only with O{sup +} ion beam assistance

    Energy Technology Data Exchange (ETDEWEB)

    Huang Xintang [Huazhong Univ. of Sci. and Technol., Wuhan (China). Nat. Lab. of Laser Technol.]|[Huazhong Normal Univ., Wuhan, HB (China). Dept. of Physics; Wang Youqing; Wang Qiuliang; Chen Qingming [Huazhong Univ. of Sci. and Technol., Wuhan (China). Nat. Lab. of Laser Technol.

    1999-08-16

    In this paper we have prepared YSZ buffer layers on stainless steel substrates by laser ablation only with O{sup +} ion beam assistance and YBCO films on YSZ/steel consequently. The relevant parameters of YSZ and YBCO film deposition are indicated. (orig.) 8 refs.

  8. In-plane aligned YBCO tape on textured YSZ buffer layer deposited on stainless steel substrate by laser ablation only with O+ ion beam assistance

    International Nuclear Information System (INIS)

    Huang Xintang; Huazhong Normal Univ., Wuhan, HB; Wang Youqing; Wang Qiuliang; Chen Qingming

    1999-01-01

    In this paper we have prepared YSZ buffer layers on stainless steel substrates by laser ablation only with O + ion beam assistance and YBCO films on YSZ/steel consequently. The relevant parameters of YSZ and YBCO film deposition are indicated. (orig.)

  9. Incoherent beam combining based on the momentum SPGD algorithm

    Science.gov (United States)

    Yang, Guoqing; Liu, Lisheng; Jiang, Zhenhua; Guo, Jin; Wang, Tingfeng

    2018-05-01

    Incoherent beam combining (ICBC) technology is one of the most promising ways to achieve high-energy, near-diffraction laser output. In this paper, the momentum method is proposed as a modification of the stochastic parallel gradient descent (SPGD) algorithm. The momentum method can improve the speed of convergence of the combining system efficiently. The analytical method is employed to interpret the principle of the momentum method. Furthermore, the proposed algorithm is testified through simulations as well as experiments. The results of the simulations and the experiments show that the proposed algorithm not only accelerates the speed of the iteration, but also keeps the stability of the combining process. Therefore the feasibility of the proposed algorithm in the beam combining system is testified.

  10. Pelletron-based MeV-range electron beam recirculation

    CERN Document Server

    Crawford, A C; Sharapa, A N; Shemyakin, A

    1999-01-01

    In this paper we describe the successful recirculation of a DC electron beam at energies 1-1.5 MeV and currents up to 0.7 A with typical relative losses of 5-20x10 sup - sup 6. Currents of 200 mA were maintained for periods of up to five hours without a single breakdown. We found that the aperture-limiting diaphragm in the gun anode significantly increased the stability of the recirculation. We also found that the stability depended strongly on vacuum pressure in the beamline. The performance of the collector with transverse magnetic fields was found to be adequate for beam currents up to 0.6 A, which is in agreement with our low-energy bench test results. (author)

  11. A fully automated and scalable timing probe-based method for time alignment of the LabPET II scanners

    Science.gov (United States)

    Samson, Arnaud; Thibaudeau, Christian; Bouchard, Jonathan; Gaudin, Émilie; Paulin, Caroline; Lecomte, Roger; Fontaine, Réjean

    2018-05-01

    A fully automated time alignment method based on a positron timing probe was developed to correct the channel-to-channel coincidence time dispersion of the LabPET II avalanche photodiode-based positron emission tomography (PET) scanners. The timing probe was designed to directly detect positrons and generate an absolute time reference. The probe-to-channel coincidences are recorded and processed using firmware embedded in the scanner hardware to compute the time differences between detector channels. The time corrections are then applied in real-time to each event in every channel during PET data acquisition to align all coincidence time spectra, thus enhancing the scanner time resolution. When applied to the mouse version of the LabPET II scanner, the calibration of 6 144 channels was performed in less than 15 min and showed a 47% improvement on the overall time resolution of the scanner, decreasing from 7 ns to 3.7 ns full width at half maximum (FWHM).

  12. On-line image guidance for frameless stereotactic radiotherapy of lung malignancies by cone beam CT: Comparison between target localization and alignment on bony anatomy

    International Nuclear Information System (INIS)

    Masi, Laura; Casamassima, Franco; Menichelli, Claudia; Pasciuti, Katia; Doro, Raffaela; Polli, Caterina; D'imporzano, Elena; Bonucci, Ivano

    2008-01-01

    Introduction. Free-breathing stereotactic radiotherapy for lung malignancies requires reliable prediction of respiratory motion and accurate target localization. A protocol was adopted for reproducibility and reduction of respiratory motion and for target localization by CBCT image guidance. Tumor respiratory displacements and tumor positioning errors relative to bony anatomy alignment are analyzed. Materials and method. Image guided SRT was performed for 99 lung malignancies. Two groups of patients were considered: group A did not perform any breathing control; group B controlled visually their respiratory cycle and volumes on an Active Breathing Coordinator (ABC) monitor during the acquisition of simulation CT and CBCT, and treatment delivery. GTV on end inhale and exhale CT data sets were fused in an ITV and the extent of tumor motion evaluated between these 2 phases. A pre-treatment CBCT was acquired and aligned to the reference CT using bony anatomy; for tumor positioning the ITV contour on the reference CT was matched to the visible tumor on CBCT. Interobserver variability of tumor positioning was evaluated. ITV and CBCT tumor dimensions were compared. Results. 3D tumor breathing displacement (mean±SD) was significantly higher for group A (14.7±9.9 mm) than for group B (4.7±3.1 mm). The detected differences between tumor and bony structure alignment below 3 mm were 68% for group B and 45% for group A, reaching statistical significance. Interobserver variability was 1.7±1.1 mm (mean±SD). Dimensions of tumor image on CBCT were consistent with ITV dimensions for group B (max difference 14%). Conclusions. The adopted protocol seems effective in reducing respiratory internal movements and margin. Tumor positioning errors relative to bony anatomy are also reduced. However bony anatomy as a surrogate of the target may still lead to some relevant positioning errors. Target visualization on CBCT is essential for an accurate localization in lung SRT

  13. Pairwise Sequence Alignment Library

    Energy Technology Data Exchange (ETDEWEB)

    2015-05-20

    Vector extensions, such as SSE, have been part of the x86 CPU since the 1990s, with applications in graphics, signal processing, and scientific applications. Although many algorithms and applications can naturally benefit from automatic vectorization techniques, there are still many that are difficult to vectorize due to their dependence on irregular data structures, dense branch operations, or data dependencies. Sequence alignment, one of the most widely used operations in bioinformatics workflows, has a computational footprint that features complex data dependencies. The trend of widening vector registers adversely affects the state-of-the-art sequence alignment algorithm based on striped data layouts. Therefore, a novel SIMD implementation of a parallel scan-based sequence alignment algorithm that can better exploit wider SIMD units was implemented as part of the Parallel Sequence Alignment Library (parasail). Parasail features: Reference implementations of all known vectorized sequence alignment approaches. Implementations of Smith Waterman (SW), semi-global (SG), and Needleman Wunsch (NW) sequence alignment algorithms. Implementations across all modern CPU instruction sets including AVX2 and KNC. Language interfaces for C/C++ and Python.

  14. Beam shaping assembly optimization for (7)Li(p,n)(7)Be accelerator based BNCT.

    Science.gov (United States)

    Minsky, D M; Kreiner, A J

    2014-06-01

    Within the framework of accelerator-based BNCT, a project to develop a folded Tandem-ElectroStatic-Quadrupole accelerator is under way at the Atomic Energy Commission of Argentina. The proposed accelerator is conceived to deliver a proton beam of 30mA at about 2.5MeV. In this work we explore a Beam Shaping Assembly (BSA) design based on the (7)Li(p,n)(7)Be neutron production reaction to obtain neutron beams to treat deep seated tumors. © 2013 Elsevier Ltd. All rights reserved.

  15. Automatic beam centering at the SSC interaction regions

    International Nuclear Information System (INIS)

    Joestlein, H.

    1984-01-01

    In the SSC interaction regions, the two colliding beams, each only a few microns in size, will have to be centered and maintained in good alignment over many hours, in order to provide the maximum possible luminosity and to minimize off-center beam-beam focussing effects. It is unlikely that sufficiently good alignment can be achieved without some kind of active feedback system, based on the beam-beam interaction rate. This memo describes such a system. In the proposed scheme, one of the beams is moved continuously and in a circular fashion about its mean transverse position. The radius of this motion is approximately 0.01 of the rms beam size at the interaction point. The motion is achieved with two sets of crossed high frequency dipole magnets, one on each side of the interaction region, suitably phased. As a consequence of this motion, the beam-beam interaction rate is modulated in synchronism with the beam motion when the beams are not centered on one another. The amplitude and phase of this modulation yields information on the magnitude and direction of the misalignment between the beams, allowing continuous display and automatic correction of any misalignment

  16. A Low-cost Beam Profiler Based On Cerium-doped Silica Fibers

    Science.gov (United States)

    Potkins, David Edward; Braccini, Saverio; Nesteruk, Konrad Pawel; Carzaniga, Tommaso Stefano; Vedda, Anna; Chiodini, Norberto; Timmermans, Jacob; Melanson, Stephane; Dehnel, Morgan Patrick

    A beam profiler called the Universal Beam Monitor (UniBEaM) has been developed by D-Pace Inc. (Canada) and the Albert Einstein Center for Fundamental Physics, Laboratory for High Energy Physics, University of Bern (Switzerland). The device is based on passing 100 to 600 micron cerium-doped optical fibers through a particle beam. Visible scintillation light from the sensor fibers is transmitted over distances of tens of meters to the light sensors with minimal signal loss and no susceptibility to electromagnetic fields. The probe has an insertion length of only 70 mm. The software plots the beam intensity distribution in the horizontal and vertical planes, and calculates the beam location and integrated profile area, which correlates well with total beam current. UniBEaM has a large dynamic range, operating with beam currents of ∼pA to mA, and a large range of particle kinetic energies of ∼keV to GeV, depending on the absorbed power density. Test data are presented for H- beams at 25keV for 500 μA, and H+ beams at 18MeV for 50pA to 10 μA. Maximum absorbed power density of the optical fiber before thermal damage is discussed in relation to dE/dx energy deposition as a function of particle type and kinetic energy. UniBEaM is well suited for a wide variety of beamlines including discovery science applications, radio-pharmaceutical production, hadron therapy, industrial ion beam applications including ion implantation, industrial electron beams, and ion source testing.

  17. Development of an Efficient Steel Beam Section for Modular Construction Based on Six-Sigma

    Directory of Open Access Journals (Sweden)

    Tae-Hyu Ha

    2016-01-01

    Full Text Available This study presents a systematic approach for the development of an efficient steel beam section for modular construction based on Six-Sigma. Although the Six-Sigma is frequently implemented in manufacturing and other service industries, it is a relatively new concept in the area of building design and construction. As a first step in this approach, market studies and surveys are conducted to obtain the opinions of potential customers. Then the opinions of customers are converted into quality characteristics for the steel beam using the quality function deployment methodology. A steel hollow flanged channel is chosen as the main modular beam shape, and the design concept is derived and developed by applying the Pugh matrix methodology. A pilot test was performed to validate the effectiveness of the developed beam section. The results indicated that the developed channel beam section showed excellent performance and retained high accuracy in fabrication, thus resulting in a significant reduction of steel consumption.

  18. Vibration based algorithm for crack detection in cantilever beam containing two different types of cracks

    Science.gov (United States)

    Behzad, Mehdi; Ghadami, Amin; Maghsoodi, Ameneh; Michael Hale, Jack

    2013-11-01

    In this paper, a simple method for detection of multiple edge cracks in Euler-Bernoulli beams having two different types of cracks is presented based on energy equations. Each crack is modeled as a massless rotational spring using Linear Elastic Fracture Mechanics (LEFM) theory, and a relationship among natural frequencies, crack locations and stiffness of equivalent springs is demonstrated. In the procedure, for detection of m cracks in a beam, 3m equations and natural frequencies of healthy and cracked beam in two different directions are needed as input to the algorithm. The main accomplishment of the presented algorithm is the capability to detect the location, severity and type of each crack in a multi-cracked beam. Concise and simple calculations along with accuracy are other advantages of this method. A number of numerical examples for cantilever beams including one and two cracks are presented to validate the method.

  19. Fiducialisation and initial alignment of CLIC component with micrometric accuracy

    CERN Document Server

    Mainaud Durand, Helene; Buzio, Marco; Caiazza, Domenico; Catalan Lasheras, Nuria; Cherif, Ahmed; Doytchinov, Iordan Petrov; Fuchs, Jean-Frederic; Gaddi, Andrea; Galindo Munoz, Natalia; Gayde, Jean-Christophe; Kamugasa, Solomon William; Modena, Michele; Novotny, Peter; Sanz, Claude; Severino, Giordana; Russenschuck, Stephan; Tshilumba, David; Vlachakis, Vasileios; Wendt, Manfred; Zorzetti, Silvia; CERN. Geneva. ATS Department

    2016-01-01

    We propose a new solution to fiducialise the three major components of the CLIC collider: quadrupoles, beam-position monitors (BPM), and accelerating structures (AS). This solution is based on the use of a copper-beryllium (CuBe) wire to locate the reference position, i.e. the symmetry axes of the components (their magnetic, respectively electromagnetic centre axis), and to determine their position in the common support assembly defining a local coordinate system, with respect to the fiducials. These alignment targets will be used later to align the support assembly in the tunnel. With such a method, several accelerator components of different types, supported by a dedicated adjustment system, can be simultaneously fiducialised and pre-aligned using the same wire, enabling a micrometric accuracy with help of a 3D coordinate measurement machine (CMM). Alternative solutions based on frequency scanning interferometry (FSI) and micro-triangulation are also under development, to perform such fiducialisation and in...

  20. Microcomb-Based True-Time-Delay Network for Microwave Beamforming With Arbitrary Beam Pattern Control

    Science.gov (United States)

    Xue, Xiaoxiao; Xuan, Yi; Bao, Chengying; Li, Shangyuan; Zheng, Xiaoping; Zhou, Bingkun; Qi, Minghao; Weiner, Andrew M.

    2018-06-01

    Microwave phased array antennas (PAAs) are very attractive to defense applications and high-speed wireless communications for their abilities of fast beam scanning and complex beam pattern control. However, traditional PAAs based on phase shifters suffer from the beam-squint problem and have limited bandwidths. True-time-delay (TTD) beamforming based on low-loss photonic delay lines can solve this problem. But it is still quite challenging to build large-scale photonic TTD beamformers due to their high hardware complexity. In this paper, we demonstrate a photonic TTD beamforming network based on a miniature microresonator frequency comb (microcomb) source and dispersive time delay. A method incorporating optical phase modulation and programmable spectral shaping is proposed for positive and negative apodization weighting to achieve arbitrary microwave beam pattern control. The experimentally demonstrated TTD beamforming network can support a PAA with 21 elements. The microwave frequency range is $\\mathbf{8\\sim20\\ {GHz}}$, and the beam scanning range is $\\mathbf{\\pm 60.2^\\circ}$. Detailed measurements of the microwave amplitudes and phases are performed. The beamforming performances of Gaussian, rectangular beams and beam notch steering are evaluated through simulations by assuming a uniform radiating antenna array. The scheme can potentially support larger PAAs with hundreds of elements by increasing the number of comb lines with broadband microcomb generation.

  1. Learning about and from others' prudence, impatience or laziness: The computational bases of attitude alignment.

    Directory of Open Access Journals (Sweden)

    Marie Devaine

    2017-03-01

    Full Text Available Peoples' subjective attitude towards costs such as, e.g., risk, delay or effort are key determinants of inter-individual differences in goal-directed behaviour. Thus, the ability to learn about others' prudent, impatient or lazy attitudes is likely to be critical for social interactions. Conversely, how adaptive such attitudes are in a given environment is highly uncertain. Thus, the brain may be tuned to garner information about how such costs ought to be arbitrated. In particular, observing others' attitude may change one's uncertain belief about how to best behave in related difficult decision contexts. In turn, learning from others' attitudes is determined by one's ability to learn about others' attitudes. We first derive, from basic optimality principles, the computational properties of such a learning mechanism. In particular, we predict two apparent cognitive biases that would arise when individuals are learning about others' attitudes: (i people should overestimate the degree to which they resemble others (false-consensus bias, and (ii they should align their own attitudes with others' (social influence bias. We show how these two biases non-trivially interact with each other. We then validate these predictions experimentally by profiling people's attitudes both before and after guessing a series of cost-benefit arbitrages performed by calibrated artificial agents (which are impersonating human individuals.

  2. Mathis software for controlling BCAM-based monitoring and alignment systems

    CERN Document Server

    Klumb, Francis; Kautzmann, Guillaume; CERN. Geneva. ATS Department

    2016-01-01

    The MATHIS Software (Monitoring and Alignment Tracking for HIE-Isolde Software) aims at providing 3D positions of physical components of the HIE-Isolde superconducting modules, accurately and permanently measured by well-designed networks of BCAM devices (Brandeis Camera Angle Monitoring). Although it is originally intended for the HIE-Isolde project, its architecture and its use cases have been extended and optimized for more general setups. Most of the configuration data are stored either within XML-formatted files or within databases. The adaptation of MATHIS for different BCAM monitoring systems therefore does not require any further code rewriting. Moreover, the software is fully cross-platform and can either be run on the specific Linux machines driving the accelerator electronic devices, or be used on independent Windows workstations as a stand-alone software. In the first case, the software mainly relies on FESA (Front End Software Architecture) which is an object-oriented real-time framework that ens...

  3. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    S. Szillasi

    2013-01-01

    The CMS detector has been gradually opened and whenever a wheel became exposed the first operation was the removal of the MABs, the sensor structures of the Hardware Barrel Alignment System. By the last days of June all 36 MABs have arrived at the Alignment Lab at the ISR where, as part of the Alignment Upgrade Project, they are refurbished with new Survey target holders. Their electronic checkout is on the way and finally they will be recalibrated. During LS1 the alignment system will be upgraded in order to allow more precise reconstruction of the MB4 chambers in Sector 10 and Sector 4. This requires new sensor components, so called MiniMABs (pictured below), that have already been assembled and calibrated. Image 6: Calibrated MiniMABs are ready for installation For the track-based alignment, the systematic uncertainties of the algorithm are under scrutiny: this study will enable the production of an improved Monte Carlo misalignment scenario and to update alignment position errors eventually, crucial...

  4. MUON DETECTORS: ALIGNMENT

    CERN Multimedia

    G. Gomez

    2012-01-01

      A new muon alignment has been produced for 2012 A+B data reconstruction. It uses the latest Tracker alignment and single-muon data samples to align both DTs and CSCs. Physics validation has been performed and shows a modest improvement in stand-alone muon momentum resolution in the barrel, where the alignment is essentially unchanged from the previous version. The reference-target track-based algorithm using only collision muons is employed for the first time to align the CSCs, and a substantial improvement in resolution is observed in the endcap and overlap regions for stand-alone muons. This new alignment is undergoing the approval process and is expected to be deployed as part of a new global tag in the beginning of December. The pT dependence of the φ-bias in curvature observed in Monte Carlo was traced to a relative vertical misalignment between the Tracker and barrel muon systems. Moving the barrel as a whole to match the Tracker cures this pT dependence, leaving only the &phi...

  5. Simulation-based Investigations of Electrostatic Beam Energy Analysers

    CERN Document Server

    Pahl, Hannes

    2015-01-01

    An energy analyser is needed to measure the beam energy profile behind the REX-EBIS at ISOLDE. The device should be able to operate with an accuracy of 1 V at voltages up to 30 kV. In order to find a working concept for an electrostatic energy analyser different designs were evaluated with simulations. A spherical device and its design issues are presented. The potential deformation effects of grids at high voltages and their influence on the energy resolution were investigated. First tests were made with a grid-free ring electrode device and show promising results.

  6. Spike Pattern Recognition for Automatic Collimation Alignment

    CERN Document Server

    Azzopardi, Gabriella; Salvachua Ferrando, Belen Maria; Mereghetti, Alessio; Redaelli, Stefano; CERN. Geneva. ATS Department

    2017-01-01

    The LHC makes use of a collimation system to protect its sensitive equipment by intercepting potentially dangerous beam halo particles. The appropriate collimator settings to protect the machine against beam losses relies on a very precise alignment of all the collimators with respect to the beam. The beam center at each collimator is then found by touching the beam halo using an alignment procedure. Until now, in order to determine whether a collimator is aligned with the beam or not, a user is required to follow the collimator’s BLM loss data and detect spikes. A machine learning (ML) model was trained in order to automatically recognize spikes when a collimator is aligned. The model was loosely integrated with the alignment implementation to determine the classification performance and reliability, without effecting the alignment process itself. The model was tested on a number of collimators during this MD and the machine learning was able to output the classifications in real-time.

  7. Deformable image registration for cone-beam CT guided transoral robotic base-of-tongue surgery

    International Nuclear Information System (INIS)

    Reaungamornrat, S; Liu, W P; Otake, Y; Uneri, A; Siewerdsen, J H; Taylor, R H; Wang, A S; Nithiananthan, S; Schafer, S; Tryggestad, E; Richmon, J; Sorger, J M

    2013-01-01

    Transoral robotic surgery (TORS) offers a minimally invasive approach to resection of base-of-tongue tumors. However, precise localization of the surgical target and adjacent critical structures can be challenged by the highly deformed intraoperative setup. We propose a deformable registration method using intraoperative cone-beam computed tomography (CBCT) to accurately align preoperative CT or MR images with the intraoperative scene. The registration method combines a Gaussian mixture (GM) model followed by a variation of the Demons algorithm. First, following segmentation of the volume of interest (i.e. volume of the tongue extending to the hyoid), a GM model is applied to surface point clouds for rigid initialization (GM rigid) followed by nonrigid deformation (GM nonrigid). Second, the registration is refined using the Demons algorithm applied to distance map transforms of the (GM-registered) preoperative image and intraoperative CBCT. Performance was evaluated in repeat cadaver studies (25 image pairs) in terms of target registration error (TRE), entropy correlation coefficient (ECC) and normalized pointwise mutual information (NPMI). Retraction of the tongue in the TORS operative setup induced gross deformation >30 mm. The mean TRE following the GM rigid, GM nonrigid and Demons steps was 4.6, 2.1 and 1.7 mm, respectively. The respective ECC was 0.57, 0.70 and 0.73, and NPMI was 0.46, 0.57 and 0.60. Registration accuracy was best across the superior aspect of the tongue and in proximity to the hyoid (by virtue of GM registration of surface points on these structures). The Demons step refined registration primarily in deeper portions of the tongue further from the surface and hyoid bone. Since the method does not use image intensities directly, it is suitable to multi-modality registration of preoperative CT or MR with intraoperative CBCT. Extending the 3D image registration to the fusion of image and planning data in stereo-endoscopic video is anticipated to

  8. Reference Beam Pattern Design for Frequency Invariant Beamforming Based on Fast Fourier Transform

    Directory of Open Access Journals (Sweden)

    Wang Zhang

    2016-09-01

    Full Text Available In the field of fast Fourier transform (FFT-based frequency invariant beamforming (FIB, there is still an unsolved problem. That is the selection of the reference beam to make the designed wideband pattern frequency invariant (FI over a given frequency range. This problem is studied in this paper. The research shows that for a given array, the selection of the reference beam pattern is determined by the number of sensors and the ratio of the highest frequency to the lowest frequency of the signal (RHL. The length of the weight vector corresponding to a given reference beam pattern depends on the reference frequency. In addition, the upper bound of the weight length to ensure the FI property over the whole frequency band of interest is also given. When the constraints are added to the reference beam, it does not affect the FI property of the designed wideband beam as long as the symmetry of the reference beam is ensured. Based on this conclusion, a scheme for reference beam design is proposed.

  9. Scanning laser beam displays based on a 2D MEMS

    Science.gov (United States)

    Niesten, Maarten; Masood, Taha; Miller, Josh; Tauscher, Jason

    2010-05-01

    The combination of laser light sources and MEMS technology enables a range of display systems such as ultra small projectors for mobile devices, head-up displays for vehicles, wearable near-eye displays and projection systems for 3D imaging. Images are created by scanning red, green and blue lasers horizontally and vertically with a single two-dimensional MEMS. Due to the excellent beam quality of laser beams, the optical designs are efficient and compact. In addition, the laser illumination enables saturated display colors that are desirable for augmented reality applications where a virtual image is used. With this technology, the smallest projector engine for high volume manufacturing to date has been developed. This projector module has a height of 7 mm and a volume of 5 cc. The resolution of this projector is WVGA. No additional projection optics is required, resulting in an infinite focus depth. Unlike with micro-display projection displays, an increase in resolution will not lead to an increase in size or a decrease in efficiency. Therefore future projectors can be developed that combine a higher resolution in an even smaller and thinner form factor with increased efficiencies that will lead to lower power consumption.

  10. Alignment Methods Developed for the Validation of the Thermal and Mechanical Behaviour of the Two Beam Test Modules for the CLIC Project

    CERN Document Server

    Mainaud Durand, Helene; Sosin, Mateusz; Rude, Vivien

    2014-01-01

    CLIC project will consist of more than 20 000 two meters long modules. A test setup made of three modules is being built at CERN to validate the assembly and integration of all components and technical systems and to validate the short range strategy of pre-alignment. The test setup has been installed in a room equipped with a sophisticated system of ventilation able to reproduce the environmental conditions of the CLIC tunnel. Some of the components have been equipped with electrical heaters to simulate the power dissipation, combined with a water cooling system integrated in the RF components. Using these installations, to have a better understanding of the thermal and mechanical behaviour of a module under different operation modes, machine cycles have been simulated; the misalignment of the components and their supports has been observed. This paper describes the measurements methods developed for such a project and the results obtained.

  11. Alignment of the drift tube detector at the neutrino oscillation experiment OPERA; Alignment des Driftroehrendetektors am Neutrino-Oszillationsexperiment OPERA

    Energy Technology Data Exchange (ETDEWEB)

    Goellnitz, Christoph

    2012-09-15

    The present thesis was composed during the course of the OPERA experiment, which aims to give a direct evidence for neutrino oscillations in the channel {nu}{sub {mu}} {yields} {nu}{sub {tau}}. The OPERA detector is designed to observe the appearance of tau neutrinos in an originally pure muon neutrino beam, the CNGS beam. As important part of the detector the precision tracker (PT), a drift tube detector, consists of 9504 drift tubes in 198 modules. In this thesis, several parts of the slow control of the PT are developed and implemented to ensure operation during data taking over several years. The main part is the geometric calibration, the alignment of the detector. The alignment procedure contains both hardware and software parts, the software methods are developed and applied. Using straight particle tracks, the detector components are geometrically corrected. A special challenge for the alignment for the PT is the fact that at this kind of low-rate experiment only a small number of particle tracks is available. With software-based corrections of the module rotation, a systematic error of 0.2 mrad has been attained, for corrections of translation, a systematic error of 32 {mu}m is reached. For the alignment between two adjacent PT walls, the statistical error is less than 8 {mu}m. All results of the position monitoring system are considered. All developed methods are tested with Monte Carlo simulations. The detector requirements ({Delta}p/p {<=} 0.25 below 25 GeV) are met. The analysis of the momentum measurement for high energies above 25 GeV demonstrates the resulting improvement. The mean momentum is falling significantly using the new alignment values. The significance of the detector alignment becomes most evident in the analysis of cosmic particles. The muon charge ratio R{sub {mu}} is expected not to be angular dependent. The {chi}{sup 2} probability of the measured distribution improves up to 58%. The muon charge ratio was also investigated in

  12. Pareto optimal pairwise sequence alignment.

    Science.gov (United States)

    DeRonne, Kevin W; Karypis, George

    2013-01-01

    Sequence alignment using evolutionary profiles is a commonly employed tool when investigating a protein. Many profile-profile scoring functions have been developed for use in such alignments, but there has not yet been a comprehensive study of Pareto optimal pairwise alignments for combining multiple such functions. We show that the problem of generating Pareto optimal pairwise alignments has an optimal substructure property, and develop an efficient algorithm for generating Pareto optimal frontiers of pairwise alignments. All possible sets of two, three, and four profile scoring functions are used from a pool of 11 functions and applied to 588 pairs of proteins in the ce_ref data set. The performance of the best objective combinations on ce_ref is also evaluated on an independent set of 913 protein pairs extracted from the BAliBASE RV11 data set. Our dynamic-programming-based heuristic approach produces approximated Pareto optimal frontiers of pairwise alignments that contain comparable alignments to those on the exact frontier, but on average in less than 1/58th the time in the case of four objectives. Our results show that the Pareto frontiers contain alignments whose quality is better than the alignments obtained by single objectives. However, the task of identifying a single high-quality alignment among those in the Pareto frontier remains challenging.

  13. Modulation Transfer Function of a Gaussian Beam Based on the Generalized Modified Atmospheric Spectrum

    Directory of Open Access Journals (Sweden)

    Chao Gao

    2016-01-01

    Full Text Available This paper investigates the modulation transfer function of a Gaussian beam pr