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Sample records for accuracy wire scanner

  1. Fast and High Accuracy Wire Scanner

    Koujili, M; Koopman, J; Ramos, D; Sapinski, M; De Freitas, J; Ait Amira, Y; Djerdir, A

    2009-01-01

    Scanning of a high intensity particle beam imposes challenging requirements on a Wire Scanner system. It is expected to reach a scanning speed of 20 m.s-1 with a position accuracy of the order of 1 μm. In addition a timing accuracy better than 1 millisecond is needed. The adopted solution consists of a fork holding a wire rotating by a maximum of 200°. Fork, rotor and angular position sensor are mounted on the same axis and located in a chamber connected to the beam vacuum. The requirements imply the design of a system with extremely low vibration, vacuum compatibility, radiation and temperature tolerance. The adopted solution consists of a rotary brushless synchronous motor with the permanent magnet rotor installed inside of the vacuum chamber and the stator installed outside. The accurate position sensor will be mounted on the rotary shaft inside of the vacuum chamber, has to resist a bake-out temperature of 200°C and ionizing radiation up to a dozen of kGy/year. A digital feedback controller allows maxi...

  2. Twisting wire scanner

    Gharibyan, V.; Delfs, A.; Koruptchenkov, I.; Noelle, D.; Tiessen, H.; Werner, M.; Wittenburg, K.

    2012-11-15

    A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors is presented.

  3. Twisting wire scanner

    A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors is presented.

  4. Improvements to Existing Jefferson Lab Wire Scanners

    McCaughan, Michael D. [JLAB; Tiefenback, Michael G. [JLAB; Turner, Dennis L. [JLAB

    2013-06-01

    This poster will detail the augmentation of selected existing CEBAF wire scanners with commercially available hardware, PMTs, and self created software in order to improve the scanners both in function and utility.

  5. Minimisation of the wire position uncertainties of the new CERN vacuum wire scanner

    AUTHOR|(CDS)2069346; Barjau Condomines, A

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new fast wire scanner is foreseen to measure small emittance beams throughout the LHC injector chain, which demands a wire travelling speed up to 20 ms-1 and position measurement accuracy of the order of a few microns. The vibrations of the mechanical parts of the system, and particularly the vibrations of the thin carbon wire, were identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations is a high priority for the design and operation of the new device. This document presents the work performed to understand the main causes of the wire vibrations observed in one of the existing wire scanner and the new proposed design.

  6. Vibration measurements of a wire scanner - Experimental setup and models

    Herranz, Juan; Barjau, Ana; Dehning, Bernd

    2016-03-01

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new performance demands a wire travelling speed up to 20 m s-1 and a position measurement accuracy of the order of 1 μm. The vibrations of the mechanical parts of the system and particularly the vibrations of the thin carbon wire have been identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations has been given high priority for the design and operation of the new device. This article presents a new strategy to measure the wire vibrations based on the piezoresistive effect of the wire itself. An electronic readout system based on a Wheatstone bridge is used to measure the variation of the carbon wire resistance, which is directly proportional to the wire elongation caused by the oscillations.

  7. The PS Booster Fast Wire Scanner

    Burger, S; Priestnall, K; Raich, U

    2003-01-01

    The very tight emittance budget for LHC type beams makes precise emittance measurements in the injector complex a necessity. The PS machine uses 2 fast wire scanners per transverse plane for emittance measurement of the circulating beams. In order to ease comparison the same type of wire scanners have been newly installed in the upstream machine, the PS Booster, where each of the 4 rings is equipped with 2 wire scanners measuring the horizontal and vertical profiles. Those wire scanners use new and more modern control and readout electronics featuring dedicated intelligent motor movement controllers, which relieves the very stringent real time constraints due to the very high speed of 20m/s. In order to be able to measure primary beams at the very low injection energy of the Booster (50MeV) secondary emission currents from the wire can be measured as well as secondary particle flows at higher primary particle energies during and after acceleration. The solution adopted for the control of the devices is descri...

  8. Comparative evaluation of ultrasound scanner accuracy in distance measurement

    Branca, F. P.; Sciuto, S. A.; Scorza, A.

    2012-10-01

    The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

  9. Improvement in measurement accuracy for hybrid scanner

    The capability to provide dense three-dimensional (3D) data (point clouds) at high speed and at high accuracy has made terrestrial laser scanners (TLS) widely used for many purposes especially for documentation, management and analysis. However, similar to other 3D sensors, proper understanding regarding the error sources is necessary to ensure high quality data. A procedure known as calibration is employed to evaluate these errors. This process is crucial for TLS in order to make it suitable for accurate 3D applications (e.g. industrial measurement, reverse engineering and monitoring). Two calibration procedures available for TLS: 1) component, and 2) system calibration. The requirements of special laboratories and tools which are not affordable by most TLS users have become principle drawback for component calibration. In contrast, system calibration only requires a room with appropriate targets. By employing optimal network configuration, this study has performed system calibration through self-calibration for Leica ScanStation C10 scanner. A laboratory with dimensions of 15.5 m × 9 m × 3 m and 138 well-distributed planar targets were used to derive four calibration parameters. Statistical analysis (e.g. t-test) has shown that only two calculated parameters, the constant rangefinder offset error (0.7 mm) and the vertical circle index error (−45.4) were significant for the calibrated scanner. Photogrammetric technique was utilised to calibrate the 3D test points at the calibration field. By using the test points, the residual pattern of raw data and self-calibration results were plotted into the graph to visually demonstrate the improvement in accuracy for Leica ScanStation C10 scanner

  10. Vacuum Actuator and Controller Design for a Fast Wire Scanner

    Dehning, B; Herranz Alvarez, J; Koujili, M; Sirvent Blasco, J L

    2012-01-01

    To cope with increasing requirements in terms of accuracy and beam intensity limits a beam wire scanner (BWS) design is under development for the CERN accelerators complex. The main parameters have been determined; the wire speed should be 20 m·s -1 when interacting with the beam and a beam width determination accuracy of 2µm under the harsh radioactive environment should be reached. To meet this goal, the proposed solution locates all moveable parts of the actuator and the angular sensors in the beam vacuum pipe in order to reduce the friction and to allow a direct position measurement. One absolute positioning sensor will be used for the brushless motor feedback and one custom, high precision incremental design will target the beam size determination. The laboratory tests set up for the actuator and the incremental sensor will be presented along with the motor control feedback loops developed with the DSpace environment using Simulink and MatLab tools. Finally, the development of the digital...

  11. Thermal analysis for wire scanners in the CSNS Linac

    Yang, Tao; Fu, Shinian; Xu, Taoguang; Xu, Zhihong; Meng, Ming; Qiu, Ruiyang; Tian, Jianmin; Zeng, Lei; Li, Peng; Li, Fang; Wang, Biao

    2014-10-01

    3 MeV H- beam from the Radio Frequency Quadrupole (RFQ) will be accelerated to 80 MeV in the CSNS (China Spallation Neutron Source) linear accelerator (Linac). The wire scanner is used to measure the transverse beam profile and the emittance, and the carbon or tungsten wire is considered to use. Thermal analysis of the wire scanners in the Linac is presented in this paper. The maximum temperature (Tm) of the wire decreases as the beam energy increases, and we also calculate the influence of all possible parameters on Tm. Tm of carbon wire is significantly lower than tungsten wire if both the beam parameters and wire geometric parameters are set to the same, which can be attributed to its higher heat capacity and radiant emissivity. In addition, we present the results of sublimation rate of the wire, which show that tungsten wire has a much lower evaporation rate than carbon wire in the same temperature, which can be attributed to the different vapor pressures of the two materials. To limit the thermionic emission, the maximum beam frequency approximately has an exponential relationship with beam rms size at a certain beam pulse width.

  12. LANSCE wire scanner AFE: analysis, design, and fabrication

    The goal of the design LANSCE-R Wire-Scanner Analog Front-end Electronics is to develop a high-performance, dual-axis wire-scanner analog front-end system implemented in a single cRIO module. This new design accommodates macropulse widths as wide as 700 μs at a maximum pulse rate of 120Hz. A lossey integrator is utilized as the integration element to eliminate the requirement for providing gating signals to each wire scanner. The long macropulse and the high repetition rate present conflicting requirements for the design of the integrator. The long macropulse requires a long integration time constant to assure minimum integrator droop for accurate charge integration, and the high repetition rate requires a short time constant to assure adequate integrator reset between macropulses. Also, grounding is a serious concern due to the small signal levels. This paper reviews the basic Wire Scanner AFE system design implemented in the cRIO-module form factor to capture the charge information from the wire sensors and the grounding topology to assure minimum noise contamination of the wire signals.

  13. Beam test of wire scanner beam size monitor

    A beam size monitor for emittance measurement is required to have around 10μm resolution for injector linac, and to have a few tenth μm resolution for an extracted beam from a damping ring in Accelerator Test Facility (ATF). A wire scanner is a one of the candidate of a beam size monitor with a high resolution. The design and development study of the wire scanning stage has been done. The beam test using Tohoku 300MeV Linac was done and the emittance was measured by this wire scanner. A detection of beam size signal was done by a scintillator gamma detector placed at downstream of the wire stage. All of the measurements are taken by the computer. The beam test results are described. (author)

  14. Feasibility studies on the direct wire readout on wire scanners in electron accelerators

    This bachelor thesis deals essentially with the signal processing of a so-called wire scanner, a special monitor, which comes to application in the beam diagnostics of particle accelerators. In this direct wire readout the voltage signal, which is induced by the particle beam in the measurement wire of the wire scanner, shall be directly read out. The aim of this thesis is to show fundamental considerations and perform studies, which study, whether and how in the future by means of a suited data transmission as well as readout electronics conclusion on the most important parameters of the beam, like position and profile, are possible. The measurement system presented here is divided in three main components: Signal measurement, signal preparation, and signal stretching. A suited test facility was developed and is presented in detail, in which then all components, like for instance the transmission cables, the wire-scanner fork, and the developed measurement circuit, are studied, which are of importance for a faultless signal transmission and presentation. Extensive measurements on the single components, as well as calculations for the signal transmission on and in the wire scanner were performed, whereby a good agreement could be found. Thereafter a comparison and a selection of the component used in this project were made. Furthermore improvement proposals, new constructions, and outlooks are presented, which could be of importance in further works.

  15. Mechanical optimisation of a high-precision fast wire scanner at CERN

    Samuelsson, Sebastian; Veness, Raymond

    Wire scanners are instruments used to measure the transverse beam prole in particle accelerators by passing a thin wire through the particle beam. To avoid the issues of vacuum leakage through the bellows and wire failure related to current designs of wire scanners, a new concept for a wire scanner has been developed at CERN. This design has all moving parts inside the beam vacuum and has a nominal wire scanning speed of 20 m/s. The demands on the design associated with this together with the high precision requirements create a need for\

  16. Tuning of MEBT-Chopper by using wire scanner monitor

    In J-PARC, a macro pulse with several hundred micro seconds is shaped into a pulse with medium bunch structure of about one MHz, by a RF chopper at MEBT section. The comb-like structured pulse is injected into the following DTL section. The remaining fraction of the beam in the bottom of the comb-like structure, is measured by a wire scanner monitor (with preamplifier) located in the downstream. The remaining fraction (compared to the nominal signal) is of the order of 0.1%. (author)

  17. Secondary particle acquisition system for the CERN beam wire scanners upgrade

    The increasing requirements of CERN experiments make essential the upgrade of beam instrumentation in general, and high accuracy beam profile monitors in particular. The CERN Beam Instrumentation Group has been working during the last years on the Wire Scanners upgrade. These systems cross a thin wire through a circulating beam, the resulting secondary particles produced from beam/wire interaction are detected to reconstruct the beam profile. For the new secondary shower acquisition system, it is necessary to perform very low noise measurements with high dynamic range coverage. The aim is to design a system without tuneable parameters and compatible for any beam wire scanner location at the CERN complex. Polycrystalline chemical vapour deposition diamond detectors (pCVD) are proposed as new detectors for this application because of their radiation hardness, fast response and linearity over a high dynamic range. For the detector readout, the acquisition electronics must be designed to exploit the detector capabilities and perform bunch by bunch measurements at 40MHz. This paper describes the design challenges of such a system, analysing different acquisition possibilities from the signal integrity point of view. The proposed system architecture is shown in detail and the development status presented

  18. EVALUATING PARAMETERS AFFECTING THE GEOREFERENCING ACCURACY OF TERRESTRIAL LASER SCANNERS

    M. Miri

    2012-09-01

    Full Text Available Today laser scanning is used as a powerful technology in measuring various simple and complex objects in cultural heritage applications. Depending on the size and the complexity of the objects, these measurements are usually made from several stations. Similar to all other surveying techniques, the coordinate systems of such measurements need to be registered. For this, a number of retro-reflective targets visible from different stations are used. In practice, the target centres are entered in the computations. The accuracy of the target centres, therefore, need to be high or the final object coordinates might not be of sufficient accuracy. A number of factors including the distance between a target and the laser scanner, the direction of the target surface with respect to the laser scanner beams, the intensity and the number of reflected laser beams affect the accuracy of target centres. In this paper, various tests are carried out to examine the effect of such factors on the accuracy of coordinates obtained for the target centres. The results show that the distance to the laser scanner and the angle between a target surface and the corresponding laser beams have considerable effects on the locational accuracy of the targets.

  19. Superharp — A wire scanner with absolute position readout for beam energy measurement at CEBAF

    Yan, C.; Adderley, P.; Barker, D.; Beaufait, J.; Capek, K.; Carlini, R.; Dahlberg, J.; Feldl, E.; Jordan, K.; Kross, B.; Oren, W.; Wojcik, R.; VanDyke, J.

    1995-02-01

    The CEBAF superharp is an upgraded beam wire scanner which provides absolute beam position readout using a shaft encoder. Superharps allow for high precision measurements of the beam's profile and position ( Δx ˜ 10 μm). The Hall C endstation at CEBAF will use three pairs of superharps to perform beam energy measurements with 10 -3 accuracy. The three pairs are installed at the beginning, the mid-point and the end of the Hall C arc beamline. Using superharps in conjunction with a dual sensor system: the direct current pick-up and the bremsstrahlung detectors, beam profile measurements can be obtained over a wide beam current range of 1 ˜ 200 μA.

  20. A wire scanner system for characterizing the BNL energy recovery LINAC beam position monitor system

    Michnoff R.; Biscardi, C.; Cerniglia, P.; Degen, C.; Gassner, D.; Hoff, L.; Hulsart, R.

    2012-04-15

    A stepper motor controlled wire scanner system has recently been modified to support testing of the Brookhaven National Laboratory (BNL) Collider-Accelerator department's Energy Recovery Linac (ERL) beam position monitor (BPM) system. The ERL BPM consists of four 9.33 mm diameter buttons mounted at 90 degree spacing in a cube with 1.875 inch inside diameter. The buttons were designed by BNL and fabricated by Times Microwave Systems. Libera brilliance single pass BPM electronic modules with 700 MHz bandpass filter, manufactured by Instrumentation Technologies, will be used to measure the transverse beam positions at 14 locations around the ERL. The wire scanner assembly provides the ability to measure the BPM button response to a pulsed wire, and evaluate and calibrate the Libera position measurement electronics. A description of the wire scanner system and test result data will be presented.

  1. Laser Wire Scanner Basic Process and Perspectives for the CTF's and CLIC Machines

    Lefèvre, T

    2002-01-01

    In a laser wire scanner, the basic idea is to replace the solid wire classically used in a standard wire scanner by a narrow laser beam. The basic process involved is the Thomson-Compton scattering process, where photons are scattered from the laser beam by the incoming electrons. By counting the number of scattered photons or degraded electrons as a function of laser position the bunch profile can be reconstructed. In this note the Compton scattering mechanism is first presented. In the framework of the CLIC project, a laser wire scanner (LWS) could be used as a non-interfering beam profile measurement both on the Drive Beam for a high current electron beam and on the Main Beam for very small electron beam sizes. A design for a LWS on the CTF2 and CTF3 machines is proposed and some considerations for the use of a LWS on the CLIC main beam are also mentioned.

  2. LANSCE-R WIRE-SCANNER ANALOG FRONT-END ELECTRONICS

    A new AFE is being developed for the new LANSCE-R wire-scanner systems. The new AFE is implemented in a National Instruments Compact RIO (cRIO) module installed a BiRa 4U BiRIO cRIO chassis specifically designed to accommodate the cRIO crate and all the wire-scanner interface, control and motor-drive electronics. A single AFE module provides interface to both X and Y wire sensors using true DC coupled transimpedance amplifiers providing collection of the wire charge signals, real-time wire integrity verification using the normal dataacquisition system, and wire bias of 0V to +/-50V. The AFE system is designed to accommodate comparatively long macropulses (>1ms) with high PRF (>120Hz) without the need to provide timing signals. The basic AFE bandwidth is flat from true DC to 50kHz with a true first-order pole at 50kHz. Numeric integration in the cRIO FPGA provides real-time pulse-to-pulse numeric integration of the AFE signal to compute the total charge collected in each macropulse. This method of charge collection eliminates the need to provide synchronization signals to the wire-scanner AFE while providing the capability to accurately record the charge from long macropulses at high PRF.

  3. Laser and electron beam diagnostics with wire scanners in the XUV-seeding experiment at FLASH

    Hass, Eugen; Azima, Armin; Curbis, Francesca; Delsim-Hashemi, Hossein; Drescher, Markus; Hipp, Ulrich; Malrezopoulos, Theopilos; Miltchev, Velizar; Mittenzwey, Manuel; Rehders, Marie; Rossbach, Joerg; Roensch-Schulenburg, Juliane; Tarkeshian, Roxana; Wieland, Marek; Boedewaldt, Joern [Universitaet Hamburg (Germany); Bajt, Sasa; Duesterer, Stefan; Honkavaara, Katja; Laarmann, Tim; Schlarb, Holger [DESY, Hamburg (Germany); Khan, S. [DELTA, Dortmund (Germany); Ischebeck, Rasmus [PSI Villigen (Switzerland)

    2011-07-01

    The free-electron laser (FLASH) in Hamburg delivers intense femtosecond laser pulses in the extreme ultra violet and soft X-ray spectral range for many kinds of experiments, like material science and femtochemistry. To improve the FEL properties in terms of spectral stability, a direct seeding experiment (sFLASH), using a high harmonic generation source as a seed laser was installed at FLASH. The longitudinal and transversal overlap of the seed laser and electron beam is crucial for the seeding process. Among others, wire scanners are used for measuring the transverse laser and electron beam profiles, to perform the transverse overlap. Wire scanners are scanning a thin wire across the electron beam or the laser while measuring the interaction between electrons or photons with the wire. The interaction produces a flux of secondary particles, which are detected with beam loss monitors or MCP detectors.

  4. Laser and electron beam diagnostics with wire scanners in the XUV-seeding experiment at FLASH

    The free-electron laser (FLASH) in Hamburg delivers intense femtosecond laser pulses in the extreme ultra violet and soft X-ray spectral range for many kinds of experiments, like material science and femtochemistry. To improve the FEL properties in terms of spectral stability, a direct seeding experiment (sFLASH), using a high harmonic generation source as a seed laser was installed at FLASH. The longitudinal and transversal overlap of the seed laser and electron beam is crucial for the seeding process. Among others, wire scanners are used for measuring the transverse laser and electron beam profiles, to perform the transverse overlap. Wire scanners are scanning a thin wire across the electron beam or the laser while measuring the interaction between electrons or photons with the wire. The interaction produces a flux of secondary particles, which are detected with beam loss monitors or MCP detectors.

  5. Interpretation of Wire-Scanner asymmetric profiles in a Low-Energy ring

    Cieslak-Kowalska, Magdalena Anna

    2016-01-01

    In the CERN PS Booster, wire-scanner profile measurements performed at injection energy are affected by a strong asymmetry. The shape was reproduced with the code PyORBIT, assuming that the effect is due to the beam evolution during the scans, under the influence of space-charge forces and Multiple Coulomb Scattering at the wire itself. Reproducing the transverse profiles during beam evolution allows to use them reliably as input for simulation benchmarking.

  6. A fast wire scanner, used to measure the transverse density distribution of beams circulating in an accelerator or storage ring.

    Maximilien Brice

    2002-01-01

    Fast wire scanners are used to measure the transverse density distribution of beams circulating in an accelerator or storage ring. In order to minimize blow-up of the beam through multiple Coulomb scattering, the wires are very thin (in the version shown here it is actually a twisted strand of carbon fibres with a total diameter of about 25 microns) and are swept through the beam at high speed (a linear motor, not mounted here, accelerates the wires to up to 20 m/s). One measures either the secondary emission current from the wire, or the signal from a scintillator/photomultiplier combination downstream from the wire scanner receiving the shower from nuclear reactions of beam particles with the wire nuclei. There are four such fast wire scanners in the 26 GeV PS and eight in the 1.4 GeV Booster.

  7. High dynamic range diamond detector acquisition system for beam wire scanner applications

    The CERN Beam Instrumentation group has been working during the last years on the beam wire scanners upgrade to cope up with the increasing requirements of CERN experiments. These devices are used to measure the beam profile by crossing a thin wire through a circulating beam, the resulting secondary particles produced from beam/wire interaction are detected and correlated with the wire position to reconstruct the beam profile. The upgraded secondary particles acquisition electronics will use polycrystalline chemical vapour deposition (pCVD) diamond detectors for particle shower measurements, with low noise acquisitions performed on the tunnel, near the detector. The digital data is transmitted to the surface through an optical link with the GBT protocol. Two integrator ASICs (ICECAL and QIE10) are being characterized and compared for detector readout with the complete acquisition chain prototype. This contribution presents the project status, the QIE10 front-end performance and the first measurements with the complete acquisition system prototype. In addition, diamond detector signals from particle showers generated by an operational beam wire scanner are analysed and compared with an operational system

  8. On the behavior of a wire of the Wire Scanner in the IPHI diagnosis line

    A proton beam of 3 MeV energy and 100 mA intensity during 200 μs and a period T a second crosses an 150 mm x 33 μm carbon wire. The particles in the packet are distributed according to a di-Gaussian law with σX = 2 mm and σY = 6 mm. In these conditions the wire of the X plane centered in the beam acquires a peak temperature of about 1800 deg. C. The intensity of the secondary electron current recovered on the wire amounts about 306 μA. The thermo-electronic current for a time t = 200 μs (at the period T) has an intensity of 45 μA, i.e. 15% of the nominal signal. These figures for current are orders of magnitude, particularly for the thermo-electronic current where an intervening parameter is affected by a high uncertainty. The calculation method gives the spatial and time distribution of the temperatures by taking into account the radiative and conductive thermic transfers as well as the linearity of the materials characteristics as functions depending on temperature

  9. Feasibility studies on the direct wire readout on wire scanners in electron accelerators; Durchfuehrbarkeitsstudien zur direkten Drahtauslese an Wirescannern in Elektronen-Beschleunigern

    Markert, Michael

    2010-10-15

    This bachelor thesis deals essentially with the signal processing of a so-called wire scanner, a special monitor, which comes to application in the beam diagnostics of particle accelerators. In this direct wire readout the voltage signal, which is induced by the particle beam in the measurement wire of the wire scanner, shall be directly read out. The aim of this thesis is to show fundamental considerations and perform studies, which study, whether and how in the future by means of a suited data transmission as well as readout electronics conclusion on the most important parameters of the beam, like position and profile, are possible. The measurement system presented here is divided in three main components: Signal measurement, signal preparation, and signal stretching. A suited test facility was developed and is presented in detail, in which then all components, like for instance the transmission cables, the wire-scanner fork, and the developed measurement circuit, are studied, which are of importance for a faultless signal transmission and presentation. Extensive measurements on the single components, as well as calculations for the signal transmission on and in the wire scanner were performed, whereby a good agreement could be found. Thereafter a comparison and a selection of the component used in this project were made. Furthermore improvement proposals, new constructions, and outlooks are presented, which could be of importance in further works.

  10. Superharp: A wire scanner with absolute position readout for beam energy measurement at CEBAF

    Superharp is an upgrade CEBAF wire scanner with absolute position readout from shaft encoder. As high precision absolute beam position probe (Δx ∼ 10μm), three pairs of superharps are installed at the entrance, the mid-point, and the exit of Hall C arc beamline in beam switch yard, which will be tuned in dispersive mode as energy spectrometer performing 10-3 beam energy measurement. With dual sensor system: the direct current pickup and the bremsstrahlung detection electronics, beam profile can be obtained by superharp at wide beam current range from 1 μA to 100 μA

  11. Sensor modeling, self-calibration and accuracy testing of panoramic cameras and laser scanners

    Amiri Parian, Jafar; Gruen, Armin

    2010-01-01

    Terrestrial Linear Array CCD-based panoramic cameras have been used for purely imaging purposes, but they also have a high potential for use in high accuracy measurement applications. The imaging geometry and the high information content of those images make them suitable candidates for quantitative image analysis. For that a particular sensor model has to be established and the inherent accuracy potential has to be investigated. We developed a sensor model for terrestrial Linear Array-based panoramic cameras by means of a modified bundle adjustment with additional parameters, which models substantial deviations of a real camera from the ideal one. We used 3D straight-line information in addition to tie points to conduct a full calibration and orientation without control point information. Due to the similarity of the operation of laser scanners to panoramic cameras the sensor model of the panoramic cameras was extended for the self-calibration of laser scanners. We present the joint sensor model for panoramic cameras and laser scanners and the results of self-calibration, which indicate a subpixel accuracy level for such highly dynamic systems. Finally we demonstrate the systems' accuracy of two typical panoramic cameras in 3D point positioning, using both a minimal number of control points and a free network adjustment. With these new panoramic imaging devices we have additional powerful sensors for image recording and efficient 3D object modeling.

  12. Performance of wire scanner beam profile monitors to determine the emittance and position of high power CW electron beams of the NBS-Los Alamos racetrack microtron

    The NBS-LANL Race Track Microtron (RTM) injector produces a sub-millimeter diameter, 600 μA, 5 MeV CW electron beam. In order to steer and focus this electron beam and to measure its emittance and energy spread, a system of wire scanner beam profile monitors has been developed. Three wire scanners are mounted in a straight line with approximately one meter spacing for emittance measurements. The fourth wire scanner is positioned after a 450 bending magnet for energy spread measurements

  13. Quantification of terrestrial laser scanner (TLS) elevation accuracy in oil palm plantation for IFSAR improvement

    Muhadi, N. A.; Abdullah, A. F.; Kassim, M. S. M.

    2016-06-01

    In order to ensure the oil palm productivity is high, plantation site should be chosen wisely. Slope is one of the essential factors that need to be taken into consideration when doing a site selection. High quality of plantation area map with elevation information is needed for decision-making especially when dealing with hilly and steep area. Therefore, accurate digital elevation models (DEMs) are required. This research aims to increase the accuracy of Interferometric Synthetic Aperture Radar (IFSAR) by integrating Terrestrial Laser Scanner (TLS) to generate DEMs. However, the focus of this paper is to evaluate the z-value accuracy of TLS data and Real-Time Kinematic GPS (RTK-GPS) as a reference. Besides, this paper studied the importance of filtering process in developing an accurate DEMs. From this study, it has been concluded that the differences of z-values between TLS and IFSAR were small if the points were located on route and when TLS data has been filtered. This paper also concludes that laser scanner (TLS) should be set up on the route to reduce elevation error.

  14. Laser Wire Scanner Compton Scattering Techniques for the Measurement of the Transverse Beam Size of Particle Beams at Future Linear Colliders

    Agapov, I; Blair, G A; Bosser, J; Braun, H H; Bravin, E; Boorman, G; Boogert, S T; Carter, J; D'amico, E; Delerue, N; Howell, D F; Doebert, S; Driouichi, C; Frisch, J; Hutchins, K Honkavaaram S; Kamps, T; Lefevre, T; Lewin, H; Paris, T; Poirier, F; Price, M T; Maccaferi, R; Malton, S; Penn, G; Ross, I N; Ross, M; Schlarb, H; Schmueser, P; Schreiber, S; Sertore, D; Walker, N; Wendt, M; Wittenburg, K

    2014-01-01

    This archive summarizes a working paper and conference proceedings related to laser wire scanner development for the Future Linear Collider (FLC) in the years 2001 to 2006. In particular the design, setup and data taking for the laser wire experiments at PETRA II and CT2 are described. The material is focused on the activities undertaken by Royal Holloway University of London (RHUL).

  15. Accuracy of the CT numbers of simulated lung nodules imaged with multi-detector CT scanners

    A study was performed to determine the accuracies and reproducibilities of the CT numbers of simulated lung nodules imaged with multi-detector CT scanners. The nodules were simulated by spherical balls of three diameters (4.8, 9.5, and 16 mm) and two compositions (50 and 100 mg/cc CaCO3 in water-equivalent plastic). All were scanned in a liquid-water-filled container at the center of a water-equivalent-plastic phantom and in air cavities within the same phantom using GE multi-detector CT scanners. The nodules were also scanned within simulated lung regions in an anthropomorphic thorax section phantom that was bolused on both sides with water-equivalent slabs. Results were compared for three scanning protocols--the protocol for the National Lung Screening Trial (NLST), the protocol for the Lung Tissue Research Consortium (LTRC) study, and a high resolution (small pitch, thin slice and small scan interval) higher dose ''gold standard'' protocol. Scans were repeated three times with each protocol to assess reproducibility. The CT numbers of the nodules in water were found to be nearly independent of nodule size. However, the presence and the size of an air cavity surrounding a nodule had a significant effect (e.g., the CT number of a 50 mg/cc nodule was 64 HU in water, 37 HU in a 1.8 cm diameter air cavity, and 19 HU in a 4.4 cm diameter air cavity). This variability of CT number with size of air cavity may affect the results of the LTRC study in which patients are scanned at both full inspiration and full expiration. The CT numbers of the 9.5 and 16 mm diameter nodules within the anthropomorphic phantom were highly reproducible (average standard deviations of 2 HU or less) for all protocols. On the other hand, both accuracy and reproducibility were significantly degraded for the 4.8 mm diameter nodules, especially for the NLST (2.5 mm thickness, 2 mm slice interval) technique. Use of thinner slice (1.25 mm) and slice interval (1.25 mm) scans that can be reconstructed

  16. Temporal Stability of the Velodyne HDL-64E S2 Scanner for High Accuracy Scanning Applications

    Craig Glennie

    2011-03-01

    Full Text Available The temporal stability and static calibration and analysis of the Velodyne HDL‑64E S2 scanning LiDAR system is discussed and analyzed. The mathematical model for measurements for the HDL-64E S2 scanner is updated to include misalignments between the angular encoder and scanner axis of rotation, which are found to be a marginally significant source of error. It is reported that the horizontal and vertical laser offsets cannot reliably be obtained with the current calibration model due to their high correlation with the horizontal and vertical offsets. By analyzing observations from two separate HDL-64E S2 scanners it was found that the temporal stability of the horizontal angle offset is near the quantization level of the encoder, but the vertical angular offset, distance offset and distance scale are slightly larger than expected. This is felt to be due to long term variations in the scanner range, whose root cause is as of yet unidentified. Nevertheless, a temporally averaged calibration dataset for each of the scanners resulted in a 25% improvement in the 3D planar misclosure residual RMSE over the standard factory calibration model.

  17. Test Measurements of a 20 ms-1 Carbon Wire Beam Scanner

    De Freitas, J; Emery, J; Herranz Alvarez, J F; Koujili, M; Ramos, D; Sapinski, M; Ait-Amira, Y; Djerdir, A

    2011-01-01

    This paper pre­sents the de­sign of the ac­tu­a­tor for the fast and high ac­cu­ra­cy Wire Scan­ner sys­tem. The ac­tu­a­tor con­sists of a ro­tary brushless syn­chronous motor with the per­ma­nent mag­net rotor in­stalled in­side the vac­u­um cham­ber and the sta­tor in­stalled out­side. The fork, per­ma­nent mag­net rotor and two an­gu­lar po­si­tion sen­sors are mount­ed on the same axis and lo­cat­ed in­side the beam vac­u­um cham­ber. The system has to re­sist a bake-out tem­per­a­ture of 200 C and ion­iz­ing radi­a­tion up to tenths of kGy/year. Max­i­mum wire trav­el­ling speed of 20 m/s and a po­si­tion mea­sure­ment ac­cu­ra­cy of 4 um is re­quired. Therefore, the sys­tem must avoid gen­er­at­ing vi­bra­tion and electromagnet­ic in­ter­fer­ence. A dig­i­tal feed­back con­troller will allow max­i­mum flex­i­bil­i­ty for the loop pa­ram­e­ters and feeds the 3-phase lin­ear power driv­er. The per­for­mance of the pr...

  18. Comparison of the Accuracy of Canon KU-1 IOL Measurer and VPLUS A/B Scanner in Axial Length Measurement

    Chuyin Chen; Zhende Lin; Bo Feng; Yonghua Li

    2003-01-01

    Purpose: To evaluate the accuracy of Canon KU-1 IOL measurer (Japanese Canon Company) and VPLUS A/B scanner (French Quantel Company) in axial length (AL)measurement.Methods:Canon KU-1 IOL measurer and VPLUS A/B scanner were used to measure axial length of human cataractous eyes before cataract surgery. Two hundred and twentytwo cases (433 eyes) were involved. The results were compared and the postoperative visual acuity, refractive results were recorded during the follow-ups to evaluate the accuracy of the two instruments.Results:In the 222 cases (433 eyes), the absolute value of the measurement differences was 0.4 mm or above in 35 eyes, 0.8 mm or above in 17 eyes, 1.2 mm or above in 12 eyes,2.0mm or above in 5 eyes. The refractive error was less than 2.0D in all patients. The mean values of ocular axial length by the two methods were 23.82 mm and 23.83 mm respectively and the difference had no statistic significance with compared t test ( P=0.902, two tail, or=0.01).Conclusion:The accurate AL measurements can be obtained with the two instruments and the measurement results should be analyzed comprehensively to obtain accurate values in the complicated cases.

  19. Accuracy Comparison of Digital Surface Models Created by Unmanned Aerial Systems Imagery and Terrestrial Laser Scanner

    Naumann, M.; Geist, M.; Bill, R.; Niemeyer, F.; Grenzdörffer, G.

    2013-08-01

    The main focus of the paper is a comparative study in which we have investigated, whether automatically generated digital surface models (DSM) obtained from unmanned aerial systems (UAS) imagery are comparable with DSM obtained from terrestrial laser scanning (TLS). The research is conducted at a pilot dike for coastal engineering. The effort and the achievable accuracy of both DSMs are compared. The error budgets of these two methods are investigated and the models obtained in each case compared against each other.

  20. Geometric accuracy of dynamic MLC tracking with an implantable wired electromagnetic transponder

    Ravkilde, Thomas; Hoejbjerre, Klaus; Fledelius, Walther; Worm, Esben (Dept. of Oncology, Aarhus Univ. Hospital (Denmark)), e-mail: thomravk@rm.dk; Keall, Paul J. (Central Clinical School, Univ. of Sydney (Australia); Dept. of Radiation Oncology, Stanford Univ. (United States)); Poulsen, Per R. (Dept. of Oncology, Aarhus Univ. Hospital (Denmark); Inst. of Clinical Medicine, Aarhus Univ. (Denmark))

    2011-08-15

    Background. Tumor motion during radiotherapy delivery can substantially deteriorate the target dose distribution. A promising method to overcome this problem is dynamic multi-leaf collimator (DMLC) tracking. The purpose of this phantom study was to integrate a wired electromagnetic (EM) transponder localization system with DMLC tracking and to investigate the geometric accuracy of the integrated system. Material and methods. DMLC tracking experiments were performed on a Trilogy accelerator with a prototype DMLC tracking system. A wired implantable EM transponder was mounted on a motion stage with a 3 mm tungsten sphere used for target visualization in continuous portal images. The three dimensional (3D) transponder position signal was used for DMLC aperture adaption. The motion stage was programmed to reproduce eight representative patient-measured trajectories for prostate and for lung tumors. The tracking system latency was determined and prediction was used for the lung tumor trajectories to account for the latency. For each trajectory, three conformal fields with a 10 cm circular MLC aperture and 72 s treatment duration were delivered: (1) a 358 deg arc field; (2) an anterior static field; and (3) a lateral static field. The tracking error was measured as the difference between the marker position and the MLC aperture in the portal images. Results. The tracking system latency was 140 ms. The mean root-mean-square (rms) of the 3D transponder localization error was 0.53/0.54 mm for prostate/lung tumor trajectories. The mean rms of the two dimensional (2D) tracking error was 0.69 mm (prostate) and 0.98 mm (lung tumors) with tracking and 3.4 mm (prostate) and 5.3 mm (lung tumors) without tracking. Conclusions. DMLC tracking was integrated with a wired EM transponder localization system and investigated for arc and static field delivery. The system provides sub-mm geometrical errors for most trajectories

  1. Geometric accuracy of dynamic MLC tracking with an implantable wired electromagnetic transponder

    Background. Tumor motion during radiotherapy delivery can substantially deteriorate the target dose distribution. A promising method to overcome this problem is dynamic multi-leaf collimator (DMLC) tracking. The purpose of this phantom study was to integrate a wired electromagnetic (EM) transponder localization system with DMLC tracking and to investigate the geometric accuracy of the integrated system. Material and methods. DMLC tracking experiments were performed on a Trilogy accelerator with a prototype DMLC tracking system. A wired implantable EM transponder was mounted on a motion stage with a 3 mm tungsten sphere used for target visualization in continuous portal images. The three dimensional (3D) transponder position signal was used for DMLC aperture adaption. The motion stage was programmed to reproduce eight representative patient-measured trajectories for prostate and for lung tumors. The tracking system latency was determined and prediction was used for the lung tumor trajectories to account for the latency. For each trajectory, three conformal fields with a 10 cm circular MLC aperture and 72 s treatment duration were delivered: (1) a 358 deg arc field; (2) an anterior static field; and (3) a lateral static field. The tracking error was measured as the difference between the marker position and the MLC aperture in the portal images. Results. The tracking system latency was 140 ms. The mean root-mean-square (rms) of the 3D transponder localization error was 0.53/0.54 mm for prostate/lung tumor trajectories. The mean rms of the two dimensional (2D) tracking error was 0.69 mm (prostate) and 0.98 mm (lung tumors) with tracking and 3.4 mm (prostate) and 5.3 mm (lung tumors) without tracking. Conclusions. DMLC tracking was integrated with a wired EM transponder localization system and investigated for arc and static field delivery. The system provides sub-mm geometrical errors for most trajectories

  2. A new borehole wire extensometer with high accuracy and stability for observation of local geodynamic processes.

    Mentes, Gy

    2012-01-01

    Very stable and reliable instruments with high accuracy are required in field measurements for continuous monitoring local geodynamic processes, such as tectonic movements, ground motions in landslide prone areas, etc. A sensitive borehole wire extensometer with low energy consumption was developed in the Geodetic and Geophysical Research Institute of the Hungarian Academy of Sciences to observe very small vertical movements (in the order of a few millimeters) of the upper layer of the soil due to hydrological, meteorological and biological processes. The newly developed instrument eliminates the disadvantages of the borehole wire extensometers which are presently used. Its sensitivity and stability are much higher than these parameters of the previous instruments. The instrument is able to measure distance variations without instrumental drift in a range of 0-4 mm with a resolution of better than 1 μm. Since the effect of the yearly temperature variations can be easily removed from the extensometric data record, the compensation for the short-periodic (daily) thermal effects on the instrument was of high priority during the design of the instrument. This paper describes the construction and calibration of the extensometer. The extensometer was installed for monitoring vertical ground movements due to hydro-meteorological processes on the high loess wall of the Danube River at Dunaföldvár, Hungary. The efficiency of the temperature compensation of the instrument was investigated in detail on the basis of the measured data series. PMID:22299988

  3. Comparison of reconstruction methods and quantitative accuracy in Siemens Inveon PET scanner

    PET reconstruction is key to the quantification of PET data. To our knowledge, no comparative study of reconstruction methods has been performed to date. In this study, we compared reconstruction methods with various filters in terms of their spatial resolution, non-uniformities (NU), recovery coefficients (RCs), and spillover ratios (SORs). In addition, the linearity of reconstructed radioactivity between linearity of measured and true concentrations were also assessed. A Siemens Inveon PET scanner was used in this study. Spatial resolution was measured with NEMA standard by using a 1 mm3 sized 18F point source. Image quality was assessed in terms of NU, RC and SOR. To measure the effect of reconstruction algorithms and filters, data was reconstructed using FBP, 3D reprojection algorithm (3DRP), ordered subset expectation maximization 2D (OSEM 2D), and maximum a posteriori (MAP) with various filters or smoothing factors (β). To assess the linearity of reconstructed radioactivity, image quality phantom filled with 18F was used using FBP, OSEM and MAP (β =1.5 and 5 × 10−5). The highest achievable volumetric resolution was 2.31 mm3 and the highest RCs were obtained when OSEM 2D was used. SOR was 4.87% for air and 3.97% for water, obtained OSEM 2D reconstruction was used. The measured radioactivity of reconstruction image was proportional to the injected one for radioactivity below 16 MBq/ml when FBP or OSEM 2D reconstruction methods were used. By contrast, when the MAP reconstruction method was used, activity of reconstruction image increased proportionally, regardless of the amount of injected radioactivity. When OSEM 2D or FBP were used, the measured radioactivity concentration was reduced by 53% compared with true injected radioactivity for radioactivity <16 MBq/ml. The OSEM 2D reconstruction method provides the highest achievable volumetric resolution and highest RC among all the tested methods and yields a linear relation between the measured and true

  4. High-Precision Surface Inspection: Uncertainty Evaluation within an Accuracy Range of 15μm with Triangulation-based Laser Line Scanners

    Dupuis, Jan; Kuhlmann, Heiner

    2014-06-01

    Triangulation-based range sensors, e.g. laser line scanners, are used for high-precision geometrical acquisition of free-form surfaces, for reverse engineering tasks or quality management. In contrast to classical tactile measuring devices, these scanners generate a great amount of 3D-points in a short period of time and enable the inspection of soft materials. However, for accurate measurements, a number of aspects have to be considered to minimize measurement uncertainties. This study outlines possible sources of uncertainties during the measurement process regarding the scanner warm-up, the impact of laser power and exposure time as well as scanner’s reaction to areas of discontinuity, e.g. edges. All experiments were performed using a fixed scanner position to avoid effects resulting from imaging geometry. The results show a significant dependence of measurement accuracy on the correct adaption of exposure time as a function of surface reflectivity and laser power. Additionally, it is illustrated that surface structure as well as edges can cause significant systematic uncertainties.

  5. Analysis of the effect of cone-beam geometry and test object configuration on the measurement accuracy of a computed tomography scanner used for dimensional measurement

    Kumar, Jagadeesha; Attridge, Alex; Wood, P. K. C.; Williams, Mark A.

    2011-03-01

    Industrial x-ray computed tomography (CT) scanners are used for non-contact dimensional measurement of small, fragile components and difficult-to-access internal features of castings and mouldings. However, the accuracy and repeatability of measurements are influenced by factors such as cone-beam system geometry, test object configuration, x-ray power, material and size of test object, detector characteristics and data analysis methods. An attempt is made in this work to understand the measurement errors of a CT scanner over the complete scan volume, taking into account only the errors in system geometry and the object configuration within the scanner. A cone-beam simulation model is developed with the radiographic image projection and reconstruction steps. A known amount of errors in geometrical parameters were introduced in the model to understand the effect of geometry of the cone-beam CT system on measurement accuracy for different positions, orientations and sizes of the test object. Simulation analysis shows that the geometrical parameters have a significant influence on the dimensional measurement at specific configurations of the test object. Finally, the importance of system alignment and estimation of correct parameters for accurate CT measurements is outlined based on the analysis.

  6. Note: Optical and electronic design of an amplitude-modulated continuous-wave laser scanner for high-accuracy distance measurement

    Jang, Junhwan; Hwang, Sungui; Park, Kyihwan, E-mail: khpark@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju (Korea, Republic of)

    2015-04-15

    To utilize a time-of-flight-based laser scanner as a distance measurement sensor, the measurable distance and accuracy are the most important performance parameters to consider. For these purposes, the optical system and electronic signal processing of the laser scanner should be optimally designed in order to reduce a distance error caused by the optical crosstalk and wide dynamic range input. Optical system design for removing optical crosstalk problem is proposed in this work. Intensity control is also considered to solve the problem of a phase-shift variation in the signal processing circuit caused by object reflectivity. The experimental results for optical system and signal processing design are performed using 3D measurements.

  7. Quantification accuracy and partial volume effect in dependence of the attenuation correction of a state-of-the-art small animal PET scanner

    Quantification accuracy and partial volume effect (PVE) of the Siemens Inveon PET scanner were evaluated. The influence of transmission source activities (40 and 160 MBq) on the quantification accuracy and the PVE were determined. Dynamic range, object size and PVE for different sphere sizes, contrast ratios and positions in the field of view (FOV) were evaluated. The acquired data were reconstructed using different algorithms and correction methods. The activity level of the transmission source and the total emission activity in the FOV strongly influenced the attenuation maps. Reconstruction algorithms, correction methods, object size and location within the FOV had a strong influence on the PVE in all configurations. All evaluated parameters potentially influence the quantification accuracy. Hence, all protocols should be kept constant during a study to allow a comparison between different scans. (paper)

  8. A simple digital-optical system to improve accuracy of hot-wire measurements

    A high precision traverse mechanism with micro-resolution was designed to capture accurately the velocity profile of the very thin turbulent attachment line on a swept body. To ensure that the traverse mechanism could position the hot wire reliably, a simple digital optical system was designed to check the performance of the traverse by measuring the displacement of the hot wire: a vertical displacement of 2.4 µm was achievable and this could be further reduced to 0.6 µm using micro-stepping. Due to the simplicity of the set-up it was equally useful for probe wall positioning and the velocity profiles captured clearly demonstrated that the optical set-up helped in resolving the near wall flow more accurately, regardless of the thinness of the boundary layer. The captured data compare well with the results from similar investigations, with arguably higher precision achieved. (paper)

  9. Research Into the Collimation and Horizontal Axis Errors Influence on the Z+F Laser Scanner Accuracy of Verticality Measurement

    Sawicki, J.; Kowalczyk, M.

    2016-06-01

    Aim of this study was to appoint values of collimation and horizontal axis errors of the laser scanner ZF 5006h owned by Department of Geodesy and Cartography, Warsaw University of Technology, and then to determine the effect of those errors on the results of measurements. An experiment has been performed, involving measurement of the test field , founded in the Main Hall of the Main Building of the Warsaw University of Technology, during which values of instrumental errors of interest were determined. Then, an universal computer program that automates the proposed algorithm and capable of applying corrections to measured target coordinates or even entire point clouds from individual stations, has been developed.

  10. Diagnostic accuracy of state-of-the-art MDCT scanners without gantry tilt in patients with oral and oropharyngeal cancer

    Purpose: Current CT-protocols for staging oral and oropharyngeal cancer include primary transversal slices and secondary tilted slices to avoid artifact-producing regions of dental metalwork. Some of the latest MDCT scanners do not allow gantry tilt. Hence, we assessed the relevance of secondary tilted slices in tumor staging. Materials and methods: Scans of a tiltable 64-row MDCT-scanner of 82 patients with oral or oropharyngeal cancer were retrospectively and independently evaluated twice by three readers: once using the primary transversal scans only, and once taking the transversal and secondary tilted scans into account. Tumor diameters and TN-stage were determined with both methods. Artifacts on transversal scans were analyzed using a 3-point-ranking-scale. Results: Image quality was impaired by severe artifacts in 24% of transversal slices of the oral cavity and in 12% of the oropharynx. The three readers detected an average of 57.7 ± 2.1 of 82 tumors (70%) on transversal CT slices. An average of 6.3 ± 0.6 more tumors (8%) were detected when transversal studies were evaluated in conjunction with secondary tilted slices, leading to a significantly (p = 0.0156–0.0313) increased average detection rate of 64.0 ± 2.0 tumors (78%). Moreover, secondary tilted slices led to a correction of underestimated tumor stages in up to six patients (7.3%). Conclusion: Tilted slices that avoid artifact-producing regions of dental metalwork significantly improve the reader's sensitivity and are of incremental value for staging of oral and oropharyngeal cancers.

  11. Diagnostic accuracy of state-of-the-art MDCT scanners without gantry tilt in patients with oral and oropharyngeal cancer

    Bannas, Peter, E-mail: p.bannas@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Habermann, Christian R., E-mail: c.habermann@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Jung, Caroline, E-mail: cjung@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Bley, Thorsten A., E-mail: t.bley@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Ittrich, Harald, E-mail: Ittrich@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Adam, Gerhard, E-mail: g.adam@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Koops, Andreas, E-mail: koops@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany)

    2012-12-15

    Purpose: Current CT-protocols for staging oral and oropharyngeal cancer include primary transversal slices and secondary tilted slices to avoid artifact-producing regions of dental metalwork. Some of the latest MDCT scanners do not allow gantry tilt. Hence, we assessed the relevance of secondary tilted slices in tumor staging. Materials and methods: Scans of a tiltable 64-row MDCT-scanner of 82 patients with oral or oropharyngeal cancer were retrospectively and independently evaluated twice by three readers: once using the primary transversal scans only, and once taking the transversal and secondary tilted scans into account. Tumor diameters and TN-stage were determined with both methods. Artifacts on transversal scans were analyzed using a 3-point-ranking-scale. Results: Image quality was impaired by severe artifacts in 24% of transversal slices of the oral cavity and in 12% of the oropharynx. The three readers detected an average of 57.7 ± 2.1 of 82 tumors (70%) on transversal CT slices. An average of 6.3 ± 0.6 more tumors (8%) were detected when transversal studies were evaluated in conjunction with secondary tilted slices, leading to a significantly (p = 0.0156–0.0313) increased average detection rate of 64.0 ± 2.0 tumors (78%). Moreover, secondary tilted slices led to a correction of underestimated tumor stages in up to six patients (7.3%). Conclusion: Tilted slices that avoid artifact-producing regions of dental metalwork significantly improve the reader's sensitivity and are of incremental value for staging of oral and oropharyngeal cancers.

  12. Development of response models for the Earth Radiation Budget Experiment (ERBE) sensors. Part 3: ERBE scanner measurement accuracy analysis due to reduced housekeeping data

    Choi, Sang H.; Chrisman, Dan A., Jr.; Halyo, Nesim

    1987-01-01

    The accuracy of scanner measurements was evaluated when the sampling frequency of sensor housekeeping (HK) data was reduced from once every scan to once every eight scans. The resulting increase in uncertainty was greatest for sources with rapid or extreme temperature changes. This analysis focused on the mirror attenuator mosaic (MAM) baffle and plate and scanner radiometer baffle due to their relatively high temperature changes during solar calibrations. Since only solar simulator data were available, the solar temperatures were approximated on these components and the radiative and thermal gradients in the MAM baffle due to reflected sunlight. Of the two cases considered for the MAM plate and baffle temperatures, one uses temperatures obtained from the ground calibration. The other attempt uses temperatures computed from the MAM baffle model. This analysis shows that the heat input variations due largely to the solar radiance and irradiance during a scan cycle are small. It also demonstrates that reasonable intervals longer than the current HK data acquisition interval should not significantly affect the estimation of a radiation field in the sensor field-of-view.

  13. Accuracies of the synthesized monochromatic CT numbers and effective atomic numbers obtained with a rapid kVp switching dual energy CT scanner

    Purpose: This study was performed to investigate the accuracies of the synthesized monochromatic images and effective atomic number maps obtained with the new GE Discovery CT750 HD CT scanner. Methods: A Gammex-RMI model 467 tissue characterization phantom and the CT number linearity section of a Phantom Laboratory Catphan 600 phantom were scanned using the dual energy (DE) feature on the GE CT750 HD scanner. Synthesized monochromatic images at various energies between 40 and 120 keV and effective atomic number (Zeff) maps were generated. Regions of interest were placed within these images/maps to measure the average monochromatic CT numbers and average Zeff of the materials within these phantoms. The true Zeff values were either supplied by the phantom manufacturer or computed using Mayneord's equation. The linear attenuation coefficients for the true CT numbers were computed using the NIST XCOM program with the input of manufacturer supplied elemental compositions and densities. The effects of small variations in the assumed true densities of the materials were also investigated. Finally, the effect of body size on the accuracies of the synthesized monochromatic CT numbers was investigated using a custom lumbar section phantom with and without an external fat-mimicking ring. Results: Other than the Zeff of the simulated lung inserts in the tissue characterization phantom, which could not be measured by DECT, the Zeff values of all of the other materials in the tissue characterization and Catphan phantoms were accurate to 15%. The accuracies of the synthesized monochromatic CT numbers of the materials in both phantoms varied with energy and material. For the 40-120 keV range, RMS errors between the measured and true CT numbers in the Catphan are 8-25 HU when the true CT numbers were computed using the nominal plastic densities. These RMS errors improve to 3-12 HU for assumed true densities within the nominal density ±0.02 g/cc range. The RMS errors between the

  14. Proton scanner

    The scanner is based on the nuclear scattering of high energy protons by the nucleons (protons and neutrons) included in the atomic nuclei. Because of the wide scattering angle, three coordinates in space of the interaction point can be computed, giving directly three dimensional radiographs. Volumic resolution is of about a few cubic-millimeters. Because the base interaction is the strong nuclear force, the atomic dependence of the information obtained is different from that of the X-ray scanner, for which the base interaction is electro-magnetic force. (orig./VJ)

  15. On Improving Accuracy of Finite-Element Solutions of the Effective-Mass Schrödinger Equation for Interdiffused Quantum Wells and Quantum Wires

    D. B., Topalović; V. V., Arsoski; Pavlović, S.; N. A., Čukarić; Ž. Tadić, M.; F. M., Peeters

    2016-01-01

    We use the Galerkin approach and the finite-element method to numerically solve the effective-mass Schrödinger equation. The accuracy of the solution is explored as it varies with the range of the numerical domain. The model potentials are those of interdiffused semiconductor quantum wells and axially symmetric quantum wires. Also, the model of a linear harmonic oscillator is considered for comparison reasons. It is demonstrated that the absolute error of the electron ground state energy level exhibits a minimum at a certain domain range, which is thus considered to be optimal. This range is found to depend on the number of mesh nodes N approximately as α0 logeα1(α2N), where the values of the constants α0, α1, and α2 are determined by fitting the numerical data. And the optimal range is found to be a weak function of the diffusion length. Moreover, it was demonstrated that a domain range adaptation to the optimal value leads to substantial improvement of accuracy of the solution of the Schrödinger equation. Supported by the Ministry of Education, Science, and Technological Development of Serbia and the Flemish fund for Scientific Research (FWO Vlaanderen)

  16. Scanner calibration revisited

    Pozhitkov Alexander E

    2010-07-01

    Full Text Available Abstract Background Calibration of a microarray scanner is critical for accurate interpretation of microarray results. Shi et al. (BMC Bioinformatics, 2005, 6, Art. No. S11 Suppl. 2. reported usage of a Full Moon BioSystems slide for calibration. Inspired by the Shi et al. work, we have calibrated microarray scanners in our previous research. We were puzzled however, that most of the signal intensities from a biological sample fell below the sensitivity threshold level determined by the calibration slide. This conundrum led us to re-investigate the quality of calibration provided by the Full Moon BioSystems slide as well as the accuracy of the analysis performed by Shi et al. Methods Signal intensities were recorded on three different microarray scanners at various photomultiplier gain levels using the same calibration slide from Full Moon BioSystems. Data analysis was conducted on raw signal intensities without normalization or transformation of any kind. Weighted least-squares method was used to fit the data. Results We found that initial analysis performed by Shi et al. did not take into account autofluorescence of the Full Moon BioSystems slide, which led to a grossly distorted microarray scanner response. Our analysis revealed that a power-law function, which is explicitly accounting for the slide autofluorescence, perfectly described a relationship between signal intensities and fluorophore quantities. Conclusions Microarray scanners respond in a much less distorted fashion than was reported by Shi et al. Full Moon BioSystems calibration slides are inadequate for performing calibration. We recommend against using these slides.

  17. Scanner sipping

    During the 4th routine inspection of Biblis A and B, the new method of 'scanner sipping' - a modified 'wet sipping' technique - has been applied for the first time. The curve of activity release from a fuel element into the water of the sipping box is continuously recorded as a function of temperature. Information on the leaktightness of the fuel element is obtained from the increase with temperature of the activity concentration of selected nuclides. The method gives more accurate information than the common method within a shorter period of time; it helps to distinguish between defects and contamination and, with a 30% shorter time required for the measurements, it helps to save personnel costs. (orig./HP)

  18. Network Security Scanner

    G. MURALI; M.Pranavi; Y.Navateja; K. Bhargavi

    2011-01-01

    Network Security Scanner (NSS) is a tool that allows auditing and monitoring remote network computers for possible vulnerabilities, checks your network for all potential methods that a hacker might use to attack it. Network Security Scanner is a complete networking utilities package that includes a wide range of tools for network security auditing, vulnerability Auditing, scanning, monitoring and more. Network Security Scanner (NSS) is an easy to use, intuitive network security scanner that c...

  19. The Threading Hole Processing Position and Accuracy of Numerical Control Electrospark Wire-electrode Cutting%数控电火花线切割穿丝孔加工位置及精度影响

    王晖; 杨德治

    2011-01-01

    With the mold industry and other manufacturing industry's rapid development, the electrospark wire-electrode cutting of various process parameters such as size precision, surface roughness and so put forward more and more requirements. In the electrospark wire-electrode cutting processing through the wire hole is a frequently encountered problems, threading hole is the starting point of molybdenum wire moving relative to a workpiece, but also the procedures for the implementation of the starting position. The threading hole location on machining accuracy and cutting speed are in a great relationship, this paper lay the threading hole position and accuracy are discussed.%随着模具产业和其它加工制造业的飞速发展,对电火花线切割各项工艺指标如尺寸精度、表面粗糙度等都提出了越来越高的要求。在电火花线切割加工中打穿丝孔是一个经常遇到的基本问题,穿丝孔是钼丝相对于工件运动的起点,同时也是程序执行的起始位置。穿丝孔的位置对于加工精度及切割速度关系甚大,文中就打好穿丝孔位置及精度问题进行了论述。

  20. Use of a wire scanner for monitoring residual gas ionization in Soreq Applied Research Accelerator Facility 20 keV/u proton/deuteron low energy beam transport beam line

    The ion source end of the Soreq Applied Research Accelerator Facility accelerator consists of a proton/deuteron ECR ion source and a low energy beam transport (LEBT) beam line. An observed reduction of the radio frequency quadrupole transmission with increase of the LEBT current prompted additional study of the LEBT beam properties. Numerous measurements have been made with the LEBT bream profiler wire biased by a variable voltage. Current-voltage characteristics in presence of the proton beam were measured even when the wire was far out of the beam. The current-voltage characteristic in this case strongly resembles an asymmetric diodelike characteristic, which is typical of Langmuir probes monitoring plasma. The measurement of biased wire currents, outside the beam, enables us to estimate the effective charge density in vacuum.

  1. Use of a wire scanner for monitoring residual gas ionization in Soreq Applied Research Accelerator Facility 20 keV∕u proton∕deuteron low energy beam transport beam line.

    Vainas, B; Eliyahu, I; Weissman, L; Berkovits, D

    2012-02-01

    The ion source end of the Soreq Applied Research Accelerator Facility accelerator consists of a proton∕deuteron ECR ion source and a low energy beam transport (LEBT) beam line. An observed reduction of the radio frequency quadrupole transmission with increase of the LEBT current prompted additional study of the LEBT beam properties. Numerous measurements have been made with the LEBT bream profiler wire biased by a variable voltage. Current-voltage characteristics in presence of the proton beam were measured even when the wire was far out of the beam. The current-voltage characteristic in this case strongly resembles an asymmetric diodelike characteristic, which is typical of Langmuir probes monitoring plasma. The measurement of biased wire currents, outside the beam, enables us to estimate the effective charge density in vacuum. PMID:22380317

  2. Recent micro-CT scanner developments at UGCT

    Dierick, Manuel; Van Loo, Denis; Masschaele, Bert; Van den Bulcke, Jan; Van Acker, Joris; Cnudde, Veerle; Van Hoorebeke, Luc

    2014-04-01

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography (www.ugct.ugent.be) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kVmax) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results.

  3. Recent micro-CT scanner developments at UGCT

    Dierick, Manuel, E-mail: Manuel.Dierick@UGent.be [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Van Loo, Denis, E-mail: info@XRE.be [XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Masschaele, Bert [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium); XRE, X-Ray Engineering bvba, De Pintelaan 111, 9000 Ghent (Belgium); Van den Bulcke, Jan [UGCT-Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Van Acker, Joris, E-mail: Joris.VanAcker@UGent.be [UGCT-Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Ghent (Belgium); Cnudde, Veerle, E-mail: Veerle.Cnudde@UGent.be [UGCT-SGIG, Department of Geology and Soil Science, Faculty of Sciences, Ghent University, Krijgslaan 281, S8, 9000 Ghent (Belgium); Van Hoorebeke, Luc, E-mail: Luc.VanHoorebeke@UGent.be [UGCT-Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Proeftuinstraat 86, 9000 Ghent (Belgium)

    2014-04-01

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography ( (www.ugct.ugent.be)) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kV{sub max}) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results.

  4. Recent micro-CT scanner developments at UGCT

    This paper describes two X-ray micro-CT scanners which were recently developed to extend the experimental possibilities of microtomography research at the Centre for X-ray Tomography ( (www.ugct.ugent.be)) of the Ghent University (Belgium). The first scanner, called Nanowood, is a wide-range CT scanner with two X-ray sources (160 kVmax) and two detectors, resolving features down to 0.4 μm in small samples, but allowing samples up to 35 cm to be scanned. This is a sample size range of 3 orders of magnitude, making this scanner well suited for imaging multi-scale materials such as wood, stone, etc. Besides the traditional cone-beam acquisition, Nanowood supports helical acquisition, and it can generate images with significant phase-contrast contributions. The second scanner, known as the Environmental micro-CT scanner (EMCT), is a gantry based micro-CT scanner with variable magnification for scanning objects which are not easy to rotate in a standard micro-CT scanner, for example because they are physically connected to external experimental hardware such as sensor wiring, tubing or others. This scanner resolves 5 μm features, covers a field-of-view of about 12 cm wide with an 80 cm vertical travel range. Both scanners will be extensively described and characterized, and their potential will be demonstrated with some key application results

  5. Verification of a CT scanner using a miniature step gauge

    Cantatore, Angela; Andreasen, J.L.; Carmignato, S; Müller, Pavel; De Chiffre, Leonardo

    2011-01-01

    The work deals with performance verification of a CT scanner using a 42mm miniature replica step gauge developed for optical scanner verification. Errors quantification and optimization of CT system set-up in terms of resolution and measurement accuracy are fundamental for use of CT scanning in dimensional metrology. Influence of workpiece orientation, magnification, source-object-detector distances and surface extraction method on metrological performances of a CT scanner was evaluated. Resu...

  6. Scanner matching optimization

    Kupers, Michiel; Klingbeil, Patrick; Tschischgale, Joerg; Buhl, Stefan; Hempel, Fritjof

    2009-03-01

    Cost of ownership of scanners for the manufacturing of front end layers is becoming increasingly expensive. The ability to quickly switch the production of a layer to another scanner in case it is down is important. This paper presents a method to match the scanner grids in the most optimal manner so that use of front end scanners in effect becomes interchangeable. A breakdown of the various components of overlay is given and we discuss methods to optimize the matching strategy in the fab. A concern here is how to separate the scanner and process induced effects. We look at the relative contributions of intrafield and interfield errors caused by the scanner and the process. Experimental results of a method to control the scanner grid are presented and discussed. We compare the overlay results before and after optimizing the scanner grids and show that the matching penalty is reduced by 20%. We conclude with some thoughts on the need to correct the remaining matching errors.

  7. Verification of a CT scanner using a miniature step gauge

    Cantatore, Angela; Andreasen, J.L.; Carmignato, S.; Müller, Pavel; De Chiffre, Leonardo

    2011-01-01

    The work deals with performance verification of a CT scanner using a 42mm miniature replica step gauge developed for optical scanner verification. Errors quantification and optimization of CT system set-up in terms of resolution and measurement accuracy are fundamental for use of CT scanning in d...

  8. Gaseous wire detectors

    This article represents a series of three lectures describing topics needed to understand the design of typical gaseous wire detectors used in large high energy physics experiments; including the electrostatic design, drift of electrons in the electric and magnetic field, the avalanche, signal creation, limits on the position accuracy as well as some problems one encounters in practical operations

  9. Colorimetric Scanner Characterisation

    Jon Y. Hardeberg

    2003-12-01

    Full Text Available In this paper, methods for the colorimetric characterisation of colour scanners are proposed and evaluated. These methods apply equally to other colour image input devices such as digital cameras. The goal of our characterisation is to establish the relationship between the device-dependent colour space of the scanner and the device-independent CIELAB colour space. The scanner characterisation is based on polynomial regression techniques. Several regression schemes have been tested. The retained method consists in applying a non-linear correction to the scanner RGB values followed by a 3rd order 3D polynomial regression function directly to CIELAB space. This method gives very good results in terms of residual colour differences. This is partly due to the fact that the RMS error that is minimised in the regression corresponds to ΔE*ab which is well correlated to visual colour differences.

  10. Measuring PET scanner sensitivity

    Sensitivity parameters derived from a plot of a scanner's true coincidence count (TCC) rates as a function of activity in a 20 cm cylindrical phantom have no direct link to image quality. Noise equivalent count (NEC) rate curves, which incorporate the noise effects of subtracting the randoms and scatter count components provide a direct link between image signal-to-noise ratios and the scatter, randoms and trues coincidence count rates. The authors have measured TCC and NEC curves with a standardized 20 cm diameter nylon cylinder for five different PET scanners with several scanner-collimator combinations. In addition, the authors have compared TCC and NEC curves on one scanner with those from an Alderson brain phantom

  11. wire chamber

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  12. Characterization of color scanners based on SVR

    Li, Bin; Zhang, Yi-xin

    2012-01-01

    By researching the principle of colorimetric characterization method and Support Vector Regression (SVR), we analyze the feasibility of nonlinear transformation from scanner RGB color space to CIELAB color space based on SVR and built a new characterization model. Then we use the MATLABR2009a software to make a data simulation experiment to verify the accuracy of this model and figure out the color differences by CIEDE2000 color difference formula. Based on CIEDE2000 color difference formula, the average, the maximum and the minimum color differences of the training set are 1.2376, 2.5593 and 0.2182, the average, the maximum and the minimum color differences of the text set are 1.9318, 4.1421 and 0.4228. From the experimental results, we can make a conclusion that SVR can realize the nonlinear transformation from scanner RGB color space to CIELAB color space and the model satisfies the accuracy of scanner characterization. Therefore, SVR can be used into the color scanner characterization management.

  13. Analysis of a low-aberration holographic scanner.

    Shiozawa, T; Iwaoka, H

    1988-05-15

    Low-aberration holographic scanners that eliminate the need tor lenses or mirrors promise to greatly reduce the cost of laser printers and image scanners. This paper describes how the spot profile of such a scanner can be predicted using the Fresnel-Kirchhoff diffraction integral, and the diffraction efficiency of the scanner can be predicted using Kogelnik's coupled-wave theory. Experimental results verity the accuracy of these design methods. For a prototype scanner used in a high-resolution He-Ne laser printer, the measured linearity error was under +/- 100 microm, and the spot size (half-intensity beamwidth) was under 60 microm for a span (scan width) of 280 mm. PMID:20531695

  14. Ionization beam scanner

    1973-01-01

    Inner structure of an ionization beam scanner, a rather intricate piece of apparatus which permits one to measure the density distribution of the proton beam passing through it. On the outside of the tank wall there is the coil for the longitudinal magnetic field, on the inside, one can see the arrangement of electrodes creating a highly homogeneous transverse electric field.

  15. Network Security Scanner

    G. Murali

    2011-11-01

    Full Text Available Network Security Scanner (NSS is a tool that allows auditing and monitoring remote network computers for possible vulnerabilities, checks your network for all potential methods that a hacker might use to attack it. Network Security Scanner is a complete networking utilities package that includes a wide range of tools for network security auditing, vulnerability Auditing, scanning, monitoring and more. Network Security Scanner (NSS is an easy to use, intuitive network security scanner that can quickly scan and audit your network computers for vulnerabilities, exploits, and information enumerations. Vulnerability management is an on-going process that protects your valuable data and it is a key component of an effective information security strategy, which provides comprehensive, preemptive protection against threats to your enterprise security. N.S.S is built on an architecture that allows for high reliability and scalability that caters for both medium and large sized networks. NSS consists of six modules. They are Host Scanning, Port Scanning, Pinging, NSLookup, Vulnerability Auditing and Trace route. NSS also performs live host detection, operating system identification, SNMP Auditing. Finds rouge services and open TCP and UDP ports. The ability varies to perform scanning over the network identifying the live hosts and guess the operating system of the remote hosts and installed programs into the remote hosts. Apart identifying the live hosts we could map the ports and list the services which are running in the host.

  16. Freestanding Complex Optical Scanners.

    Frisbie, David A.

    A complex freestanding optical mark recognition (OMR) scanner is one which is not on-line to an external processor; it has intelligence stemming from an internal processor located within the unit or system. The advantages and disadvantages of a complex OMR can best be assessed after identifying the scanning needs and constraints of the potential…

  17. Microarray Scanner for Fluorescence Detection

    2003-01-01

    A novel pseudo confocal microarray scanner is introduced, in which one dimension scanning is performed by a galvanometer optical scanner and a telecentric objective, another dimension scanning is performed by a stepping motor.

  18. Current Concept of Geometrical Accuracy

    Görög Augustín; Görögová Ingrid

    2014-01-01

    Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners). During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the fiel...

  19. Wire Chamber

    1986-01-01

    Two wire chambers made originally for the R807 Experiment at CERN's Intersecting Storage Rings. In 1986 they were used for the PS 201 experiment (Obelix Experiment) at LEAR, the Low Energy Antiproton Ring. The group of researchers from Turin, using the chambers at that time, changed the acquisition system using for the first time 8 bit (10 bit non linear) analog to digital conversion for incoming signals from the chambers. The acquisition system was controlled by 54 CPU and 80 digital signal processors. The power required for all the electronics was 40 kW. For the period, this system was one of the most powerful on-line apparatus in the world. The Obelix Experiment was closed in 1996. To find more about how a wire chamber works, see the description for object CERN-OBJ-DE-038.

  20. Extension of a thin-wire algorithm for wires moved laterally within a mesh

    Burke, G J; Steich, D J

    1998-11-01

    It was shown that the accuracy of results for wires moved laterally from mesh edges can be greatly improved by taking account of the behavior of the field in the vicinity of the wire. Also, the distance to the end of the wire can be adjusted within a cell by using a general second-order difference form for the derivative. Making the wire location completely independent of the mesh would require the additional ability to tilt the wire with respect to the edges. This seems to be a considerably more difficult problem than moving the wires laterally, since the component of the mesh field parallel to the wire gets mixed with the larger radial electric field due to charge on the wire. Simply averaging the mesh fields did not seem to work well, except in the case where the wire was tilted in one coordinate plane, and the mesh fields above and below the plane of the wire, on edges orthogonal to the wire normal, could be averaged. Further study is needed to develop a more general capability to tilt a wire with respect to the mesh.

  1. Coronary calcium scoring: modelling, predicting and correcting for the effect of CT scanner spatial resolution on Agatston and volume scores

    The purpose of this study was to evaluate the impact of spatial resolution on coronary calcium scoring by x-ray CT, to assess the scoring performance of different CT scanners as they are operated in the field and to correct for the effects of CT scanner spatial resolution on coronary calcium scoring. A phantom consisting of five aluminium wires of known diameter in water was used to measure spatial resolution and to assess scoring performance. Fourteen CT scanners (three helical, two dual, two electron-beam and seven multi-detector) from four manufacturers were evaluated, some under different operating conditions. One scanner was monitored over a 3 month period and again 6 months later. Both spatial resolution and image pixel size significantly affect calcium scoring results. Spatial resolution can be measured with a precision of about 2%. Scanner spatial resolution ranged from 1 to 1.7 mm full-width-half-maximum (FWHM), and pixel size from 0.25 to 0.86 mm. Spatial resolution differences introduce systematic scoring differences that range from 38% to 1100% depending on wire size. Significant temporal variations in spatial resolution were observed in the monitored scanner. By correcting all the scanners to the same target spatial resolution, the standard deviation of individual scanners with respect to a mean value (the spread) can be reduced by 25-70% for different wires. In conclusion, scanner spatial resolution significantly affects calcium scoring and should be controlled for. Scanner performance can change over time. Under ideal conditions, CT scanners should be operated with a standard spatial resolution for calcium scoring. When this is not possible, post-processing correction is a viable alternative

  2. Unconventional applications of wire bonding create opportunities for microsystem integration

    Automatic wire bonding is a highly mature, cost-efficient and broadly available back-end process, intended to create electrical interconnections in semiconductor chip packaging. Modern production wire-bonding tools can bond wires with speeds of up to 30 bonds per second with placement accuracies of better than 2 μm, and the ability to form each wire individually into a desired shape. These features render wire bonding a versatile tool also for integrating wires in applications other than electrical interconnections. Wire bonding has been adapted and used to implement a variety of innovative microstructures. This paper reviews unconventional uses and applications of wire bonding that have been reported in the literature. The used wire-bonding techniques and materials are discussed, and the implemented applications are presented. They include the realization and integration of coils, transformers, inductors, antennas, electrodes, through silicon vias, plugs, liquid and vacuum seals, plastic fibers, shape memory alloy actuators, energy harvesters and sensors. (topical review)

  3. The cobalt-60 container scanner

    The Institute of Nuclear Energy Technology (INET) has successfully designed and constructed a container (cargo) scanner, which uses cobalt-60 of 100-300 Ci as radiation source. The following performances of the Cobalt-60 container scanner have been achieved at INET: a) IQI (Image Quality Indicator) - 2.5% behind 100 mm of steel; b) CI (Contrast Indicator) - 0.7% behind 100 mm of steel; c) SP (Steel Penetration) - 240 mm of steel; d) Maximum Dose per Scanning - 0.02mGy; e) Throughput - twenty 40-foot containers per hour. These performances are equal or similar to those of the accelerator scanners. Besides these nice enough inspection properties, the Cobalt-60 scanner possesses many other special features which are better than accelerator scanners: a) cheap price - it will be only or two tenths of the accelerator scanner's; b) low radiation intensity - the radiation protection problem is much easier to solve and a lot of money can be saved on the radiation shielding building; c) much smaller area for installation and operation; d) simple operation and convenient maintenance; e) high reliability and stability. The Cobalt-60 container (or cargo) scanner is satisfied for boundary customs, seaports, airports and railway stations etc. Because of the nice special features said above, it is more suitable to be applied widely. Its high properties and low price will make it have much better application prospects

  4. Voxel-based classification of FDG PET in dementia using inter-scanner normalization.

    Thiele, Frank; Young, Stewart; Buchert, Ralph; Wenzel, Fabian

    2013-08-15

    Statistical mapping of FDG PET brain images has become a common tool in differential diagnosis of patients with dementia. We present a voxel-based classification system of neurodegenerative dementias based on partial least squares (PLS). Such a classifier relies on image databases of normal controls and dementia cases as training data. Variations in PET image characteristics can be expected between databases, for example due to differences in instrumentation, patient preparation, and image reconstruction. This study evaluates (i) the impact of databases from different scanners on classification accuracy and (ii) a method to improve inter-scanner classification. Brain FDG PET databases from three scanners (A, B, C) at two clinical sites were evaluated. Diagnostic categories included normal controls (NC, nA=26, nB=20, nC=24 for each scanner respectively), Alzheimer's disease (AD, nA=44, nB=11, nC=16), and frontotemporal dementia (FTD, nA=13, nB=13, nC=5). Spatially normalized images were classified as NC, AD, or FTD using partial least squares. Supervised learning was employed to determine classifier parameters, whereby available data is sub-divided into training and test sets. Four different database setups were evaluated: (i) "in-scanner": training and test data from the same scanner, (ii) "x-scanner": training and test data from different scanners, (iii) "train other": train on both x-scanners, and (iv) "train all": train on all scanners. In order to moderate the impact of inter-scanner variations on image evaluation, voxel-by-voxel scaling was applied based on "ratio images". Good classification accuracy of on average 94% was achieved for the in-scanner setups. Accuracy deteriorated for setups with mismatched scanners (79-91%). Ratio-image normalization improved all results with mismatched scanners (85-92%). In conclusion, automatic classification of individual FDG PET in differential diagnosis of dementia is feasible. Accuracy can vary with respect to scanner or

  5. Industrial CT scanner, TOSCANER-3000

    By the combined use of techniques of medical CT scanner and industrial X ray, development was made of a novel industrial CT scanner first in Japan, with plastics, ceramics, rubber, aluminium etc. for the subject. Being able to produce fine tomograms in a short time, to memorize and reserve test data, and to analyze the tomograms by means of rich functions of image processing, it can be widely utilized for quality control and inspection of products. (author)

  6. Nogle muligheder i scanner data

    Juhl, Hans Jørn

    2000-01-01

    I artiklen gives en diskussion af en række af de muligheder for effektivisering af marketingaktiviteter, der er til stede for såvel mærkevareudbyder som detaillist, ved udnyttelse af information fra scanner data......I artiklen gives en diskussion af en række af de muligheder for effektivisering af marketingaktiviteter, der er til stede for såvel mærkevareudbyder som detaillist, ved udnyttelse af information fra scanner data...

  7. Densitometry of autoradiographs by scanner

    One of the advantages of the autoradiography technique is the possibility of obtaining the distribution of the chemical elements over the whole surface samples. A method for transformation of the autoradiography image into an electronic format with the use of the digital document scanners of different types has been developed for computer analysis purposes. It is shown that the technique developed allows us to obtain the two-dimensional distribution of optical density of autoradiograms, replacing one-dimensional densitometry with the using of a microphotometer. A comparison with conventional densitometry is presented. In our work we examined both Small Office Home Office (SOHO) and drum type scanners. Drum scanners give a linear response within a wide range of optical density (up to 2.5), whereas SOHO-scanners possess a linear dependence characteristics up to 0.5. We have demonstrated that the response of SOHO-scanners can be approximated reasonably well by an exponential dependence permitting the optical density measurement to be extended to 2. The effects of the driver as well as of other parameters (gamma, contrast, brightness, filters and etc.) on the final image were studied. The digital scanners were used as tools for 2-D densitometry to investigate the distribution of Co, Fe, Pt and Ir bearing phases in geological samples

  8. REMEDY OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM)

    Sinha, S. K.

    2010-01-01

    WEDM is extensively used these days for generating complex geometries with tight tolerances on difficult-tomachine materials. Therefore, demand for improvement in precision has been ever increasing. The main source of inaccuracy is wire-lag, the cause and effect of which is well-known. Research has been going on to overcome this drawback. So far, the techniques suggested for improvement in accuracy are, in general, based on monitoring the machining process at hardware-level, which is not only...

  9. EFFECTS OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM

    S. K. SINHA

    2010-11-01

    Full Text Available WEDM is very useful wherever complex geometry with tight tolerances needs to be generated on hard materials. In view of modern and sophisticated technology readily available these days, the expectation of accuracy in WEDM is ever-increasing, and therefore, techniques for the improvement in WEDM must be developed. The main cause of inaccuracy is wire-lag, the cause and effect of which is described in the present work, along with a technique to obviate the problem in straight cutting. In a subsequent paper, a software approach (since the problem gets too complicated for improvement of accuracy in contour cutting is described.

  10. Estimating Single Tree Stem Volume of Pinus sylvestris Using Airborne Laser Scanner and Multispectral Line Scanner Data

    Barbara Koch

    2011-05-01

    Full Text Available So far, only a few studies have been carried out in central European forests to estimate individual tree stem volume of pine trees from high resolution remote sensing data. In this article information derived from airborne laser scanner and multispectral line scanner data were tested to predict the stem volume of 178 pines (Pinus sylvestris in a study site in the south-west of Germany. First, tree crowns were automatically delineated using both multispectral and laser scanner data. Next, tree height, crown diameter and crown volume were derived for each crown segment. All combinations of the derived tree features were used as explanatory variables in allometric models to predict the stem volume. A model with tree height and crown diameter had the best performance with respect to the prediction accuracy determined by a leave-one-out cross-validation: Root Mean Square Error (RMSE = 24.02% and Bias = 1.36%.

  11. Aircraft Scanners = NASA Digital Aerial Scanners (TMS, TIMS, NS001): Pre 1996

    U.S. Geological Survey, Department of the Interior — The Aircraft Scanners data set contains digital imagery acquired from several multispectral scanners including NS-001 Mutispectral scanner, Daedalus thematic mapper...

  12. Measurement of MRI scanner noise

    The present paper describes a simple method for the analysis of MRI scanner noise. Besides the heating of body tissue by strong RF radiation and the formation of circular currents in the body induced bey switching field gradients, a noise level of more than 100 dB(A) during the measurement belongs to the potential risks of MRI [1,2]. This risk is of particular concern for staff and accompanying persons who remain close to the scanner for different reasons (e.g., monitoring of anesthetized patients, reassuring of children). For this reason, and given the scanty information on noise provided in the manuals of the scanners, it is useful to quantify the noise level more exactly. This applies also to the evaluation of different sound-reducing methods for the patient. This presents the results of noise level measurements in the tomograph and in its surrounding, with and without noise reduction by headphones. (orig.)

  13. Geometric calibration between PET scanner and structured light scanner

    Kjer, Hans Martin; Olesen, Oline Vinter; Paulsen, Rasmus Reinhold;

    2011-01-01

    is a structured light scanner placed just above the patient tunnel on the High Resolution Research Tomograph (HRRT, Siemens). It continuously registers point clouds of a part of the patient's face. The relative motion is estimated as the rigid transformation between frames. A geometric calibration...

  14. Temporal analysis of multispectral scanner data.

    Richardson, A. J.; Wiegand, C. L.; Torline, R. J.

    1973-01-01

    Multispectral scanner reflectance data were sampled for bare soil, cotton, sorghum, corn, and citrus at four dates during a growing season (April, May, June, and July 1969) to develop a time-dependent signature for crop and soil discrimination. Discrimination tests were conducted for single-date and multidate formats using training and test data sets. For classifications containing several crops, the multidate or temporal approach improved discrimination compared with the single-date approach. The multidate approach also preserved recognition accuracy better in going from training fields to test fields than the single-date analysis. The spectral distinctiveness of bare soil versus vegetation resulted in essentially equal discrimination using single-date versus multidate data for those two categories.

  15. An RF dosimeter for independent SAR measurement in MRI scanners

    Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B1) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ∼3%. With the torso landmarked at the xiphoid, human adult whole‑body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average

  16. Automatic inventory of components by laser 3D scanner

    One of the existing needs in nuclear decommissioning projects is to provide an inventory of components to be dismantled, which is available from its spatial location and elements that exist in your environment. The Laser scanner technology is a system of data acquisition that allows 3D models composed of millions of points, it's models with pinpoint accuracy and are available in a very short space of time. (Author)

  17. Barcode scanner for ring dosemeters

    A barcode scanner for circular bar codes was developed as an additional module for a dosimeter-reader manufactured in the USA. The new scanner had to fulfill all existing interface specifications (power supply, serial interface) to be integrated seamlessly into the existing instrument. The size of the barcode reader had to be compact enough to fit into the instrument without the need for additional external components. The barcode scanner has been realized using image processing technology. The system is designed in a way to fulfill all the functions of the 'old' laser barcode scanner (decoding of linear codes) plus the additional function of decoding circular barcodes in parallel. The system consists of CCD (charge coupled device) camera, infrared illumination, image processing hardware (frame grabber) and computer. The computer runs an image processing software developed in C. The result of the development effort is a fully functional prototype that is to be adapted for serial production (with minor modifications) by the US-manufacturer. (author)

  18. Wire bonding in microelectronics

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  19. A virtual spectral CT scanner

    Full text: Spectral computed tomography (sCT) brings a promise of improved tissue discrimination when compared to conventional CT. At the heart of this new technology are energy selective photon counting detectors (PCD) combined with theorics on how to select optimal energy bins for discriminating two or more materials. Several theories have been published on how to select these energy bins, but so far the diagnostic utility of optimised sCT has not been fully exploited. This work presents a first step towards a virtual sCT scanner based on the well bench marked BEAMnrc Monte Carlo code and the computer power of the University of Canterbury BlueFern supe computer. A computational model of a recently developed sCT scanner (MARS-CT) has been developed to produce virtual X-ray projection data through an imaging object. The energy and position of all transmitted photons impinging on the detector plane can be extracted without the additional complications introduced by non ideal behaviour (such as charge-sharing) of current detectors. The photons are grouped into selective energy bins to produce energy selective projection images of the imaging object (see Fig. I). This enables the comparison of conventional CT with optimised spectral CT. Furthermore, the virtual sCT scanner is an ideal tool to compare and evaluate the different theoretical models (which optimise different metrics) in terms of relevant clinical parameters such as image contrast. In further work we are planning to include the physical limitations of the detector so the virtual sCT scanner closely resembles the MARS CT scanner.

  20. Laser Wire Stripper

    1983-01-01

    NASA-developed space shuttle technology is used in a laser wire stripper designed by Raytheon Company. Laser beams cut through insulation on a wire without damaging conductive metal, because laser radiation that melts plastic insulation is reflected by the metal. The laser process is fast, clean, precise and repeatable. It eliminates quality control problems and the expense of rejected wiring.

  1. 21 CFR 892.1220 - Fluorescent scanner.

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fluorescent scanner. 892.1220 Section 892.1220...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1220 Fluorescent scanner. (a) Identification. A fluorescent scanner is a device intended to measure the induced fluorescent radiation in the body by...

  2. Scanner color management model based on improved back-propagation neural network

    Xinwu Li

    2008-01-01

    Scanner color management is one of the key techniques for color reproduction in information optics.A new scanner color management model is presented based on analyzing rendering principle of scanning objects.In this model,a standard color target is taken as experimental sample.Color blocks in color shade area are used to substitute complete color space to solve the difficulties in selecting experimental color blocks.Immune genetic algorithm is used to correct back-propagation neural network(BPNN)to speed up the convergence of the model.Experimental results show that the model can improve the accuracy of scanner color management.

  3. Application of intra-oral dental scanners in the digital workflow of implantology

    Meer, van der, D; Andriessen, F.S.; Wismeijer, D.; Ren, Y.

    2012-01-01

    Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. Materials and methods: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intra-oral scanners: the CEREC (Sirona), the iTero (Cadent) and the Lava COS (3M). In software the digital files were imported and the distance between the centres of the cylinders and the angulation b...

  4. Application of Intra-Oral Dental Scanners in the Digital Workflow of Implantology

    Wicher J van der Meer; Frank S Andriessen; Daniel Wismeijer; Yijin Ren

    2012-01-01

    Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. Materials and methods: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intra-oral scanners: the CEREC (Sirona), the iTero (Cadent) and the Lava COS (3M). In software the digital files were imported and the distance between the centres of the cylinders and the angulation b...

  5. Effect of wire shape on wire array discharge

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  6. Free-space wavelength-multiplexed optical scanner demonstration.

    Yaqoob, Zahid; Riza, Nabeel A

    2002-09-10

    Experimental demonstration of a no-moving-parts free-space wavelength-multiplexed optical scanner (W-MOS) is presented. With fast tunable lasers or optical filters and planar wavelength dispersive elements such as diffraction gratings, this microsecond-speed scanner enables large several-centimeter apertures for subdegree angular scans. The proposed W-MOS design incorporates a unique optical amplifier and variable optical attenuator combination that enables the calibration and modulation of the scanner response, leading to any desired scanned laser beam power shaping. The experimental setup uses a tunable laser centered at 1560 nm and a 600-grooves/mm blazed reflection grating to accomplish an angular scan of 12.92 degrees as the source is tuned over an 80-nm bandwidth. The values for calculated maximum optical beam divergance, required wavelength resolution, beam-pointing accuracy, and measured scanner insertion loss are 1.076 mrad, 0.172 nm, 0.06 mrad, and 4.88 dB, respectively. PMID:12224780

  7. A New Proton CT Scanner

    Coutrakon, G; Boi, S; Dyshkant, A; Erdelyi, B; Hedin, D; Johnson, E; Krider, J; Rykalin, V; Uzunyan, S A; Zutshi, V; Fordt, R; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P; Naimuddin, M

    2014-01-01

    The design, construction, and preliminary testing of a second generation proton CT scanner is presented. All current treatment planning systems at proton therapy centers use X-ray CT as the primary imaging modality for treatment planning to calculate doses to tumor and healthy tissues. One of the limitations of X-ray CT is in the conversion of X-ray attenuation coefficients to relative (proton) stopping powers, or RSP. This results in more proton range uncertainty, larger target volumes and therefore, more dose to healthy tissues. To help improve this, we present a novel scanner capable of high dose rates, up to 2~MHz, and large area coverage, 20~x~24~cm$^2$, for imaging an adult head phantom and reconstructing more accurate RSP values.

  8. Design of a multisensor optical surface scanner

    Bhatia, Gulab H.; Smith, Kirk E.; Commean, Paul K.; Whitestone, Jennifer J.; Vannier, Michael W.

    1994-10-01

    A reconfigurable, optical, 3D scanning system with sub-second acquisition of human body surface data was designed and simulated. Sensor elements (digital cameras/light beam projectors) that meet resolution, accuracy, and speed requirements are included in the system design. The sensors are interfaced to video frame grabber(s) under computer control resulting in a modular, low cost system. System operation and data processing are performed using a desktop graphics workstation. Surface data collected with this system can be oversampled to improve resolution and accuracy (viewed by overlapping camera/projector pairs). Multi- resolution data can be collected for different surfaces simultaneously or separately. Modeling and calibration of this reconfigurable system are achieved via a robust optimal estimation technique. Reconstruction software that allows seamless merging of a range data from multiple sensors has been implemented. Laser scanners that acquire body surface range data using one or two sensors require several seconds for data collection. Surface digitization of inaminate objects is feasible with such devices, but their use in human surface metrology is limited due to motion artifacts and occluded surfaces. Use of multiple, independent active sensors providing rapid collection and multi-resolution data enable sampling of complex human surface morphology not otherwise practical. 3D facial surface data has provided accurate measurements used in facial/craniofacial plastic surgery and modern personal protective equipment systems. Whole body data obtained with this new system is applicable to human factors research, medical diagnosis/treatment, and industrial design.

  9. REMEDY OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM

    S. K. SINHA

    2010-12-01

    Full Text Available WEDM is extensively used these days for generating complex geometries with tight tolerances on difficult-tomachine materials. Therefore, demand for improvement in precision has been ever increasing. The main source of inaccuracy is wire-lag, the cause and effect of which is well-known. Research has been going on to overcome this drawback. So far, the techniques suggested for improvement in accuracy are, in general, based on monitoring the machining process at hardware-level, which is not only tedious but involves extra expenditure also. In the present paper, a software approach for improvement in accuracy is described, which does not require any additional investment on the machine, and still gives very good results.

  10. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic18F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R2 = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast

  11. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    Huang, Chuan; Brady, Thomas J.; El Fakhri, Georges; Ouyang, Jinsong, E-mail: ouyang.jinsong@mgh.harvard.edu [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Ackerman, Jerome L. [Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Petibon, Yoann [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2014-04-15

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic{sup 18}F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R{sup 2} = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast.

  12. Optical position feedback for electrostatically driven MOEMS scanners

    Tortschanoff, A.; Baumgart, M.; Frank, A.; Wildenhain, M.; Sandner, T.; Schenk, H.; Kenda, A.

    2012-03-01

    For MOEMS devices which do not have intrinsic on-chip feedback, position information can be provided with optical methods, most simply by using a reflection from the backside of a MOEMS scanner. Measurement of timing signals using fast differential photodiodes can be used for resonant scanner mirrors performing sinusoidal motion with large amplitude. While this approach provides excellent accuracy it cannot be directly extended to arbitrary trajectories or static deflection angles. Another approach is based on the measurement of the position of the reflected laser beam with a quadrant diode. In this work, we present position sensing devices based on either principle and compare both approaches showing first experimental results from the implemented devices

  13. Wire + Arc Additive Manufacturing

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  14. Wire-bond inspection in IC assembly

    Rajeswari, Mandava; Rodd, Mike G.

    1996-02-01

    Wire-bonding in IC assembly process involves making a physical connection between the IC 'die' and the 'lead' by bonding wires between the two. Inspection of wire-bond quality is a' highly labor-intensive process and currently efforts are being made to automate it. This paper presents the results of a research conducted into developing a comprehensive automated wire- bond visual inspection system that is capable of performing final accept/reject inspection, providing on-line process feedback, and assisting in process validation. The proposed inspection system consists of the inspection of the bond on a bond pad, the bond on a lead and the inter-connecting wire between a bond pad and its corresponding lead. The algorithms are based on simple and easily extractable features that ensure achieving the desired accuracy and speed. A novel but simple illumination system is proposed to obtain the images of the inter- connecting wires. The proposed system is validated using several state-of-the-art IC samples. This work is sponsored by the Ministry of Science Technology and Environment, Malaysia and Intel Technology Pvt. Ltd., Malaysia.

  15. Photovoltaic Wire Project

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  16. 1998 wire development workshop proceedings

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  17. 1998 wire development workshop proceedings

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development

  18. Initial results of the quality control in 11 computed tomography scanners at Curitiba

    The aim of this study was to evaluate the image quality of 11 scanners installed in public and private centers of Curitiba, Brazil. This sample represents 30% of the CT scanners in the city so far. The ACR CT accreditation phantom was used to verify the accomplishment of the scanners performance to the international quality requirements. The results indicate that efforts should be concentrated in the maintenance of the equipments and specific training of the technicians. Most of the scanners have showed some non-conformity. In 27,5% of the sample the positioning requirement wasn't accomplished. The CT number accuracy evaluation showed that in 72,3 % of the scanners the CT numbers were out of the tolerance range, reaching values 35% greater than the limit. The low contrast resolution criteria weren't accomplished in 9% of the scanners. The main concern is that there isn't a specific program to evaluate the image quality of the CT scanners neither to estimate the CT doses in the procedures. (author)

  19. Comparison of working efficiency of terrestrial laser scanner in day and night conditions

    Arslan, A. E.; Kalkan, K.

    2013-10-01

    Terrestrial Laser Scanning is a popular and widely used technique to scan existing objects, document historical sites and items, and remodel them if and when needed. Their ability to collect thousands of point data per second makes them an invaluable tool in many areas from engineering to historical reconstruction. There are many scanners in the market with different technical specifications. One main technical specification of laser scanners is range and illumination. In this study, it is tested to be determined the optimal working times of a laser scanner and the scanners consistency with its specifications sheet. In order to conduct this work, series of GNSS measurements in Istanbul Technical University have been carried out, connected to the national reference network, to determine precise positions of target points and the scanner, which makes possible to define a precise distance between the scanner and targets. Those ground surveys has been used for calibration and registration purposes. Two different scan campaigns conducted at 12 am and 11 pm to compare working efficiency of laser scanner in different illumination conditions and targets are measured with a handheld spectro-radiometer in order to determine their reflective characteristics. The obtained results are compared and their accuracies have been analysed.

  20. Wire Array Photovoltaics

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  1. Selecting a CT scanner for cardiac imaging: the heart of the matter.

    Lewis, Maria A; Pascoal, Ana; Keevil, Stephen F; Lewis, Cornelius A

    2016-09-01

    Coronary angiography to assess the presence and degree of arterial stenosis is an examination now routinely performed on CT scanners. Although developments in CT technology over recent years have made great strides in improving the diagnostic accuracy of this technique, patients with certain characteristics can still be "difficult to image". The various groups will benefit from different technological enhancements depending on the type of challenge they present. Good temporal and spatial resolution, wide longitudinal (z-axis) detector coverage and high X-ray output are the key requirements of a successful CT coronary angiography (CTCA) scan. The requirement for optimal patient dose is a given. The different scanner models recommended for CTCA all excel in different aspects. The specification data presented here for these scanners and the explanation of the impact of the different features should help in making a more informed decision when selecting a scanner for CTCA. PMID:27302494

  2. Current Concept of Geometrical Accuracy

    Görög Augustín

    2014-06-01

    Full Text Available Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners. During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the field of geometric tolerance. It is necessary to bring an overview of the basic concepts and definitions in the field. It will prevent the use of outdated and invalidated terms and definitions in the field. The knowledge presented in the contribution will provide the new perspective of the measurement that will be evaluated according to the current standards.

  3. Current Concept of Geometrical Accuracy

    Görög, Augustín; Görögová, Ingrid

    2014-06-01

    Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutteŕs geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners). During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the field of geometric tolerance. It is necessary to bring an overview of the basic concepts and definitions in the field. It will prevent the use of outdated and invalidated terms and definitions in the field. The knowledge presented in the contribution will provide the new perspective of the measurement that will be evaluated according to the current standards.

  4. Gamma scanner conceptual design report

    The Fuels and Materials Examination Facility (FMEF) will include several stations for the nondestructive examination of irradiated fuels. One of these stations will be the gamma scanner which will be employed to detect gamma radiation from the irradiated fuel pins. The conceptual design of the gamma scan station is described. The gamma scanner will use a Standard Exam Stage (SES) as a positioner and transport mechanism for the fuel pins which it will obtain from a magazine. A pin guide mechanism mounted on the face of the collimator will assure that the fuel pins remain in front of the collimator during scanning. The collimator has remotely adjustable tungsten slits and can be manually rotated to align the slit at various angles. A shielded detector cart located in the operating corridor holds an intrinsic germanium detector and associated sodium-iodide anticoincidence detector. The electronics associated with the counting system consist of standard NIM modules to process the detector signals and a stand-alone multichannel analyzer (MCA) for counting data accumulation. Data from the MCA are bussed to the station computer for analysis and storage on magnetic tape. The station computer controls the collimator, the MCA, a source positioner and the SES through CAMAC-based interface hardware. Most of the electronic hardware is commercially available but some interfaces will require development. Conceptual drawings are included for mechanical hardware that must be designed and fabricated

  5. Automating wiring formboard design

    Van den Berg, T.

    2013-01-01

    Increase in aircraft wiring complexity call for manufacturing design improvements to reduce cost and lead-time. To achieve such improvements, a joint research project was performed by the Flight Performance and Propulsion (FPP) group and Fokker Elmo BV, the second largest aircraft wiring harness man

  6. Water Desalination with Wires.

    Porada, S; Sales, B B; Hamelers, H V M; Biesheuvel, P M

    2012-06-21

    We show the significant potential of water desalination using a novel capacitive wire-based technology in which anode/cathode wire pairs are constructed from coating a thin porous carbon electrode layer on top of electrically conducting rods (or wires). By alternately dipping an array of electrode pairs in freshwater with and in brine without an applied cell voltage, we create an ion adsorption/desorption cycle. We show experimentally how in six subsequent cycles we can reduce the salinity of 20 mM feed (brackish) water by a factor of 3, while application of a cation exchange membrane on the cathode wires makes the desalination factor increase to 4. Theoretical modeling rationalizes the experimental findings, and predicts that system performance can be significantly enhanced by material modifications. To treat large volumes of water, multiple stacks of wire pairs can be used simultaneously in a "merry-go-round" operational mode. PMID:26285717

  7. X-ray microtomographic scanners

    Syryamkin, V. I., E-mail: klestov-simon@mail.ru; Klestov, S. A., E-mail: klestov-simon@mail.ru [National Research Tomsk State University, Tomsk, 634050 (Russian Federation)

    2015-11-17

    The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. In conclusion, the main applications of X-ray tomography are presented.

  8. Laser Scanner For Automatic Storage

    Carvalho, Fernando D.; Correia, Bento A.; Rebordao, Jose M.; Rodrigues, F. Carvalho

    1989-01-01

    The automated magazines are beeing used at industry more and more. One of the problems related with the automation of a Store House is the identification of the products envolved. Already used for stock management, the Bar Codes allows an easy way to identify one product. Applied to automated magazines, the bar codes allows a great variety of items in a small code. In order to be used by the national producers of automated magazines, a devoted laser scanner has been develloped. The Prototype uses an He-Ne laser whose beam scans a field angle of 75 degrees at 16 Hz. The scene reflectivity is transduced by a photodiode into an electrical signal, which is then binarized. This digital signal is the input of the decodifying program. The machine is able to see barcodes and to decode the information. A parallel interface allows the comunication with the central unit, which is responsible for the management of automated magazine.

  9. Combined PET/MRI scanner

    Schlyer, David; Woody, Craig L.; Rooney, William; Vaska, Paul; Stoll, Sean; Pratte, Jean-Francois; O'Connor, Paul

    2007-10-23

    A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

  10. Immediate Feedback on Accuracy and Performance: The Effects of Wireless Technology on Food Safety Tracking at a Distribution Center

    Goomas, David T.

    2012-01-01

    The effects of wireless ring scanners, which provided immediate auditory and visual feedback, were evaluated to increase the performance and accuracy of order selectors at a meat distribution center. The scanners not only increased performance and accuracy compared to paper pick sheets, but were also instrumental in immediate and accurate data…

  11. Discriminant analyses of Bendix scanner data

    Richardson, A. J.; Wiegand, C. L.; Leamer, R. W.; Gerbermann, A. H.; Torline, R. J.

    1972-01-01

    Flights over Weslaco, Texas are discussed, using the 9-channel Bendix scanner, providing calibrated data in the 380 to 1000 nm wavelength interval. These flights were at 2000 ft. These data gave seasonal coverage from the time signals, representing mainly the soil background. The ground truth data are provided; signature processing studies relating scanner data to ground truth were also carried out.

  12. Sewer Scanner and Evaluation Technology (SSET)

    ECT Team, Purdue

    2007-01-01

    The investment in sanitary sewer collection system represent a major component of $20 trillion of U.S. investment in civil infrastructure systems. Sewer Scanner and Evaluation Technology (SSET) will overcome weaknesses of the closed circuit television and provide the engineer with more and higher quality information for rehabilitation decision making process by utilizing optical scanner and gyroscope technology.

  13. A dedicated tool for PET scanner simulations using FLUKA

    Positron emission tomography (PET) is a well-established medical imaging technique. It is based on the detection of pairs of annihilation gamma rays from a beta+-emitting radionuclide, usually inoculated in the body via a biologically active molecule. Apart from its wide-spread use for clinical diagnosis, new applications are proposed. This includes notably the usage of PET for treatment monitoring of radiation therapy with protons and ions. PET is currently the only available technique for non-invasive monitoring of ion beam dose delivery, which was tested in several clinical pilot studies. For hadrontherapy, the distribution of positron emitters, produced by the ion beam, can be analyzed to verify the correct treatment delivery. The adaptation of previous PET scanners to new environments and the necessity of more precise diagnostics by better image quality triggered the development of new PET scanner designs. The use of Monte Carlo (MC) codes is essential in the early stages of the scanner design to simulate the transport of particles and nuclear interactions from therapeutic ion beams or radioisotopes and to predict radiation fields in tissues and radiation emerging from the patient. In particular, range verification using PET is based on the comparison of detected and simulated activity distributions. The accuracy of the MC code for the relevant physics processes is obviously essential for such applications. In this work we present new developments of the physics models with importance for PET monitoring and integrated tools for PET scanner simulations for FLUKA, a fully-integrated MC particle-transport code, which is widely used for an extended range of applications (accelerator shielding, detector and target design, calorimetry, activation, dosimetry, medical physics, radiobiology, ...). The developed tools include a PET scanner geometry builder and a dedicated scoring routine for coincident event determination. The geometry builder allows the efficient

  14. Thermosonic wire bonding of IC devices using palladium wire

    The feasibility of replacing gold wire by palladium wire in thermosonic wire bonding of CMOS and bipolar devices are studied in terms of the manufacturability, physical, electrical and assembly performance. The results that palladium wire is a viable option for bonding the bipolar devices but not the CMOS devices

  15. Development of a mixed pixel filter for improved dimension estimation using AMCW laser scanner

    Wang, Qian; Sohn, Hoon; Cheng, Jack C. P.

    2016-09-01

    Accurate dimension estimation is desired in many fields, but the traditional dimension estimation methods are time-consuming and labor-intensive. In the recent decades, 3D laser scanners have become popular for dimension estimation due to their high measurement speed and accuracy. Nonetheless, scan data obtained by amplitude-modulated continuous-wave (AMCW) laser scanners suffer from erroneous data called mixed pixels, which can influence the accuracy of dimension estimation. This study develops a mixed pixel filter for improved dimension estimation using AMCW laser scanners. The distance measurement of mixed pixels is firstly formulated based on the working principle of laser scanners. Then, a mixed pixel filter that can minimize the classification errors between valid points and mixed pixels is developed. Validation experiments were conducted to verify the formulation of the distance measurement of mixed pixels and to examine the performance of the proposed mixed pixel filter. Experimental results show that, for a specimen with dimensions of 840 mm × 300 mm, the overall errors of the dimensions estimated after applying the proposed filter are 1.9 mm and 1.0 mm for two different scanning resolutions, respectively. These errors are much smaller than the errors (4.8 mm and 3.5 mm) obtained by the scanner's built-in filter.

  16. Copper wire bonding

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  17. Utilization of low-field MR scanners

    The evident advantage of high-field MR (magnetic resonance) scanners is their higher signal-to-noise ratio, which results in improved imaging. While no reliable efficacy studies exist that compare the diagnostic capabilities of low-versus high-field scanners, the adoption and acceptance of low-field MRI (magnetic resonance imaging) is subject to biases. On the other hand, the cost savings associated with low-field MRI hardware are obvious. The running costs of a non-superconductive low-field scanner show even greater differences in favor of low-field scanners. Patient anxiety and safety issues also reflect the advantages of low-field scanners. Recent technological developments in the realm of low-field MR scanners will lead to higher image quality, shorter scan times, and refined imaging protocols. Interventional and intraoperative use also supports the installation of low-field MR scanners. Utilization of low-field systems has the potential to enhance overall cost reductions with little or no loss of diagnostic performance. (author)

  18. Time-Domain Simulation of Three Dimensional Quantum Wires.

    Sullivan, Dennis M; Mossman, Sean; Kuzyk, Mark G

    2016-01-01

    A method is presented to calculate the eigenenergies and eigenfunctions of quantum wires. This is a true three-dimensional method based on a direct implementation of the time-dependent Schrödinger equation. It makes no approximations to the Schrödinger equation other than the finite-difference approximation of the space and time derivatives. The accuracy of our method is tested by comparing it to analytical results in a cylindrical wire. PMID:27124603

  19. Time-Domain Simulation of Three Dimensional Quantum Wires

    Mossman, Sean; Kuzyk, Mark G.

    2016-01-01

    A method is presented to calculate the eigenenergies and eigenfunctions of quantum wires. This is a true three-dimensional method based on a direct implementation of the time-dependent Schrödinger equation. It makes no approximations to the Schrödinger equation other than the finite-difference approximation of the space and time derivatives. The accuracy of our method is tested by comparing it to analytical results in a cylindrical wire. PMID:27124603

  20. Optical design for POS hologram scanner

    Yamazaki, Kozo; Ichikawa, Toshiyuki; Ikeda, Hiroyuki; Inagaki, Takefumi

    1986-08-01

    This paper presents newly developed optical design techniques for a shallow-type POS hologram scanner. POS scanner optical design involves design of the scan pattern to read the bar code and design of the detection system. For scan pattern design, we have developed a "readability map" method and a "scanning diagram" method. Detection system design took into account laser safety standards, and we used a technique for estimating the power of the detected signal. We have realized a shallow-type POS hologram scanner which is only 16cm high and can be operated from a sitting position.

  1. Absolute Temperature Monitoring Using RF Radiometry in the MRI Scanner.

    El-Sharkawy, Abdel-Monem M; Sotiriadis, Paul P; Bottomley, Paul A; Atalar, Ergin

    2006-11-01

    Temperature detection using microwave radiometry has proven value for noninvasively measuring the absolute temperature of tissues inside the body. However, current clinical radiometers operate in the gigahertz range, which limits their depth of penetration. We have designed and built a noninvasive radiometer which operates at radio frequencies (64 MHz) with ∼100-kHz bandwidth, using an external RF loop coil as a thermal detector. The core of the radiometer is an accurate impedance measurement and automatic matching circuit of 0.05 Ω accuracy to compensate for any load variations. The radiometer permits temperature measurements with accuracy of ±0.1°K, over a tested physiological range of 28° C-40° C in saline phantoms whose electric properties match those of tissue. Because 1.5 T magnetic resonance imaging (MRI) scanners also operate at 64 MHz, we demonstrate the feasibility of integrating our radiometer with an MRI scanner to monitor RF power deposition and temperature dosimetry, obtaining coarse, spatially resolved, absolute thermal maps in the physiological range. We conclude that RF radiometry offers promise as a direct, noninvasive method of monitoring tissue heating during MRI studies and thereby providing an independent means of verifying patient-safe operation. Other potential applications include titration of hyper- and hypo-therapies. PMID:18026562

  2. Optical tomographic in-air scanner for external radiation beam 3D gel dosimetry

    Full text: Optical CT scanners are used to measure 3D radiation dose distributions in radiosensitive gels. For radiotherapy dose verification, 3D dose measurements are useful for verification of complex linear accelerator treatment planning and delivery techniques. Presently optical CTs require the use of a liquid bath to match the refractive index of the gel to minimise refraction of the light rays leading to distortion and artifacts. This work aims to develop a technique for scanning gel samples in free-air, without the requirement for a matching liquid bath. The scanner uses a He-Ne laser beam, fanned across the acrylic cylindrical gel container by a rotating mirror. The gel container was designed to produce parallel light ray paths through the gel. A pin phantom was used to quantify geometrical distortion of the reconstructed image, while uniform field exposures were used to consider noise, uniformity and artifacts. Small diameter wires provided an indication of the spatial resolution of the scanner. Pin phantom scans show geometrical distortion comparable to scanners using matching fluid baths. Noise, uniformity and artifacts were not found to be major limitations for this scanner approach. Spatial resolution was limited by laser beam spot size, typically 0.4 mm full width half maximum. A free-air optical CT scanner has been developed with the advantage of scanning without a matching fluid bath. Test results show it has potential to provide suitable quality 3D dosimetry measurements for external beam dose verification, while offering significant advantages in convenience and efficiency for routine use.

  3. Radiographic verification of pedicle screw pilot hole placement in thoracic spine using Kirschner wires versus spiral wires

    LIU Yi 刘一; ZHANG Shao-kun 张绍昆; MIAO Wei-wei 苗巍巍; SHAN Yu-xing 单玉兴; SUN Da-hui 孙大辉; WANG Bai 王柏; LI Yin-liang 李印良; HUANG Xiao-gang 黄晓刚

    2003-01-01

    Objective: To evaluate the feasibility of the pedicle screw pilot holes placement in thoracic spine using the spiral wires as the guide pin.Methods: The pedicle screw pilot holes were drilled within the center of the pedicle and the lateral and medial pedicle walls were violated in 9 human dried thoracic vertebrae.Kirschner wires or spiral wires were separately placed in the holes, and then the posteroanterior and lateral radiographs were taken.The radiographs were evaluated by 3 experienced spine surgeons and 3 young orthopedists.After radiographs were shown to these observers, they combined the posteroanterior and lateral radiographs in each place and determined whether the pedicle screw pilot hole violated the pedicle cortex or not.The results were analyzed by a statistical software.Results: Sensitivity, specificity and accuracy of the method using spiral wires to detect pedicle pilot hole placement were significantly higher than those of using Kirschner wires.With a true posteroanterior radiograph, the sensitivity, specificity and accuracy of the method using spiral wires approximated or attained 100%.Conclusions: The method of intrapedicular pilot hole placement verification using spiral wires is effective for guiding the accurate placement of pedicle screws.

  4. A Cross-Platform Smartphone Brain Scanner

    Larsen, Jakob Eg; Stopczynski, Arkadiusz; Stahlhut, Carsten; Petersen, Michael Kai; Hansen, Lars Kai

    We describe a smartphone brain scanner with a low-costwireless 14-channel Emotiv EEG neuroheadset interfacingwith multiple mobile devices. This personal informaticssystem enables minimally invasive and continuouscapturing of brain imaging data in natural settings. Thesystem applies an inverse...

  5. Get Mobile – The Smartphone Brain Scanner

    Stahlhut, Carsten; Stopczynski, Arkadiusz; Petersen, Michael Kai; Larsen, Jakob Eg; Hansen, Lars Kai

    2012-01-01

    This demonstration will provide live-interaction with a smartphone brain scanner consisting of a low-cost wireless 14-channel EEG headset (Emotiv Epoc) and a mobile device. With our system it is possible to perform real-time functional brain imaging on a smartphone device, including stimulus delivery, data acquisition, logging, brain state decoding, and 3D visualization of the cortical EEG sources. Implementation of the smartphone brain scanner is based on the Qt framework and benefits from t...

  6. Modern wiring practice

    Steward, W E

    2012-01-01

    Continuously in print since 1952, Modern Wiring Practice has now been fully revised to provide an up-to-date source of reference to building services design and installation in the 21st century. This compact and practical guide addresses wiring systems design and electrical installation together in one volume, creating a comprehensive overview of the whole process for contractors and architects, as well as electricians and other installation engineers. Best practice is incorporated throughout, combining theory and practice with clear and accessible explanation, all

  7. Electric wiring domestic

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  8. Wiring and lighting

    Kitcher, Chris

    2013-01-01

    Wiring and Lighting provides a comprehensive guide to DIY wiring around the home. It sets out the regulations and legal requirements surrounding electrical installation work, giving clear guidelines that will enable the reader to understand what electrical work they are able to carry out, and what the testing and certification requirements are once the work is completed. Topics covered include: Different types of circuits; Types of cables and cable installation under floors and through joists; Isolating, earthing and bonding; Accessory boxes and fixings; Voltage bands; Detailed advice on safe

  9. a Light-Weight Laser Scanner for Uav Applications

    Tommaselli, A. M. G.; Torres, F. M.

    2016-06-01

    Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  10. MEMS temperature scanner: principles, advances, and applications

    Otto, Thomas; Saupe, Ray; Stock, Volker; Gessner, Thomas

    2010-02-01

    Contactless measurement of temperatures has gained enormous significance in many application fields, ranging from climate protection over quality control to object recognition in public places or military objects. Thereby measurement of linear or spatially temperature distribution is often necessary. For this purposes mostly thermographic cameras or motor driven temperature scanners are used today. Both are relatively expensive and the motor drive devices are limited regarding to the scanning rate additionally. An economic alternative are temperature scanner devices based on micro mirrors. The micro mirror, attached in a simple optical setup, reflects the emitted radiation from the observed heat onto an adapted detector. A line scan of the target object is obtained by periodic deflection of the micro scanner. Planar temperature distribution will be achieved by perpendicularly moving the target object or the scanner device. Using Planck radiation law the temperature of the object is calculated. The device can be adapted to different temperature ranges and resolution by using different detectors - cooled or uncooled - and parameterized scanner parameters. With the basic configuration 40 spatially distributed measuring points can be determined with temperatures in a range from 350°C - 1000°C. The achieved miniaturization of such scanners permits the employment in complex plants with high building density or in direct proximity to the measuring point. The price advantage enables a lot of applications, especially new application in the low-price market segment This paper shows principle, setup and application of a temperature measurement system based on micro scanners working in the near infrared range. Packaging issues and measurement results will be discussed as well.

  11. VEGETATION CHARACTERISTICS USING MULTI-RETURN TERRESTRIAL LASER SCANNER

    F. Pirotti

    2012-09-01

    Full Text Available Distinguishing vegetation characteristics in a terrestrial laser scanner dataset is an interesting issue for environmental assessment. Methods for filtering vegetation points to distinguish them from ground class have been widely studied mostly on datasets derived from airborne laser scanner, less so for terrestrial laser scanners (TLS. Recent developments in terrestrial laser sensors – further ranges, faster acquisition and multiple return echoes for some models – has risen interest for surface modelling applications. The downside of TLS is that a typical dataset has a very dense cloud, with obvious side-effects on post-processing time. Here we use a scan from a sensor which provides evaluation of multiple target echoes providing with more than 70 million points on our study area. The area presents a complex set of features ranging from dense vegetation undergrowth to very steep and uneven terrain. The method consists on a first step which subsets the original points to define ground candidates by taking into account the ordinal return number and the amplitude. Next a custom progressive morphological filter (closing operation is applied on ground candidate points using multidimensional (varying resolutions grids and a structure element to determine cell values. Vegetation density mapping over the area is then estimated using a weighted ration of point counts in the tri-dimensional space over each cell. The overall result is a pipeline for processing TLS points clouds with minimal user interaction, producing a Digital Terrain Model (DTM, a Digital Surface Model (DSM a vegetation density map and a derived canopy height model (CHM. Results on DTM show an accuracy (RMSE of 0.307 m with a mean error of 0.0573 m compared to a control DTM extracted from Terrascan's progressive triangulation procedure. The derived CHM was tested over 30 tree heights resulting in 27 trees having an absolute error value below 0.2 m (three were just below 0.7 m.

  12. A World without Wires

    Panettieri, Joseph C.

    2006-01-01

    The wireless bandwagon is rolling across Mississippi, picking up a fresh load of converts and turning calamity into opportunity. Traditional wired school networks, many of which unraveled during Hurricane Katrina, are giving way to advanced wireless mesh networks that frequently include voice-over-IP (VoIP) capabilities. Vendor funding is helping…

  13. Wire chamber conference

    This booklet contains program and the abstracts of the papers presented at the conference, most of them dealing with performance testing of various types of wire chambers. The publication of proceedings is planned as a special issue of 'Nuclear instruments and methods' later on. All abstracts are in English. An author index for the book of abstracts is given. (A.N.)

  14. Practical wiring in SI units

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  15. Wire EDM for Refractory Materials

    Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

    1982-01-01

    In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

  16. Guard wires in spark chambers

    The experiments with spark counters have shown that by surrounding the anode wire with two wires of a larger diameter, an increase of the detection efficiency of about 25% is observed. The analysis of the amplitudes of the pulses in those guard wires with the coincident pulses in the anode wire shows that is is possible to determine. The ionizing particle incidence position with rather simple and conventional electronic circuitry. (author). 5 refs, 7 figs

  17. Feasibility study of small animal imaging using clinical PET/CT scanner

    Hsu, Wen-Lin; Chen, Chia-Lin; Wang, Ze-Jing; Wu, Tung-Hsin; Liu, Dai-Wei; Lee, Jason J. S.

    2007-02-01

    The feasibility of small animal imaging using a clinical positron emission tomography/computed tomography (PET/CT) scanner with [F-18]-fluoro-2-deoxy- D-glucose (FDG) was evaluated. Two protocols in PET/CT system, single-mouse high-resolution mode (SHR) and multi-mouse high throughput mode (MHT) protocol were employed to investigate the ability of the scanner and also explored the performance differences between microPET and clinical PET/CT. In this study, we have found that even the clinical PET/CT scanner could not compete with the microPET scanner, especially in spatial resolution; the high-resolution CT image could advance the anatomical information to sub-millimeter level. Besides, CT-based attenuation correction can improve the image uniformity characteristics and quantification accuracy, and the large bore of a human whole-body scanner broadens the possibility of high throughput studies. Considering all the benefits, clinical PET/CT imaging might be a potential alternative for small animal study.

  18. LHC magnet quench test with beam loss generated by wire scan

    Sapinski, M; Dahlerup-Petersen, K; Dehning, B; Emery, j; Ferrari, A; Guerrero, A; Holzer, E B; Koujili, M; Lechner, A; Nebot, E; Scheubel, M; Steckert, J; Verweij, A; Wenninger, J

    2011-01-01

    Beam losses with millisecond duration have been observed in the LHC in 2010 and 2011. They are thought to be provoked by dust particles falling into the beam. These losses could compromise the LHC availability if they provoke quenches of superconducting magnets. In order to investigate the quench limits for this loss mechanism, a quench test using a wire scanner has been performed, with the wire movement through the beam mimicking a loss with similar spatial and temporal distribution as in the case of dust particles. This paper will show the conclusions reached for millisecond-duration dust-provoked quench limits. It will include details on the maximum energy deposited in the coil as estimated using FLUKA code, showing a reasonable agreement with quench limit estimated from the heat transfer code QP3. In addition, information on the damage limit for carbon wires in proton beamswill be presented, following electronmicroscope analysis which revealed strong wire sublimation.

  19. Cognition for robot scanner based remote welding

    Thombansen, U.; Ungers, Michael

    2014-02-01

    The effort for reduced cycle times in manufacturing has supported the development of remote welding systems which use a combination of scanners for beam delivery and robots for scanner positioning. Herein, close coupling of both motions requires a precise command of the robot trajectory and the scanner positioning to end up with a combined beam delivery. Especially the path precision of the robot plays a vital role in this kinematic chain. In this paper, a sensor system is being presented which allows tracking the motion of the laser beam against the work piece. It is based on a camera system which is coaxially connected to the scanner thus observing the relative motion of the laser beam relative to the work piece. The acquired images are processed with computer vision algorithms from the field of motion detection. The suitability of the algorithms is being demonstrated with a motion tracking tool which visualizes the homogeneity of the tracking result. The reported solution adds cognitive capabilities to manufacturing systems for robot scanner based materials processing. It allows evaluation of the relative motion between work piece and the laser beam. Moreover, the system can be used to adapt system programming during set-up of a manufacturing task or to evaluate the functionality of a manufacturing system during production. The presented sensor system will assist in optimizing manufacturing processes.

  20. Strain sensing systems tailored for tensile measurement of fragile wires

    Fundamental stress versus strain measurements were completed on superconducting Nb3Sn wires within the framework of IEC/TC90 and VAMAS/TWA16. A key task was the assessment of sensing systems regarding resolution, accuracy, and precision when measuring Young's modulus. Prior to actual Nb3Sn wire measurements metallic wires, consisting of copper and stainless steel having diameters similar to the Nb3Sn wire, were extensively investigated with respect to their elastic line properties using different types of extensometers. After these calibration tests Nb3Sn wire measurements of different companies resulted in several important facts with respect to total size and weight of the used extensometers. The size could be correlated to the initial stage of stress versus strain behaviour. In fact, the effect of wire curls resulting from the production line had a profound effect on Young's modulus measurements. Within this context, the possibility of determining Young's modulus from unloading compliance lines in the plastic regime of the stress-strain curve was considered. The data obtained using this test methodology were discussed under consideration of the composite nature of Nb3Sn wire. In addition, a non-contacting sensing system based on a double-beam laser extensometer was used to investigate the potential of this new sensing system

  1. Traveling wire electrode increases productivity of Electrical Discharge Machining /EDM/ equipment

    Kotora, J., Jr.; Smith, S. V.

    1967-01-01

    Traveling wire electrode on electrical discharge machining /EDM/ equipment reduces the time requirements for precision cutting. This device enables cutting with a minimum of lost material and without inducing stress beyond that inherent in the material. The use of wire increases accuracy and enables tighter tolerances to be maintained.

  2. Electro-optic and acousto-optic laser beam scanners

    Heberle, Johannes; Bechtold, Peter; Strauß, Johannes; Schmidt, Michael

    2016-03-01

    Electro-optical deflectors (EOD) and acousto-optical deflectors (AOD) are based on deflection of laser light within a solid state medium. As they do not contain any moving parts, they yield advantages compared to mechanical scanners which are conventionally used for laser beam deflection. Even for arbitrary scan paths high feed rates can be achieved. In this work the principles of operation and characteristic properties of EOD and AOD are presented. Additionally, a comparison to mirror based mechanical deflectors regarding deflection angles, speed and accuracy is made in terms of resolvable spots and the rate of resolvable spots. Especially, the latter one is up to one order of magnitude higher for EOD and AOD systems compared to conventional systems. Further characteristic properties such as response time, damage threshold, efficiency and beam distortions are discussed. Solid state laser beam deflectors are usually characterized by small deflection angles but high angular deflection velocities. As mechanical deflectors exhibit opposite properties an arrangement of a mechanical scanner combined with a solid state deflector provides a solution with the benefits of both systems. As ultrashort pulsed lasers with average power above 100 W and repetition rates in the MHz range have been available for several years this approach can be applied to fully exploit their capabilities. Thereby, pulse overlap can be reduced and by this means heat affected zones are prevented to provide proper processing results.

  3. 2D X-ray scanner and its uses in laboratory reservoir characterization measurements

    Maloney, D.; Doggett, K.

    1997-08-01

    X-ray techniques are used in petroleum laboratories for a variety of reservoir characterization measurements. This paper describes the configuration of a 2D X-ray scanner and many of the ways in which it simplifies and improves accuracy`s of laboratory measurements. Linear X-ray scanners are most often used to provide descriptions of fluid saturations within core plugs during flow tests. We configured our linear scanner for both horizontal and vertical movement. Samples can be scanned horizontally, vertically, or according to horizontal and vertical grids. X-ray measurements are fast, allowing measurements of two- and three-phase fluid saturations during both steady- and unsteady-state flow processes. Rock samples can be scanned while they are subjected to stress, pore pressure, and temperature conditions simulating those of a petroleum reservoir. Many types of measurements are possible by selecting appropriate X-ray power settings, dopes, filters, and collimator configurations. The scanner has been used for a variety of applications besides fluid saturation measurements. It is useful for measuring porosity distributions in rocks, concentrations of X-ray dopes within flow streams during tracer tests, gap widths in fracture flow cells, fluid interface levels in PVT cells and fluid separators, and other features and phenomena.

  4. Task force report on computerized tomographic scanners

    1978-10-01

    Computerized axial tomography (CAT) scanning was the focus of a task force established by the Bergen-Passaic Health Systems Agency in New Jersey. The task force reviewed the literature on CAT technology and its applications, surveyed four northeastern hospitals with operating CAT scanning installations, and created three working subcommittees which produced written reports. It was agreed by task force members that certain criteria should be used when evaluating applications for CAT scanners, e.g., service area, staff resources, emergency room activity, radiotherapy, 24-hour scanner coverage, the medically indigent, and cost. Overall, it was determined that CAT is a proven diagnostic tool of significant value and that it should be available to residents of the Bergen-Passaic health service area. Since the CAT field is rapidly evolving and changing, however, it was not possible to define quantitatively the long-term need for and supply of CAT scanners in the region. Appendixes present supporting data on the task force findings.

  5. Functional Extensions To High Performance Document Scanners

    Green, W. B.; Chansky, L. M.; Land, R. A.; Van den Heuvel, R. C.; Kraemer, E. J.; Steele, L. W.; Sherrill, C. J.

    1989-07-01

    Document processing systems based on electronic imaging technology are evolving rapidly, motivated by technology advances in optical storage, image scanners, image compression, high speed digital communications, and high resolution displays. These evolving systems require high speed reliable image scanning systems to create the digital image data base that is at the heart of the applications addressed by these evolving systems. High speed production document scanners must provide the capability of converting a wide variety of input material into high quality digital imagery. The required capabilities include: (i) the ability to scan varying sizes and weights of paper, (ii) image enhancement techniques adequate to produce quality imagery from a document material that may depart significantly from standard high contrast black and white office correspondence, (iii) standard compression options, and (iv) a standard interface to a host or control processor providing full control of all scanner operations and all image processing options. As electronic document processing systems proliferate, additional capabilities will be required to support automated or semi-automated document indexing and selective capture of document content. Capabilities now present on microfilming systems will be required as options or features on document capture systems. These capabilities will include: endorsers, bar code readers, and optical character recognition (OCR) capability. Bar code and OCR capabilities will be required to support automated indexing of scanned material, and OCR capability within specific areas of scanned document material will be required to support indexing and specific application needs. These features will also be supported and controlled through a standard host interface. This paper describes the architecture of the TDC DocuScan Digital Image Scanner. The scanner is a double-sided scanner that produces compressed imagery of both sides of a scanned page in under two

  6. Medical imaging with a microwave tomographic scanner.

    Jofre, L; Hawley, M S; Broquetas, A; de los Reyes, E; Ferrando, M; Elias-Fusté, A R

    1990-03-01

    A microwave tomographic scanner for biomedical applications is presented. The scanner consists of a 64 element circular array with a useful diameter of 20 cm. Electronically scanning the transmitting and receiving antennas allows multiview measurements with no mechanical movement. Imaging parameters are appropriate for medical use: a spatial resolution of 7 mm and a contrast resolution of 1% for a measurement time of 3 s. Measurements on tissue-simulating phantoms and volunteers, together with numerical simulations, are presented to assess the system for absolute imaging of tissue distribution and for differential imaging of physiological, pathological, and induced changes in tissues. PMID:2329003

  7. Miniature rotating transmissive optical drum scanner

    Lewis, Robert (Inventor); Parrington, Lawrence (Inventor); Rutberg, Michael (Inventor)

    2013-01-01

    A miniature rotating transmissive optical scanner system employs a drum of small size having an interior defined by a circumferential wall rotatable on a drum axis, an optical element positioned within the interior of the drum, and a light-transmissive lens aperture provided at an angular position in the circumferential wall of the drum for scanning a light beam to or from the optical element in the drum along a beam azimuth angle as the drum is rotated. The miniature optical drum scanner configuration obtains a wide scanning field-of-view (FOV) and large effective aperture is achieved within a physically small size.

  8. A simple scanner for Compton tomography

    Cesareo, R; Brunetti, A; Golosio, B; Castellano, A

    2002-01-01

    A first generation CT-scanner was designed and constructed to carry out Compton images. This CT-scanner is composed of a 80 kV, 5 mA X-ray tube and a NaI(Tl) X-ray detector; the tube is strongly collimated, generating a X-ray beam of 2 mm diameter, whilst the detector is not collimated to collect Compton photons from the whole irradiated cylinder. The performances of the equipment were tested contemporaneous transmission and Compton images.

  9. From Wires to Cosmology

    Amin, Mustafa A

    2015-01-01

    We provide a statistical framework for characterizing stochastic particle production in the early universe via a precise correspondence to current conduction in wires with impurities. Our approach is particularly useful when the microphysics is uncertain and the dynamics are complex, but only coarse-grained information is of interest. We study scenarios with multiple interacting fields and derive the evolution of the particle occupation numbers from a Fokker-Planck equation. At late times, the typical occupation numbers grow exponentially which is the analog of Anderson localization for disordered wires. Some statistical features of the occupation numbers show hints of universality in the limit of a large number of interactions and/or a large number of fields. For test cases, excellent agreement is found between our analytic results and numerical simulations.

  10. Randomly Wired Multistage Networks

    Maggs, Bruce M.

    1993-01-01

    Randomly wired multistage networks have recently been shown to outperform traditional multistage networks in three respects. First, they have fast deterministic packet-switching and circuit-switching algorithms for routing permutations. Second, they are nonblocking, and there are on-line algorithms for establishing new connections in them, even if many requests for connections are made simultaneously. Finally, and perhaps most importantly, they are highly fault tolerant.

  11. Fast beam steering with full polarization control using a galvanometric optical scanner and polarization controller

    Jofre M.; Anzolin G.; Steinlechner F.; Oliverio N.; Torres J. P.; Pruneri V.; Mitchell M.W.

    2012-01-01

    Optical beam steering is a key element in many industrial and scientific applications like in material processing, information technologies, medical imaging and laser display. Even though galvanometer-based scanners offer flexibility, speed and accuracy at a relatively low cost, they still lack the necessary control over the polarization required for certain applications. We report on the development of a polarization steerable system assembled with a fiber polarization controller and a galva...

  12. Industrial X-ray CT scanner

    New inspection needs are being posed as a result of recent development of new materials and new technology. Introduced is a newly developed industrial X-ray CT Scanner including application examples, which will answer to some of the new needs

  13. A PET scanner developed by CERN

    Laurent Guiraud

    1998-01-01

    This image shows a Position Emission Tomography (PET) scanner at the Hopital Cantonal Universitaire de Genève. Development of the multiwire proportional chamber at CERN in the mid-1970s was soon seen as a potential device for medical imaging. It is much more sensitive than previous devices and greatly reduced the dose of radiation received by the patient.

  14. Ultrasonic Scanner Control and Data Acquisition

    Hemann, John

    2002-01-01

    The research accomplishments under this grant were very extensive in the areas of ULTRASONIC SCANNER CONTROL AND DATA ACQUISITION. Rather than try to summarize all this research I have enclosed research papers and reports which were completed with the hnding provided by the grant. These papers and reports are listed below:

  15. Dual wire welding torch and method

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  16. Moisture-insensitive optical fingerprint scanner based on polarization resolved in-finger scattered light.

    Back, Seon-Woo; Lee, Yong-Geon; Lee, Sang-Shin; Son, Geun-Sik

    2016-08-22

    A moisture-insensitive optical fingerprint scanner (FPS) that is based on polarization resolved in-finger light is proposed and realized. Incident visible light, which is selectively fed to a fingerprint sample via a polarization beam splitter (PBS), is deemed to be partially scattered backward by tissues associated with the skin of the finger. The backscattered light is mostly index-guided in the ridge comprising the fingerprint, which has a higher refractive index, and is drastically dispersed in the valley, which is typically filled with water or air and so has a lower index. However, when light reflects directly off the surface of the finger skin, it fundamentally prevents the scanned image from being determined. The proposed FPS produces bright and dark intensity patterns that are alternately created on the surface of the PBS and correspond to the ridges and valleys, respectively. Thus, this method can especially distinguish between a fake synthetic fingerprint and a genuine fingerprint due to its use of in-finger scattered light. The scanner has been rigorously designed by carrying out ray-optic simulations depending on the wavelength, with tissue-induced scattering taken into account. The device was constructed by incorporating a wire-grid type PBS in conjunction with visible LED sources, including blue, green and red. The scanner adopting a blue LED, which exhibits the strongest light scattering, resulted in the best fingerprint image, enabling enhanced fidelity under the wet and dry situations. Finally, a fake synthetic fingerprint could be successfully discriminated. PMID:27557199

  17. Right wire in orthodontics: a review

    Ali, Hashim

    2015-01-01

    Quality of orthodontic wire such as stiffness, hardness, resiliency, elasticity and working range are important determinants of the effectivenes of tooth movement. Commonly used types of orthodontic arch wire:1) stainless steel(ss) wire, 2) conventional nickel- titanium (NiTi)alloy wire,3) improved super elastic NiTi- alloy wire( also called low hysteresis(LH)wire), and titanium molybdenum alloy(TMA) wire.

  18. Inter-site and inter-scanner diffusion MRI data harmonization.

    Mirzaalian, H; Ning, L; Savadjiev, P; Pasternak, O; Bouix, S; Michailovich, O; Grant, G; Marx, C E; Morey, R A; Flashman, L A; George, M S; McAllister, T W; Andaluz, N; Shutter, L; Coimbra, R; Zafonte, R D; Coleman, M J; Kubicki, M; Westin, C F; Stein, M B; Shenton, M E; Rathi, Y

    2016-07-15

    We propose a novel method to harmonize diffusion MRI data acquired from multiple sites and scanners, which is imperative for joint analysis of the data to significantly increase sample size and statistical power of neuroimaging studies. Our method incorporates the following main novelties: i) we take into account the scanner-dependent spatial variability of the diffusion signal in different parts of the brain; ii) our method is independent of compartmental modeling of diffusion (e.g., tensor, and intra/extra cellular compartments) and the acquired signal itself is corrected for scanner related differences; and iii) inter-subject variability as measured by the coefficient of variation is maintained at each site. We represent the signal in a basis of spherical harmonics and compute several rotation invariant spherical harmonic features to estimate a region and tissue specific linear mapping between the signal from different sites (and scanners). We validate our method on diffusion data acquired from seven different sites (including two GE, three Philips, and two Siemens scanners) on a group of age-matched healthy subjects. Since the extracted rotation invariant spherical harmonic features depend on the accuracy of the brain parcellation provided by Freesurfer, we propose a feature based refinement of the original parcellation such that it better characterizes the anatomy and provides robust linear mappings to harmonize the dMRI data. We demonstrate the efficacy of our method by statistically comparing diffusion measures such as fractional anisotropy, mean diffusivity and generalized fractional anisotropy across multiple sites before and after data harmonization. We also show results using tract-based spatial statistics before and after harmonization for independent validation of the proposed methodology. Our experimental results demonstrate that, for nearly identical acquisition protocol across sites, scanner-specific differences can be accurately removed using the

  19. Occurrence and characteristics of mutual interference between LIDAR scanners

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  20. Dual-Antenna Terrestrial Laser Scanner Georeferencing Using Auxiliary Photogrammetric Observations

    Benjamin Wilkinson

    2015-09-01

    Full Text Available Terrestrial laser scanning typically requires the use of artificial targets for registration and georeferencing the data. This equipment can be burdensome to transport and set up, representing expense in both time and labor. Environmental factors such as terrain can sometimes make target placement dangerous or impossible, or lead to weak network geometry and therefore degraded product accuracy. The use of additional sensors can help reduce the required number of artificial targets and, in some cases, eliminate the need for them altogether. The research presented here extends methods for direct georeferencing of terrestrial laser scanner data using a dual GNSS antenna apparatus with additional photogrammetric observations from a scanner-mounted camera. Novel combinations of observations and processing methods were tested on data collected at two disparate sites in order to find the best method in terms of processing efficiency and product quality. In addition, a general model for the scanner and auxiliary data is given which can be used for least-squares adjustment and uncertainty estimation in similar systems with varied and diverse configurations. We found that the dual-antenna system resulted in cm-level accuracy practical for many applications and superior to conventional one-antenna systems, and that auxiliary photogrammetric observation significantly increased accuracy of the dual-antenna solution.

  1. Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

    Yoshida, Eiji, E-mail: rush@nirs.go.jp; Tashima, Hideaki; Yamaya, Taiga

    2014-11-01

    In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate

  2. Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

    In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate

  3. Review of wire chamber aging

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

  4. AUTOMATED CONTROL AND REAL-TIME DATA PROCESSING OF WIRE SCANNER/HALO SCRAPER MEASUREMENTS

    The Low-Energy Demonstration Accelerator (LEDA), assembled and operating at Los Alamos National Laboratory, provides the platform for obtaining measurements of high-power proton beam-halo formation. Control system software and hardware have been integrated and customized to enable the production of real-time beam-halo profiles. The Experimental Physics and Industrial Control System (EPICS) hosted on a VXI platform, Interactive Data Language (IDL) programs hosted on UNIX platforms, and LabVIEW (LV) Virtual Instruments hosted on a PC platform have been integrated and customized to provide real-time, synchronous motor control, data acquisition, and data analysis of data acquired through specialized DSP instrumentation. These modules communicate through EPICS Channel Access (CA) communication protocol extensions to control and manage execution flow ensuring synchronous data acquisition and real-time processing of measurement data. This paper describes the software integration and management scheme implemented to produce these real-time beam profiles

  5. Applications of Optical Scanners in an Academic Center.

    Molinari, Carol; Tannenbaum, Robert S.

    1995-01-01

    Describes optical scanners, including how the technology works; applications in data management and research; development of instructional materials; and providing community services. Discussion includes the three basic types of optical scanners: optical character recognition (OCR), optical mark readers (OMR), and graphic scanners. A sidebar…

  6. Adhesion strength study of IBAD-MOCVD-based 2G HTS wire using a peel test

    A peel test was used to study the adhesion strength of a commercial grade 2G HTS wire which features a characteristic multilayer structure with the rare earth-based MOCVD superconducting film deposited on an IBAD-MgO template. The peel test could be carried out at various peeling angles (from 90° to 180°) and the peel strength of a wire was defined as the steady-state peeling load determined from a load-displacement curve. The test results had good reproducibility and accuracy, making the test a reliable and useful method for studying the adhesion strength of the wire. By characterizing the peeled surfaces the weakest interface in a wire could be identified. The peel strength data of the wire was analyzed together with the performance of the experimental magnet coils fabricated using the wire. The effect of the silver contact layer annealing on the peel strength is discussed.

  7. Shot noise in parallel wires

    Lagerqvist, Johan; Chen, Yu-Chang; Di Ventra, Massimiliano

    2004-01-01

    We report first-principles calculations of shot noise properties of parallel carbon wires in the regime in which the interwire distance is much smaller than the inelastic mean free path. We find that, with increasing interwire distance, the current approaches rapidly a value close to twice the current of each wire, while the Fano factor, for the same distances, is still larger than the Fano factor of a single wire. This enhanced Fano factor is the signature of the correlation between electron...

  8. THERMAL CONDUCTIVITY OF METALLIC WIRES

    LU XIANG; GU JI-HUA; CHU JUN-HAO

    2001-01-01

    The effect of radial thickness on the thermal conductivity of a free standing wire is investigated. The thermal conductivity is evaluated using the Boltzmann equation. A simple expression for the reduction in conductivity due to the increase of boundary scattering is presented. A comparison is made between the experimental results of indium wires and the theoretical calculations. It is shown that this decrease of conductivity in wires is smaller than that in film where heat flux is perpendicular to the surface.

  9. Wire explosion in water

    Prukner, Václav; Koláček, Karel; Schmidt, Jiří; Frolov, Oleksandr; Štraus, Jaroslav

    Praha, 2007 - (Schmidt, J.; Simek, M.; Pekarek, S.; Prukner, V.). s. 145-145 ISBN 978-80-87026-00-7. [XXVIII International conference on phenomena in ionized gases ICPIG’07/28th./. 15.7.2007-20.7.2007, Prague] R&D Projects: GA ČR GA202/06/1324; GA AV ČR KJB100430702; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z20430508 Keywords : Wire explosion * x-ray * laser * plasma Subject RIV: BL - Plasma and Gas Discharge Physics

  10. Wire explosion in water

    Prukner, Václav; Koláček, Karel; Schmidt, Jiří; Frolov, Oleksandr; Štraus, Jaroslav

    Prague: Institute of Plasma Physics AS CR,v.v.i, 2008 - (Schmidt, J.; Šimek, M.; Pekárek, S.; Prukner, V.), s. 1279-1281. (ICPIG. 28). ISBN 978-80-87026-01-4. [XXVIII International conference on phenomena in ionized gases ICPIG’07. Prague (CZ), 15.07.2007-20.07.2007] R&D Projects: GA ČR GA202/06/1324; GA AV ČR KJB100430702; GA MŠk 1P04LA235 Institutional research plan: CEZ:AV0Z20430508 Keywords : Wire explosion * x-ray * laser * plasma Subject RIV: BL - Plasma and Gas Discharge Physics

  11. Wiring regulations in brief

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  12. Wire communication engineering

    This book describes wire telecommunication engineering/ It is divided into eleven chapter, which deal with Introduction with development of telecommunication, voice and sound wave and communication network, Telegraphy with summary of telegraphy, code of telegraphy, communication speed, morse and telex, Telephone on structure, circuit and image telephone, Traffic on telecommunication traffic, transmission of line about theory, cable line and loaded cable, carrier communication with carrier telegraphy and carrier telephone, optical communication with types, structure, specialty, laser and equipment, DATA, Mobile telecommunication on summary, mobile telephone, radio paging and digital mobile telecommunication, ISDN with channel of ISDN, and service of ISDN, and design of telecommunication.

  13. Evaluation of a pulsed terrestrial laser scanner based on ISO standards

    Tsakiri, M.; Pagounis, V.; Arabatzi, O.

    2015-03-01

    The evaluation of the accuracy and precision of measuring equipment is critical in order to achieve results that meet the specifications of a given project. Standard calibration models and field procedures exist for all traditional surveying instruments, but are still lacking for recently developed technologies like terrestrial laser scanners (TLS). The main reason is limited knowledge of errors that affect these systems, owing to the proprietary design of the scanners and their software, and the integration of many potential sources of error. Owing to the difficulty of separating the different error sources of TLS, it is proposed in this paper that a test procedure can assess the overall achievable precision for a scanner instrument without individual errors being known. The proposed tests are based on the International Organization for Standardization specifications for geodetic instruments (www.iso.org). The tests can be performed in either a controlled or uncontrolled environment, which is advantageous for on-the-job calibration. A pulsed terrestrial laser scanner (Leica Scanstation 2) was used as a test subject and the evaluation results indicated that the specific instrument performed well within the manufacturer’s specifications.

  14. Evaluation of a pulsed terrestrial laser scanner based on ISO standards

    The evaluation of the accuracy and precision of measuring equipment is critical in order to achieve results that meet the specifications of a given project. Standard calibration models and field procedures exist for all traditional surveying instruments, but are still lacking for recently developed technologies like terrestrial laser scanners (TLS). The main reason is limited knowledge of errors that affect these systems, owing to the proprietary design of the scanners and their software, and the integration of many potential sources of error. Owing to the difficulty of separating the different error sources of TLS, it is proposed in this paper that a test procedure can assess the overall achievable precision for a scanner instrument without individual errors being known. The proposed tests are based on the International Organization for Standardization specifications for geodetic instruments (www.iso.org). The tests can be performed in either a controlled or uncontrolled environment, which is advantageous for on-the-job calibration. A pulsed terrestrial laser scanner (Leica Scanstation 2) was used as a test subject and the evaluation results indicated that the specific instrument performed well within the manufacturer’s specifications. (paper)

  15. Improved attenuation correction for freely moving animal brain PET studies using a virtual scanner geometry

    Angelis, Georgios I.; Ryder, William J.; Kyme, Andre Z.; Fulton, Roger R.; Meikle, Steven R.

    2014-03-01

    Attenuation correction in positron emission tomography brain imaging of freely moving animals can be very challenging since the body of the animal is often within the field of view and introduces a non negligible atten- uating factor that can degrade the quantitative accuracy of the reconstructed images. An attractive approach that avoids the need for a transmission scan involves the generation of the convex hull of the animal's head based on the reconstructed emission images. However, this approach ignores the potential attenuation introduced by the animal's body. In this work, we propose a virtual scanner geometry, which moves in synchrony with the animal's head and discriminates between those events that traverse only the animal's head (and therefore can be accurately compensated for attenuation) and those that might have also traversed the animal's body. For each pose a new virtual scanner geometry was defined and therefore a new system matrix was calculated leading to a time-varying system matrix. This new approach was evaluated on phantom data acquired on the microPET Focus 220 scanner using a custom-made rat phantom. Results showed that when the animal's body is within the FOV and not accounted for during attenuation correction it can lead to bias of up to 10%. On the contrary, at- tenuation correction was more accurate when the virtual scanner was employed leading to improved quantitative estimates (bias <2%), without the need to account for the animal's body.

  16. Laser scanner 3D terrestri e mobile

    Mario Ciamba

    2013-08-01

    Full Text Available Recentemente si è svolto a Roma un evento dimostrativo per informare, professionisti e ricercatori del settore inerente il rilievo strumentale, sulle recenti innovazioni che riguardano i laser scanner 3d. Il mercato della strumentazione dedicata al rilevamento architettonico e dell'ambiente, offre molte possibilità di scelta. Oggi i principali marchi producono strumenti sempre più efficienti ed ideati per ambiti di applicazione specifici, permettendo ai professionisti, la giusta scelta in termini di prestazioni ed economia.A demonstration event was recently held in Rome with the aim to inform professionals and researchers on recent innovations on instrumental survey related to the 3d laser scanner. The market of instrumentation for architectural survey offers many possibilitiesof choice. Today the major brands produce instruments that are more efficient and designed for specific areas of application, allowing the right choice in terms of performance and economy.

  17. Compact conscious animal positron emission tomography scanner

    Schyler, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois; Volkow, Nora

    2006-10-24

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

  18. Development of high pressure pipe scanners

    This report describes an automatic ultrasonic scanning system for pressure pipe welds, which was developed in this project using recent advanced technologies on mobile robot and computer. The system consists of two modules: a robot scanner module which navigates and manipulates scanning devices, and a data acquisition module which generates ultrasonic signal and processes the data from the scanner. The robot has 4 magnetic wheels and 2 -axis manipulator on which ultrasonic transducer attached. The wheeled robot can navigate curved surface such as outer wall of circular pipes. Magnetic wheels were optimally designed through magnetic field analysis. Free surface sensing and line tracking control algorithm were developed and implemented, and the control devices and software can be used in practical inspection works. We expect our system can contribute to reduction of inspection time, performance enhancement, and effective management of inspection results

  19. Inferring Consideration Set from Scanner Data

    Wirawan Dony Dahana; Nozomi Nakajima

    2011-01-01

    Consideration set has been one of main research topics in marketing field for a long time. Using interview data, many studies have been conducted to investigate the nature of its content. However, only few studies tried to do so by using consumer purchase history. By modeling the process of consideration and choice set formation, in this research we try to elicit consumer consideration set from scanner data. Some managerial implications for marketing decisions derived from the information of ...

  20. Get Mobile – The Smartphone Brain Scanner

    Stahlhut, Carsten; Stopczynski, Arkadiusz; Petersen, Michael Kai;

    This demonstration will provide live-interaction with a smartphone brain scanner consisting of a low-cost wireless 14-channel EEG headset (Emotiv Epoc) and a mobile device. With our system it is possible to perform real-time functional brain imaging on a smartphone device, including stimulus deli......) that are based on Linux operating systems. Thus our system runs on multiple platforms, including Maemo/MeeGo based smartphones, Android-based smartphones and tablet devices....

  1. Determining Block Detector Positions for PET Scanners

    Pierce, Larry; Miyaoka, Robert; Lewellen, Tom; Alessio, Adam; Kinahan, Paul

    2009-01-01

    We present an algorithm for accurate localization of block detectors in a positron emission tomography (PET) scanner. Accurate reconstruction of PET images requires precise knowledge of the physical position and orientation of the detectors. However, in some systems, block detector positioning and orientation can have relatively large tolerances, leading to implicit errors in the coincidence line-of-response (LOR) positioning. To compensate we utilize a rotating point source phantom where the...

  2. Scanner-based macroscopic color variation estimation

    Kuo, Chunghui; Lai, Di; Zeise, Eric

    2006-01-01

    Flatbed scanners have been adopted successfully in the measurement of microscopic image artifacts, such as granularity and mottle, in print samples because of their capability of providing full color, high resolution images. Accurate macroscopic color measurement relies on the use of colorimeters or spectrophotometers to provide a surrogate for human vision. The very different color response characteristics of flatbed scanners from any standard colorimetric response limits the utility of a flatbed scanner as a macroscopic color measuring device. This metamerism constraint can be significantly relaxed if our objective is mainly to quantify the color variations within a printed page or between pages where a small bias in measured colors can be tolerated as long as the color distributions relative to the individual mean values is similar. Two scenarios when converting color from the device RGB color space to a standardized color space such as CIELab are studied in this paper, blind and semi-blind color transformation, depending on the availability of the black channel information. We will show that both approaches offer satisfactory results in quantifying macroscopic color variation across pages while the semi-blind color transformation further provides fairly accurate color prediction capability.

  3. Software development for modeling positrons emission tomograph scanners

    The Geant4 Application for Tomographic Emission (GATE) is an international platform recognized and used to develop Computational Model Exposure (CME) in the context of Nuclear Medicine, although currently there are dedicated modules for applications in Radiotherapy and Computed Tomography (CT). GATE uses Monte Carlo (MC) methods, and has a scripting language of its own. The writing of scripts for simulation of a PET scanner in GATE involves a number of interrelated steps, and the accuracy of the simulation is dependent on the correct setup of the geometries involved, since the physical processes depend on them, as well as the modeling of electronic detectors in module Digitizer, for example. The manual implementation of this setup can be a source of errors, especially for users without experience in the field of simulations or without any previous knowledge of a programming language, and also due to the the fact that the modeling process in GATE still remains bounded to LINUX / UNIX based systems, an environment only familiar to a few. This becomes an obstacle for beginners and prevents the use of GATE by a larger number of users interested in optimizing their experiments and/or clinical protocols through a more accessible, fast and friendly application. The objective of this work is therefore to develop a user-friendly software for the modeling of Positron Emission Tomography called GUIGATE (Graphical User Interface for GATE), with specific modules dedicated to quality control in PET scanners. The results exhibit the features available in this first version of GUIGATE, present in a set of windows that allow users to create their input files, perform and display in real time the model and analyze its output file in a single environment, allowing so intuitively access the entire architecture of the GATE simulation and to CERN's data analyzer, the ROOT. (author)

  4. Telescope with a wide field of view internal optical scanner

    Degnan, III, John James (Inventor); Zheng, Yunhui (Inventor)

    2012-01-01

    A telescope with internal scanner utilizing either a single optical wedge scanner or a dual optical wedge scanner and a controller arranged to control a synchronous rotation of the first and/or second optical wedges, the wedges constructed and arranged to scan light redirected by topological surfaces and/or volumetric scatterers. The telescope with internal scanner further incorporates a first converging optical element that receives the redirected light and transmits the redirected light to the scanner, and a second converging optical element within the light path between the first optical element and the scanner arranged to reduce an area of impact on the scanner of the beam collected by the first optical element.

  5. The Current in a Wire

    Thompson, Keith

    2009-01-01

    This little problem arose because I was frustrated with the standard electromagnetism texts, which show the magnetic field due to a current-bearing wire outside the wire [proportional to] 1/r and inside [proportional to] r. However, they never point out that the moving electrons must be influenced by the magnetic field created by the other moving…

  6. Precise measurement of internal sense-wire locations in high energy physics detectors

    The central tracking region of the Solenoidal Detector Collaboration detector being designed to operate at the Superconducting Super Collider will utilize gas-filled straw tubes for particle tracking; the straws, each containing a thin central wire for charge collection, will be collected into modules of a few hundred straws each. It is crucial for proper interpretation of the data that the positions of the sense wires be known to very high precision. A pattern-deviation scanning system is being investigated for determining if the sense wires in constructed modules are within 35 μm of their intended locations. The system involves moving a module in steps through a broad x-ray beam and comparing a response matrix of transmission measurements to a template which is characteristic of a ''perfectly'' aligned module. The pattern-deviation scanner approach is described and simulation results are presented. (author)

  7. Terrestrial Laser Scanner, Terrestrial SAR-RAR and topographic data: an integration proposal for monitoring the temple of Sagrada Familia in Barcelona

    Marambio Castillo, Alejandro Esteban; Pucci, Barbara; Jungner, Andreas; Núñez Andrés, María Amparo; Buill Pozuelo, Felipe

    2009-01-01

    In this paper three techniques are proposed to be integrated: Terrestrial Synthetic Aperture Radar, Terrestrial Laser Scanner and Traditional Topography. Terrestrial Synthetic Aperture Radar (SAR) is an evolving instrument that can be been used to detect deformations with high accuracy. The Ground-Based SAR instrument used in this paper has an intrinsic accuracy of submillimeter level which makes it suitable for high accuracy deformation detection. It is however fundamental to be ...

  8. Electroplated superconducting wire

    A hard chromium solution has been considered the least efficient of all plating solutions. This is not exactly true if the correct plating conditions are used. The accepted efficiency is only 12% but that is only true for the parameters that were used long ago to make the determination. At 12% efficiency it would be impossible to plate Superconductor wire. The world's chromium plating shops have been plating at a .001 (.025u) per hour rate since the turn of the century. Shops in the Cleveland, Ohio area have been limiting their plating rate to .006 (152u) since 1935. A few have used .012 (304u) to .030 (762u) per hour for specialized jobs. These figures would indicate the apparent efficiency of the old 100 to 1 chromium, sulfate solution can be higher than 60%. The industry uses a 3 bus bar tank with wide spacing between anode and cathode. This results in high solution resistance and high heat generation and consequently slow plating rates. The Reversible Rack 2 Bus Bar System uses very close anode to cathode spacings. This results in the high plating rates with improved quality deposits. When first asked to chromium plate pure nickel wire reel to reel in long lengths, companies making reel to reel machines were asked if chromium plating was practical. In every case, the answer was it couldn't be done. Gold, tin and zinc plating was being done reel to reel. Using the same parameters that were used to determine a chromium solution efficiency was only 12%, these other metal solutions check out close to 100%

  9. The impact of different alignment strategies on the overall performance of a white light scanner according to sphere spacing error specified in VDI 2634

    Klaas, Erik; Kropp, Johannes; Mongon, Bill

    2011-03-01

    System alignment strategies impact the overall performance of white light scanners, in particular affecting the uncertainty that is determined using the sphere spacing error specified in the VDI 2634 guideline. This paper addresses the accuracy of optical white light or so called "topometric" scanners. In almost any application of such scanners it is necessary to put together scans from different directions: from a couple of scans to a couple of hundred scans. Accuracy for the scanner itself can usually be well described for a single scan. However, the accuracy for assembled data sets from many scans is harder to estimate and specify as it depends on many more parameters as well as on the alignment strategy being used. This paper will describe different alignment strategies including the use of robots, tracking systems, and targets, as well as best fitting methods. The impact of these methods on the resulting overall accuracy is described and demonstrated using real test examples. In addition, different methods of achieving these accuracy numbers will be presented including using guidelines such as provided in VDI 2634. This paper will briefly touch on the basic principles of white light scanning to understand the potential as well as to illustrate the limitations of these techniques. This paper is intended to provide a useful guideline for engineers or quality managers who want to establish or learn more about new scanning technologies, with special attention given to the accuracy issues.

  10. Performance of a commercial optical CT scanner and polymer gel dosimeters for 3-D dose verification

    Performance analysis of a commercial three-dimensional (3-D) dose mapping system based on optical CT scanning of polymer gels is presented. The system consists of BANGreg3 polymer gels (MGS Research, Inc., Madison, CT), OCTOPUSTM laser CT scanner (MGS Research, Inc., Madison, CT), and an in-house developed software for optical CT image reconstruction and 3-D dose distribution comparison between the gel, film measurements and the radiation therapy treatment plans. Various sources of image noise (digitization, electronic, optical, and mechanical) generated by the scanner as well as optical uniformity of the polymer gel are analyzed. The performance of the scanner is further evaluated in terms of the reproducibility of the data acquisition process, the uncertainties at different levels of reconstructed optical density per unit length and the effects of scanning parameters. It is demonstrated that for BANGregistered3 gel phantoms held in cylindrical plastic containers, the relative dose distribution can be reproduced by the scanner with an overall uncertainty of about 3% within approximately 75% of the radius of the container. In regions located closer to the container wall, however, the scanner generates erroneous optical density values that arise from the reflection and refraction of the laser rays at the interface between the gel and the container. The analysis of the accuracy of the polymer gel dosimeter is exemplified by the comparison of the gel/OCT-derived dose distributions with those from film measurements and a commercial treatment planning system (Cadplan, Varian Corporation, Palo Alto, CA) for a 6 cmx6 cm single field of 6 MV x rays and a 3-D conformal radiotherapy (3DCRT) plan. The gel measurements agree with the treatment plans and the film measurements within the '3%-or-2 mm' criterion throughout the usable, artifact-free central region of the gel volume. Discrepancies among the three data sets are analyzed

  11. Potentials of small, lightweight and low cost Multi-Echo Laser Scanners for detecting Grape Berries

    Djuricic, A.; Weinmann, M.; Jutzi, B.

    2014-06-01

    Mobile sensor devices offer great opportunities for automatic scene analysis and object recognition. Nowadays a new generation of ranging devices is available, like laser scanners which are small and light weighted. Concerning these improvements specific applications can be tackled. In this contribution we focus on vineyard monitoring for detecting and counting grape berries with a small, lightweight and low cost multi-echo laser scanner. Therefore a Hokuyo UTM-30LX-EW laser range finder is utilized for capturing the data in close range up to 1m. In order to process the data the following methodology is proposed: after smoothing and morphological techniques are applied on the laserscanning intensity and range images the number of visible grape berries is determined from the resulting segments. The approach performs with a detection accuracy of above 84%. The results reveal the high potential of such close range ranging devices for locating and counting grape berries. Thus, the methodology provides practical support for viticulture applications.

  12. Fast beam steering with full polarization control using a galvanometric optical scanner and polarization controller

    Jofre, M; Steinlechner, F; Oliverio, N; Torres, J P; Pruneri, V; Mitchell, M W; 10.1364/OE.20.012247

    2012-01-01

    Optical beam steering is a key element in many industrial and scientific applications like in material processing, information technologies, medical imaging and laser display. Even though galvanometer-based scanners offer flexibility, speed and accuracy at a relatively low cost, they still lack the necessary control over the polarization required for certain applications. We report on the development of a polarization steerable system assembled with a fiber polarization controller and a galvanometric scanner, both controlled by a digital signal processor board. The system implements control of the polarization decoupled from the pointing direction through a feed-forward control scheme. This enables to direct optical beams to a desired direction without affecting its initial polarization state. When considering the full working field of view, we are able to compensate polarization angle errors larger than 0.2 rad, in a temporal window of less than $\\sim 20$ ms. Given the unification of components to fully cont...

  13. Plasma chemistry in wire chambers

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

  14. Parametric optimization of wire cut electrical discharge machining

    M. Durairaj

    2014-03-01

    Full Text Available Wire Electrical Discharge Machining is a manufacturing process whereby a desired shape is obtained using electrical discharges (or by repetitive spark cycle.  Precision and intricate machining are the strengths.  Machining parameters tables provided by the machine tool manufacturers often do not meet the operator requirements. Selection of optimum machining and machining parameters combinations is needed for obtaining higher cutting efficiency and accuracy. In this present study, machining is done using Wire-Cut EDM and optimization of surface roughness is done using Taguchi’s design of experiments. Experimentation was planned as per Taguchi’s L’16 orthogonal array. Each experiment has been performed under different cutting conditions of gap voltage, pulse ON time, and pulse OFF time and Wire feed. Dielectric fluid pressure, wire speed, wire tension, resistance and cutting length are taken as fixed parameters. Inconel 800 was selected as a work material to conduct the experiments. From experimental results, the surface roughness was determined for each machining performance criteria. Signal to noise ratio was applied to measure the performance characteristics deviating from the actual value. Finally, experimental confirmation was carried out to identify the effectiveness of this proposed method.   Keywords: Optimization; Taguchi’s L-16 Orthogonal Array; Surface Roughness; S/N Ratio.

  15. System analysis of bar code laser scanner

    Wang, Jianpu; Chen, Zhaofeng; Lu, Zukang

    1996-10-01

    This paper focuses on realizing the three important aspects of bar code scanner: generating a high quality scanning light beam, acquiring a fairly even distribution characteristic of light collection, achieving a low signal dynamic range over a large depth of field. To do this, we analyze the spatial distribution and propagation characteristics of scanning laser beam, the vignetting characteristic of optical collection system and their respective optimal design; propose a novel optical automatic gain control method to attain a constant collection over a large working depth.

  16. Biomedical Imaging and Sensing using Flatbed Scanners

    Göröcs, Zoltán; Ozcan, Aydogan

    2014-01-01

    In this Review, we provide an overview of flatbed scanner based biomedical imaging and sensing techniques. The extremely large imaging field-of-view (e.g., ~600–700 cm2) of these devices coupled with their cost-effectiveness provide unique opportunities for digital imaging of samples that are too large for regular optical microscopes, and for collection of large amounts of statistical data in various automated imaging or sensing tasks. Here we give a short introduction to the basic features o...

  17. Positron Scanner for Locating Brain Tumors

    Rankowitz, S.; Robertson, J. S.; Higinbotham, W. A.; Rosenblum, M. J.

    1962-03-01

    A system is described that makes use of positron emitting isotopes for locating brain tumors. This system inherently provides more information about the distribution of radioactivity in the head in less time than existing scanners which use one or two detectors. A stationary circular array of 32 scintillation detectors scans a horizontal layer of the head from many directions simultaneously. The data, consisting of the number of counts in all possible coincidence pairs, are coded and stored in the memory of a Two-Dimensional Pulse-Height Analyzer. A unique method of displaying and interpreting the data is described that enables rapid approximate analysis of complex source distribution patterns. (auth)

  18. Inter laboratory comparison of industrial CT scanners

    Angel, Jais Andreas Breusch; Cantatore, Angela; De Chiffre, Leonardo

    2012-01-01

    In this report results from an intercomparison of industrial CT scanners are presented. Three audit items, similar to common industrial parts, were selected for circulation: a single polymer part with complex geometry (Item 1), a simple geometry part made of two polymers (Item 2) and a miniature...... step gauge produced using a polymer replica material (Item 3). The items circulated among six participants in Denmark and Germany. The circulation took place between March 2011 and June 2011. The items were measured according to a given protocol....

  19. Calibrations for analyzing industrial samples on medical CT scanners

    Presented in this paper are calibrations for obtaining meaningful CT data for industrial samples using medical scanners. Calibrations were made using a second generation, dual slice Technicare Deltascan 100 scanner with a tungsten source, seven BGO detectors (three per slice plus one reference), a DEC PDP 11/04 computer system, and a set scan circle size of 11.4 inches. The unit operates at a tube current and voltage of 120 KV and 25 mA, respectively. While some calibrations are specific to the Deltascan 100, others can be applied to most medical instruments. Two types of calibrations are presented: (1) those that involve changes only to the sample; and (2) those that involve changes to the scanner and scanner software. The first type is necessary for cases in which a leased or rented scanner that cannot be modified is being used. Both types are useful for cases in which scanner modification is possible

  20. Target Price Accuracy

    Alexander G. Kerl

    2011-01-01

    This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown) 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio). However, target price accuracy is positive...

  1. Wire ropes tension, endurance, reliability

    Feyrer, Klaus

    2015-01-01

    The main goal of this book is to present the methods used to calculate the most important parameters for ropes, and to explain how they are applied on the basis of numerous sample calculations. The book, based on the most important chapters of the German book DRAHTSEILE, has been updated to reflect the latest developments, with the new edition especially focusing on computational methods for wire ropes. Many new calculations and examples have also been added to facilitate the dimensioning and calculation of mechanical characteristics of wire ropes. This book offers a valuable resource for all those working with wire ropes, including construction engineers, operators and supervisors of machines and installations involving wire ropes.

  2. Liquid fraction measurement by wire-mesh sensor in air-water stratified flows

    In this study, we carried out experiments for measuring the liquid fraction by using the commercial wire-mesh sensor which consists of 16x16 wires and high-speed camera in air-water stratified flows. For evaluating the accuracy of the wire-mesh sensor, static experiment was performed. Also the liquid fractions measured by the wire-mesh sensor in horizontal loop that pipe has inner diameter 40 mm and length is 5 m was compared with that by the high-speed camera. Deviation for the liquid fraction between the wire-mesh sensor and the high-speed camera is 0.02, small. Also it seems to have good agreements since it is showing similar trend. (author)

  3. Was the Scanner Calibration Slide used for its intended purpose?

    Zong Yaping

    2011-04-01

    Full Text Available Abstract In the article, Scanner calibration revisited, BMC Bioinformatics 2010, 11:361, Dr. Pozhitkov used the Scanner Calibration Slide, a key product of Full Moon BioSystems to generate data in his study of microarray scanner PMT response and proposed a mathematic model for PMT response 1. In the end, the author concluded that "Full Moon BioSystems calibration slides are inadequate for performing calibration," and recommended "against using these slides." We found these conclusions are seriously flawed and misleading, and his recommendation against using the Scanner Calibration Slide was not properly supported.

  4. Pulsed wire magnetic field measurement of MPW 14 at PLS

    A 14 cm-period multipole wiggler (MPW 14) was measured using a pulsed wire measurement (PWM) method. The PWM system uses a subminiature photo interrupter, which has a very sensitive output to the changes on the area of optical aperture. To improve the accuracy of measurement, the trigger pulses are synchronized with the background oscillation of the system. The magnetic field profile of the MPW 14 measured with PWM method was compared with that obtained with a Hall probe mapping

  5. Trends in Wire Electrical Discharge Machining (WEDM): A Review

    Ms. Sharanya S. Nair; Ms. Nehal Joshi

    2014-01-01

    The exponential growth of manufacturing industries and production and the increased need of accuracy and precision throws the spotlight on the nontraditional machining processes. The machining of metals and nonmetals having special properties like high strength, high hardness and toughness is done by non- conventional machining methods. Wire electrical discharge machining is one of the earliest non-traditional machining processes. This machining process competes with conventional ...

  6. Parametric optimization of wire cut electrical discharge machining

    Durairaj, M; A.K.S. Ansari; M. H. Gauthamkumar

    2014-01-01

    Wire Electrical Discharge Machining is a manufacturing process whereby a desired shape is obtained using electrical discharges (or) by repetitive spark cycle.  Precision and intricate machining are the strengths.  Machining parameters tables provided by the machine tool manufacturers often do not meet the operator requirements. Selection of optimum machining and machining parameters combinations is needed for obtaining higher cutting efficiency and accuracy. In this present study, machining i...

  7. High-picture quality industrial CT scanner

    Industrial X-ray-CT-scanners, which provide cross-sectional images of a tested sample without destroying it, are attracting attention as a new nondestructive inspection device. In 1982, Toshiba commenced the development of industrial CT scanners, and introduced the 'TOSCANER' -3000 and-4000 series. Now, the state of the art 'TOSCANER'-20000 series of CT systems has been developed incorporating the latest computer tomography and image processing technology, such as the T9506 image processor. One of the advantages of this system is its applicability to a wide range of X-ray energy . The 'TOSCANER'-20000 series can be utilized for inspecting castings and other materials with relatively low-transparency to X-rays, as well as ceramics, composite materials and other materials with high X-ray transparency. A further feature of the new system is its high-picture quality, with a high-spatial resolution resulting from a pixel size of 0.2x0.2(mm). (author)

  8. Interferometric Laser Scanner for Direction Determination

    Gennady Kaloshin

    2016-01-01

    Full Text Available In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5–10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km.

  9. Interferometric Laser Scanner for Direction Determination.

    Kaloshin, Gennady; Lukin, Igor

    2016-01-01

    In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5-10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km. PMID:26805841

  10. Quest for an open MRI scanner.

    Bertora, Franco; Borceto, Alice; Viale, Andrea; Sandini, Giulio

    2014-01-01

    A study of the motor cortex during the programming, execution and mental representation of voluntary movement is of great relevance; its evaluation in conditions close to reality is necessary, given the close integration of the visuomotor, sensory feedback and proprioceptive systems, as of yet, a functional Magnetic Resonance Imaging (fMRI) scanner allowing a human subject to maintain erect stance, observe the surroundings and conserve limb freedom is still a dream. The need for high field suggests a solenoid magnet geometry that forces an unnatural posture that affects the results, particularly when the motor cortex is investigated. In contrast in a motor functional study, the scanner should allow the subject to sit or stand, with unobstructed sight and unimpeded movement. Two approaches are presented here to solve this problem. In the first approach, an increased field intensity in an open magnet is obtained lining the "back wall" of the cavity with a sheet of current: this boosts the field intensity at the cost of the introduction of a gradient, which has to be canceled by the introduction of an opposite gradient; The second approach is an adaptation of the "double doughnut" architecture, in which the cavity widens at the center to provide additional room for the subject. The detailed design of this kind of structure has proven the feasibility of the solution. PMID:25227008

  11. Antenna Near-Field Probe Station Scanner

    Zaman, Afroz J. (Inventor); Lee, Richard Q. (Inventor); Darby, William G. (Inventor); Barr, Philip J. (Inventor); Lambert, Kevin M (Inventor); Miranda, Felix A. (Inventor)

    2011-01-01

    A miniaturized antenna system is characterized non-destructively through the use of a scanner that measures its near-field radiated power performance. When taking measurements, the scanner can be moved linearly along the x, y and z axis, as well as rotationally relative to the antenna. The data obtained from the characterization are processed to determine the far-field properties of the system and to optimize the system. Each antenna is excited using a probe station system while a scanning probe scans the space above the antenna to measure the near field signals. Upon completion of the scan, the near-field patterns are transformed into far-field patterns. Along with taking data, this system also allows for extensive graphing and analysis of both the near-field and far-field data. The details of the probe station as well as the procedures for setting up a test, conducting a test, and analyzing the resulting data are also described.

  12. A hybrid scanner for positron imaging

    A hybrid scanner has been built, which is specially designed for total body metabolic studies with short-lived labelled compounds. The scanner consists of two parallel detectors, 40-cm long, one above and one below the patient, which move along the body. The positions of scintillations along the detectors are detected by photomultipliers at the ends of the crystals, and the positions of scintillations along the patient's body are derived from the position of the mechanism carrying the detectors. Both single photon and coincidence modes are possible. The collimation was optimized for semi-dynamic total-body metabolic studies. The sensitivity of the instrument to a point source is about 400 counts/μCi per minute in the single photon mode and 60 counts/μCi per minute in the coincidence mode with positron energy. The resolution is 28 mm versus 22 mm (FWHM), and the maximal count rates with 25% loss are 22 000 versus 1700 counts/s. The scanning speed can be varied from 0.5 to 20 cm/s and the instrument is designed to scan five times per minute over one metre of the body. This makes relatively accurate measurements possible on phenomena that occur over 2 to 20 minutes. As preliminary applications the accumulation of 18F in a rabbit and a study of ethanol metabolism in a human subject are described. (author)

  13. Method of manufacturing superconductor wire

    Motowidlo, Leszek

    2014-09-16

    A method for forming Nb.sub.3Sn superconducting wire is provided. The method employs a powder-in-tube process using a high-tin intermetallic compound, such as MnSn.sub.2, for producing the Nb.sub.3Sn. The use of a high-tin intermetallic compound enables the process to perform hot extrusion without melting the high-tin intermetallic compound. Alternatively, the method may entail drawing the wire without hot extrusion.

  14. Topology Optimized Photonic Wire Splitters

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Jensen, Jakob Søndergaard;

    2006-01-01

    Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm.......Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm....

  15. 49 CFR 236.74 - Protection of insulated wire; splice in underground wire.

    2010-10-01

    ... underground wire. 236.74 Section 236.74 Transportation Other Regulations Relating to Transportation (Continued... wire; splice in underground wire. Insulated wire shall be protected from mechanical injury. The insulation shall not be punctured for test purposes. Splice in underground wire shall have...

  16. 49 CFR 234.241 - Protection of insulated wire; splice in underground wire.

    2010-10-01

    ... underground wire. 234.241 Section 234.241 Transportation Other Regulations Relating to Transportation... of insulated wire; splice in underground wire. Insulated wire shall be protected from mechanical injury. The insulation shall not be punctured for test purposes. A splice in underground wire shall...

  17. HTS Wire Development Workshop: Proceedings

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  18. 1 mil gold bond wire study.

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  19. Design of a portable CAT scanner for utility pole inspection

    Work is under way at the University of Missouri, Columbia (UMC) to design, build, and test a portable computerized axial tomography (CAT) device for the nondestructive, field imaging of wooden utility poles. CAT is a well-established medical technology that has recently been applied to a number of industrial applications. Wooden utility poles are prone to rot and decay at ground level; current techniques to assess this loss of strength are relatively primitive, i.e., tapping the pole (hitting the pole with a hammer) or boring into the pole for samples and then testing inside the bore hole with an electrical pulse device. The accuracy in identifying poles needing replacement using these techniques is ∼ 70%. Since the cost of replacing a pole ranges from hundreds to thousands of dollars, an accurate, nondestructive method is needed. CAT can accurately image a wooden utility pole (since the size, density, and atomic elements of a pole are similar to the human head to torso), as was confirmed by imaging poles using the UMC nuclear engineering EMI-1010 medical scanner. Detailed images have been produced showing the ring structure of the wood and voids due to rot or decay. Images approaching this quality have also been produced on living trees using semiportable systems by other researchers

  20. ELECTROCHEMICAL MICROMACHINING USING VIBRATILE TUNGSTEN WIRE FOR HIGH-ASPECT-RATIO MICROSTRUCTURES

    Wang, K

    2010-01-01

    Electrochemical micromachining can remove electrically conductive materials with the transferring of ions, so that high precision is achievable. A novel method for fabricating high-aspect-ratio microstructures by electrochemical micromachining using vibratile tungsten wire was proposed in this paper. The slight vibration of tungsten wire can improve the machining stability. The relations between the machining accuracy and machining parameters were experimentally studied. Micro groove with the...

  1. Asymmetric gradient coil design for use in a short, open bore magnetic resonance imaging scanner

    Wang, Yaohui; Liu, Feng; Li, Yu; Tang, Fangfang; Crozier, Stuart

    2016-08-01

    A conventional cylindrical whole-body MRI scanner has a long bore that may cause claustrophobia for some patients in addition to being inconvenient for healthcare workers accessing the patient. A short-bore scanner usually offers a small sized imaging area, which is impractical for imaging some body parts, such as the torso. This work proposes a novel asymmetric gradient coil design that offers a full-sized imaging area close to one end of the coil. In the new design, the primary and shielding coils are connected at one end whilst separated at the other, allowing the installation of the cooling system and shim trays. The proposed coils have a larger wire gap, higher efficiency, lower inductance, less resistance and a higher figure of merit than the non-connected coils. This half-connected coil structure not only improves the coils' electromagnetic performance, but also slightly attenuates acoustic radiation at most frequencies when compared to a non-connected gradient coil. It is also quieter in some frequency bands than a conventional symmetric gradient coil.

  2. Wire chambers revisited

    Multiwire proportional chambers (MWPCs) have long been used as position-sensitive charged particle detectors in nuclear and high-energy physics. MWPCs are large-area gas-filled ionisation chambers in which large arrays of fine wires are used to measure the position of ionisation produced in the gas by the passage of charged particles. The important properties of MWPCs are high-spatial-resolution, large-area, high-count-rate performance at low cost. For research applications, detectors several metres square have been built and small-area detectors have a charged particle resolution of 0.4 mm at a count rate of several million per second. Modification is required to MWPCs for nuclear medicine imaging. A gamma rays or X-rays cannot be detected directly, they must be converted into photo- or Compton scatter electrons. Photon-electron conversion requires the use of high atomic number materials in the body of the chamber. Pressurised xenon is the most useful form of ''gas only'' photon-electron convertor and has been used successfully in a gamma camera for the detection of gamma rays at energies below 100 keV. This camera has been developed specifically for high-count-rate first-pass cardiac imaging. This high-pressure xenon gas MWPC is the key to a highly competitive system which can outperform scintillator-based systems. The count rate performance is close to a million counts per second and the intrinsic spatial resolution is better than the best scintillator-based camera.The only clinical detector have been developed for positron emission tomography, where thin lead or lead-glass can provide an acceptable convertor for 511 keV photons. Two MWPC positron cameras have been evaluated clinically and one is now routine use in clinical oncology. The problems of detection efficiency have not been solved by these detectors although reliability and large-area PET imaging have been proven. (orig./HSI)

  3. Scanner OPC signatures: automatic vendor-to-vendor OPE matching

    Renwick, Stephen P.

    2009-03-01

    As 193nm lithography continues to be stretched and the k1 factor decreases, optical proximity correction (OPC) has become a vital part of the lithographer's tool kit. Unfortunately, as is now well known, the design variations of lithographic scanners from different vendors cause them to have slightly different optical-proximity effect (OPE) behavior, meaning that they print features through pitch in distinct ways. This in turn means that their response to OPC is not the same, and that an OPC solution designed for a scanner from Company 1 may or may not work properly on a scanner from Company 2. Since OPC is not inexpensive, that causes trouble for chipmakers using more than one brand of scanner. Clearly a scanner-matching procedure is needed to meet this challenge. Previously, automatic matching has only been reported for scanners of different tool generations from the same manufacturer. In contrast, scanners from different companies have been matched using expert tuning and adjustment techniques, frequently requiring laborious test exposures. Automatic matching between scanners from Company 1 and Company 2 has remained an unsettled problem. We have recently solved this problem and introduce a novel method to perform the automatic matching. The success in meeting this challenge required three enabling factors. First, we recognized the strongest drivers of OPE mismatch and are thereby able to reduce the information needed about a tool from another supplier to that information readily available from all modern scanners. Second, we developed a means of reliably identifying the scanners' optical signatures, minimizing dependence on process parameters that can cloud the issue. Third, we carefully employed standard statistical techniques, checking for robustness of the algorithms used and maximizing efficiency. The result is an automatic software system that can predict an OPC matching solution for scanners from different suppliers without requiring expert intervention.

  4. Necessity and clinical application of diagnostic CT in PET-CT scanner

    PET scanning has a definite clinical impact on diagnosis, initial staging, restaging, monitoring therapeutic effects of malignancies, and on assessment of myocardial viability. Whereas, PET scans has false positive diagnosis and false negative diagnosis of malignant lesions. It leads to reduce specifity in PET imaging. application of diagnostic CT, especially applying contrast enhanced CT scans, three dimensional technique, CTA(CT angiography), CT perfusion and CT virtual endoscopy can realize dominance complementation with PET and CT, PET-CT imaging diagnosis combines with PET and CT diagnostic technique, it improves sensitivity, specifity, and accuracy in clinical application of PET-CT scanner. (authors)

  5. Track counting and thickness measurement of LR115 radon detectors using a commercial image scanner

    An original optical method for track counting and film thickness determination of etched LR115 radon detectors was developed. The method offers several advantages compared with standard techniques. In particular, it is non-destructive, very simple and rather inexpensive, since it uses a commercial scanner and a free software. The complete analysis and the calibration procedure carried out for the determination of radon specific activity are reported. A comparison with the results of spark counting defines the accuracy and the precision of the new technique. (authors)

  6. Improved Accurate Extrinsic Calibration Algorithm of Camera and Two-dimensional Laser Scanner

    Jianlei Kong; Lei Yan; Jinhao Liu; Qingqing Huang; Xiaokang Ding

    2013-01-01

    In the object detecting system composed of a camera and a two-dimensional laser scanner (2DLS), the extrinsic calibration is an essential step to operate properly. However, the edge points of object cannot be detected accurately by 2DLS due to angular resolution limit, which caused loss of accuracy of the extrinsic calibration between camera and 2DLS. In this paper a new algorithm is proposed to solve this problem. Firstly, the least-squares method was applied to linearly fit laser data locat...

  7. Robotic aircraft scanner for neutron radiographic inspection

    A robotic positioner and manipulator, a key component of a mobile neutron radiography system (MNRS) for aircraft inspection, is described. The MNRS is designed to inspect military aircraft for hidden corrosion in aluminum structures. The MNRS is comprised of an accelerator-based (Kaman A-711 sealed tube neutron generator using the deuterium-tritium reaction) thermal neutron source, electronic neutron imaging system, robotic positioner and manipulator for the source/imager, control trailer housing system control electronics and digital image processing system, mobile dark room for film processing, self-contained electrical power source, and radiation safety system. For in situ aircraft inspection, the robotic scanner is programmed (in a teach/learn mode) to scan a region of the components (e.g., wings, stabilizers, etc.) using a control pendant

  8. An improved image algorithm for CT scanners

    A common artifact in CT head-section images is a cupping or broad ''whitening'' effect near the skull which is due at least in part to the polychromaticity of the x-ray beam. In this paper, a general method is presented for removing this artifact empirically by a combination of two approaches. The gross cupping is removed by modifying the raw transmission data prior to reconstruction. The residual whitening near the bone is removed by conveniently modifying the reconstruction-filter function. Examples of the modifications are shown using the ASE CT scanner. The method convolves or deconvolves the CT image with an appropriate point spread function. Since the filter-function modifications conceptually done in real space rather than in frequency space, the details of the modifications are more easily understood

  9. Thermionic scanner pinpoints work function of emitter surfaces

    Rasor, N. S.

    1966-01-01

    In the electron tube testing, a thermionic scanner makes accurate spatial resolution measurements of the metallic surface work functions of emitters. The scanner determines the emitter function and its local departures from the mean value on a point-by-point basis for display on an oscilloscope.

  10. Radiation dosimetry of computed tomography x-ray scanners

    This report describes the development and application of the methods employed in National Radiation Laboratory (NRL) surveys of computed tomography x-ray scanners (CT scanners). It includes descriptions of the phantoms and equipment used, discussion of the various dose parameters measured, the principles of the various dosimetry systems employed and some indication of the doses to occupationally exposed personnel