WorldWideScience

Sample records for measured time points

  1. Legibility Evaluation Using Point-of-regard Measurement

    Science.gov (United States)

    Saito, Daisuke; Saito, Keiichi; Saito, Masao

    Web site visibility has become important because of the rapid dissemination of World Wide Web, and combinations of foreground and background colors are crucial in providing high visibility. In our previous studies, the visibilities of several web-safe color combinations were examined using a psychological method. In those studies, simple stimuli were used because of experimental restriction. In this paper, legibility of sentences on web sites was examined using a psychophisiological method, point-of-regard measurement, to obtain other practical data. Ten people with normal color sensations ranging from ages 21 to 29 were recruited. The number of characters per line in each page was arranged in the same number, and the four representative achromatic web-safe colors, that is, #000000, #666666, #999999 and #CCCCCC, were examined. The reading time per character and the gaze time per line were obtained from point-of-regard measurement, and the normalized with the reading time and the gaze time of the three colors were calculated and compared. As the results, it was shown that the time of reading and gaze become long at the same ratio when the contrast decreases by point-of-regard measurement. Therefore, it was indicated that the legibility of color combinations could be estimated by point-of-regard measurement.

  2. Measures and time points relevant for post-surgical follow-up in patients with inflammatory arthritis: a pilot study

    Directory of Open Access Journals (Sweden)

    Tägil Magnus

    2009-05-01

    Full Text Available Abstract Background Rheumatic diseases commonly affect joints and other structures in the hand. Surgery is a traditional way to treat hand problems in inflammatory rheumatic diseases with the purposes of pain relief, restore function and prevent progression. There are numerous measures to choose from, and a combination of outcome measures is recommended. This study evaluated if instruments commonly used in rheumatologic clinical practice are suitable to measure outcome of hand surgery and to identify time points relevant for follow-up. Methods Thirty-one patients (median age 56 years, median disease duration 15 years with inflammatory rheumatic disease and need for post-surgical occupational therapy intervention formed this pilot study group. Hand function was assessed regarding grip strength (Grippit, pain (VAS, range of motion (ROM (Signals of Functional Impairment (SOFI and grip ability (Grip Ability Test (GAT. Activities of daily life (ADL were assessed by means of Disabilities of the Arm, Shoulder and Hand Outcome (DASH and Canadian Occupational Performance Measure (COPM. The instruments were evaluated by responsiveness and feasibility; follow-up points were 0, 3, 6 and 12 months. Results All instruments showed significant change at one or more follow-up points. Satisfaction with activities (COPM showed the best responsiveness (SMR>0.8, while ROM measured with SOFI had low responsiveness at most follow-up time points. The responsiveness of the instruments was stable between 6 and 12 month follow-up which imply that 6 month is an appropriate time for evaluating short-term effect of hand surgery in rheumatic diseases. Conclusion We suggest a core set of instruments measuring pain, grip strength, grip ability, perceived symptoms and self-defined daily activities. This study has shown that VAS pain, the Grippit instrument, GAT, DASH symptom scale and COPM are suitable outcome instruments for hand surgery, while SOFI may be a more insensitive

  3. Comparison of Travel-Time and Amplitude Measurements for Deep-Focusing Time-Distance Helioseismology

    Science.gov (United States)

    Pourabdian, Majid; Fournier, Damien; Gizon, Laurent

    2018-04-01

    The purpose of deep-focusing time-distance helioseismology is to construct seismic measurements that have a high sensitivity to the physical conditions at a desired target point in the solar interior. With this technique, pairs of points on the solar surface are chosen such that acoustic ray paths intersect at this target (focus) point. Considering acoustic waves in a homogeneous medium, we compare travel-time and amplitude measurements extracted from the deep-focusing cross-covariance functions. Using a single-scattering approximation, we find that the spatial sensitivity of deep-focusing travel times to sound-speed perturbations is zero at the target location and maximum in a surrounding shell. This is unlike the deep-focusing amplitude measurements, which have maximum sensitivity at the target point. We compare the signal-to-noise ratio for travel-time and amplitude measurements for different types of sound-speed perturbations, under the assumption that noise is solely due to the random excitation of the waves. We find that, for highly localized perturbations in sound speed, the signal-to-noise ratio is higher for amplitude measurements than for travel-time measurements. We conclude that amplitude measurements are a useful complement to travel-time measurements in time-distance helioseismology.

  4. Model plant Key Measurement Points

    International Nuclear Information System (INIS)

    Schneider, R.A.

    1984-01-01

    For IAEA safeguards a Key Measurement Point is defined as the location where nuclear material appears in such a form that it may be measured to determine material flow or inventory. This presentation describes in an introductory manner the key measurement points and associated measurements for the model plant used in this training course

  5. LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter.

    Science.gov (United States)

    Liu, Wanli

    2017-03-08

    The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated.

  6. Exceptional points and quantum correlations in precise measurements

    International Nuclear Information System (INIS)

    Thilagam, A

    2012-01-01

    We examine the physical manifestations of exceptional points and passage times in a two-level system which is subjected to quantum measurements and which admits a non-Hermitian description. Using an effective Hamiltonian acting in the two-dimensional space spanned by the evolving initial and final states, the effects of highly precise quantum measurements in which the monitoring device interferes significantly with the evolution dynamics of the monitored two-level system is analyzed. The dynamics of a multipartite system consisting of the two-level system, a source of external potential and the measurement device is examined using correlation measures such as entanglement and non-classical quantum correlations. Results show that the quantum correlations between the monitored (monitoring) systems is considerably decreased (increased) as the measurement precision nears the exceptional point, at which the passage time is half of the measurement duration. The results indicate that the underlying mechanism by which the non-classical correlations of quantum systems are transferred from one subsystem to another may be better revealed via use of geometric approaches. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Quantum physics with non-Hermitian operators’. (paper)

  7. Point Measurements of Fermi Velocities by a Time-of-Flight Method

    DEFF Research Database (Denmark)

    Falk, David S.; Henningsen, J. O.; Skriver, Hans Lomholt

    1972-01-01

    The present paper describes in detail a new method of obtaining information about the Fermi velocity of electrons in metals, point by point, along certain contours on the Fermi surface. It is based on transmission of microwaves through thin metal slabs in the presence of a static magnetic field...... applied parallel to the surface. The electrons carry the signal across the slab and arrive at the second surface with a phase delay which is measured relative to a reference signal; the velocities are derived by analyzing the magnetic field dependence of the phase delay. For silver we have in this way...... obtained one component of the velocity along half the circumference of the centrally symmetric orbit for B→∥[100]. The results are in agreement with current models for the Fermi surface. For B→∥[011], the electrons involved are not moving in a symmetry plane of the Fermi surface. In such cases one cannot...

  8. Enhancement of precision and reduction of measuring points in tomographic reconstructions

    International Nuclear Information System (INIS)

    Lustfeld, H.; Hirschfeld, J.A.; Reissel, M.; Steffen, B.

    2011-01-01

    Accurate external measurements are required in tomographic problems to obtain a reasonable knowledge of the internal structures. Crucial is the distribution of the external measuring points. We suggest a procedure how to systematically optimize this distribution viz. to increase the precision (i.e. to shrink error bars) of the reconstruction by detecting the important and by eliminating the irrelevant measuring points. In a realistic numerical example we apply our scheme to magnetotomography of fuel cells. The result is striking: Starting from a smooth distribution of measuring points on a surface of a cuboid around the fuel cell, the number of measuring points can systematically be reduced by more than 90%. At the same time the precision increases by a factor of nearly 3.

  9. Acid dew point measurements in combustion gases using the dew point measuring system AH 85100

    Energy Technology Data Exchange (ETDEWEB)

    Fehler, D.

    1984-01-01

    Measuring system for continuous monitoring of the SO/sub 2//SO/sub 3/ dew point in the flue gas, characterized by a low failure rate, applicability inside the flue gas duct, maintenance-free continuous operation, and self-cleaning. The measuring principle is the cooling of the sensor element down to the 'onset condensation' message. Sensor surface temperatures are listed and evaluated as flue gas dew point temperatures. The measuring system is described. (DOMA).

  10. When should we recommend use of dual time-point and delayed time-point imaging techniques in FDG PET?

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Gang [Philadelphia VA Medical Center, Department of Radiology, Philadelphia, PA (United States); Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Torigian, Drew A.; Alavi, Abass [Hospital of the University of Pennsylvania, Department of Radiology, Philadelphia, PA (United States); Zhuang, Hongming [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2013-05-15

    FDG PET and PET/CT are now widely used in oncological imaging for tumor characterization, staging, restaging, and response evaluation. However, numerous benign etiologies may cause increased FDG uptake indistinguishable from that of malignancy. Multiple studies have shown that dual time-point imaging (DTPI) of FDG PET may be helpful in differentiating malignancy from benign processes. However, exceptions exist, and some studies have demonstrated significant overlap of FDG uptake patterns between benign and malignant lesions on delayed time-point images. In this review, we summarize our experience and opinions on the value of DTPI and delayed time-point imaging in oncology, with a review of the relevant literature. We believe that the major value of DTPI and delayed time-point imaging is the increased sensitivity due to continued clearance of background activity and continued FDG accumulation in malignant lesions, if the same diagnostic criteria (as in the initial standard single time-point imaging) are used. The specificity of DTPI and delayed time-point imaging depends on multiple factors, including the prevalence of malignancies, the patient population, and the cut-off values (either SUV or retention index) used to define a malignancy. Thus, DTPI and delayed time-point imaging would be more useful if performed for evaluation of lesions in regions with significant background activity clearance over time (such as the liver, the spleen, the mediastinum), and if used in the evaluation of the extent of tumor involvement rather than in the characterization of the nature of any specific lesion. Acute infectious and non-infectious inflammatory lesions remain as the major culprit for diminished diagnostic performance of these approaches (especially in tuberculosis-endemic regions). Tumor heterogeneity may also contribute to inconsistent performance of DTPI. The authors believe that selective use of DTPI and delayed time-point imaging will improve diagnostic accuracy and

  11. Acid dew point measurement in flue gases

    Energy Technology Data Exchange (ETDEWEB)

    Struschka, M.; Baumbach, G.

    1986-06-01

    The operation of modern boiler plants requires the continuous measurement of the acid dew point in flue gases. An existing measuring instrument was modified in such a way that it can determine acid dew points reliably, reproduceably and continuously. The authors present the mechanisms of the dew point formation, the dew point measuring principle, the modification and the operational results.

  12. Uniqueness in time measurement

    International Nuclear Information System (INIS)

    Lorenzen, P.

    1981-01-01

    According to P. Janich a clock is defined as an apparatus in which a point ( hand ) is moving uniformly on a straight line ( path ). For the definition of uniformly first the scaling (as a constant ratio of velocities) is defined without clocks. Thereafter the uniqueness of the time measurement can be proved using the prove of scaling of all clocks. But the uniqueness can be defined without scaling, as it is pointed out here. (orig.) [de

  13. Dual-time-point Imaging and Delayed-time-point Fluorodeoxyglucose-PET/Computed Tomography Imaging in Various Clinical Settings

    DEFF Research Database (Denmark)

    Houshmand, Sina; Salavati, Ali; Antonsen Segtnan, Eivind

    2016-01-01

    The techniques of dual-time-point imaging (DTPI) and delayed-time-point imaging, which are mostly being used for distinction between inflammatory and malignant diseases, has increased the specificity of fluorodeoxyglucose (FDG)-PET for diagnosis and prognosis of certain diseases. A gradually incr...

  14. Evaluation of 2-point, 3-point, and 6-point Dixon magnetic resonance imaging with flexible echo timing for muscle fat quantification.

    Science.gov (United States)

    Grimm, Alexandra; Meyer, Heiko; Nickel, Marcel D; Nittka, Mathias; Raithel, Esther; Chaudry, Oliver; Friedberger, Andreas; Uder, Michael; Kemmler, Wolfgang; Quick, Harald H; Engelke, Klaus

    2018-06-01

    The purpose of this study is to evaluate and compare 2-point (2pt), 3-point (3pt), and 6-point (6pt) Dixon magnetic resonance imaging (MRI) sequences with flexible echo times (TE) to measure proton density fat fraction (PDFF) within muscles. Two subject groups were recruited (G1: 23 young and healthy men, 31 ± 6 years; G2: 50 elderly men, sarcopenic, 77 ± 5 years). A 3-T MRI system was used to perform Dixon imaging on the left thigh. PDFF was measured with six Dixon prototype sequences: 2pt, 3pt, and 6pt sequences once with optimal TEs (in- and opposed-phase echo times), lower resolution, and higher bandwidth (optTE sequences) and once with higher image resolution (highRes sequences) and shortest possible TE, respectively. Intra-fascia PDFF content was determined. To evaluate the comparability among the sequences, Bland-Altman analysis was performed. The highRes 6pt Dixon sequences served as reference as a high correlation of this sequence to magnetic resonance spectroscopy has been shown before. The PDFF difference between the highRes 6pt Dixon sequence and the optTE 6pt, both 3pt, and the optTE 2pt was low (between 2.2% and 4.4%), however, not to the highRes 2pt Dixon sequence (33%). For the optTE sequences, difference decreased with the number of echoes used. In conclusion, for Dixon sequences with more than two echoes, the fat fraction measurement was reliable with arbitrary echo times, while for 2pt Dixon sequences, it was reliable with dedicated in- and opposed-phase echo timing. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Is direct measurement of time possible?

    Science.gov (United States)

    Reynolds, Thomas

    2017-08-01

    Is direct measurement of time possible? The answer to this question may depend upon how one understands time. Is time an essential constituent of physical reality? Or is what scientists are talking about when they use the symbol ‘t’ or the word ‘time’ an human cultural construct, as the Chief of the USA NIST Divisions of Time and Frequency and of Quantum Physics has suggested. Few aspects of physics do not reference activity to time, but many discussions within either view of time seem to use one same, largely traditional, language of time. Briefly considering the question of measurement, including from a formal measure-theoretic point of view, clarifies the situation.

  16. Reactor coolant flow measurements at Point Lepreau

    International Nuclear Information System (INIS)

    Brenciaglia, G.; Gurevich, Y.; Liu, G.

    1996-01-01

    The CROSSFLOW ultrasonic flow measurement system manufactured by AMAG is fully proven as reliable and accurate when applied to large piping in defined geometries for such applications as feedwater flows measurement. Its application to direct reactor coolant flow (RCF) measurements - both individual channel flows and bulk flows such as pump suction flow - has been well established through recent work by AMAG at Point Lepreau, with application to other reactor types (eg. PWR) imminent. At Point Lepreau, Measurements have been demonstrated at full power; improvements to consistently meet ±1% accuracy are in progress. The development and recent customization of CROSSFLOW to RCF measurement at Point Lepreau are described in this paper; typical measurement results are included. (author)

  17. Accurate dew-point measurement over a wide temperature range using a quartz crystal microbalance dew-point sensor

    Science.gov (United States)

    Kwon, Su-Yong; Kim, Jong-Chul; Choi, Buyng-Il

    2008-11-01

    Quartz crystal microbalance (QCM) dew-point sensors are based on frequency measurement, and so have fast response time, high sensitivity and high accuracy. Recently, we have reported that they have the very convenient attribute of being able to distinguish between supercooled dew and frost from a single scan through the resonant frequency of the quartz resonator as a function of the temperature. In addition to these advantages, by using three different types of heat sinks, we have developed a QCM dew/frost-point sensor with a very wide working temperature range (-90 °C to 15 °C). The temperature of the quartz surface can be obtained effectively by measuring the temperature of the quartz crystal holder and using temperature compensation curves (which showed a high level of repeatability and reproducibility). The measured dew/frost points showed very good agreement with reference values and were within ±0.1 °C over the whole temperature range.

  18. Accurate dew-point measurement over a wide temperature range using a quartz crystal microbalance dew-point sensor

    International Nuclear Information System (INIS)

    Kwon, Su-Yong; Kim, Jong-Chul; Choi, Buyng-Il

    2008-01-01

    Quartz crystal microbalance (QCM) dew-point sensors are based on frequency measurement, and so have fast response time, high sensitivity and high accuracy. Recently, we have reported that they have the very convenient attribute of being able to distinguish between supercooled dew and frost from a single scan through the resonant frequency of the quartz resonator as a function of the temperature. In addition to these advantages, by using three different types of heat sinks, we have developed a QCM dew/frost-point sensor with a very wide working temperature range (−90 °C to 15 °C). The temperature of the quartz surface can be obtained effectively by measuring the temperature of the quartz crystal holder and using temperature compensation curves (which showed a high level of repeatability and reproducibility). The measured dew/frost points showed very good agreement with reference values and were within ±0.1 °C over the whole temperature range

  19. A Calibrated Test-Set for Measurement of Access-Point Time Specifications in Hybrid Wired/Wireless Industrial Communication †

    Directory of Open Access Journals (Sweden)

    Federico Tramarin

    2018-05-01

    Full Text Available In factory automation and process control systems, hybrid wired/wireless networks are often deployed to connect devices of difficult reachability such as those mounted on mobile equipment. A widespread implementation of these networks makes use of Access Points (APs to implement wireless extensions of Real-Time Ethernet (RTE networks via the IEEE 802.11 Wireless LAN (WLAN. Unfortunately, APs may introduce random delays in frame forwarding, mainly related to their internal behavior (e.g., queue management, processing times, that clearly impact the overall worst case execution time of real-time tasks involved in industrial process control systems. As a consequence, the knowledge of such delays becomes a crucial design parameter, and their estimation is definitely of utter importance. In this scenario, the paper presents an original and effective method to measure the aforementioned delays introduced by APs, exploiting a hybrid loop-back link and a simple, yet accurate set-up with moderate instrumentation requirements. The proposed method, which requires an initial calibration phase by means of a reference AP, has been successfully tested on some commercial APs to prove its effectiveness. The proposed measurement procedure is proven to be general and, as such, can be profitably adopted in even different scenarios.

  20. Measurement of β-decay end point energy with planar HPGe detector

    Science.gov (United States)

    Bhattacharjee, T.; Pandit, Deepak; Das, S. K.; Chowdhury, A.; Das, P.; Banerjee, D.; Saha, A.; Mukhopadhyay, S.; Pal, S.; Banerjee, S. R.

    2014-12-01

    The β - γ coincidence measurement has been performed with a segmented planar Hyper-Pure Germanium (HPGe) detector and a single coaxial HPGe detector to determine the end point energies of nuclear β-decays. The experimental end point energies have been determined for some of the known β-decays in 106Rh →106Pd. The end point energies corresponding to three weak branches in 106Rh →106Pd decay have been measured for the first time. The γ ray and β particle responses for the planar HPGe detector were simulated using the Monte Carlo based code GEANT3. The experimentally obtained β spectra were successfully reproduced with the simulation.

  1. Mass measurement on the rp-process waiting point {sup 72}Kr

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, D. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Kolhinen, V.S. [Jyvaeskylae Univ. (Finland); Audi, G. [CSNSM-IN2P3-Centre National de la Recherche Scientifique (CNRS), 91 - Orsay (FR)] [and others

    2004-06-01

    The mass of one of the three major waiting points in the astrophysical rp-process {sup 72}Kr was measured for the first time with the Penning trap mass spectrometer ISOLTRAP. The measurement yielded a relative mass uncertainty of {delta}m/m=1.2 x 10{sup -7} ({delta}m=8 keV). Other Kr isotopes, also needed for astrophysical calculations, were measured with more than one order of magnitude improved accuracy. We use the ISOLTRAP masses of{sup 72-74}Kr to reanalyze the role of the {sup 72}Kr waiting point in the rp-process during X-ray bursts. (orig.)

  2. Measurement of β-decay end point energy with planar HPGe detector

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, T., E-mail: btumpa@vecc.gov.in [Physics Group, Variable Energy Cyclotron Centre, Kolkata 700 064 (India); Pandit, Deepak [Physics Group, Variable Energy Cyclotron Centre, Kolkata 700 064 (India); Das, S.K. [RCD-BARC, Variable Energy Cyclotron Centre, Kolkata 700 064 (India); Chowdhury, A.; Das, P. [Physics Group, Variable Energy Cyclotron Centre, Kolkata 700 064 (India); Banerjee, D. [RCD-BARC, Variable Energy Cyclotron Centre, Kolkata 700 064 (India); Saha, A.; Mukhopadhyay, S.; Pal, S.; Banerjee, S.R. [Physics Group, Variable Energy Cyclotron Centre, Kolkata 700 064 (India)

    2014-12-11

    The β–γ coincidence measurement has been performed with a segmented planar Hyper-Pure Germanium (HPGe) detector and a single coaxial HPGe detector to determine the end point energies of nuclear β-decays. The experimental end point energies have been determined for some of the known β-decays in {sup 106}Rh→{sup 106}Pd. The end point energies corresponding to three weak branches in {sup 106}Rh→{sup 106}Pd decay have been measured for the first time. The γ ray and β particle responses for the planar HPGe detector were simulated using the Monte Carlo based code GEANT3. The experimentally obtained β spectra were successfully reproduced with the simulation.

  3. Visualizing Robustness of Critical Points for 2D Time-Varying Vector Fields

    KAUST Repository

    Wang, B.

    2013-06-01

    Analyzing critical points and their temporal evolutions plays a crucial role in understanding the behavior of vector fields. A key challenge is to quantify the stability of critical points: more stable points may represent more important phenomena or vice versa. The topological notion of robustness is a tool which allows us to quantify rigorously the stability of each critical point. Intuitively, the robustness of a critical point is the minimum amount of perturbation necessary to cancel it within a local neighborhood, measured under an appropriate metric. In this paper, we introduce a new analysis and visualization framework which enables interactive exploration of robustness of critical points for both stationary and time-varying 2D vector fields. This framework allows the end-users, for the first time, to investigate how the stability of a critical point evolves over time. We show that this depends heavily on the global properties of the vector field and that structural changes can correspond to interesting behavior. We demonstrate the practicality of our theories and techniques on several datasets involving combustion and oceanic eddy simulations and obtain some key insights regarding their stable and unstable features. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  4. Visualizing Robustness of Critical Points for 2D Time-Varying Vector Fields

    KAUST Repository

    Wang, B.; Rosen, P.; Skraba, P.; Bhatia, H.; Pascucci, V.

    2013-01-01

    Analyzing critical points and their temporal evolutions plays a crucial role in understanding the behavior of vector fields. A key challenge is to quantify the stability of critical points: more stable points may represent more important phenomena or vice versa. The topological notion of robustness is a tool which allows us to quantify rigorously the stability of each critical point. Intuitively, the robustness of a critical point is the minimum amount of perturbation necessary to cancel it within a local neighborhood, measured under an appropriate metric. In this paper, we introduce a new analysis and visualization framework which enables interactive exploration of robustness of critical points for both stationary and time-varying 2D vector fields. This framework allows the end-users, for the first time, to investigate how the stability of a critical point evolves over time. We show that this depends heavily on the global properties of the vector field and that structural changes can correspond to interesting behavior. We demonstrate the practicality of our theories and techniques on several datasets involving combustion and oceanic eddy simulations and obtain some key insights regarding their stable and unstable features. © 2013 The Author(s) Computer Graphics Forum © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  5. Dew-point measurements at high water vapour pressure

    Science.gov (United States)

    Lomperski, S.; Dreier, J.

    1996-05-01

    A dew-point meter capable of measuring humidity at high vapour pressure and high temperature has been constructed and tested. Humidity measurements in pure steam were made over the temperature range 100 - 1500957-0233/7/5/003/img1C and a vapour pressure range of 1 - 4 bar. The dew-point meter performance was assessed by comparing measurements with a pressure transmitter and agreement between the two was within 0957-0233/7/5/003/img2% relative humidity. Humidity measurements in steam - air mixtures were also made and the dew-point meter readings were compared to those of a zirconia oxygen sensor. For these tests the dew-point meter readings were generally within 0957-0233/7/5/003/img2% relative humidity of the oxygen sensor measurements.

  6. Spatially heterogeneous dynamics investigated via a time-dependent four-point density correlation function

    DEFF Research Database (Denmark)

    Lacevic, N.; Starr, F. W.; Schrøder, Thomas

    2003-01-01

    correlation function g4(r,t) and corresponding "structure factor" S4(q,t) which measure the spatial correlations between the local liquid density at two points in space, each at two different times, and so are sensitive to dynamical heterogeneity. We study g4(r,t) and S4(q,t) via molecular dynamics......Relaxation in supercooled liquids above their glass transition and below the onset temperature of "slow" dynamics involves the correlated motion of neighboring particles. This correlated motion results in the appearance of spatially heterogeneous dynamics or "dynamical heterogeneity." Traditional...... two-point time-dependent density correlation functions, while providing information about the transient "caging" of particles on cooling, are unable to provide sufficiently detailed information about correlated motion and dynamical heterogeneity. Here, we study a four-point, time-dependent density...

  7. Portable Dew Point Mass Spectrometry System for Real-Time Gas and Moisture Analysis

    Science.gov (United States)

    Arkin, C.; Gillespie, Stacey; Ratzel, Christopher

    2010-01-01

    A portable instrument incorporates both mass spectrometry and dew point measurement to provide real-time, quantitative gas measurements of helium, nitrogen, oxygen, argon, and carbon dioxide, along with real-time, quantitative moisture analysis. The Portable Dew Point Mass Spectrometry (PDP-MS) system comprises a single quadrupole mass spectrometer and a high vacuum system consisting of a turbopump and a diaphragm-backing pump. A capacitive membrane dew point sensor was placed upstream of the MS, but still within the pressure-flow control pneumatic region. Pressure-flow control was achieved with an upstream precision metering valve, a capacitance diaphragm gauge, and a downstream mass flow controller. User configurable LabVIEW software was developed to provide real-time concentration data for the MS, dew point monitor, and sample delivery system pressure control, pressure and flow monitoring, and recording. The system has been designed to include in situ, NIST-traceable calibration. Certain sample tubing retains sufficient water that even if the sample is dry, the sample tube will desorb water to an amount resulting in moisture concentration errors up to 500 ppm for as long as 10 minutes. It was determined that Bev-A-Line IV was the best sample line to use. As a result of this issue, it is prudent to add a high-level humidity sensor to PDP-MS so such events can be prevented in the future.

  8. Dew point fast measurement in organic vapor mixtures using quartz resonant sensor

    Science.gov (United States)

    Nie, Jing; Liu, Jia; Meng, Xiaofeng

    2017-01-01

    A fast dew point sensor has been developed for organic vapor mixtures by using the quartz crystal with sensitive circuits. The sensor consists of the quartz crystal and a cooler device. Proactive approach is taken to produce condensation on the surface of the quartz crystal, and it will lead to a change in electrical features of the quartz crystal. The cessation of oscillation was measured because this phenomenon is caused by dew condensation. Such a phenomenon can be used to detect the dew point. This method exploits the high sensitivity of the quartz crystal but without frequency measurement and also retains the stability of the resonant circuit. It is strongly anti-interfered. Its performance was evaluated with acetone-methanol mixtures under different pressures. The results were compared with the dew points predicted from the universal quasi-chemical equation to evaluate the performance of the proposed sensor. Though the maximum deviations of the sensor are less than 1.1 °C, it still has a fast response time with a recovery time of less than 10 s, providing an excellent dehumidifying performance.

  9. History and Point in Time in Enterprise Applications

    Directory of Open Access Journals (Sweden)

    Constantin Gelu APOSTOL

    2006-01-01

    Full Text Available First part points out the main differences between temporal and non-temporal databases. In the second part, based on identification of the three main categories of time involved in database applications: user-defined time, valid time and transaction time, some relevant solutions for their implementation are discussed, mainly from the point of view of database organization and data access level of enterprise applications. The final part is dedicated to the influences of historical data in the business logic and presentation levels of enterprise applications and in application services, as security, workflow, reporting.

  10. Homeless Point-In-Time (2007-2016)

    Data.gov (United States)

    City and County of Durham, North Carolina — These raw data sets contain Point-in-Time (PIT) estimates and national PIT estimates of homelessness as well as national estimates of homelessness by state and...

  11. Scattering analysis of point processes and random measures

    International Nuclear Information System (INIS)

    Hanisch, K.H.

    1984-01-01

    In the present paper scattering analysis of point processes and random measures is studied. Known formulae which connect the scattering intensity with the pair distribution function of the studied structures are proved in a rigorous manner with tools of the theory of point processes and random measures. For some special fibre processes the scattering intensity is computed. For a class of random measures, namely for 'grain-germ-models', a new formula is proved which yields the pair distribution function of the 'grain-germ-model' in terms of the pair distribution function of the underlying point process (the 'germs') and of the mean structure factor and the mean squared structure factor of the particles (the 'grains'). (author)

  12. Dew point measurement technique utilizing fiber cut reflection

    Science.gov (United States)

    Kostritskii, S. M.; Dikevich, A. A.; Korkishko, Yu. N.; Fedorov, V. A.

    2009-05-01

    The fiber optical dew point hygrometer based on change of reflection coefficient for fiber cut has been developed and examined. We proposed and verified the model of condensation detector functioning principle. Experimental frost point measurements on air with different frost points have been performed.

  13. Boiling point measurements on liquid UO2

    International Nuclear Information System (INIS)

    Bober, M.; Singer, J.; Trapp, M.

    1986-01-01

    In analogy to the classic boiling point method, a quasi-stationary millisecond laser-heating technique was applied to measure the saturated-vapour pressure curve of liquid UO 2 in the temperature range of 3500 to 4500 K. The result is represented by log p(MPa) 5.049 -23042/T(K) according to an average heat of vaporization of 441 kJ/mol and a normal boiling point of 3808 K. Besides, spectral emissivities of liquid UO 2 were measured at the pyrometer wavelengths of 752 and 1064 nm. (author)

  14. Simultaneous measurement of passage through the restriction point and MCM loading in single cells

    Science.gov (United States)

    Håland, T. W.; Boye, E.; Stokke, T.; Grallert, B.; Syljuåsen, R. G.

    2015-01-01

    Passage through the Retinoblastoma protein (RB1)-dependent restriction point and the loading of minichromosome maintenance proteins (MCMs) are two crucial events in G1-phase that help maintain genome integrity. Deregulation of these processes can cause uncontrolled proliferation and cancer development. Both events have been extensively characterized individually, but their relative timing and inter-dependence remain less clear. Here, we describe a novel method to simultaneously measure MCM loading and passage through the restriction point. We exploit that the RB1 protein is anchored in G1-phase but is released when hyper-phosphorylated at the restriction point. After extracting cells with salt and detergent before fixation we can simultaneously measure, by flow cytometry, the loading of MCMs onto chromatin and RB1 binding to determine the order of the two events in individual cells. We have used this method to examine the relative timing of the two events in human cells. Whereas in BJ fibroblasts released from G0-phase MCM loading started mainly after the restriction point, in a significant fraction of exponentially growing BJ and U2OS osteosarcoma cells MCMs were loaded in G1-phase with RB1 anchored, demonstrating that MCM loading can also start before the restriction point. These results were supported by measurements in synchronized U2OS cells. PMID:26250117

  15. Junction leakage measurements with micro four-point probes

    DEFF Research Database (Denmark)

    Lin, Rong; Petersen, Dirch Hjorth; Wang, Fei

    2012-01-01

    We present a new, preparation-free method for measuring the leakage current density on ultra-shallow junctions. The junction leakage is found by making a series of four-point sheet resistance measurements on blanket wafers with variable electrode spacings. The leakage current density is calculated...... using a fit of the measured four-point resistances to an analytical two-sheet model. The validity of the approximation involved in the two-sheet model is verified by a comparison to finite element model calculations....

  16. The timing of control signals underlying fast point-to-point arm movements.

    Science.gov (United States)

    Ghafouri, M; Feldman, A G

    2001-04-01

    It is known that proprioceptive feedback induces muscle activation when the facilitation of appropriate motoneurons exceeds their threshold. In the suprathreshold range, the muscle-reflex system produces torques depending on the position and velocity of the joint segment(s) that the muscle spans. The static component of the torque-position relationship is referred to as the invariant characteristic (IC). According to the equilibrium-point (EP) hypothesis, control systems produce movements by changing the activation thresholds and thus shifting the IC of the appropriate muscles in joint space. This control process upsets the balance between muscle and external torques at the initial limb configuration and, to regain the balance, the limb is forced to establish a new configuration or, if the movement is prevented, a new level of static torques. Taken together, the joint angles and the muscle torques generated at an equilibrium configuration define a single variable called the EP. Thus by shifting the IC, control systems reset the EP. Muscle activation and movement emerge following the EP resetting because of the natural physical tendency of the system to reach equilibrium. Empirical and simulation studies support the notion that the control IC shifts and the resulting EP shifts underlying fast point-to-point arm movements are gradual rather than step-like. However, controversies exist about the duration of these shifts. Some studies suggest that the IC shifts cease with the movement offset. Other studies propose that the IC shifts end early in comparison to the movement duration (approximately, at peak velocity). The purpose of this study was to evaluate the duration of the IC shifts underlying fast point-to-point arm movements. Subjects made fast (hand peak velocity about 1.3 m/s) planar arm movements toward different targets while grasping a handle. Hand forces applied to the handle and shoulder/elbow torques were, respectively, measured from a force sensor placed

  17. Attention flexibly trades off across points in time.

    Science.gov (United States)

    Denison, Rachel N; Heeger, David J; Carrasco, Marisa

    2017-08-01

    Sensory signals continuously enter the brain, raising the question of how perceptual systems handle this constant flow of input. Attention to an anticipated point in time can prioritize visual information at that time. However, how we voluntarily attend across time when there are successive task-relevant stimuli has been barely investigated. We developed a novel experimental protocol that allowed us to assess, for the first time, both the benefits and costs of voluntary temporal attention when perceiving a short sequence of two or three visual targets with predictable timing. We found that when humans directed attention to a cued point in time, their ability to perceive orientation was better at that time but also worse earlier and later. These perceptual tradeoffs across time are analogous to those found across space for spatial attention. We concluded that voluntary attention is limited, and selective, across time.

  18. A simple method for regional cerebral blood flow measurement by one-point arterial blood sampling and 123I-IMP microsphere model (part 2). A study of time correction of one-point blood sample count

    International Nuclear Information System (INIS)

    Masuda, Yasuhiko; Makino, Kenichi; Gotoh, Satoshi

    1999-01-01

    In our previous paper regarding determination of the regional cerebral blood flow (rCBF) using the 123 I-IMP microsphere model, we reported that the accuracy of determination of the integrated value of the input function from one-point arterial blood sampling can be increased by performing correction using the 5 min: 29 min ratio for the whole-brain count. However, failure to carry out the arterial blood collection at exactly 5 minutes after 123 I-IMP injection causes errors with this method, and there is thus a time limitation. We have now revised out method so that the one-point arterial blood sampling can be performed at any time during the interval between 5 minutes and 20 minutes after 123 I-IMP injection, with addition of a correction step for the sampling time. This revised method permits more accurate estimation of the integral of the input functions. This method was then applied to 174 experimental subjects: one-point blood samples collected at random times between 5 and 20 minutes, and the estimated values for the continuous arterial octanol extraction count (COC) were determined. The mean error rate between the COC and the actual measured continuous arterial octanol extraction count (OC) was 3.6%, and the standard deviation was 12.7%. Accordingly, in 70% of the cases, the rCBF was able to be estimated within an error rate of 13%, while estimation was possible in 95% of the cases within an error rate of 25%. This improved method is a simple technique for determination of the rCBF by 123 I-IMP microsphere model and one-point arterial blood sampling which no longer shows a time limitation and does not require any octanol extraction step. (author)

  19. Optimizing the diagnostic power with gastric emptying scintigraphy at multiple time points

    Directory of Open Access Journals (Sweden)

    Gajewski Byron J

    2011-05-01

    Full Text Available Abstract Background Gastric Emptying Scintigraphy (GES at intervals over 4 hours after a standardized radio-labeled meal is commonly regarded as the gold standard for diagnosing gastroparesis. The objectives of this study were: 1 to investigate the best time point and the best combination of multiple time points for diagnosing gastroparesis with repeated GES measures, and 2 to contrast and cross-validate Fisher's Linear Discriminant Analysis (LDA, a rank based Distribution Free (DF approach, and the Classification And Regression Tree (CART model. Methods A total of 320 patients with GES measures at 1, 2, 3, and 4 hour (h after a standard meal using a standardized method were retrospectively collected. Area under the Receiver Operating Characteristic (ROC curve and the rate of false classification through jackknife cross-validation were used for model comparison. Results Due to strong correlation and an abnormality in data distribution, no substantial improvement in diagnostic power was found with the best linear combination by LDA approach even with data transformation. With DF method, the linear combination of 4-h and 3-h increased the Area Under the Curve (AUC and decreased the number of false classifications (0.87; 15.0% over individual time points (0.83, 0.82; 15.6%, 25.3%, for 4-h and 3-h, respectively at a higher sensitivity level (sensitivity = 0.9. The CART model using 4 hourly GES measurements along with patient's age was the most accurate diagnostic tool (AUC = 0.88, false classification = 13.8%. Patients having a 4-h gastric retention value >10% were 5 times more likely to have gastroparesis (179/207 = 86.5% than those with ≤10% (18/113 = 15.9%. Conclusions With a mixed group of patients either referred with suspected gastroparesis or investigated for other reasons, the CART model is more robust than the LDA and DF approaches, capable of accommodating covariate effects and can be generalized for cross institutional applications, but

  20. Analysis of point source size on measurement accuracy of lateral point-spread function of confocal Raman microscopy

    Science.gov (United States)

    Fu, Shihang; Zhang, Li; Hu, Yao; Ding, Xiang

    2018-01-01

    Confocal Raman Microscopy (CRM) has matured to become one of the most powerful instruments in analytical science because of its molecular sensitivity and high spatial resolution. Compared with conventional Raman Microscopy, CRM can perform three dimensions mapping of tiny samples and has the advantage of high spatial resolution thanking to the unique pinhole. With the wide application of the instrument, there is a growing requirement for the evaluation of the imaging performance of the system. Point-spread function (PSF) is an important approach to the evaluation of imaging capability of an optical instrument. Among a variety of measurement methods of PSF, the point source method has been widely used because it is easy to operate and the measurement results are approximate to the true PSF. In the point source method, the point source size has a significant impact on the final measurement accuracy. In this paper, the influence of the point source sizes on the measurement accuracy of PSF is analyzed and verified experimentally. A theoretical model of the lateral PSF for CRM is established and the effect of point source size on full-width at half maximum of lateral PSF is simulated. For long-term preservation and measurement convenience, PSF measurement phantom using polydimethylsiloxane resin, doped with different sizes of polystyrene microspheres is designed. The PSF of CRM with different sizes of microspheres are measured and the results are compared with the simulation results. The results provide a guide for measuring the PSF of the CRM.

  1. Zero Point of Historical Time

    Directory of Open Access Journals (Sweden)

    R.S. Khakimov

    2014-02-01

    Full Text Available Historical studies are based on the assumption that there is a reference-starting point of the space-time – the Zero point of coordinate system. Due to the bifurcation in the Zero Point, the course of social processes changes sharply and the probabilistic causality replaces the deterministic one. For this reason, changes occur in the structure of social relations and statehood form as well as in the course of the ethnic processes. In such a way emerges a new discourse of the national behavior. With regard to the history of the Tatars and Tatarstan, such bifurcation points occurred in the periods of the formation: 1 of the Turkic Khaganate, which began to exist from the 6th century onward and became a qualitatively new State system that reformatted old elements in the new matrix introducing a new discourse of behavior; 2 of the Volga-Kama Bulgaria, where the rivers (Kama, Volga, Vyatka became the most important trade routes determining the singularity of this State. Here the nomadic culture was connected with the settled one and Islam became the official religion in 922; 3 and of the Golden Hordе, a powerful State with a remarkable system of communication, migration of huge human resources for thousands of kilometers, and extensive trade, that caused severe “mutations” in the ethnic terms and a huge mixing of ethnic groups. Given the dwelling space of Tatar population and its evolution within Russia, it can be argued that the Zero point of Tatar history, which conveyed the cultural invariants until today, begins in the Golden Horde. Neither in the Turkic khaganate nor in the Bulgar State, but namely in the Golden Horde. Despite the radical changes, the Russian Empire failed to transform the Tatars in the Russians. Therefore, contemporary Tatars preserved the Golden Horde tradition as a cultural invariant.

  2. Dual time point 18FDG-PET/CT versus single time point 18FDG-PET/CT for the differential diagnosis of pulmonary nodules - A meta-analysis

    International Nuclear Information System (INIS)

    Zhang, Li; Wang, Yinzhong; Lei, Junqiang; Tian, Jinhui; Zhai, Yanan

    2013-01-01

    Background: Lung cancer is one of the most common cancer types in the world. An accurate diagnosis of lung cancer is crucial for early treatment and management. Purpose: To perform a comprehensive meta-analysis to evaluate the diagnostic performance of dual time point 18F-fluorodexyglucose position emission tomography/computed tomography (FDG-PET/CT) and single time point 18FDG-PET/CT in the diagnosis of pulmonary nodules. Material and Methods: PubMed (1966-2011.11), EMBASE (1974-2011.11), Web of Science (1972-2011.11), Cochrane Library (-2011.11), and four Chinese databases; CBM (1978-2011.11), CNKI (1994-2011.11), VIP (1989-2011.11), and Wanfang Database (1994-2011.11) were searched. Summary sensitivity, summary specificity, summary diagnostic odds ratios (DOR), and summary positive likelihood ratios (LR+) and negative likelihood ratios (LR-) were obtained using Meta-Disc software. Summary receiver-operating characteristic (SROC) curves were used to evaluate the diagnostic performance of dual time point 18FDG-PET/CT and single time point 18FDG-PET/CT. Results: The inclusion criteria were fulfilled by eight articles, with a total of 415 patients and 430 pulmonary nodules. Compared with the gold standard (pathology or clinical follow-up), the summary sensitivity of dual time point 18FDG-PET/CT was 79% (95%CI, 74.0 - 84.0%), and its summary specificity was 73% (95%CI, 65.0-79.0%); the summary LR+ was 2.61 (95%CI, 1.96-3.47), and the summary LR- was 0.29 (95%CI, 0.21 - 0.41); the summary DOR was 10.25 (95%CI, 5.79 - 18.14), and the area under the SROC curve (AUC) was 0.8244. The summary sensitivity for single time point 18FDG-PET/CT was 77% (95%CI, 71.9 - 82.3%), and its summary specificity was 59% (95%CI, 50.6 - 66.2%); the summary LR+ was 1.97 (95%CI, 1.32 - 2.93), and the summary LR- was 0.37 (95%CI, 0.29 - 0.49); the summary DOR was 6.39 (95%CI, 3.39 - 12.05), and the AUC was 0.8220. Conclusion: The results indicate that dual time point 18FDG-PET/CT and single

  3. Measures of Noncircularity and Fixed Points of Contractive Multifunctions

    Directory of Open Access Journals (Sweden)

    Marrero Isabel

    2010-01-01

    Full Text Available In analogy to the Eisenfeld-Lakshmikantham measure of nonconvexity and the Hausdorff measure of noncompactness, we introduce two mutually equivalent measures of noncircularity for Banach spaces satisfying a Cantor type property, and apply them to establish a fixed point theorem of Darbo type for multifunctions. Namely, we prove that every multifunction with closed values, defined on a closed set and contractive with respect to any one of these measures, has the origin as a fixed point.

  4. Precise pointing knowledge for SCIAMACHY solar occultation measurements

    Directory of Open Access Journals (Sweden)

    K. Bramstedt

    2012-11-01

    Full Text Available We present a method to precisely determine the viewing direction for solar occultation instruments from scans over the solar disk. Basic idea is the fit of the maximum intensity during the scan, which corresponds to the center of the solar disk in the scanning direction. We apply this method to the solar occultation measurements of the satellite instrument SCIAMACHY, which scans the Sun in elevation direction. The achieved mean precision is 0.46 mdeg, which corresponds to an tangent height error of about 26 m for individual occultation sequences. The deviation of the derived elevation angle from the geolocation information given along with the product has a seasonal cycle with an amplitude of 2.26 mdeg, which is in tangent height an amplitude of about 127 m. The mean elevation angle offset is −4.41 mdeg (249 m. SCIAMACHY's sun follower device controls the azimuth viewing direction during the occultation measurements. The derived mean azimuth direction has an standard error of 0.65 mdeg, which is about 36 m in horizontal direction at the tangent point. We observe also a seasonal cycle of the azimuth mispointing with an amplitude of 2.3 mdeg, which is slightly increasing with time. The almost constant mean offset is 88 mdeg, which is about 5.0 km horizontal offset at the tangent point.

  5. Space Technology 5 Multi-point Measurements of Near-Earth Magnetic Fields: Initial Results

    Science.gov (United States)

    Slavin, James A.; Le, G.; Strangeway, R. L.; Wang, Y.; Boardsen, S.A.; Moldwin, M. B.; Spence, H. E.

    2007-01-01

    The Space Technology 5 (ST-5) mission successfully placed three micro-satellites in a 300 x 4500 km dawn-dusk orbit on 22 March 2006. Each spacecraft carried a boom-mounted vector fluxgate magnetometer that returned highly sensitive and accurate measurements of the geomagnetic field. These data allow, for the first time, the separation of temporal and spatial variations in field-aligned current (FAC) perturbations measured in low-Earth orbit on time scales of approximately 10 sec to 10 min. The constellation measurements are used to directly determine field-aligned current sheet motion, thickness and current density. In doing so, we demonstrate two multi-point methods for the inference of FAC current density that have not previously been possible in low-Earth orbit; 1) the "standard method," based upon s/c velocity, but corrected for FAC current sheet motion, and 2) the "gradiometer method" which uses simultaneous magnetic field measurements at two points with known separation. Future studies will apply these methods to the entire ST-5 data set and expand to include geomagnetic field gradient analyses as well as field-aligned and ionospheric currents.

  6. Time Series UAV Image-Based Point Clouds for Landslide Progression Evaluation Applications.

    Science.gov (United States)

    Al-Rawabdeh, Abdulla; Moussa, Adel; Foroutan, Marzieh; El-Sheimy, Naser; Habib, Ayman

    2017-10-18

    Landslides are major and constantly changing threats to urban landscapes and infrastructure. It is essential to detect and capture landslide changes regularly. Traditional methods for monitoring landslides are time-consuming, costly, dangerous, and the quality and quantity of the data is sometimes unable to meet the necessary requirements of geotechnical projects. This motivates the development of more automatic and efficient remote sensing approaches for landslide progression evaluation. Automatic change detection involving low-altitude unmanned aerial vehicle image-based point clouds, although proven, is relatively unexplored, and little research has been done in terms of accounting for volumetric changes. In this study, a methodology for automatically deriving change displacement rates, in a horizontal direction based on comparisons between extracted landslide scarps from multiple time periods, has been developed. Compared with the iterative closest projected point (ICPP) registration method, the developed method takes full advantage of automated geometric measuring, leading to fast processing. The proposed approach easily processes a large number of images from different epochs and enables the creation of registered image-based point clouds without the use of extensive ground control point information or further processing such as interpretation and image correlation. The produced results are promising for use in the field of landslide research.

  7. A new diagnostic accuracy measure and cut-point selection criterion.

    Science.gov (United States)

    Dong, Tuochuan; Attwood, Kristopher; Hutson, Alan; Liu, Song; Tian, Lili

    2017-12-01

    Most diagnostic accuracy measures and criteria for selecting optimal cut-points are only applicable to diseases with binary or three stages. Currently, there exist two diagnostic measures for diseases with general k stages: the hypervolume under the manifold and the generalized Youden index. While hypervolume under the manifold cannot be used for cut-points selection, generalized Youden index is only defined upon correct classification rates. This paper proposes a new measure named maximum absolute determinant for diseases with k stages ([Formula: see text]). This comprehensive new measure utilizes all the available classification information and serves as a cut-points selection criterion as well. Both the geometric and probabilistic interpretations for the new measure are examined. Power and simulation studies are carried out to investigate its performance as a measure of diagnostic accuracy as well as cut-points selection criterion. A real data set from Alzheimer's Disease Neuroimaging Initiative is analyzed using the proposed maximum absolute determinant.

  8. Method to Minimize the Low-Frequency Neutral-Point Voltage Oscillations With Time-Offset Injection for Neutral-Point-Clamped Inverters

    DEFF Research Database (Denmark)

    Choi, Ui-Min; Blaabjerg, Frede; Lee, Kyo-Beum

    2015-01-01

    time of small- and medium-voltage vectors. However, if the power factor is lower, there is a limitation to eliminate neutral-point oscillations. In this case, the proposed method can be improved by changing the switching sequence properly. Additionally, a method for neutral-point voltage balancing......This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time offset to the three-phase turn-on times. The proper time offset is simply calculated considering the phase currents and dwell...

  9. Observation of environmental radioactivity at definite time and definite point

    International Nuclear Information System (INIS)

    Inokoshi, Yukio; Fukuchi, Ryoichi; Irie, Takayuki; Hosoda, Nagako; Okano, Yasuhiro; Shindo, Koutaro

    1990-01-01

    The measurement of environmental radioactivity in Tokyo Metropolis was carried out. The objects of measurement were rainwater, atmospheric floating dusts, spatial dose and the activated sludge in sewage treatment plants. Rainwater, atmospheric floating dusts and spatial dose were analyzed mainly considering radioactive fallout, and activated sludge was analyzed mainly considering radioactive medical matters. For the analysis of nuclides, a Ge(Li) semiconductor detector was used, and spatial dose rate was measured with a DBM type dose rate meter. In activated sludge, the nuclides used for radioactive medicines were found, but in rainwater, atmospheric floating dusts and spatial dose, particular abnormality was not found. The objective of this investigation is to collect over long period at definite time and definite points the data on environmental radioactivity in Tokyo, thus to grasp the level of normal values, and in abnormal case, to clarify the cause and to evaluate the exposure dose. The instruments used, the method of measuring each object and the results are reported. (K.I.)

  10. Application of spatial time domain reflectometry measurements in heterogeneous, rocky substrates

    Science.gov (United States)

    Gonzales, C.; Scheuermann, A.; Arnold, S.; Baumgartl, T.

    2016-10-01

    Measurement of soil moisture across depths using sensors is currently limited to point measurements or remote sensing technologies. Point measurements have limitations on spatial resolution, while the latter, although covering large areas may not represent real-time hydrologic processes, especially near the surface. The objective of the study was to determine the efficacy of elongated soil moisture probes—spatial time domain reflectometry (STDR)—and to describe transient soil moisture dynamics of unconsolidated mine waste rock materials. The probes were calibrated under controlled conditions in the glasshouse. Transient soil moisture content was measured using the gravimetric method and STDR. Volumetric soil moisture content derived from weighing was compared with values generated from a numerical model simulating the drying process. A calibration function was generated and applied to STDR field data sets. The use of elongated probes effectively assists in the real-time determination of the spatial distribution of soil moisture. It also allows hydrologic processes to be uncovered in the unsaturated zone, especially for water balance calculations that are commonly based on point measurements. The elongated soil moisture probes can potentially describe transient substrate processes and delineate heterogeneity in terms of the pore size distribution in a seasonally wet but otherwise arid environment.

  11. Time Eigenstates for Potential Functions without Extremal Points

    Directory of Open Access Journals (Sweden)

    Gabino Torres-Vega

    2013-09-01

    Full Text Available In a previous paper, we introduced a way to generate a time coordinate system for classical and quantum systems when the potential function has extremal points. In this paper, we deal with the case in which the potential function has no extremal points at all, and we illustrate the method with the harmonic and linear potentials.

  12. Two-Gyro Pointing Stability of HST measured with ACS

    Science.gov (United States)

    Koekemoer, Anton M.; Kozhurina-Platais, Vera; Riess, Adam; Sirianni, Marco; Biretta, John; Pavlovsky

    2005-06-01

    We present the results of the pointing stability tests for HST, as measured with the ACS/ HRC during the Two-Gyro test program conducted in February 2005. We measure the shifts of 185 exposures of the globular clusters NGC6341 and Omega Centauri, obtained over a total of 13 orbits, and compare the measured pointings to those that were commanded in the observing program. We find in all cases that the measured shifts and rotations have the same level of accuracy as those that were commanded in three-gyro mode. Specifically, the pointing offsets during an orbit relative to the first exposure can be characterized with distributions having a dispersion of 2.3 milliarcseconds for shifts and 0.00097 degrees for rotations, thus less than 0.1 HRC pixels, and agree extremely well with similar values measured for comparable exposures obtained in three-gyro mode. In addition, we successfully processed these two-gyro test data through the MultiDrizzle software which is used in the HST pipeline to perform automated registration, cosmic ray rejection and image combination for multiple exposure sequences, and we find excellent agreement with similar exposures obtained in three-gyro mode. In summary, we find no significant difference between the quality of HST pointing as measured from these two-gyro test data, relative to the nominal behavior of HST in regular three-gyro operations.

  13. A quartz crystal microbalance dew point sensor without frequency measurement

    Science.gov (United States)

    Wang, Guohua; Zhang, Weishuo; Wang, Shuo; Sun, Jinglin

    2014-11-01

    This work deals with the design of a dew point sensor based on Quartz Crystal Microbalance (QCM) without measuring the frequency. This idea is inspired by the fact that the Colpitts oscillation circuit will stop oscillating when the QCM works in the liquid media. The quartz crystal and the electrode are designed through the finite element simulation and the stop oscillating experiment is conducted to verify the sensibility. Moreover, the measurement result is calibrated to approach the true value. At last a series of dew points at the same temperature is measured with the designed sensor. Results show that the designed dew point sensor is able to detect the dew point with the proper accuracy.

  14. Automatic continuous dew point measurement in combustion gases

    Energy Technology Data Exchange (ETDEWEB)

    Fehler, D.

    1986-08-01

    Low exhaust temperatures serve to minimize energy consumption in combustion systems. This requires accurate, continuous measurement of exhaust condensation. An automatic dew point meter for continuous operation is described. The principle of measurement, the design of the measuring system, and practical aspects of operation are discussed.

  15. A Feedback Optimal Control Algorithm with Optimal Measurement Time Points

    Directory of Open Access Journals (Sweden)

    Felix Jost

    2017-02-01

    Full Text Available Nonlinear model predictive control has been established as a powerful methodology to provide feedback for dynamic processes over the last decades. In practice it is usually combined with parameter and state estimation techniques, which allows to cope with uncertainty on many levels. To reduce the uncertainty it has also been suggested to include optimal experimental design into the sequential process of estimation and control calculation. Most of the focus so far was on dual control approaches, i.e., on using the controls to simultaneously excite the system dynamics (learning as well as minimizing a given objective (performing. We propose a new algorithm, which sequentially solves robust optimal control, optimal experimental design, state and parameter estimation problems. Thus, we decouple the control and the experimental design problems. This has the advantages that we can analyze the impact of measurement timing (sampling independently, and is practically relevant for applications with either an ethical limitation on system excitation (e.g., chemotherapy treatment or the need for fast feedback. The algorithm shows promising results with a 36% reduction of parameter uncertainties for the Lotka-Volterra fishing benchmark example.

  16. Point-Connecting Measurements of the Hallux Valgus Deformity: A New Measurement and Its Clinical Application

    Science.gov (United States)

    Seo, Jeong-Ho; Boedijono, Dimas

    2016-01-01

    Purpose The aim of this study was to investigate new point-connecting measurements for the hallux valgus angle (HVA) and the first intermetatarsal angle (IMA), which can reflect the degree of subluxation of the first metatarsophalangeal joint (MTPJ). Also, this study attempted to compare the validity of midline measurements and the new point-connecting measurements for the determination of HVA and IMA values. Materials and Methods Sixty feet of hallux valgus patients who underwent surgery between 2007 and 2011 were classified in terms of the severity of HVA, congruency of the first MTPJ, and type of chevron metatarsal osteotomy. On weight-bearing dorsal-plantar radiographs, HVA and IMA values were measured and compared preoperatively and postoperatively using both the conventional and new methods. Results Compared with midline measurements, point-connecting measurements showed higher inter- and intra-observer reliability for preoperative HVA/IMA and similar or higher inter- and intra-observer reliability for postoperative HVA/IMA. Patients who underwent distal chevron metatarsal osteotomy (DCMO) had higher intraclass correlation coefficient for inter- and intra-observer reliability for pre- and post-operative HVA and IMA measured by the point-connecting method compared with the midline method. All differences in the preoperative HVAs and IMAs determined by both the midline method and point-connecting methods were significant between the deviated group and subluxated groups (p=0.001). Conclusion The point-connecting method for measuring HVA and IMA in the subluxated first MTPJ may better reflect the severity of a HV deformity with higher reliability than the midline method, and is more useful in patients with DCMO than in patients with proximal chevron metatarsal osteotomy. PMID:26996576

  17. Four-point potential drop measurements for materials characterization

    International Nuclear Information System (INIS)

    Bowler, Nicola

    2011-01-01

    The technique of measuring the voltage difference (potential drop) between two of the four electrodes of a four-point probe, in order to determine conductivity or surface resistivity of a test piece, is well established in the direct-current (dc) or quasi-dc regime. The technique finds wide usage in the semiconductor industry for the purpose of measuring surface resistivity of semiconductors, and also in the measurement of conductivity of metals, particularly of ferromagnetic metals for which conductivity cannot be easily measured using eddy-current nondestructive evaluation (NDE). In these applications, the conductivity of the test piece is deduced from an analytic formula that depends on the geometry of the probe and test piece. Such a formula requires, as an input, the measured value of the potential drop. Several analytical expressions exist for a variety of test-piece geometries and probe arrangements. Recently, it has been shown that broadband measurements of the potential drop, known as 'alternating current potential drop' (ac PD) measurements, can be used not only to obtain the conductivity of a test piece, but also its linear permeability μ. The beauty of this measurement is that the two parameters are completely decoupled in the quasi-static regime. In fact, μ does not appear in the quasi-static expression for σ. Hence, σ may be obtained from low-frequency ac PD measurements and then μ may be deduced as the frequency increases beyond the quasi-static regime, once σ is known. In this review, both dc and ac solutions that are useful in determining the conductivity of metals and semiconductors, and the permeability of ferromagnetic conductors, are summarized. In particular, flat test pieces with arbitrary thickness are considered. At the next level of complexity, a solution for a half-space coated with a surface layer is given, along with a discussion of the use of the four-point potential drop method for determining thickness of a surface layer, such

  18. In situ optoacoustic measurement of the pointing stability of femtosecond laser beams

    Science.gov (United States)

    Pushkarev, D.; Mitina, E.; Uryupina, D.; Volkov, R.; Karabytov, A.; Savel'ev, A.

    2018-02-01

    A new method for the in situ acoustic measurement of the beam pointing stability (BPS) of powerful pulsed lasers is tested. A broadband (~6 MHz) piezoelectric transducer placed a few millimeters from the laser spark produces an electric pulse. We show that variation in time of the position of this pulse can be used to assess the BPS down to 1 µrad in a few hundred laser shots. The estimated value coincides well with the BPS estimated using standard measurement in the far field.

  19. Measure of departure from marginal point-symmetry for two-way contingency tables

    Directory of Open Access Journals (Sweden)

    Kouji Yamamoto

    2013-05-01

    Full Text Available For two-way contingency tables, Tomizawa (1985 considered the point-symmetry and marginal point-symmetry models, and Tomizawa, Yamamoto and Tahata (2007 proposed a measure to represent the degree of departure from point-symmetry. The present paper proposes a measure to represent the degree of departure from marginal pointsymmetry for two-way tables. The proposed measure is expressed by using Cressie-Read power-divergence or Patil-Taillie diversity index. This measure would be useful for comparing the degrees of departure from marginal point-symmetry in several tables. The relationship between the degree of departure from marginal point-symmetry and the measure is shown when it is reasonable to assume underlying bivariate normal distribution. Examples are shown.

  20. Use of a large time-compensated scintillation detector in neutron time-of-flight measurements

    International Nuclear Information System (INIS)

    Goodman, C.D.

    1979-01-01

    A scintillator for neutron time-of-flight measurements is positioned at a desired angle with respect to the neutron beam, and as a function of the energy thereof, such that the sum of the transit times of the neutrons and photons in the scintillator are substantially independent of the points of scintillations within the scintillator. Extrapolated zero timing is employed rather than the usual constant fraction timing. As a result, a substantially larger scintillator can be employed that substantially increases the data rate and shortens the experiment time. 3 claims

  1. Dual time point FDG-PET/CT imaging...; Potential tool for diagnosis of breast cancer

    International Nuclear Information System (INIS)

    Zytoon, A.A.; Murakami, K.; El-Kholy, M.R.; El-Shorbagy, E.

    2008-01-01

    Aim: This prospective study was designed to assess the utility of the dual time point imaging technique using 2- [ 18 F]-fluoro-2-deoxy-D-glucose (FDG) positron-emission tomography/computed tomography (PET/CT) to detect primary breast cancer and to determine whether it is useful for the detection of small and non-invasive cancers, as well as cancers in dense breast tissue. Methods: One hundred and eleven patients with newly diagnosed breast cancer underwent two sequential PET/CT examinations (dual time point imaging) for preoperative staging. The maximum standardized uptake value (SUVmax) of FDG was measured from both time points. The percentage change in SUVmax (ΔSUVmax%) between time points 1 (SUVmax1) and 2 (SUVmax2) was calculated. The patients were divided into groups: invasive (n = 82), non invasive (n = 29); large (>10 mm; n = 80), small (≤10 mm; n = 31); tumours in dense breasts (n = 61), and tumours in non-dense breasts (n = 50). The tumour:background (T:B) ratios at both time points were measured and the ΔSUVmax%, ΔT:B% values were calculated. All PET study results were correlated with the histopathology results. Results: Of the 111 cancer lesions, 88 (79.3%) showed an increase and 23 (20.7%) showed either no change [10 (9%)] or a decrease [13 (11.7%)] in the SUVmax over time. Of the 111 contralateral normal breasts, nine (8.1%) showed an increase and 102 (91.9%) showed either no change [17 (15.3%)] or a decrease [85 (76.6%)] in the SUVmax over time. The mean ± SD of SUVmax1, SUVmax2, Δ%SUVmax were 4.9 ± 3.6, 6.0 ± 4.5, and 22.6 ± 13.1% for invasive cancers, 4.1 ± 3.8, 4.4 ± 4.8, and -2.4 ± 18.5% for non-invasive cancers, 2.3 ± 1.9, 2.7 ± 2.3, and 12.9 ± 21.1% for small cancers, 5.6 ± 3.7, 6.8 ± 4.8, and 17.3 ± 17.1% for large cancers, 4.9 ± 3.7, 5.8 ± 4.8, and 15.1 ± 17.6% for cancers in dense breast, and 4.5 ± 3.6, 5.4 ± 4.5, and 17.2 ± 19.2% for cancers in non-dense breast. The receiver-operating characteristic (ROC) analysis

  2. Meta-Analysis of Effect Sizes Reported at Multiple Time Points Using General Linear Mixed Model

    Science.gov (United States)

    Musekiwa, Alfred; Manda, Samuel O. M.; Mwambi, Henry G.; Chen, Ding-Geng

    2016-01-01

    Meta-analysis of longitudinal studies combines effect sizes measured at pre-determined time points. The most common approach involves performing separate univariate meta-analyses at individual time points. This simplistic approach ignores dependence between longitudinal effect sizes, which might result in less precise parameter estimates. In this paper, we show how to conduct a meta-analysis of longitudinal effect sizes where we contrast different covariance structures for dependence between effect sizes, both within and between studies. We propose new combinations of covariance structures for the dependence between effect size and utilize a practical example involving meta-analysis of 17 trials comparing postoperative treatments for a type of cancer, where survival is measured at 6, 12, 18 and 24 months post randomization. Although the results from this particular data set show the benefit of accounting for within-study serial correlation between effect sizes, simulations are required to confirm these results. PMID:27798661

  3. Method to minimize the low-frequency neutral-point voltage oscillations with time-offset injection for neutral-point-clamped inverters

    DEFF Research Database (Denmark)

    Choi, Uimin; Lee, Kyo-Beum; Blaabjerg, Frede

    2013-01-01

    This paper proposes a method to reduce the low-frequency neutral-point voltage oscillations. The neutral-point voltage oscillations are considerably reduced by adding a time-offset to the three phase turn-on times. The proper time-offset is simply calculated considering the phase currents and dwell...

  4. Point splitting in a curved space-time background

    International Nuclear Information System (INIS)

    Liggatt, P.A.J.; Macfarlane, A.J.

    1979-01-01

    A prescription is given for point splitting in a curved space-time background which is a natural generalization of that familiar in quantum electrodynamics and Yang-Mills theory. It is applied (to establish its validity) to the verification of the gravitational anomaly in the divergence of a fermion axial current. Notable features of the prescription are that it defines a point-split current that can be differentiated straightforwardly, and that it involves a natural way of averaging (four-dimensionally) over the directions of point splitting. The method can extend directly from the spin-1/2 fermion case treated to other cases, e.g., to spin-3/2 Rarita-Schwinger fermions. (author)

  5. INDIAN POINT REACTOR REACTIVITY AND FLUX DISTRIBUTION MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Batch, M. L.; Fischer, F. E.

    1963-11-15

    The reactivity of the Indian Point core was measured near zero reactivity at various shim and control rod patterns. Flux distribution measurements were also made, and the results are expressed in terms of power peaking factors and normalized detector response during rod withdrawal. (D.L.C.)

  6. A travel time forecasting model based on change-point detection method

    Science.gov (United States)

    LI, Shupeng; GUANG, Xiaoping; QIAN, Yongsheng; ZENG, Junwei

    2017-06-01

    Travel time parameters obtained from road traffic sensors data play an important role in traffic management practice. A travel time forecasting model is proposed for urban road traffic sensors data based on the method of change-point detection in this paper. The first-order differential operation is used for preprocessing over the actual loop data; a change-point detection algorithm is designed to classify the sequence of large number of travel time data items into several patterns; then a travel time forecasting model is established based on autoregressive integrated moving average (ARIMA) model. By computer simulation, different control parameters are chosen for adaptive change point search for travel time series, which is divided into several sections of similar state.Then linear weight function is used to fit travel time sequence and to forecast travel time. The results show that the model has high accuracy in travel time forecasting.

  7. Nonlinear triple-point problems on time scales

    Directory of Open Access Journals (Sweden)

    Douglas R. Anderson

    2004-04-01

    Full Text Available We establish the existence of multiple positive solutions to the nonlinear second-order triple-point boundary-value problem on time scales, $$displaylines{ u^{Delta abla}(t+h(tf(t,u(t=0, cr u(a=alpha u(b+delta u^Delta(a,quad eta u(c+gamma u^Delta(c=0 }$$ for $tin[a,c]subsetmathbb{T}$, where $mathbb{T}$ is a time scale, $eta, gamma, deltage 0$ with $Beta+gamma>0$, $0

  8. Knee point search using cascading top-k sorting with minimized time complexity.

    Science.gov (United States)

    Wang, Zheng; Tseng, Shian-Shyong

    2013-01-01

    Anomaly detection systems and many other applications are frequently confronted with the problem of finding the largest knee point in the sorted curve for a set of unsorted points. This paper proposes an efficient knee point search algorithm with minimized time complexity using the cascading top-k sorting when a priori probability distribution of the knee point is known. First, a top-k sort algorithm is proposed based on a quicksort variation. We divide the knee point search problem into multiple steps. And in each step an optimization problem of the selection number k is solved, where the objective function is defined as the expected time cost. Because the expected time cost in one step is dependent on that of the afterwards steps, we simplify the optimization problem by minimizing the maximum expected time cost. The posterior probability of the largest knee point distribution and the other parameters are updated before solving the optimization problem in each step. An example of source detection of DNS DoS flooding attacks is provided to illustrate the applications of the proposed algorithm.

  9. Noise evaluation of a point autofocus surface topography measuring instrument

    Science.gov (United States)

    Maculotti, Giacomo; Feng, Xiaobing; Galetto, Maurizio; Leach, Richard

    2018-06-01

    In this work, the measurement noise of a point autofocus surface topography measuring instrument is evaluated, as the first step towards establishing a route to traceability for this type of instrument. The evaluation is based on the determination of the metrological characteristics for noise as outlined in draft ISO specification standards by using a calibrated optical flat. The static noise and repeatability of the autofocus sensor are evaluated. The influence of environmental disturbances on the measured surface topography and the built-in software to compensate for such influences are also investigated. The instrument was found to have a measurement noise of approximately 2 nm or, when expressed with the measurement bandwidth, 0.4 nm for a single-point measurement.

  10. Null-point titration measurements of free magnesium in stored erythrocytes

    International Nuclear Information System (INIS)

    Bock, J.L.; Yusuf, Y.; Puntillo, E.

    1987-01-01

    Free intracellular magnesium concentration (Mg/sub i/) was measured in stored human erythrocytes, using null-point titration with ionophore A23187. For cells stored 31 P NMR spectroscopy, which showed a decrease in Mg/sub i/ with storage. However, the NMR measurements are performed with no pretreatment of the cells, while the null-point method requires an initial washing step, which alters pH/sub i/ and may also alter Mg/sub i/. The titration-measured Mg/sub i/ values are still surprisingly low for long-stored cells, considering that depletion of ATP and 2,3-DPG should release bound Mg. Using the titration-measured Mg/sub i/ values along with measurements of total Mg, ATP, and 2,3-DPG, they estimate that an additional buffer contains about 47% of total Mg in cells stored 21 days. Mg/sub i/ determinations by both 31 P NMR and null-point titration thus indicate that erythrocyte Mg is largely bound to a high-capacity, low-affinity buffer whose relative importance increases during cell storage. Discrepancies between the methods require further investigation

  11. Change detection in polarimetric SAR data over several time points

    DEFF Research Database (Denmark)

    Conradsen, Knut; Nielsen, Allan Aasbjerg; Skriver, Henning

    2014-01-01

    A test statistic for the equality of several variance-covariance matrices following the complex Wishart distribution is introduced. The test statistic is applied successfully to detect change in C-band EMISAR polarimetric SAR data over four time points.......A test statistic for the equality of several variance-covariance matrices following the complex Wishart distribution is introduced. The test statistic is applied successfully to detect change in C-band EMISAR polarimetric SAR data over four time points....

  12. TH-AB-202-08: A Robust Real-Time Surface Reconstruction Method On Point Clouds Captured From a 3D Surface Photogrammetry System

    International Nuclear Information System (INIS)

    Liu, W; Sawant, A; Ruan, D

    2016-01-01

    Purpose: Surface photogrammetry (e.g. VisionRT, C-Rad) provides a noninvasive way to obtain high-frequency measurement for patient motion monitoring in radiotherapy. This work aims to develop a real-time surface reconstruction method on the acquired point clouds, whose acquisitions are subject to noise and missing measurements. In contrast to existing surface reconstruction methods that are usually computationally expensive, the proposed method reconstructs continuous surfaces with comparable accuracy in real-time. Methods: The key idea in our method is to solve and propagate a sparse linear relationship from the point cloud (measurement) manifold to the surface (reconstruction) manifold, taking advantage of the similarity in local geometric topology in both manifolds. With consistent point cloud acquisition, we propose a sparse regression (SR) model to directly approximate the target point cloud as a sparse linear combination from the training set, building the point correspondences by the iterative closest point (ICP) method. To accommodate changing noise levels and/or presence of inconsistent occlusions, we further propose a modified sparse regression (MSR) model to account for the large and sparse error built by ICP, with a Laplacian prior. We evaluated our method on both clinical acquired point clouds under consistent conditions and simulated point clouds with inconsistent occlusions. The reconstruction accuracy was evaluated w.r.t. root-mean-squared-error, by comparing the reconstructed surfaces against those from the variational reconstruction method. Results: On clinical point clouds, both the SR and MSR models achieved sub-millimeter accuracy, with mean reconstruction time reduced from 82.23 seconds to 0.52 seconds and 0.94 seconds, respectively. On simulated point cloud with inconsistent occlusions, the MSR model has demonstrated its advantage in achieving consistent performance despite the introduced occlusions. Conclusion: We have developed a real-time

  13. Measured emotional intelligence ability and grade point average in nursing students.

    Science.gov (United States)

    Codier, Estelle; Odell, Ellen

    2014-04-01

    For most schools of nursing, grade point average is the most important criteria for admission to nursing school and constitutes the main indicator of success throughout the nursing program. In the general research literature, the relationship between traditional measures of academic success, such as grade point average and postgraduation job performance is not well established. In both the general population and among practicing nurses, measured emotional intelligence ability correlates with both performance and other important professional indicators postgraduation. Little research exists comparing traditional measures of intelligence with measured emotional intelligence prior to graduation, and none in the student nurse population. This exploratory, descriptive, quantitative study was undertaken to explore the relationship between measured emotional intelligence ability and grade point average of first year nursing students. The study took place at a school of nursing at a university in the south central region of the United States. Participants included 72 undergraduate student nurse volunteers. Emotional intelligence was measured using the Mayer-Salovey-Caruso Emotional Intelligence Test, version 2, an instrument for quantifying emotional intelligence ability. Pre-admission grade point average was reported by the school records department. Total emotional intelligence (r=.24) scores and one subscore, experiential emotional intelligence(r=.25) correlated significantly (>.05) with grade point average. This exploratory, descriptive study provided evidence for some relationship between GPA and measured emotional intelligence ability, but also demonstrated lower than average range scores in several emotional intelligence scores. The relationship between pre-graduation measures of success and level of performance postgraduation deserves further exploration. The findings of this study suggest that research on the relationship between traditional and nontraditional

  14. Global Stability of Polytopic Linear Time-Varying Dynamic Systems under Time-Varying Point Delays and Impulsive Controls

    Directory of Open Access Journals (Sweden)

    M. de la Sen

    2010-01-01

    Full Text Available This paper investigates the stability properties of a class of dynamic linear systems possessing several linear time-invariant parameterizations (or configurations which conform a linear time-varying polytopic dynamic system with a finite number of time-varying time-differentiable point delays. The parameterizations may be timevarying and with bounded discontinuities and they can be subject to mixed regular plus impulsive controls within a sequence of time instants of zero measure. The polytopic parameterization for the dynamics associated with each delay is specific, so that (q+1 polytopic parameterizations are considered for a system with q delays being also subject to delay-free dynamics. The considered general dynamic system includes, as particular cases, a wide class of switched linear systems whose individual parameterizations are timeinvariant which are governed by a switching rule. However, the dynamic system under consideration is viewed as much more general since it is time-varying with timevarying delays and the bounded discontinuous changes of active parameterizations are generated by impulsive controls in the dynamics and, at the same time, there is not a prescribed set of candidate potential parameterizations.

  15. Surface-sensitive conductivity measurement using a micro multi-point probe approach

    DEFF Research Database (Denmark)

    Perkins, Edward; Barreto, Lucas; Wells, Justin

    2013-01-01

    An instrument for microscale electrical transport measurements in ultra-high vacuum is presented. The setup is constructed around collinear lithographically-created multi-point probes with a contact spacing down to 500 nm. Most commonly, twelve-point probes are used. These probes are approached...... measurements with an equidistant four-point probe for a wide range of contact spacings. In this way, it is possible to distinguish between bulk-like and surface-like conduction. The paper describes the design of the instrument and the approach to data and error analysis. Application examples are given...

  16. Measurement of the Four-Point Susceptibility of an Out-of-Equilibrium Colloidal Solution of Nanoparticles Using Time-Resolved Light Scattering

    DEFF Research Database (Denmark)

    Maggi, Claudio; Di Leonardo, Ricardo; ruocco, giancarlo

    2012-01-01

    The spatial fluctuations of the dynamics of a colloidal system composed of nanoparticles are probed by a novel experimental setup, which combines homodyne and heterodyne dynamic light scattering focused onto a micron-sized volume via a microscope objective. The technique is used to measure the four-point...

  17. Measuring Business Cycle Time.

    OpenAIRE

    Stock, James H

    1987-01-01

    The business cycle analysis of Arthur F. Burns and Wesley C. Mitchell and the National Bureau of Economic Research presumed that aggregate economic variables evolve on a time scale defined by business cycle turning points rather than by months or quarters. Do macroeconomic variables appear to evolve on an economic rather than a calendar time scale? Evidence presented here suggests that they do. However, the estimated economic time scales are only weakly related to business cycle time scales, ...

  18. Measurement standards and the general problem of reference points in chemical analysis

    International Nuclear Information System (INIS)

    Richter, W.; Dube, G.

    2002-01-01

    Besides the measurement standards available in general metrology in the form of the realisations of the units of measurement, measurement standards of chemical composition are needed for the vast field of chemical measurement (measurements of the chemical composition), because it is the main aim of such measurements to quantify non-isolated substances, often in complicated matrices, to which the 'classical' measurement standards and their lower- level derivatives are not directly applicable. At present, material artefacts as well as standard measurement devices serve as chemical measurement standards. These are measurement standards in the full metrological sense only, however, if they are firmly linked to the SI unit in which the composition represented by the standard is expressed. This requirement has the consequence that only a very restricted number of really reliable chemical measurement standards exist at present. Since it is very difficult and time consuming to increase this number substantially and, on the other hand, reliable reference points are increasingly needed for all kinds of chemical measurements, primary methods of measurement and high-level reference measurements will play an increasingly important role for the establishment of worldwide comparability and hence mutual acceptance of chemical measurement results. (author)

  19. Title XVI / Supplemental Security Record Point In Time (SSRPT)

    Data.gov (United States)

    Social Security Administration — This is the point-in-time database to house temporary Supplemental Security Record (SSR) images produced during the course of the operating day before they can be...

  20. Measuring Operational Success: Establishing Criteria to Benchmark the Point of Culmination

    National Research Council Canada - National Science Library

    Caraccilo, Dominic

    1997-01-01

    ... has for the establishment of criteria that measure operational success on the battlefield. This void, in-turn, impacts directly on the operational commander's capability to identify his point(s) of culmination...

  1. Electrical conduction through surface superstructures measured by microscopic four-point probes

    DEFF Research Database (Denmark)

    Hasegawa, S.; Shiraki, I.; Tanabe, F.

    2003-01-01

    For in-situ measurements of the local electrical conductivity of well-defined crystal surfaces in ultra-high vacuum, we have developed two kinds of microscopic four-point probe methods. One involves a "four-tip STM prober," in which four independently driven tips of a scanning tunneling microscope...... (STM) are used for measurements of four-point probe conductivity. The probe spacing can be changed from 500 nm to 1 mm. The other method involves monolithic micro-four-point probes, fabricated on silicon chips, whose probe spacing is fixed around several mum. These probes are installed in scanning...

  2. Flight-time spread of uniform field sector magnet system for use in nuclear life-time measurements

    International Nuclear Information System (INIS)

    Sakata, Akihiko; Mamei, Masayuki; Yamada, Yoshihiro; Ohira, Kyozo

    1984-01-01

    A nuclear life-time measurement apparatus incorporating a deflecting β-ray spectrometer with electron pre-accelerator has been constructed. A new arrangement consisting of two double angular focusing sector magnets based on the principle of symmetry has been devised so as to reduce the time spread in the spectrometer, which up till now has been the weak point of such systems. The time spread in the spectrometer was estimated to be asymptotically equals 0.1 ns by a simulation method, and good agreement was obtained between this estimated value and the experimental value. A prompt time resolution of 1.25 ns (FWHM) was obtained. The half-lives of the 199 and 401 keV levels in 75 As were measured with an acceleration voltage up to 30 kV to check the reliability of the apparatus. The values were found to be 0.87+-0.04 ns and 1.74+-0.05 ns, respectively, in good agreement with previous measurements. (author)

  3. Clinical Significance of F 18 FP CIT Dual Time Point PET Imaging in Idiopathic Parkinson's Disease

    International Nuclear Information System (INIS)

    Oh, Jin Kyoung; Yoo, Ik Dong; Seo, Ye Young; Chung, Youg An; Yoo, Ie Ryung; Kim, Sung Hoon; Song, In Uk

    2011-01-01

    The purpose of this study was to investigate the diagnostic value of dual time point F 18 FP CIT PET imaging in idiopathic Parkinson's disease (PD). Twenty four patients with PD (mean age 69.6) and 18 healthy people (mean age 70.26) underwent two sequential PET/CT scans (dual time point imaging) at 90 and 210 min after F 18 FP CIT injection. Tracer activity of region of interest was measured in the caudate, putamen and a reference region in the brain from both time points. The outcome parameter was the striatooccipital ratio (SOR). Normal SOR values were obtained in the control group. The percent change in tracer activity between 90 and 210 min images was calculated. The SOR values and the percent change in tracer activity were compared between the patients and healthy control group. The SOR values for the caudate, anterior and posterior putamen at both 90 and 210 min images were significantly reduced in the patients with PD. The lowest P value was obtained for the anterior and posterior putamen (p<0.001) at both time points. There were significant differences of the percent change in tracer activity for the anterior and posterior putamen in the two groups (p=0.01) F 18 FP CIT PET scans at 90 and 210 min after injection are both able to diagnose PD. Therefore, the 90 min image by itself in sufficient for diagnosing PD.

  4. An Equipment to Measure the Freezing Point of Soils under Higher Pressure

    Science.gov (United States)

    Wang, Dayan; Guan, Hui; Wen, Zhi; Ma, Wei

    2014-05-01

    control electron universal testing machines. All of above mentioned advantages of this equipment ensures one to catch up the moment soil turns from the thawed state into ice and enable one to determine the freezing point experimentally by recording the temperature-time history (cooling curve) at particular points within the sample used for analysis. Therefore, this equipment has excellent characteristics such as compact construction, convenient operation, high reliability and the measuring accuracy. The authors would like to thank the following agents for their financial supports: the National Natural Science Foundation (No.41071048),Hundred Talent Young Scientists program of the Chinese Academy of Sciences granted to Dr. Zhi Wen.

  5. FBX dosimetry for point dose measurements in head and neck cancer patients

    International Nuclear Information System (INIS)

    Balraj, A.; Thakur, P.K.; Bhatnagar, S.; Vidyasagar, P.B.; Nirhali, Amit; Semwal, M.K.

    2007-01-01

    FBX dosimeter is mainly based on the determination of the radiation dose from the chemical changes produced in an irradiated medium, which can be measured by Spectrophotometry or Colorimetry, for which adequate FBX solution of 2 ml required for measuring the optical density (OD). To measure the point dose using 2 ml solution may lead to error in the measured dose since the solution may occupy 2 cc volume of the point measured. In head and neck carcinoma patients, the treatment area involves curvatures. Fixing 2 ml vial at the body surface is difficult and leads to give wrong readings. In this study we have measured the entrance and exit dose by filling 0.5 ml solution in a flexible catheter and placed at a point in the patient body surface during the radiation treatment. The solution was diluted adding 1.5 ml distilled water to measure the OD in the colorimeter

  6. Measurement and correction of leaf open times in helical tomotherapy

    International Nuclear Information System (INIS)

    Sevillano, David; Mínguez, Cristina; Sánchez, Alicia; Sánchez-Reyes, Alberto

    2012-01-01

    Purpose: The binary multileaf collimator (MLC) is one of the most important components in helical tomotherapy (HT), as it modulates the dose delivered to the patient. However, methods to ensure MLC quality in HT treatments are lacking. The authors obtained data on the performance of the MLC in treatments administered in their department in order to assess possible delivery errors due to the MLC. Correction methods based on their data are proposed. Methods: Twenty sinograms from treatments delivered using both of the authors HT systems were measured and analyzed by recording the fluence collected by the imaging detector. Planned and actual sinograms were compared using distributions of leaf open time (LOT) errors, as well as differences in fluence reconstructed at each of the 51 projections into which the treatment planning system divides each rotation for optimization purposes. They proposed and applied a method based on individual leaf error correction and the increase in projection time to prevent latency effects when LOT is close to projection time. In order to analyze the dosimetric impact of the corrections, inphantom measurements were made for four corrected treatments. Results: The LOTs measured were consistent with those planned. Most of the mean errors in LOT distributions were within 1 ms with standard deviations of over 4 ms. Reconstructed fluences showed good results, with over 90% of points passing the 3% criterion, except in treatments with a short mean LOT, where the percentage of passing points was as low as 66%. Individual leaf errors were as long as 4 ms in some cases. Corrected sinograms improved error distribution, with standard deviations of over 3 ms and increased percentages of points passing 3% in the fluence per angle analysis, especially in treatments with a short mean LOT and those that were more subject to latency effects. The minimum percentage of points within 3% increased to 86%. In-phantom measurements of the corrected treatments

  7. Measurement and correction of leaf open times in helical tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sevillano, David; Minguez, Cristina; Sanchez, Alicia; Sanchez-Reyes, Alberto [Department of Medical Physics, Tomotherapy Unit, Grupo IMO, Madrid 28010 (Spain)

    2012-11-15

    Purpose: The binary multileaf collimator (MLC) is one of the most important components in helical tomotherapy (HT), as it modulates the dose delivered to the patient. However, methods to ensure MLC quality in HT treatments are lacking. The authors obtained data on the performance of the MLC in treatments administered in their department in order to assess possible delivery errors due to the MLC. Correction methods based on their data are proposed. Methods: Twenty sinograms from treatments delivered using both of the authors HT systems were measured and analyzed by recording the fluence collected by the imaging detector. Planned and actual sinograms were compared using distributions of leaf open time (LOT) errors, as well as differences in fluence reconstructed at each of the 51 projections into which the treatment planning system divides each rotation for optimization purposes. They proposed and applied a method based on individual leaf error correction and the increase in projection time to prevent latency effects when LOT is close to projection time. In order to analyze the dosimetric impact of the corrections, inphantom measurements were made for four corrected treatments. Results: The LOTs measured were consistent with those planned. Most of the mean errors in LOT distributions were within 1 ms with standard deviations of over 4 ms. Reconstructed fluences showed good results, with over 90% of points passing the 3% criterion, except in treatments with a short mean LOT, where the percentage of passing points was as low as 66%. Individual leaf errors were as long as 4 ms in some cases. Corrected sinograms improved error distribution, with standard deviations of over 3 ms and increased percentages of points passing 3% in the fluence per angle analysis, especially in treatments with a short mean LOT and those that were more subject to latency effects. The minimum percentage of points within 3% increased to 86%. In-phantom measurements of the corrected treatments

  8. Micro-four-point Probe Hall effect Measurement method

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Hansen, Ole; Lin, Rong

    2008-01-01

    barriers and with a magnetic field applied normal to the plane of the sheet. Based on this potential, analytical expressions for the measured four-point resistance in presence of a magnetic field are derived for several simple sample geometries. We show how the sheet resistance and Hall effect...

  9. Integrated CMOS dew point sensors for relative humidity measurement

    Science.gov (United States)

    Savalli, Nicolo; Baglio, Salvatore; Castorina, Salvatore; Sacco, Vincenzo; Tringali, Cristina

    2004-07-01

    This work deals with the development of integrated relative humidity dew point sensors realized by adopting standard CMOS technology for applications in various fields. The proposed system is composed by a suspended plate that is cooled by exploiting integrated Peltier cells. The cold junctions of the cells have been spread over the plate surface to improve the homogeneity of the temperature distribution over its surface, where cooling will cause the water condensation. The temperature at which water drops occur, named dew point temperature, is a function of the air humidity. Measurement of such dew point temperature and the ambient temperature allows to know the relative humidity. The detection of water drops is achieved by adopting a capacitive sensing strategy realized by interdigited fixed combs, composed by the upper layer of the adopted process. Such a capacitive sensor, together with its conditioning circuit, drives a trigger that stops the cooling of the plate and enables the reading of the dew point temperature. Temperature measurements are achieved by means of suitably integrated thermocouples. The analytical model of the proposed system has been developed and has been used to design a prototype device and to estimate its performances. In such a prototype, the thermoelectric cooler is composed by 56 Peltier cells, made by metal 1/poly 1 junctions. The plate has a square shape with 200 μm side, and it is realized by exploiting the oxide layers. Starting from the ambient temperature a temperature variation of ΔT = 15 K can be reached in 10 ms thus allowing to measure a relative humidity greater than 40%.

  10. A rapid and robust gradient measurement technique using dynamic single-point imaging.

    Science.gov (United States)

    Jang, Hyungseok; McMillan, Alan B

    2017-09-01

    We propose a new gradient measurement technique based on dynamic single-point imaging (SPI), which allows simple, rapid, and robust measurement of k-space trajectory. To enable gradient measurement, we utilize the variable field-of-view (FOV) property of dynamic SPI, which is dependent on gradient shape. First, one-dimensional (1D) dynamic SPI data are acquired from a targeted gradient axis, and then relative FOV scaling factors between 1D images or k-spaces at varying encoding times are found. These relative scaling factors are the relative k-space position that can be used for image reconstruction. The gradient measurement technique also can be used to estimate the gradient impulse response function for reproducible gradient estimation as a linear time invariant system. The proposed measurement technique was used to improve reconstructed image quality in 3D ultrashort echo, 2D spiral, and multi-echo bipolar gradient-echo imaging. In multi-echo bipolar gradient-echo imaging, measurement of the k-space trajectory allowed the use of a ramp-sampled trajectory for improved acquisition speed (approximately 30%) and more accurate quantitative fat and water separation in a phantom. The proposed dynamic SPI-based method allows fast k-space trajectory measurement with a simple implementation and no additional hardware for improved image quality. Magn Reson Med 78:950-962, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  11. Measurement and estimation of dew point for SNG. [Comparison of calculated and measured values

    Energy Technology Data Exchange (ETDEWEB)

    Furuyama, Y.

    1974-08-01

    Toho Gas measured and estimated SNG dew points in high-pressure deliveries by calculating the theoretical values by the high-pressure gas-liquid equilibrium theory using the pressure-extrapolation method to reach K = 1, and the BWR method to estimate fugacity, then verifying these values experimentally. The experimental values were measured at 161.7 to 367.5 psi using the conventional static and circulation methods, in addition to a newly developed method consisting of circulating a known composition of gas mixtures, partially freezing them, and monitoring the dew point by observing the droplets on a mirror cooled by blowing liquid nitrogen. Good agreement was found between the calculated and the experimental values.

  12. MDCT evaluation of aortic root and aortic valve prior to TAVI. What is the optimal imaging time point in the cardiac cycle?

    Energy Technology Data Exchange (ETDEWEB)

    Jurencak, Tomas; Turek, Jakub; Nijssen, Estelle C. [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Kietselaer, Bastiaan L.J.H. [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Maastricht University Medical Center, CARIM School for Cardiovascular Diseases, Maastricht (Netherlands); Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Mihl, Casper; Kok, Madeleine; Wildberger, Joachim E.; Das, Marco [Maastricht University Medical Center, Department of Radiology, P. Debyelaan 25, P.O. Box 5800, AZ, Maastricht (Netherlands); Maastricht University Medical Center, CARIM School for Cardiovascular Diseases, Maastricht (Netherlands); Ommen, Vincent G.V.A. van [Maastricht University Medical Center, Department of Cardiology, Maastricht (Netherlands); Garsse, Leen A.F.M. van [Maastricht University Medical Center, Department of Cardiothoracic Surgery, Maastricht (Netherlands)

    2015-07-15

    To determine the optimal imaging time point for transcatheter aortic valve implantation (TAVI) therapy planning by comprehensive evaluation of the aortic root. Multidetector-row CT (MDCT) examination with retrospective ECG gating was retrospectively performed in 64 consecutive patients referred for pre-TAVI assessment. Eighteen different parameters of the aortic root were evaluated at 11 different time points in the cardiac cycle. Time points at which maximal (or minimal) sizes were determined, and dimension differences to other time points were evaluated. Theoretical prosthesis sizing based on different measurements was compared. Largest dimensions were found between 10 and 20 % of the cardiac cycle for annular short diameter (10 %); mean diameter (10 %); effective diameter and circumference-derived diameter (20 %); distance from the annulus to right coronary artery ostium (10 %); aortic root at the left coronary artery level (20 %); aortic root at the widest portion of coronary sinuses (20 %); and right leaflet length (20 %). Prosthesis size selection differed depending on the chosen measurements in 25-75 % of cases. Significant changes in anatomical structures of the aortic root during the cardiac cycle are crucial for TAVI planning. Imaging in systole is mandatory to obtain maximal dimensions. (orig.)

  13. Coordinate alignment of combined measurement systems using a modified common points method

    Science.gov (United States)

    Zhao, G.; Zhang, P.; Xiao, W.

    2018-03-01

    The co-ordinate metrology has been extensively researched for its outstanding advantages in measurement range and accuracy. The alignment of different measurement systems is usually achieved by integrating local coordinates via common points before measurement. The alignment errors would accumulate and significantly reduce the global accuracy, thus need to be minimized. In this thesis, a modified common points method (MCPM) is proposed to combine different traceable system errors of the cooperating machines, and optimize the global accuracy by introducing mutual geometric constraints. The geometric constraints, obtained by measuring the common points in individual local coordinate systems, provide the possibility to reduce the local measuring uncertainty whereby enhance the global measuring certainty. A simulation system is developed in Matlab to analyze the feature of MCPM using the Monto-Carlo method. An exemplary setup is constructed to verify the feasibility and efficiency of the proposed method associated with laser tracker and indoor iGPS systems. Experimental results show that MCPM could significantly improve the alignment accuracy.

  14. Shape measurement system for single point incremental forming (SPIF) manufacts by using trinocular vision and random pattern

    International Nuclear Information System (INIS)

    Setti, Francesco; Bini, Ruggero; Lunardelli, Massimo; Bosetti, Paolo; Bruschi, Stefania; De Cecco, Mariolino

    2012-01-01

    Many contemporary works show the interest of the scientific community in measuring the shape of artefacts made by single point incremental forming. In this paper, we will present an algorithm able to detect feature points with a random pattern, check the compatibility of associations exploiting multi-stereo constraints and reject outliers and perform a 3D reconstruction by dense random patterns. The algorithm is suitable for a real-time application, in fact it needs just three images and a synchronous relatively fast processing. The proposed method has been tested on a simple geometry and results have been compared with a coordinate measurement machine acquisition. (paper)

  15. Job Demands, Burnout, and Teamwork in Healthcare Professionals Working in a General Hospital that Was Analysed At Two Points in Time

    Science.gov (United States)

    Mijakoski, Dragan; Karadzhinska-Bislimovska, Jovanka; Stoleski, Sasho; Minov, Jordan; Atanasovska, Aneta; Bihorac, Elida

    2018-01-01

    AIM: The purpose of the paper was to assess job demands, burnout, and teamwork in healthcare professionals (HPs) working in a general hospital that was analysed at two points in time with a time lag of three years. METHODS: Time 1 respondents (N = 325) were HPs who participated during the first wave of data collection (2011). Time 2 respondents (N = 197) were HPs from the same hospital who responded at Time 2 (2014). Job demands, burnout, and teamwork were measured with Hospital Experience Scale, Maslach Burnout Inventory, and Hospital Survey on Patient Safety Culture, respectively. RESULTS: Significantly higher scores of emotional exhaustion (21.03 vs. 15.37, t = 5.1, p Teamwork levels were similar at both points in time (Time 1 = 3.84 vs. Time 2 = 3.84, t = 0.043, p = 0.97). CONCLUSION: Actual longitudinal study revealed significantly higher mean values of emotional exhaustion and depersonalization in 2014 that could be explained by significantly increased job demands between analysed points in time. PMID:29731948

  16. Dual time-point FDG PET/CT for differentiating benign from ...

    African Journals Online (AJOL)

    Maximum standard uptake values (SUVmax) with the greatest uptake in the lesion were calculated for two time points (SUV1 and SUV2), and the percentage change over time per lesion was calculated (%DSUV). Routine histological findings served as the gold standard. Results. Histological examination showed that 14 ...

  17. Guidelines for time-to-event end-point definitions in trials for pancreatic cancer. Results of the DATECAN initiative (Definition for the Assessment of Time-to-event End-points in CANcer trials).

    Science.gov (United States)

    Bonnetain, Franck; Bonsing, Bert; Conroy, Thierry; Dousseau, Adelaide; Glimelius, Bengt; Haustermans, Karin; Lacaine, François; Van Laethem, Jean Luc; Aparicio, Thomas; Aust, Daniela; Bassi, Claudio; Berger, Virginie; Chamorey, Emmanuel; Chibaudel, Benoist; Dahan, Laeticia; De Gramont, Aimery; Delpero, Jean Robert; Dervenis, Christos; Ducreux, Michel; Gal, Jocelyn; Gerber, Erich; Ghaneh, Paula; Hammel, Pascal; Hendlisz, Alain; Jooste, Valérie; Labianca, Roberto; Latouche, Aurelien; Lutz, Manfred; Macarulla, Teresa; Malka, David; Mauer, Muriel; Mitry, Emmanuel; Neoptolemos, John; Pessaux, Patrick; Sauvanet, Alain; Tabernero, Josep; Taieb, Julien; van Tienhoven, Geertjan; Gourgou-Bourgade, Sophie; Bellera, Carine; Mathoulin-Pélissier, Simone; Collette, Laurence

    2014-11-01

    Using potential surrogate end-points for overall survival (OS) such as Disease-Free- (DFS) or Progression-Free Survival (PFS) is increasingly common in randomised controlled trials (RCTs). However, end-points are too often imprecisely defined which largely contributes to a lack of homogeneity across trials, hampering comparison between them. The aim of the DATECAN (Definition for the Assessment of Time-to-event End-points in CANcer trials)-Pancreas project is to provide guidelines for standardised definition of time-to-event end-points in RCTs for pancreatic cancer. Time-to-event end-points currently used were identified from a literature review of pancreatic RCT trials (2006-2009). Academic research groups were contacted for participation in order to select clinicians and methodologists to participate in the pilot and scoring groups (>30 experts). A consensus was built after 2 rounds of the modified Delphi formal consensus approach with the Rand scoring methodology (range: 1-9). For pancreatic cancer, 14 time to event end-points and 25 distinct event types applied to two settings (detectable disease and/or no detectable disease) were considered relevant and included in the questionnaire sent to 52 selected experts. Thirty experts answered both scoring rounds. A total of 204 events distributed over the 14 end-points were scored. After the first round, consensus was reached for 25 items; after the second consensus was reached for 156 items; and after the face-to-face meeting for 203 items. The formal consensus approach reached the elaboration of guidelines for standardised definitions of time-to-event end-points allowing cross-comparison of RCTs in pancreatic cancer. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. "Atmospheric Radiation Measurement (ARM) Research Facility at Oliktok Point Alaska"

    Science.gov (United States)

    Helsel, F.; Ivey, M.; Hardesty, J.; Roesler, E. L.; Dexheimer, D.

    2017-12-01

    Scientific Infrastructure To Support Atmospheric Science, Aerosol Science and UAS's for The Department Of Energy's Atmospheric Radiation Measurement Programs At The Mobile Facility 3 Located At Oliktok Point, Alaska.The Atmospheric Radiation Measurement (ARM) Program's Mobile Facility 3 (AMF3) located at Oliktok Point, Alaska is a U.S. Department of Energy (DOE) site designed to collect data and help determine the impact that clouds and aerosols have on solar radiation. AMF3 provides a scientific infrastructure to support instruments and collect arctic data for the international arctic research community. The infrastructure at AMF3/Oliktok is designed to be mobile and it may be relocated in the future to support other ARM science missions. AMF3's present base line instruments include: scanning precipitation Radars, cloud Radar, Raman Lidar, Eddy correlation flux systems, Ceilometer, Balloon sounding system, Atmospheric Emitted Radiance Interferometer (AERI), Micro-pulse Lidar (MPL) Along with all the standard metrological measurements. In addition AMF3 provides aerosol measurements with a Mobile Aerosol Observing System (MAOS). Ground support for Unmanned Aerial Systems (UAS) and tethered balloon flights. Data from these instruments and systems are placed in the ARM data archives and are available to the international research community. This poster will discuss what instruments and systems are at the ARM Research Facility at Oliktok Point Alaska.

  19. Four-point probe measurements using current probes with voltage feedback to measure electric potentials

    Science.gov (United States)

    Lüpke, Felix; Cuma, David; Korte, Stefan; Cherepanov, Vasily; Voigtländer, Bert

    2018-02-01

    We present a four-point probe resistance measurement technique which uses four equivalent current measuring units, resulting in minimal hardware requirements and corresponding sources of noise. Local sample potentials are measured by a software feedback loop which adjusts the corresponding tip voltage such that no current flows to the sample. The resulting tip voltage is then equivalent to the sample potential at the tip position. We implement this measurement method into a multi-tip scanning tunneling microscope setup such that potentials can also be measured in tunneling contact, allowing in principle truly non-invasive four-probe measurements. The resulting measurement capabilities are demonstrated for \

  20. Time resolved mass flow measurements for a fast gas delivery system

    International Nuclear Information System (INIS)

    Ruden, E.L.; Degnan, J.H.; Hussey, T.W.; Scott, M.C.; Graham, J.D.; Coffey, S.K.

    1992-01-01

    A technique is demonstrated whereby the delivered mass and flow rate vs. time of a short rise time gas delivery system may be accurately determined. The gas mass M which flows past a point in a gas delivery system by an arbitrary time t may be accurately measured if that point is sealed off within a time interval short compared to the mass flow time scale. If the ejected mass is allowed to equilibrate in a known volume after being cut off from its source, a conventional static pressure measurement before and after injection, and application of the ideal gas law suffices. Assuming reproducibility, a time history M(t) may be generated, allowing the flow rate vs. time dM(t)/dt to be determined. Mass flow measurements are presented for a fast delivery system in which the flow of argon through a 3.2 mm I.D., 0.76 mm thick copper tube is cut off by imploding (θ pinching) the tube using a single turn tungsten magnetic field coil. Pinch discharge parameters are 44 μf, 20 kV, 47 nH, 3.5 mΩ, 584 kA, and 8.63 ps current period. Optical measurements of the tube's internal area vs. time indicate that the tube is sealed 2 ps from the time the tube is still 90% open (7 μs from the start of pinch current). The pinch delay is varied from 500--1,500 ps from the valve trigger (0--1,000 ps from the start of gas flow). The mass injected into the test volume is ∼ 100 μg during this interval. The leak rate of the sealed tube results in a mass increase of only ∼ 0.1 μg by the time the pressure gauge stabilizes (6 s). Results are correlated with piezoelectric probe measurements of the gas flow and 2-D axisymmetric numerical simulations of the θ pinch process. Simulations of a θ pinch suitable for characterizing an annular supersonic nozzle typical of those used in gas puff z pinches are discussed

  1. Computationally determining the salience of decision points for real-time wayfinding support

    Directory of Open Access Journals (Sweden)

    Makoto Takemiya

    2012-06-01

    Full Text Available This study introduces the concept of computational salience to explain the discriminatory efficacy of decision points, which in turn may have applications to providing real-time assistance to users of navigational aids. This research compared algorithms for calculating the computational salience of decision points and validated the results via three methods: high-salience decision points were used to classify wayfinders; salience scores were used to weight a conditional probabilistic scoring function for real-time wayfinder performance classification; and salience scores were correlated with wayfinding-performance metrics. As an exploratory step to linking computational and cognitive salience, a photograph-recognition experiment was conducted. Results reveal a distinction between algorithms useful for determining computational and cognitive saliences. For computational salience, information about the structural integration of decision points is effective, while information about the probability of decision-point traversal shows promise for determining cognitive salience. Limitations from only using structural information and motivations for future work that include non-structural information are elicited.

  2. Multiscale analysis of heart rate dynamics: entropy and time irreversibility measures.

    Science.gov (United States)

    Costa, Madalena D; Peng, Chung-Kang; Goldberger, Ary L

    2008-06-01

    Cardiovascular signals are largely analyzed using traditional time and frequency domain measures. However, such measures fail to account for important properties related to multiscale organization and non-equilibrium dynamics. The complementary role of conventional signal analysis methods and emerging multiscale techniques, is, therefore, an important frontier area of investigation. The key finding of this presentation is that two recently developed multiscale computational tools--multiscale entropy and multiscale time irreversibility--are able to extract information from cardiac interbeat interval time series not contained in traditional methods based on mean, variance or Fourier spectrum (two-point correlation) techniques. These new methods, with careful attention to their limitations, may be useful in diagnostics, risk stratification and detection of toxicity of cardiac drugs.

  3. Two-point method uncertainty during control and measurement of cylindrical element diameters

    Science.gov (United States)

    Glukhov, V. I.; Shalay, V. V.; Radev, H.

    2018-04-01

    The topic of the article is devoted to the urgent problem of the reliability of technical products geometric specifications measurements. The purpose of the article is to improve the quality of parts linear sizes control by the two-point measurement method. The article task is to investigate methodical extended uncertainties in measuring cylindrical element linear sizes. The investigation method is a geometric modeling of the element surfaces shape and location deviations in a rectangular coordinate system. The studies were carried out for elements of various service use, taking into account their informativeness, corresponding to the kinematic pairs classes in theoretical mechanics and the number of constrained degrees of freedom in the datum element function. Cylindrical elements with informativity of 4, 2, 1 and θ (zero) were investigated. The uncertainties estimation of in two-point measurements was made by comparing the results of of linear dimensions measurements with the functional diameters maximum and minimum of the element material. Methodical uncertainty is formed when cylindrical elements with maximum informativeness have shape deviations of the cut and the curvature types. Methodical uncertainty is formed by measuring the element average size for all types of shape deviations. The two-point measurement method cannot take into account the location deviations of a dimensional element, so its use for elements with informativeness less than the maximum creates unacceptable methodical uncertainties in measurements of the maximum, minimum and medium linear dimensions. Similar methodical uncertainties also exist in the arbitration control of the linear dimensions of the cylindrical elements by limiting two-point gauges.

  4. Comparisons of temperature, pressure and humidity measurements by balloon-borne radiosondes and frost point hygrometers during MOHAVE-2009

    Directory of Open Access Journals (Sweden)

    D. F. Hurst

    2011-12-01

    Full Text Available We compare coincident, in situ, balloon-borne measurements of temperature (T and pressure (P by two radiosondes (Vaisala RS92, Intermet iMet-1-RSB and similar measurements of relative humidity (RH by RS92 sondes and frost point hygrometers. Data from a total of 28 balloon flights with at least one pair of radiosondes are analyzed in 1-km altitude bins to quantify measurement differences between the sonde sensors and how they vary with altitude. Each comparison (T, P, RH exposes several profiles of anomalously large measurement differences. Measurement difference statistics, calculated with and without the anomalous profiles, are compared to uncertainties quoted by the radiosonde manufacturers. Excluding seven anomalous profiles, T differences between 19 pairs of RS92 and iMet sondes exceed their measurement uncertainty limits (2 σ 31% of the time and reveal a statistically significant, altitude-independent bias of 0.5 ± 0.2 °C. Similarly, RS92-iMet P differences in 22 non-anomalous profiles exceed their uncertainty limits 23% of the time, with a disproportionate 83% of the excessive P differences at altitudes >16 km. The RS92-iMet pressure differences increase smoothly from −0.6 hPa near the surface to 0.8 hPa above 25 km. Temperature and P differences between all 14 pairs of RS92 sondes exceed manufacturer-quoted, reproducibility limits (σ 28% and 11% of the time, respectively. About 95% of the excessive T differences are eliminated when 5 anomalous RS92-RS92 profiles are excluded. Only 5% of RH measurement differences between 14 pairs of RS92 sondes exceed the manufacturer's measurement reproducibility limit (σ. RH measurements by RS92 sondes are also compared to RH values calculated from frost point hygrometer measurements and coincident T measurements by the radiosondes. The influences of RS92-iMet Tand P differences on RH values and water vapor mixing

  5. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    DEFF Research Database (Denmark)

    Kertzscher Schwencke, Gustavo Adolfo Vladimir; Andersen, Claus E.; Tanderup, Kari

    2014-01-01

    Purpose:This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction ......, and the AEDA’s capacity to distinguish between true and false error scenarios. The study further shows that the AEDA can offer guidance in decision making in the event of potential errors detected with real-time in vivo point dosimetry....... of the dosimeter position reconstruction. Given its nearly exclusive dependence on stable dosimeter positioning, the AEDA allows for a substantially simplified and time efficient real-time in vivo BT dosimetry implementation. Methods:In the event of a measured potential treatment error, the AEDA proposes the most...

  6. Measurements on pointing error and field of view of Cimel-318 Sun photometers in the scope of AERONET

    Directory of Open Access Journals (Sweden)

    B. Torres

    2013-08-01

    Full Text Available Sensitivity studies indicate that among the diverse error sources of ground-based sky radiometer observations, the pointing error plays an important role in the correct retrieval of aerosol properties. The accurate pointing is specially critical for the characterization of desert dust aerosol. The present work relies on the analysis of two new measurement procedures (cross and matrix specifically designed for the evaluation of the pointing error in the standard instrument of the Aerosol Robotic Network (AERONET, the Cimel CE-318 Sun photometer. The first part of the analysis contains a preliminary study whose results conclude on the need of a Sun movement correction for an accurate evaluation of the pointing error from both new measurements. Once this correction is applied, both measurements show equivalent results with differences under 0.01° in the pointing error estimations. The second part of the analysis includes the incorporation of the cross procedure in the AERONET routine measurement protocol in order to monitor the pointing error in field instruments. The pointing error was evaluated using the data collected for more than a year, in 7 Sun photometers belonging to AERONET sites. The registered pointing error values were generally smaller than 0.1°, though in some instruments values up to 0.3° have been observed. Moreover, the pointing error analysis shows that this measurement can be useful to detect mechanical problems in the robots or dirtiness in the 4-quadrant detector used to track the Sun. Specifically, these mechanical faults can be detected due to the stable behavior of the values over time and vs. the solar zenith angle. Finally, the matrix procedure can be used to derive the value of the solid view angle of the instruments. The methodology has been implemented and applied for the characterization of 5 Sun photometers. To validate the method, a comparison with solid angles obtained from the vicarious calibration method was

  7. Branch Point Withdrawal in Elongational Startup Flow by Time-Resolved Small Angle Neutron Scattering

    KAUST Repository

    Ruocco, N.

    2016-05-27

    We present a small angle neutron scattering (SANS) investigation of a blend composed of a dendritic polymer and a linear matrix with comparable viscosity in start-up of an elongational flow at Tg + 50. The two-generation dendritic polymer is diluted to 10% by weight in a matrix of a long well-entangled linear chains. Both components consist of mainly 1,4-cis-polyisoprene but differ in isotopic composition. The resulting scattering contrast is sufficiently high to permit time-resolved measurements of the system structure factor during the start-up phase and to follow the retraction processes involving the inner sections of the branched polymer in the nonlinear deformation response. The outer branches and the linear matrix, on the contrary, are in the linear deformation regime. The linear matrix dominates the rheological signature of the blend and the influence of the branched component can barely be detected. However, the neutron scattering intensity is predominantly that of the (branched) minority component so that its dynamics is clearly evident. In the present paper, we use the neutron scattering data to validate the branch point withdrawal process, which could not be unambiguously discerned from rheological measurements in this blend. The maximal tube stretch that the inner branches experience, before the relaxed outer arm material is incorporated into the tube is determined. The in situ scattering experiments demonstrate for the first time the leveling-off of the strain as the result of branch point withdrawal and chain retraction directly on the molecular level. We conclude that branch point motion in the mixture of architecturally complex polymers occurs earlier than would be expected in a purely branched system, presumably due to the different topological environment that the linear matrix presents to the hierarchically deep-buried tube sections. © 2016 American Chemical Society.

  8. Branch Point Withdrawal in Elongational Startup Flow by Time-Resolved Small Angle Neutron Scattering

    KAUST Repository

    Ruocco, N.; Auhl, D.; Bailly, C.; Lindner, P.; Pyckhout-Hintzen, W.; Wischnewski, A.; Leal, L. G.; Hadjichristidis, Nikolaos; Richter, D.

    2016-01-01

    We present a small angle neutron scattering (SANS) investigation of a blend composed of a dendritic polymer and a linear matrix with comparable viscosity in start-up of an elongational flow at Tg + 50. The two-generation dendritic polymer is diluted to 10% by weight in a matrix of a long well-entangled linear chains. Both components consist of mainly 1,4-cis-polyisoprene but differ in isotopic composition. The resulting scattering contrast is sufficiently high to permit time-resolved measurements of the system structure factor during the start-up phase and to follow the retraction processes involving the inner sections of the branched polymer in the nonlinear deformation response. The outer branches and the linear matrix, on the contrary, are in the linear deformation regime. The linear matrix dominates the rheological signature of the blend and the influence of the branched component can barely be detected. However, the neutron scattering intensity is predominantly that of the (branched) minority component so that its dynamics is clearly evident. In the present paper, we use the neutron scattering data to validate the branch point withdrawal process, which could not be unambiguously discerned from rheological measurements in this blend. The maximal tube stretch that the inner branches experience, before the relaxed outer arm material is incorporated into the tube is determined. The in situ scattering experiments demonstrate for the first time the leveling-off of the strain as the result of branch point withdrawal and chain retraction directly on the molecular level. We conclude that branch point motion in the mixture of architecturally complex polymers occurs earlier than would be expected in a purely branched system, presumably due to the different topological environment that the linear matrix presents to the hierarchically deep-buried tube sections. © 2016 American Chemical Society.

  9. Direct measurement of resistance of multiwalled carbon nanotubes using micro four-point probes

    DEFF Research Database (Denmark)

    Dohn, Søren; Mølhave, Kristian; Bøggild, Peter

    2005-01-01

    -point resistance at specific positions along the nanotubes, was measured by microprobes with different microelectrocle spacings. Individual nanotubes were investigated in more detail by measuring current as a function of bias voltage until the point of failure and the results are compared to previously reported...

  10. Accuracy of Handheld Point-of-Care Fingertip Lactate Measurement in the Emergency Department

    Directory of Open Access Journals (Sweden)

    Gaieski, David G

    2013-02-01

    Full Text Available Introduction: Early recognition of elevated lactate levels in sepsis may hasten the detection of those patients eligible for aggressive resuscitation. Point-of-care (POC testing is now increasingly available for use in the emergency department (ED. We examined the accuracy and time-saving effect of a handheld POC device for the measurement of fingertip and whole blood lactate as compared with reference laboratory testing in critically ill ED patients.Methods: A convenience sample of adult ED patients receiving serum lactate testing was prospectively enrolled at an urban, tertiary care US hospital. Consenting patients underwent fingertip POC lactate measurement with a portable device and simultaneous whole blood sampling for analysis by both the POC device and standard laboratory analyzer (‘‘reference method’’. Lactate measurements were compared by intraclass correlation (ICC and Bland and Altman plots. Differences in time to test result were compared by paired t test.Results: Twenty-four patients, 19 (79% with sepsis and 21 (88% with lactate levels below 4 mmol/L, were included from April 2005 to May 2005. Fingertip POC and whole blood POC lactate measurements each correlated tightly with the reference method (ICC ¼ 0.90 and ICC ¼ 0.92, respectively. Mean time between obtaining fingertip lactate samples and whole blood reference lactate samples was 8 6 13 minutes. Mean time between obtaining POC and reference laboratory lactate results was 65 minutes (95% confidence interval, 30–103.Conclusion: Fingertip POC lactate measurement is an accurate method to determine lactate levels in infected ED patients with normal or modestly elevated lactate values and significantly decreases time to test results. These findings should be verified in a larger, more critically ill, ED population. [West J Emerg Med. 2013;14(1:58-62.

  11. Job Demands, Burnout, and Teamwork in Healthcare Professionals Working in a General Hospital that Was Analysed At Two Points in Time.

    Science.gov (United States)

    Mijakoski, Dragan; Karadzhinska-Bislimovska, Jovanka; Stoleski, Sasho; Minov, Jordan; Atanasovska, Aneta; Bihorac, Elida

    2018-04-15

    The purpose of the paper was to assess job demands, burnout, and teamwork in healthcare professionals (HPs) working in a general hospital that was analysed at two points in time with a time lag of three years. Time 1 respondents (N = 325) were HPs who participated during the first wave of data collection (2011). Time 2 respondents (N = 197) were HPs from the same hospital who responded at Time 2 (2014). Job demands, burnout, and teamwork were measured with Hospital Experience Scale, Maslach Burnout Inventory, and Hospital Survey on Patient Safety Culture, respectively. Significantly higher scores of emotional exhaustion (21.03 vs. 15.37, t = 5.1, p job demands were found at Time 2. Teamwork levels were similar at both points in time (Time 1 = 3.84 vs. Time 2 = 3.84, t = 0.043, p = 0.97). Actual longitudinal study revealed significantly higher mean values of emotional exhaustion and depersonalization in 2014 that could be explained by significantly increased job demands between analysed points in time.

  12. Real-time estimation of FLE for point-based registration

    Science.gov (United States)

    Wiles, Andrew D.; Peters, Terry M.

    2009-02-01

    In image-guide surgery, optimizing the accuracy in localizing the surgical tools within the virtual reality environment or 3D image is vitally important, significant effort has been spent reducing the measurement errors at the point of interest or target. This target registration error (TRE) is often defined by a root-mean-square statistic which reduces the vector data to a single term that can be minimized. However, lost in the data reduction is the directionality of the error which, can be modelled using a 3D covariance matrix. Recently, we developed a set of expressions that modeled the TRE statistics for point-based registrations as a function of the fiducial marker geometry, target location and the fiducial localizer error (FLE). Unfortunately, these expressions are only as good as the definition of the FLE. In order to close the gap, we have subsequently developed a closed form expression that estimates the FLE as a function of the estimated fiducial registration error (FRE, the error between the measured fiducials and the best fit locations of those fiducials). The FRE covariance matrix is estimated using a sliding window technique and used as input into the closed form expression to estimate the FLE. The estimated FLE can then used to estimate the TRE which, can be given to the surgeon to permit the procedure to be designed such that the errors associated with the point-based registrations are minimized.

  13. Noncontact on-machine measurement system based on capacitive displacement sensors for single-point diamond turning

    Science.gov (United States)

    Li, Xingchang; Zhang, Zhiyu; Hu, Haifei; Li, Yingjie; Xiong, Ling; Zhang, Xuejun; Yan, Jiwang

    2018-04-01

    On-machine measurements can improve the form accuracy of optical surfaces in single-point diamond turning applications; however, commercially available linear variable differential transformer sensors are inaccurate and can potentially scratch the surface. We present an on-machine measurement system based on capacitive displacement sensors for high-precision optical surfaces. In the proposed system, a position-trigger method of measurement was developed to ensure strict correspondence between the measurement points and the measurement data with no intervening time-delay. In addition, a double-sensor measurement was proposed to reduce the electric signal noise during spindle rotation. Using the proposed system, the repeatability of 80-nm peak-to-valley (PV) and 8-nm root-mean-square (RMS) was achieved through analyzing four successive measurement results. The accuracy of 109-nm PV and 14-nm RMS was obtained by comparing with the interferometer measurement result. An aluminum spherical mirror with a diameter of 300 mm was fabricated, and the resulting measured form error after one compensation cut was decreased to 254 nm in PV and 52 nm in RMS. These results confirm that the measurements of the surface form errors were successfully used to modify the cutting tool path during the compensation cut, thereby ensuring that the diamond turning process was more deterministic. In addition, the results show that the noise level was significantly reduced with the reference sensor even under a high rotational speed.

  14. Terahertz time domain interferometry of a SIS tunnel junction and a quantum point contact

    Energy Technology Data Exchange (ETDEWEB)

    Karadi, Chandu [Univ. of California, Berkeley, CA (United States). Dept. of Physics

    1995-09-01

    The author has applied the Terahertz Time Domain Interferometric (THz-TDI) technique to probe the ultrafast dynamic response of a Superconducting-Insulating-Superconducting (SIS) tunnel junction and a Quantum Point Contact (QPC). The THz-TDI technique involves monitoring changes in the dc current induced by interfering two picosecond electrical pulses on the junction as a function of time delay between them. Measurements of the response of the Nb/AlOxNb SIS tunnel junction from 75--200 GHz are in full agreement with the linear theory for photon-assisted tunneling. Likewise, measurements of the induced current in a QPC as a function of source-drain voltage, gate voltage, frequency, and magnetic field also show strong evidence for photon-assisted transport. These experiments together demonstrate the general applicability of the THz-TDI technique to the characterization of the dynamic response of any micron or nanometer scale device that exhibits a non-linear I-V characteristic.

  15. Terahertz time domain interferometry of a SIS tunnel junction and a quantum point contact

    International Nuclear Information System (INIS)

    Karadi, C.; Lawrence Berkeley Lab., CA

    1995-09-01

    The author has applied the Terahertz Time Domain Interferometric (THz-TDI) technique to probe the ultrafast dynamic response of a Superconducting-Insulating-Superconducting (SIS) tunnel junction and a Quantum Point Contact (QPC). The THz-TDI technique involves monitoring changes in the dc current induced by interfering two picosecond electrical pulses on the junction as a function of time delay between them. Measurements of the response of the Nb/AlO x /Nb SIS tunnel junction from 75--200 GHz are in full agreement with the linear theory for photon-assisted tunneling. Likewise, measurements of the induced current in a QPC as a function of source-drain voltage, gate voltage, frequency, and magnetic field also show strong evidence for photon-assisted transport. These experiments together demonstrate the general applicability of the THz-TDI technique to the characterization of the dynamic response of any micron or nanometer scale device that exhibits a non-linear I-V characteristic. 133 refs., 49 figs

  16. A measured-ZMP(Zero-Moment-Point)-referenced control of biped locomotion robots

    International Nuclear Information System (INIS)

    Kume, Etsuo; Akimoto, Masayuki

    1994-01-01

    For the control of biped locomotion, the model-referenced-control or programmed control method is widely used. In this method, the instantaneous torque of actuator equipped at each joint is controlled so as to equalize measured angle to input joint angle based on the prescribed motion. The drawback is that this method can not deal with the dynamic change of walking such as that due to unknown external force. To resolve such the drawback, we propose a new control method as follows: given a prescribed motion as a set of gait, namely gait of starting walk, cyclic walk, and stopping walk including a standard trajectory of the Zero-Moment-Point (ZMP), the trunk motion to compensate the legs' motion is generated in real time using the current ZMP measured by sensing device. The proposed method will be validated through some numerical simulations. (author)

  17. Magnetic field pitch angle and perpendicular velocity measurements from multi-point time-delay estimation of poloidal correlation reflectometry

    Science.gov (United States)

    Prisiazhniuk, D.; Krämer-Flecken, A.; Conway, G. D.; Happel, T.; Lebschy, A.; Manz, P.; Nikolaeva, V.; Stroth, U.; the ASDEX Upgrade Team

    2017-02-01

    In fusion machines, turbulent eddies are expected to be aligned with the direction of the magnetic field lines and to propagate in the perpendicular direction. Time delay measurements of density fluctuations can be used to calculate the magnetic field pitch angle α and perpendicular velocity {{v}\\bot} profiles. The method is applied to poloidal correlation reflectometry installed at ASDEX Upgrade and TEXTOR, which measure density fluctuations from poloidally and toroidally separated antennas. Validation of the method is achieved by comparing the perpendicular velocity (composed of the E× B drift and the phase velocity of turbulence {{v}\\bot}={{v}E× B}+{{v}\\text{ph}} ) with Doppler reflectometry measurements and with neoclassical {{v}E× B} calculations. An important condition for the application of the method is the presence of turbulence with a sufficiently long decorrelation time. It is shown that at the shear layer the decorrelation time is reduced, limiting the application of the method. The magnetic field pitch angle measured by this method shows the expected dependence on the magnetic field, plasma current and radial position. The profile of the pitch angle reproduces the expected shape and values. However, comparison with the equilibrium reconstruction code cliste suggests an additional inclination of turbulent eddies at the pedestal position (2-3°). This additional angle decreases towards the core and at the edge.

  18. Two-point concrete resistivity measurements: interfacial phenomena at the electrode–concrete contact zone

    International Nuclear Information System (INIS)

    McCarter, W J; Taha, H M; Suryanto, B; Starrs, G

    2015-01-01

    Ac impedance spectroscopy measurements are used to critically examine the end-to-end (two-point) testing technique employed in evaluating the bulk electrical resistivity of concrete. In particular, this paper focusses on the interfacial contact region between the electrode and specimen and the influence of contacting medium and measurement frequency on the impedance response. Two-point and four-point electrode configurations were compared and modelling of the impedance response was undertaken to identify and quantify the contribution of the electrode–specimen contact region on the measured impedance. Measurements are presented in both Bode and Nyquist formats to aid interpretation. Concretes mixes conforming to BSEN206-1 and BS8500-1 were investigated which included concretes containing the supplementary cementitious materials fly ash and ground granulated blast-furnace slag. A measurement protocol is presented for the end-to-end technique in terms of test frequency and electrode–specimen contacting medium in order to minimize electrode–specimen interfacial effect and ensure correct measurement of bulk resistivity. (paper)

  19. Time-Lapse Measurement of Wellbore Integrity

    Science.gov (United States)

    Duguid, A.

    2017-12-01

    Well integrity is becoming more important as wells are used longer or repurposed. For CO2, shale gas, and other projects it has become apparent that wells represent the most likely unintended migration pathway for fluids out of the reservoir. Comprehensive logging programs have been employed to determine the condition of legacy wells in North America. These studies provide examples of assessment technologies. Logging programs have included pulsed neutron logging, ultrasonic well mapping, and cement bond logging. While these studies provide examples of what can be measured, they have only conducted a single round of logging and cannot show if the well has changed over time. Recent experience with time-lapse logging of three monitoring wells at a US Department of Energy sponsored CO2 project has shown the full value of similar tools. Time-lapse logging has shown that well integrity changes over time can be identified. It has also shown that the inclusion of and location of monitoring technologies in the well and the choice of construction materials must be carefully considered. Two of the wells were approximately eight years old at the time of study; they were constructed with steel and fiberglass casing sections and had lines on the outside of the casing running to the surface. The third well was 68 years old when it was studied and was originally constructed as a production well. Repeat logs were collected six or eight years after initial logging. Time-lapse logging showed the evolution of the wells. The results identified locations where cement degraded over time and locations that showed little change. The ultrasonic well maps show clearly that the lines used to connect the monitoring technology to the surface are visible and have a local effect on cement isolation. Testing and sampling was conducted along with logging. It provided insight into changes identified in the time-lapse log results. Point permeability testing was used to provide an in-situ point

  20. Measurement Back-Action in Quantum Point-Contact Charge Sensing

    Directory of Open Access Journals (Sweden)

    Bruno Küng

    2010-06-01

    Full Text Available Charge sensing with quantum point-contacts (QPCs is a technique widely used in semiconductor quantum-dot research. Understanding the physics of this measurement process, as well as finding ways of suppressing unwanted measurement back-action, are therefore both desirable. In this article, we present experimental studies targeting these two goals. Firstly, we measure the effect of a QPC on electron tunneling between two InAs quantum dots, and show that a model based on the QPC’s shot-noise can account for it. Secondly, we discuss the possibility of lowering the measurement current (and thus the back-action used for charge sensing by correlating the signals of two independent measurement channels. The performance of this method is tested in a typical experimental setup.

  1. An elevated neutrophil-lymphocyte ratio is associated with adverse outcomes following single time-point paracetamol (acetaminophen) overdose: a time-course analysis.

    Science.gov (United States)

    Craig, Darren G; Kitto, Laura; Zafar, Sara; Reid, Thomas W D J; Martin, Kirsty G; Davidson, Janice S; Hayes, Peter C; Simpson, Kenneth J

    2014-09-01

    The innate immune system is profoundly dysregulated in paracetamol (acetaminophen)-induced liver injury. The neutrophil-lymphocyte ratio (NLR) is a simple bedside index with prognostic value in a number of inflammatory conditions. To evaluate the prognostic accuracy of the NLR in patients with significant liver injury following single time-point and staggered paracetamol overdoses. Time-course analysis of 100 single time-point and 50 staggered paracetamol overdoses admitted to a tertiary liver centre. Timed laboratory samples were correlated with time elapsed after overdose or admission, respectively, and the NLR was calculated. A total of 49/100 single time-point patients developed hepatic encephalopathy (HE). Median NLRs were higher at both 72 (P=0.0047) and 96 h after overdose (P=0.0041) in single time-point patients who died or were transplanted. Maximum NLR values by 96 h were associated with increasing HE grade (P=0.0005). An NLR of more than 16.7 during the first 96 h following overdose was independently associated with the development of HE [odds ratio 5.65 (95% confidence interval 1.67-19.13), P=0.005]. Maximum NLR values by 96 h were strongly associated with the requirement for intracranial pressure monitoring (Pparacetamol overdoses. Future studies should assess the value of incorporating the NLR into existing prognostic and triage indices of single time-point paracetamol overdose.

  2. Optimal time points sampling in pathway modelling.

    Science.gov (United States)

    Hu, Shiyan

    2004-01-01

    Modelling cellular dynamics based on experimental data is at the heart of system biology. Considerable progress has been made to dynamic pathway modelling as well as the related parameter estimation. However, few of them gives consideration for the issue of optimal sampling time selection for parameter estimation. Time course experiments in molecular biology rarely produce large and accurate data sets and the experiments involved are usually time consuming and expensive. Therefore, to approximate parameters for models with only few available sampling data is of significant practical value. For signal transduction, the sampling intervals are usually not evenly distributed and are based on heuristics. In the paper, we investigate an approach to guide the process of selecting time points in an optimal way to minimize the variance of parameter estimates. In the method, we first formulate the problem to a nonlinear constrained optimization problem by maximum likelihood estimation. We then modify and apply a quantum-inspired evolutionary algorithm, which combines the advantages of both quantum computing and evolutionary computing, to solve the optimization problem. The new algorithm does not suffer from the morass of selecting good initial values and being stuck into local optimum as usually accompanied with the conventional numerical optimization techniques. The simulation results indicate the soundness of the new method.

  3. Optimization of Control Points Number at Coordinate Measurements based on the Monte-Carlo Method

    Science.gov (United States)

    Korolev, A. A.; Kochetkov, A. V.; Zakharov, O. V.

    2018-01-01

    Improving the quality of products causes an increase in the requirements for the accuracy of the dimensions and shape of the surfaces of the workpieces. This, in turn, raises the requirements for accuracy and productivity of measuring of the workpieces. The use of coordinate measuring machines is currently the most effective measuring tool for solving similar problems. The article proposes a method for optimizing the number of control points using Monte Carlo simulation. Based on the measurement of a small sample from batches of workpieces, statistical modeling is performed, which allows one to obtain interval estimates of the measurement error. This approach is demonstrated by examples of applications for flatness, cylindricity and sphericity. Four options of uniform and uneven arrangement of control points are considered and their comparison is given. It is revealed that when the number of control points decreases, the arithmetic mean decreases, the standard deviation of the measurement error increases and the probability of the measurement α-error increases. In general, it has been established that it is possible to repeatedly reduce the number of control points while maintaining the required measurement accuracy.

  4. Beam derived trigger system for multibunch time-of-flight measurement

    International Nuclear Information System (INIS)

    Fox, J.; Pellegrin, J.L.

    1981-01-01

    Particle time-of-flight measurement requires accurate triggers in synchronism with each bunch, and occurring in a sequence which depends on the position of the observer around the storage ring. A system has been devised for tagging the colliding bunches at each interaction point; it allows one to record which pair of bunches is colliding at any time and any location around the machine. Besides bunch identification, the time-of-flight triggers are also expected to have a time stability better than the bunch length itself. A system is presented here which exhibits time variations of less than 80 psec over a 20 to 1 range of beam current, while the jitter is at least an order of magnitude smaller. 4 refs., 4 figs

  5. Interferometry with flexible point source array for measuring complex freeform surface and its design algorithm

    Science.gov (United States)

    Li, Jia; Shen, Hua; Zhu, Rihong; Gao, Jinming; Sun, Yue; Wang, Jinsong; Li, Bo

    2018-06-01

    The precision of the measurements of aspheric and freeform surfaces remains the primary factor restrict their manufacture and application. One effective means of measuring such surfaces involves using reference or probe beams with angle modulation, such as tilted-wave-interferometer (TWI). It is necessary to improve the measurement efficiency by obtaining the optimum point source array for different pieces before TWI measurements. For purpose of forming a point source array based on the gradients of different surfaces under test, we established a mathematical model describing the relationship between the point source array and the test surface. However, the optimal point sources are irregularly distributed. In order to achieve a flexible point source array according to the gradient of test surface, a novel interference setup using fiber array is proposed in which every point source can be independently controlled on and off. Simulations and the actual measurement examples of two different surfaces are given in this paper to verify the mathematical model. Finally, we performed an experiment of testing an off-axis ellipsoidal surface that proved the validity of the proposed interference system.

  6. Noise and time delay induce critical point in a bistable system

    Science.gov (United States)

    Zhang, Jianqiang; Nie, Linru; Yu, Lilong; Zhang, Xinyu

    2014-07-01

    We study relaxation time Tc of time-delayed bistable system driven by two cross-correlated Gaussian white noises that one is multiplicative and the other is additive. By means of numerical calculations, the results indicate that: (i) Combination of noise and time delay can induce two critical points about the relaxation time at some certain noise cross-correlation strength λ under the condition that the multiplicative intensity D equals to the additive noise intensity α. (ii) For each fixed D or α, there are two symmetrical critical points which locates in the regions of positive and negative correlations, respectively. Namely, as λ equals to the critical value λc, Tc is independent of the delay time and the result of Tc versus τ is a horizontal line, but as |λ|>|λc| (or |λ|decreases) with the delay time increasing. (iii) In the presence of D = α, the change of λc with D is two symmetrical curves about the axis of λc = 0, and the critical value λc is close to zero for a smaller D, which approaches to +1 or -1 for a greater D.

  7. End points for adjuvant therapy trials: has the time come to accept disease-free survival as a surrogate end point for overall survival?

    Science.gov (United States)

    Gill, Sharlene; Sargent, Daniel

    2006-06-01

    The intent of adjuvant therapy is to eradicate micro-metastatic residual disease following curative resection with the goal of preventing or delaying recurrence. The time-honored standard for demonstrating efficacy of new adjuvant therapies is an improvement in overall survival (OS). This typically requires phase III trials of large sample size with lengthy follow-up. With the intent of reducing the cost and time of completing such trials, there is considerable interest in developing alternative or surrogate end points. A surrogate end point may be employed as a substitute to directly assess the effects of an intervention on an already accepted clinical end point such as mortality. When used judiciously, surrogate end points can accelerate the evaluation of new therapies, resulting in the more timely dissemination of effective therapies to patients. The current review provides a perspective on the suitability and validity of disease-free survival (DFS) as an alternative end point for OS. Criteria for establishing surrogacy and the advantages and limitations associated with the use of DFS as a primary end point in adjuvant clinical trials and as the basis for approval of new adjuvant therapies are discussed.

  8. A FAST METHOD FOR MEASURING THE SIMILARITY BETWEEN 3D MODEL AND 3D POINT CLOUD

    Directory of Open Access Journals (Sweden)

    Z. Zhang

    2016-06-01

    Full Text Available This paper proposes a fast method for measuring the partial Similarity between 3D Model and 3D point Cloud (SimMC. It is crucial to measure SimMC for many point cloud-related applications such as 3D object retrieval and inverse procedural modelling. In our proposed method, the surface area of model and the Distance from Model to point Cloud (DistMC are exploited as measurements to calculate SimMC. Here, DistMC is defined as the weighted distance of the distances between points sampled from model and point cloud. Similarly, Distance from point Cloud to Model (DistCM is defined as the average distance of the distances between points in point cloud and model. In order to reduce huge computational burdens brought by calculation of DistCM in some traditional methods, we define SimMC as the ratio of weighted surface area of model to DistMC. Compared to those traditional SimMC measuring methods that are only able to measure global similarity, our method is capable of measuring partial similarity by employing distance-weighted strategy. Moreover, our method is able to be faster than other partial similarity assessment methods. We demonstrate the superiority of our method both on synthetic data and laser scanning data.

  9. Application of Time Domain PARET to the measured responses of a building

    International Nuclear Information System (INIS)

    Lager, D.L.

    1979-01-01

    The application of the Time Domain PARET (TDP) algorithm to data obtained from the measured responses of a three story reinforced concrete building approximately 465 feet long by 220 feet wide by 40 feet high, with 12 to 18 inch thick walls, is described. The measurements were taken by Agbabian Associates, El Segundo, California. The structure was excited by a device developed at Agbabian that uses a mass sliding down a rod to cut metal disks attached to the rod. The result is a series of impulse forces driving the building at the attachment point of the rod. The responses measured were the accelerations at two locations on the structure. A constraint imposed was that the equipment in the building must remain operating during the time the measurements were made

  10. Measuring the relative efficiencies of automated telling machines and point of sales

    Directory of Open Access Journals (Sweden)

    Sara Farajzadeh

    2015-11-01

    Full Text Available During the past few years, many people have been interested in purchasing goods and services via point of sales (POS. They have also wished to pay their bills, withdraw cash or transfer funds using automated telling machines (ATMs. These two facilities help banks’ customers carry less amount of cash and do their daily banking activities any time even when the banks are closed. This paper presents an empirical investigation to measure the relative efficiency of nearly 600 POS and ATM units associated with Bank Melli Iran located in city of Tehran, Iran. Using data envelopment analysis, the study has disclosed that only small portions of POS and ATM are working efficiently.

  11. High-resolution wave number spectrum using multi-point measurements in space – the Multi-point Signal Resonator (MSR technique

    Directory of Open Access Journals (Sweden)

    Y. Narita

    2011-02-01

    Full Text Available A new analysis method is presented that provides a high-resolution power spectrum in a broad wave number domain based on multi-point measurements. The analysis technique is referred to as the Multi-point Signal Resonator (MSR and it benefits from Capon's minimum variance method for obtaining the proper power spectral density of the signal as well as the MUSIC algorithm (Multiple Signal Classification for considerably reducing the noise part in the spectrum. The mathematical foundation of the analysis method is presented and it is applied to synthetic data as well as Cluster observations of the interplanetary magnetic field. Using the MSR technique for Cluster data we find a wave in the solar wind propagating parallel to the mean magnetic field with relatively small amplitude, which is not identified by the Capon spectrum. The Cluster data analysis shows the potential of the MSR technique for studying waves and turbulence using multi-point measurements.

  12. Edge effects in four-point direct current potential drop measurements on metal plates

    International Nuclear Information System (INIS)

    Lu, Y; Bowler, N; Bowler, J R; Huang, Y

    2009-01-01

    Four-point direct current potential drop (DCPD) measurements are commonly used to measure the conductivity (or resistivity) of semiconductors and ferrous or non-ferrous metals. The measured electrical potential difference is often interpreted in terms of analytic expressions developed for large plates that are either 'thin' or 'thick' relative to the probe length. It is well known that the presence of the back surface of a plate leads to a solution expressed in terms of an infinite series representing the current source and its images. This approach can be generalized to account for multiple surfaces in order to obtain a solution for a finite plate, but convergence of the series is poor when the plate dimensions are similar to or smaller than the separation of the current injection and extraction points. Here, Fourier series representations of the infinite sums are obtained. It is shown that the Fourier series converge with many fewer terms than the series obtained from image theory, for plates with dimensions similar to or smaller than the separation of the current injection and extraction points. Comparing calculated results for the potential drop obtained by a four-point probe centred on finite plates of varying dimension, with those for a probe in contact with a large (laterally infinite) plate, estimates are given of the uncertainty due to edge effects in measurements on small plates interpreted using analytic formulae developed for large plates. It is also shown that these uncertainties due to edge effects are reduced, for a given plate size, if the probe pick-up points are moved closer to the current injection points, rather than adopting the common arrangement in which the four probe points are equally spaced. Calculated values of DCPD are compared with experimental data taken on aluminium and spring-steel plates of various sizes and excellent agreement is obtained.

  13. Edge effects in four-point direct current potential drop measurements on metal plates

    Science.gov (United States)

    Lu, Y.; Bowler, N.; Bowler, J. R.; Huang, Y.

    2009-07-01

    Four-point direct current potential drop (DCPD) measurements are commonly used to measure the conductivity (or resistivity) of semiconductors and ferrous or non-ferrous metals. The measured electrical potential difference is often interpreted in terms of analytic expressions developed for large plates that are either 'thin' or 'thick' relative to the probe length. It is well known that the presence of the back surface of a plate leads to a solution expressed in terms of an infinite series representing the current source and its images. This approach can be generalized to account for multiple surfaces in order to obtain a solution for a finite plate, but convergence of the series is poor when the plate dimensions are similar to or smaller than the separation of the current injection and extraction points. Here, Fourier series representations of the infinite sums are obtained. It is shown that the Fourier series converge with many fewer terms than the series obtained from image theory, for plates with dimensions similar to or smaller than the separation of the current injection and extraction points. Comparing calculated results for the potential drop obtained by a four-point probe centred on finite plates of varying dimension, with those for a probe in contact with a large (laterally infinite) plate, estimates are given of the uncertainty due to edge effects in measurements on small plates interpreted using analytic formulae developed for large plates. It is also shown that these uncertainties due to edge effects are reduced, for a given plate size, if the probe pick-up points are moved closer to the current injection points, rather than adopting the common arrangement in which the four probe points are equally spaced. Calculated values of DCPD are compared with experimental data taken on aluminium and spring-steel plates of various sizes and excellent agreement is obtained.

  14. A point-based rendering approach for real-time interaction on mobile devices

    Institute of Scientific and Technical Information of China (English)

    LIANG XiaoHui; ZHAO QinPing; HE ZhiYing; XIE Ke; LIU YuBo

    2009-01-01

    Mobile device is an Important interactive platform. Due to the limitation of computation, memory, display area and energy, how to realize the efficient and real-time interaction of 3D models based on mobile devices is an important research topic. Considering features of mobile devices, this paper adopts remote rendering mode and point models, and then, proposes a transmission and rendering approach that could interact in real time. First, improved simplification algorithm based on MLS and display resolution of mobile devices is proposed. Then, a hierarchy selection of point models and a QoS transmission control strategy are given based on interest area of operator, interest degree of object in the virtual environment and rendering error. They can save the energy consumption. Finally, the rendering and interaction of point models are completed on mobile devices. The experiments show that our method is efficient.

  15. Planning GPS Measurements of a Linear Object for a Specified Time Interval

    Directory of Open Access Journals (Sweden)

    Specht Cezary

    2017-12-01

    Full Text Available The previous measurement campaigns planning used in geodesy is conducted exclusively for individual points. For the natural process aimed at the adoption of the introduction of the planning (prediction of constellation state in navigation, which is characterized by the movement, one should adopt measurement campaigns planning for linear objects. In contrast to the existing planning solutions, focused on point presentation of the state of the constellation of navigation system, the author of this article rearranges the proposal of determination of geometrical factors, and their summation. In the presented simulation, one has specified the route of passing at certain times and it was assumed that the receiver will move with variable motion. One has defined the geometric ratios (PDOP, which allow to distinguish the results corresponding to the adopted criteria for the measurement of linear object to be conducted with the best possible accuracy.

  16. PolyWaTT: A polynomial water travel time estimator based on Derivative Dynamic Time Warping and Perceptually Important Points

    Science.gov (United States)

    Claure, Yuri Navarro; Matsubara, Edson Takashi; Padovani, Carlos; Prati, Ronaldo Cristiano

    2018-03-01

    Traditional methods for estimating timing parameters in hydrological science require a rigorous study of the relations of flow resistance, slope, flow regime, watershed size, water velocity, and other local variables. These studies are mostly based on empirical observations, where the timing parameter is estimated using empirically derived formulas. The application of these studies to other locations is not always direct. The locations in which equations are used should have comparable characteristics to the locations from which such equations have been derived. To overcome this barrier, in this work, we developed a data-driven approach to estimate timing parameters such as travel time. Our proposal estimates timing parameters using historical data of the location without the need of adapting or using empirical formulas from other locations. The proposal only uses one variable measured at two different locations on the same river (for instance, two river-level measurements, one upstream and the other downstream on the same river). The recorded data from each location generates two time series. Our method aligns these two time series using derivative dynamic time warping (DDTW) and perceptually important points (PIP). Using data from timing parameters, a polynomial function generalizes the data by inducing a polynomial water travel time estimator, called PolyWaTT. To evaluate the potential of our proposal, we applied PolyWaTT to three different watersheds: a floodplain ecosystem located in the part of Brazil known as Pantanal, the world's largest tropical wetland area; and the Missouri River and the Pearl River, in United States of America. We compared our proposal with empirical formulas and a data-driven state-of-the-art method. The experimental results demonstrate that PolyWaTT showed a lower mean absolute error than all other methods tested in this study, and for longer distances the mean absolute error achieved by PolyWaTT is three times smaller than empirical

  17. Multi-Point Measurements to Characterize Radiation Belt Electron Precipitation Loss

    Science.gov (United States)

    Blum, L. W.

    2017-12-01

    Multipoint measurements in the inner magnetosphere allow the spatial and temporal evolution of various particle populations and wave modes to be disentangled. To better characterize and quantify radiation belt precipitation loss, we utilize multi-point measurements both to study precipitating electrons directly as well as the potential drivers of this loss process. Magnetically conjugate CubeSat and balloon measurements are combined to estimate of the temporal and spatial characteristics of dusk-side precipitation features and quantify loss due to these events. To then understand the drivers of precipitation events, and what determines their spatial structure, we utilize measurements from the dual Van Allen Probes to estimate spatial and temporal scales of various wave modes in the inner magnetosphere, and compare these to precipitation characteristics. The structure, timing, and spatial extent of waves are compared to those of MeV electron precipitation during a few individual events to determine when and where EMIC waves cause radiation belt electron precipitation. Magnetically conjugate measurements provide observational support of the theoretical picture of duskside interaction of EMIC waves and MeV electrons leading to radiation belt loss. Finally, understanding the drivers controlling the spatial scales of wave activity in the inner magnetosphere is critical for uncovering the underlying physics behind the wave generation as well as for better predicting where and when waves will be present. Again using multipoint measurements from the Van Allen Probes, we estimate the spatial and temporal extents and evolution of plasma structures and their gradients in the inner magnetosphere, to better understand the drivers of magnetospheric wave characteristic scales. In particular, we focus on EMIC waves and the plasma parameters important for their growth, namely cold plasma density and cool and warm ion density, anisotropy, and composition.

  18. Accuracy of multi-point boundary crossing time analysis

    Directory of Open Access Journals (Sweden)

    J. Vogt

    2011-12-01

    Full Text Available Recent multi-spacecraft studies of solar wind discontinuity crossings using the timing (boundary plane triangulation method gave boundary parameter estimates that are significantly different from those of the well-established single-spacecraft minimum variance analysis (MVA technique. A large survey of directional discontinuities in Cluster data turned out to be particularly inconsistent in the sense that multi-point timing analyses did not identify any rotational discontinuities (RDs whereas the MVA results of the individual spacecraft suggested that RDs form the majority of events. To make multi-spacecraft studies of discontinuity crossings more conclusive, the present report addresses the accuracy of the timing approach to boundary parameter estimation. Our error analysis is based on the reciprocal vector formalism and takes into account uncertainties both in crossing times and in the spacecraft positions. A rigorous error estimation scheme is presented for the general case of correlated crossing time errors and arbitrary spacecraft configurations. Crossing time error covariances are determined through cross correlation analyses of the residuals. The principal influence of the spacecraft array geometry on the accuracy of the timing method is illustrated using error formulas for the simplified case of mutually uncorrelated and identical errors at different spacecraft. The full error analysis procedure is demonstrated for a solar wind discontinuity as observed by the Cluster FGM instrument.

  19. Equilibrium-point control hypothesis examined by measured arm stiffness during multijoint movement.

    Science.gov (United States)

    Gomi, H; Kawato

    1996-04-05

    For the last 20 years, it has been hypothesized that well-coordinated, multijoint movements are executed without complex computation by the brain, with the use of springlike muscle properties and peripheral neural feedback loops. However, it has been technically and conceptually difficult to examine this "equilibrium-point control" hypothesis directly in physiological or behavioral experiments. A high-performance manipulandum was developed and used here to measure human arm stiffness, the magnitude of which during multijoint movement is important for this hypothesis. Here, the equilibrium-point trajectory was estimated from the measured stiffness, the actual trajectory, and the generated torque. Its velocity profile differed from that of the actual trajectory. These results argue against the hypothesis that the brain sends as a motor command only an equilibrium-point trajectory similar to the actual trajectory.

  20. Design of an omnidirectional single-point photodetector for large-scale spatial coordinate measurement

    Science.gov (United States)

    Xie, Hongbo; Mao, Chensheng; Ren, Yongjie; Zhu, Jigui; Wang, Chao; Yang, Lei

    2017-10-01

    In high precision and large-scale coordinate measurement, one commonly used approach to determine the coordinate of a target point is utilizing the spatial trigonometric relationships between multiple laser transmitter stations and the target point. A light receiving device at the target point is the key element in large-scale coordinate measurement systems. To ensure high-resolution and highly sensitive spatial coordinate measurement, a high-performance and miniaturized omnidirectional single-point photodetector (OSPD) is greatly desired. We report one design of OSPD using an aspheric lens, which achieves an enhanced reception angle of -5 deg to 45 deg in vertical and 360 deg in horizontal. As the heart of our OSPD, the aspheric lens is designed in a geometric model and optimized by LightTools Software, which enables the reflection of a wide-angle incident light beam into the single-point photodiode. The performance of home-made OSPD is characterized with working distances from 1 to 13 m and further analyzed utilizing developed a geometric model. The experimental and analytic results verify that our device is highly suitable for large-scale coordinate metrology. The developed device also holds great potential in various applications such as omnidirectional vision sensor, indoor global positioning system, and optical wireless communication systems.

  1. Bayesian inference for multivariate point processes observed at sparsely distributed times

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Gulddahl; Møller, Jesper; Aukema, B.H.

    We consider statistical and computational aspects of simulation-based Bayesian inference for a multivariate point process which is only observed at sparsely distributed times. For specicity we consider a particular data set which has earlier been analyzed by a discrete time model involving unknown...... normalizing constants. We discuss the advantages and disadvantages of using continuous time processes compared to discrete time processes in the setting of the present paper as well as other spatial-temporal situations. Keywords: Bark beetle, conditional intensity, forest entomology, Markov chain Monte Carlo...

  2. Definition of distance for nonlinear time series analysis of marked point process data

    Energy Technology Data Exchange (ETDEWEB)

    Iwayama, Koji, E-mail: koji@sat.t.u-tokyo.ac.jp [Research Institute for Food and Agriculture, Ryukoku Univeristy, 1-5 Yokotani, Seta Oe-cho, Otsu-Shi, Shiga 520-2194 (Japan); Hirata, Yoshito; Aihara, Kazuyuki [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)

    2017-01-30

    Marked point process data are time series of discrete events accompanied with some values, such as economic trades, earthquakes, and lightnings. A distance for marked point process data allows us to apply nonlinear time series analysis to such data. We propose a distance for marked point process data which can be calculated much faster than the existing distance when the number of marks is small. Furthermore, under some assumptions, the Kullback–Leibler divergences between posterior distributions for neighbors defined by this distance are small. We performed some numerical simulations showing that analysis based on the proposed distance is effective. - Highlights: • A new distance for marked point process data is proposed. • The distance can be computed fast enough for a small number of marks. • The method to optimize parameter values of the distance is also proposed. • Numerical simulations indicate that the analysis based on the distance is effective.

  3. Measuring the exhaust gas dew point of continuously operated combustion plants

    Energy Technology Data Exchange (ETDEWEB)

    Fehler, D.

    1985-07-16

    Low waste-gas temperatures represent one means of minimizing the energy consumption of combustion facilities. However, condensation should be prevented to occur in the waste gas since this could result in a destruction of parts. Measuring the waste-gas dew point allows to control combustion parameters in such a way as to be able to operate at low temperatures without danger of condensation. Dew point sensors will provide an important signal for optimizing combustion facilities.

  4. Dew-point hygrometry system for measurement of evaporative water loss in infants.

    Science.gov (United States)

    Ariagno, R L; Glotzbach, S F; Baldwin, R B; Rector, D M; Bowley, S M; Moffat, R J

    1997-03-01

    Evaporation of water from the skin is an important mechanism in thermal homeostasis. Resistance hygrometry, in which the water vapor pressure gradient above the skin surface is calculated, has been the measurement method of choice in the majority of pediatric investigations. However, resistance hygrometry is influenced by changes in ambient conditions such as relative humidity, surface temperature, and convection currents. We have developed a ventilated capsule method that minimized these potential sources of measurement error and that allowed second-by-second, long-term, continuous measurements of evaporative water loss in sleeping infants. Air with a controlled reference humidity (dew-point temperature = 0 degree C) is delivered to a small, lightweight skin capsule and mixed with the vapor on the surface of the skin. The dew point of the resulting mixture is measured by using a chilled mirror dew-point hygrometer. The system indicates leaks, is mobile, and is accurate within 2%, as determined by gravimetric calibration. Examples from a recording of a 13-wk-old full-term infant obtained by using the system give evaporative water loss rates of approximately 0.02 mgH2O.cm-2.min-1 for normothermic baseline conditions and values up to 0.4 mgH2O.cm-2. min-1 when the subject was being warmed. The system is effective for clinical investigations that require dynamic measurements of water loss.

  5. Noise temperature measurements for the determination of the thermodynamic temperature of the melting point of palladium

    Energy Technology Data Exchange (ETDEWEB)

    Edler, F.; Kuhne, M.; Tegeler, E. [Bundesanstalt Physikalisch-Technische, Berlin (Germany)

    2004-02-01

    The thermodynamic temperature of the melting point of palladium in air was measured by noise thermometric methods. The temperature measurement was based on noise comparison using a two-channel arrangement to eliminate parasitic noises of electronic components by cross correlation. Three miniature fixed points filled with pure palladium (purity: {approx}99.99%, mass: {approx}90 g) were used to realize the melts of the fixed point metal. The measured melting temperature of palladium in air amounted to 1552.95 deg C {+-} 0.21 K (k = 2). This temperature is 0.45 K lower than the temperature of the melting point of palladium measured by radiation thermometry. (authors)

  6. Note: A dual-channel sensor for dew point measurement based on quartz crystal microbalance

    Science.gov (United States)

    Li, Ning; Meng, Xiaofeng; Nie, Jing

    2017-05-01

    A new sensor with dual-channel was designed for eliminating the temperature effect on the frequency measurement of the quartz crystal microbalance (QCM) in dew point detection. The sensor uses active temperature control, produces condensation on the surface of QCM, and then detects the dew point. Both the single-channel and the dual-channel methods were conducted based on the device. The measurement error of the single-channel method was less than 0.5 °C at the dew point range of -2 °C-10 °C while the dual-channel was 0.3 °C. The results showed that the dual-channel method was able to eliminate the temperature effect and yield better measurement accuracy.

  7. Usefulness of Time-Point Serum Cortisol and ACTH Measurements for the Adjustment of Glucocorticoid Replacement in Adrenal Insufficiency.

    Science.gov (United States)

    Rousseau, Elise; Joubert, Michael; Trzepla, Géraldine; Parienti, Jean Jacques; Freret, Thomas; Vanthygem, Marie Christine; Desailloud, Rachel; Lefebvre, Hervé; Coquerel, Antoine; Reznik, Yves

    2015-01-01

    Adjustment of daily hydrocortisone dose on clinical criteria lacks sensitivity for fine tuning. Long term hydrocortisone (HC) over-replacement may lead to increased morbidity and mortality in patients with adrenal insufficiency (AI). Biochemical criteria may help detecting over- or under-replacement but have been poorly evaluated. Multicenter, institutional, pharmacokinetic study on ACTH and cortisol plasma profiles during HC replacement in 27 AI patients compared to 29 matched controls. All AI patients were administered HC thrice daily at doses of 6, 10 and 14 mg/m2/d. Blood samples were drawn hourly from 0800h to 1900h. The main outcome measures were: i) plasma peak cortisol and cortisol area under the curve (AUC) in AI patients compared to controls, ii) correlations between cortisol AUC vs single-point cortisol or ACTH decrease from baseline (ΔACTH) and iii) the predictive value of the two latters for obtaining AI patients' cortisol AUC in the control range. Cortisol peaks were observed 1h after each HC intake and a dose response was demonstrated for cortisol peak and cortisol AUC. The comparison of AI patients' cortisol AUC to controls showed that 81.5% AI patients receiving 6mg/m2/d were adequately replaced, whereas most patients receiving higher doses were over-replaced. The correlation coefficient between 1000h/1400h cortisol concentrations and 0800-1900h cortisol AUC were 0.93/0.88 respectively, whereas the 0800-1200h ΔACTH fairly correlated with 0800-1900h cortisol AUC (R = 0.57). ROC curve analysis indicated that the 1000h and 1400h cortisol concentrations best predicted over-replacement. Patients receiving a 6mg/m2 hydrocortisone daily dose exhibited the most physiological daytime cortisol profile. Single point plasma cortisol correlated with daytime cortisol AUC in AI patients. Although hydrocortisone dose should be currently determined on clinical grounds, our data suggest that single point plasma cortisol may be an adjunct for further hydrocortisone

  8. Free-time and fixed end-point multi-target optimal control theory: Application to quantum computing

    International Nuclear Information System (INIS)

    Mishima, K.; Yamashita, K.

    2011-01-01

    Graphical abstract: The two-state Deutsch-Jozsa algortihm used to demonstrate the utility of free-time and fixed-end point multi-target optimal control theory. Research highlights: → Free-time and fixed-end point multi-target optimal control theory (FRFP-MTOCT) was constructed. → The features of our theory include optimization of the external time-dependent perturbations with high transition probabilities, that of the temporal duration, the monotonic convergence, and the ability to optimize multiple-laser pulses simultaneously. → The advantage of the theory and a comparison with conventional fixed-time and fixed end-point multi-target optimal control theory (FIFP-MTOCT) are presented by comparing data calculated using the present theory with those published previously [K. Mishima, K. Yamashita, Chem. Phys. 361 (2009) 106]. → The qubit system of our interest consists of two polar NaCl molecules coupled by dipole-dipole interaction. → The calculation examples show that our theory is useful for minor adjustment of the external fields. - Abstract: An extension of free-time and fixed end-point optimal control theory (FRFP-OCT) to monotonically convergent free-time and fixed end-point multi-target optimal control theory (FRFP-MTOCT) is presented. The features of our theory include optimization of the external time-dependent perturbations with high transition probabilities, that of the temporal duration, the monotonic convergence, and the ability to optimize multiple-laser pulses simultaneously. The advantage of the theory and a comparison with conventional fixed-time and fixed end-point multi-target optimal control theory (FIFP-MTOCT) are presented by comparing data calculated using the present theory with those published previously [K. Mishima, K. Yamashita, Chem. Phys. 361, (2009), 106]. The qubit system of our interest consists of two polar NaCl molecules coupled by dipole-dipole interaction. The calculation examples show that our theory is useful for minor

  9. Resolution enhancement of scanning four-point-probe measurements on two-dimensional systems

    DEFF Research Database (Denmark)

    Hansen, Torben Mikael; Stokbro, Kurt; Hansen, Ole

    2003-01-01

    A method to improve the resolution of four-point-probe measurements of two-dimensional (2D) and quasi-2D systems is presented. By mapping the conductance on a dense grid around a target area and postprocessing the data, the resolution can be improved by a factor of approximately 50 to better than 1....../15 of the four-point-probe electrode spacing. The real conductance sheet is simulated by a grid of discrete resistances, which is optimized by means of a standard optimization algorithm, until the simulated voltage-to-current ratios converges with the measurement. The method has been tested against simulated...

  10. Empiric model for mean generation time adjustment factor for classic point kinetics equations

    Energy Technology Data Exchange (ETDEWEB)

    Goes, David A.B.V. de; Martinez, Aquilino S.; Goncalves, Alessandro da C., E-mail: david.goes@poli.ufrj.br, E-mail: aquilino@lmp.ufrj.br, E-mail: alessandro@con.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Departamento de Engenharia Nuclear

    2017-11-01

    Point reactor kinetics equations are the easiest way to observe the neutron production time behavior in a nuclear reactor. These equations are derived from the neutron transport equation using an approximation called Fick's law leading to a set of first order differential equations. The main objective of this study is to review classic point kinetics equation in order to approximate its results to the case when it is considered the time variation of the neutron currents. The computational modeling used for the calculations is based on the finite difference method. The results obtained with this model are compared with the reference model and then it is determined an empirical adjustment factor that modifies the point reactor kinetics equation to the real scenario. (author)

  11. Empiric model for mean generation time adjustment factor for classic point kinetics equations

    International Nuclear Information System (INIS)

    Goes, David A.B.V. de; Martinez, Aquilino S.; Goncalves, Alessandro da C.

    2017-01-01

    Point reactor kinetics equations are the easiest way to observe the neutron production time behavior in a nuclear reactor. These equations are derived from the neutron transport equation using an approximation called Fick's law leading to a set of first order differential equations. The main objective of this study is to review classic point kinetics equation in order to approximate its results to the case when it is considered the time variation of the neutron currents. The computational modeling used for the calculations is based on the finite difference method. The results obtained with this model are compared with the reference model and then it is determined an empirical adjustment factor that modifies the point reactor kinetics equation to the real scenario. (author)

  12. Four-point probe measurements of a direct current potential drop on layered conductive cylinders

    International Nuclear Information System (INIS)

    Lu, Yi; Bowler, John R

    2012-01-01

    We have determined the steady state electric field due to direct current flowing via point contacts at the cylindrical surface of a uniformly layered conductive rod of finite length. The solution allows one to use four-point probe potential drop measurements to estimate the conductivity or thickness of the layer assuming that the other parameters are known. The electrical potential in the rod has a zero radial derivative at its surface except at the injection and extractions points. This means that the required solution can be expressed in terms of a Green’s function satisfying a Neumann boundary condition. Four-point measurements have been made to demonstrate the validity of theoretical results. (paper)

  13. Four-point probe measurements of a direct current potential drop on layered conductive cylinders

    Science.gov (United States)

    Lu, Yi; Bowler, John R.

    2012-11-01

    We have determined the steady state electric field due to direct current flowing via point contacts at the cylindrical surface of a uniformly layered conductive rod of finite length. The solution allows one to use four-point probe potential drop measurements to estimate the conductivity or thickness of the layer assuming that the other parameters are known. The electrical potential in the rod has a zero radial derivative at its surface except at the injection and extractions points. This means that the required solution can be expressed in terms of a Green’s function satisfying a Neumann boundary condition. Four-point measurements have been made to demonstrate the validity of theoretical results.

  14. Remote sensing of temperature and wind using acoustic travel-time measurements

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Manuela; Fischer, Gabi; Raabe, Armin; Weisse, Frank [Leipzig Univ. (Germany). Inst. fuer Meteorologie; Ziemann, Astrid [Technische Univ. Dresden (Germany). Professur fuer Meteorologie

    2013-04-15

    A remote sensing technique to detect area-averaged temperature and flow properties within an area under investigation, utilizing acoustic travel-time measurements, is introduced. This technique uses the dependency of the speed of acoustic signals on the meteorological parameters temperature and wind along the propagation path. The method itself is scalable: It is applicable for investigation areas with an extent of some hundred square metres as well as for small-scale areas in the range of one square metre. Moreover, an arrangement of the acoustic transducers at several height levels makes it possible to determine profiles and gradients of the meteorological quantities. With the help of two examples the potential of this remote sensing technique for simultaneously measuring averaged temperature and flow fields is demonstrated. A comparison of time histories of temperature and wind values derived from acoustic travel-time measurements with point measurements shows a qualitative agreement whereas calculated root-mean-square errors differ for the two example applications. They amount to 1.4 K and 0.3 m/s for transducer distances of 60 m and 0.4 K and 0.2 m/s for transducer distances in the range of one metre. (orig.)

  15. Real-Time Unsteady Loads Measurements Using Hot-Film Sensors

    Science.gov (United States)

    Mangalam, Arun S.; Moes, Timothy R.

    2004-01-01

    Several flight-critical aerodynamic problems such as buffet, flutter, stall, and wing rock are strongly affected or caused by abrupt changes in unsteady aerodynamic loads and moments. Advanced sensing and flow diagnostic techniques have made possible simultaneous identification and tracking, in realtime, of the critical surface, viscosity-related aerodynamic phenomena under both steady and unsteady flight conditions. The wind tunnel study reported here correlates surface hot-film measurements of leading edge stagnation point and separation point, with unsteady aerodynamic loads on a NACA 0015 airfoil. Lift predicted from the correlation model matches lift obtained from pressure sensors for an airfoil undergoing harmonic pitchup and pitchdown motions. An analytical model was developed that demonstrates expected stall trends for pitchup and pitchdown motions. This report demonstrates an ability to obtain unsteady aerodynamic loads in real time, which could lead to advances in air vehicle safety, performance, ride-quality, control, and health management.

  16. Comparative evaluation of SUV, tumor-to-blood standard uptake ratio (SUR), and dual time point measurements for assessment of the metabolic uptake rate in FDG PET.

    Science.gov (United States)

    Hofheinz, Frank; Hoff, Jörg van den; Steffen, Ingo G; Lougovski, Alexandr; Ego, Kilian; Amthauer, Holger; Apostolova, Ivayla

    2016-12-01

    We have demonstrated recently that the tumor-to-blood standard uptake ratio (SUR) is superior to tumor standardized uptake value (SUV) as a surrogate of the metabolic uptake rate K m of fluorodeoxyglucose (FDG), overcoming several of the known shortcomings of the SUV approach: excellent linear correlation of SUR and K m from Patlak analysis was found using dynamic imaging of liver metastases. However, due to the perfectly standardized uptake period used for SUR determination and the comparatively short uptake period, these results are not automatically valid and applicable for clinical whole-body examinations in which the uptake periods (T) are distinctly longer and can vary considerably. Therefore, the aim of this work was to investigate the correlation between SUR derived from clinical static whole-body scans and K m-surrogate derived from dual time point (DTP) measurements. DTP (18)F-FDG PET/CT was performed in 90 consecutive patients with histologically proven non-small cell lung cancer (NSCLC). In the PET images, the primary tumor was delineated with an adaptive threshold method. For determination of the blood SUV, an aorta region of interest (ROI) was delineated manually in the attenuation CT and transferred to the PET image. Blood SUV was computed as the mean value of the aorta ROI. SUR values were computed as ratio of tumor SUV and blood SUV. SUR values from the early time point of each DTP measurement were scan time corrected to 75 min postinjection (SURtc). As surrogate of K m, we used the SUR(T) slope, K slope, derived from DTP measurements since it is proportional to the latter under the given circumstances. The correlation of SUV and SURtc with K slope was investigated. The prognostic value of SUV, SURtc, and K slope for overall survival (OS) and progression-free survival (PFS) was investigated with univariate Cox regression in a homogeneous subgroup (N=31) treated with primary chemoradiation. Correlation analysis revealed for both, SUV and SURtc, a

  17. Study of time dependence and spectral composition of the signal in circuit of ac electric point motors

    Directory of Open Access Journals (Sweden)

    S. Yu. Buryak

    2014-12-01

    Full Text Available Purpose. The paper is aimed to establish the dependence of changes in the time domain and spectral components of the current in the circuit of the AC electric point motor on its technical condition, to identify the common features for the same type of damage. It is necessary using the analysis of the received signals to carry out the remote diagnosis and determination of faults and defects of electric point motors. In addition it suggested to accelerate the process of the failure, malfunction and damage search. Authors propose the automated approach to the service of remote floor automation equipment, which is located in the envelope of trains. Reduction of the threat to life and health of staff by reducing the residence time in the zone of train movement. Reduce the impact of human factors on the result of service. Methodology. The paper studies the structure, parameters and characteristics, the operation and maintenance characteristics of the AC electric point motors. Determination of the main types of possible faults in the process depending on the operating conditions. Presentation of the electric motor as an object of diagnosis. Findings. The time dependences of the current in the circuit of electric point motor for its various states was obtained. The connection between the technical condition of electric point motor and the performance of current curve in time and spectral domains was established. The revealed deviations from the reference signal were justified. According to the obtained results it was made the conclusion. Originality. A method for diagnosing the state of the AC electric point motor by the time dependence and the spectral composition of the current in its circuit was proposed. The connection diagram to the motor windings based on non-infringement of electric parameters of connection circuit in the actual operating conditions was applied. Practical value. The obtained results suggest the possibility and feasibility of

  18. Evaluation of magnetic helicity density in the wave number domain using multi-point measurements in space

    Directory of Open Access Journals (Sweden)

    Y. Narita

    2009-10-01

    Full Text Available We develop an estimator for the magnetic helicity density, a measure of the spiral geometry of magnetic field lines, in the wave number domain as a wave diagnostic tool based on multi-point measurements in space. The estimator is numerically tested with a synthetic data set and then applied to an observation of magnetic field fluctuations in the Earth foreshock region provided by the four-point measurements of the Cluster spacecraft. The energy and the magnetic helicity density are determined in the frequency and the wave number domain, which allows us to identify the wave properties in the plasma rest frame correcting for the Doppler shift. In the analyzed time interval, dominant wave components have parallel propagation to the mean magnetic field, away from the shock at about Alfvén speed and a left-hand spatial rotation sense of helicity with respect to the propagation direction, which means a right-hand temporal rotation sense of polarization. These wave properties are well explained by the right-hand resonant beam instability as the driving mechanism in the foreshock. Cluster observations allow therefore detailed comparisons with various theories of waves and instabilities.

  19. Influence of temporally variable groundwater flow conditions on point measurements and contaminant mass flux estimations

    DEFF Research Database (Denmark)

    Rein, Arno; Bauer, S; Dietrich, P

    2009-01-01

    Monitoring of contaminant concentrations, e.g., for the estimation of mass discharge or contaminant degradation rates. often is based on point measurements at observation wells. In addition to the problem, that point measurements may not be spatially representative. a further complication may ari...

  20. Iterative image reconstruction for positron emission tomography based on a detector response function estimated from point source measurements

    International Nuclear Information System (INIS)

    Tohme, Michel S; Qi Jinyi

    2009-01-01

    The accuracy of the system model in an iterative reconstruction algorithm greatly affects the quality of reconstructed positron emission tomography (PET) images. For efficient computation in reconstruction, the system model in PET can be factored into a product of a geometric projection matrix and sinogram blurring matrix, where the former is often computed based on analytical calculation, and the latter is estimated using Monte Carlo simulations. Direct measurement of a sinogram blurring matrix is difficult in practice because of the requirement of a collimated source. In this work, we propose a method to estimate the 2D blurring kernels from uncollimated point source measurements. Since the resulting sinogram blurring matrix stems from actual measurements, it can take into account the physical effects in the photon detection process that are difficult or impossible to model in a Monte Carlo (MC) simulation, and hence provide a more accurate system model. Another advantage of the proposed method over MC simulation is that it can easily be applied to data that have undergone a transformation to reduce the data size (e.g., Fourier rebinning). Point source measurements were acquired with high count statistics in a relatively fine grid inside the microPET II scanner using a high-precision 2D motion stage. A monotonically convergent iterative algorithm has been derived to estimate the detector blurring matrix from the point source measurements. The algorithm takes advantage of the rotational symmetry of the PET scanner and explicitly models the detector block structure. The resulting sinogram blurring matrix is incorporated into a maximum a posteriori (MAP) image reconstruction algorithm. The proposed method has been validated using a 3 x 3 line phantom, an ultra-micro resolution phantom and a 22 Na point source superimposed on a warm background. The results of the proposed method show improvements in both resolution and contrast ratio when compared with the MAP

  1. Test-retest reliability and minimal detectable change of two simplified 3-point balance measures in patients with stroke.

    Science.gov (United States)

    Chen, Yi-Miau; Huang, Yi-Jing; Huang, Chien-Yu; Lin, Gong-Hong; Liaw, Lih-Jiun; Lee, Shih-Chieh; Hsieh, Ching-Lin

    2017-10-01

    The 3-point Berg Balance Scale (BBS-3P) and 3-point Postural Assessment Scale for Stroke Patients (PASS-3P) were simplified from the BBS and PASS to overcome the complex scoring systems. The BBS-3P and PASS-3P were more feasible in busy clinical practice and showed similarly sound validity and responsiveness to the original measures. However, the reliability of the BBS-3P and PASS-3P is unknown limiting their utility and the interpretability of scores. We aimed to examine the test-retest reliability and minimal detectable change (MDC) of the BBS-3P and PASS-3P in patients with stroke. Cross-sectional study. The rehabilitation departments of a medical center and a community hospital. A total of 51 chronic stroke patients (64.7% male). Both balance measures were administered twice 7 days apart. The test-retest reliability of both the BBS-3P and PASS-3P were examined by intraclass correlation coefficients (ICC). The MDC and its percentage over the total score (MDC%) of each measure was calculated for examining the random measurement errors. The ICC values of the BBS-3P and PASS-3P were 0.99 and 0.97, respectively. The MDC% (MDC) of the BBS-3P and PASS-3P were 9.1% (5.1 points) and 8.4% (3.0 points), respectively, indicating that both measures had small and acceptable random measurement errors. Our results showed that both the BBS-3P and the PASS-3P had good test-retest reliability, with small and acceptable random measurement error. These two simplified 3-level balance measures can provide reliable results over time. Our findings support the repeated administration of the BBS-3P and PASS-3P to monitor the balance of patients with stroke. The MDC values can help clinicians and researchers interpret the change scores more precisely.

  2. The effect of time duration in the network and radial method toward the accuracy in measuring the deformation at Muria

    International Nuclear Information System (INIS)

    Ari Nugroho and Hadi Suntoko

    2011-01-01

    The Deformation monitoring activities in the vicinity of Mount Muria are recommended by the IAEA (International Atomic Energy Agency) to be done for 5 years. The purpose of these activities is to determine the rate of the deformation caused by the volcanic activity of Mount Muria, as a basic study in analyzing the volcanic hazard toward the NPP (Nuclear Power Plant). The whole coordinate points measured encompass the district of Jepara, Pati, Demak, and Kudus. In 2010 deformation measurements were periodically conducted for 4 times a year using two geodetic GPS units of Trimble R7 GNSS type through the network method. The measurements were carried out at seven points of interest and at one reference point in March, April, May and December. Each session of the measurements was performed for 2.5 hours. In 2011 the deformation measurements were periodically conducted for 4 times a year by means of the radial method. The measurements were made at eight points of interest and at one reference point in April and May, June and July. Each session of measurements was performed for 10 hours. Based on the results of the measurements by means of the network method in 2010, it was concluded that the range of horizontal and vertical accuracy is between 6-10 mm and 25-46 mm, while the results of the measurements of the radial method in 2011 is 4-7 mm, and 16-28 mm respectively. Furthermore, it provides the evidence that the radial method tends to has better result than the network method if it is applied 4 times longer than the network method, resulting the accuracy below 7 mm and 28 mm for horizontal and vertical respectively. (author)

  3. Novel technique for prediction of time points for scheduling of multipurpose batch plants

    CSIR Research Space (South Africa)

    Seid, R

    2012-01-01

    Full Text Available . Consequently this avoids costly computational times due to iterations. In the model by Majozi and Zhu (2001) the sequence constraint that pertains to tasks that consume and produce the same state, the starting time of the consuming task at time point p must...

  4. Critical point measurement of some polycyclic aromatic hydrocarbons

    International Nuclear Information System (INIS)

    Nikitin, Eugene D.; Popov, Alexander P.

    2015-01-01

    Highlights: • Critical properties of five polycyclic aromatic hydrocarbons were measured. • These hydrocarbons decompose at near-critical temperatures. • Pulse-heating method with short residence times was used. - Abstract: The critical temperatures and the critical pressures of five polycyclic aromatic compounds, namely, acenaphthene, fluorene, anthracene, phenanthrene, and pyrene have been measured. All the compounds studied decompose at near-critical temperatures. A pulse-heating technique applicable to measuring the critical properties of thermally unstable compounds has been used. The times from the beginning of a heating pulse to the moment of reaching the critical temperature were from (0.06 to 0.85) ms. The short residence times provide little degradation of the substances in the course of the experiments. The experimental critical parameters of the polycyclic aromatic compounds have been compared with those estimated by five predictive methods. The acentric factors of polycyclic aromatic compounds studied have been calculated

  5. A Doubly Stochastic Change Point Detection Algorithm for Noisy Biological Signals

    Directory of Open Access Journals (Sweden)

    Nathan Gold

    2018-01-01

    Full Text Available Experimentally and clinically collected time series data are often contaminated with significant confounding noise, creating short, noisy time series. This noise, due to natural variability and measurement error, poses a challenge to conventional change point detection methods. We propose a novel and robust statistical method for change point detection for noisy biological time sequences. Our method is a significant improvement over traditional change point detection methods, which only examine a potential anomaly at a single time point. In contrast, our method considers all suspected anomaly points and considers the joint probability distribution of the number of change points and the elapsed time between two consecutive anomalies. We validate our method with three simulated time series, a widely accepted benchmark data set, two geological time series, a data set of ECG recordings, and a physiological data set of heart rate variability measurements of fetal sheep model of human labor, comparing it to three existing methods. Our method demonstrates significantly improved performance over the existing point-wise detection methods.

  6. The reproducibility of some thermometric fixed points and the accuracy of temperature measurements using platinum resistance thermometers

    Energy Technology Data Exchange (ETDEWEB)

    Ancsin, J. [National Research Council of Canada, Ottawa, ON (Canada). Inst. for National Measurement Standards; Mendez-Lango, E. [Centro Nacional de Metrologia (CENAM), Div. Termometria, Queretaro (Mexico)

    1999-07-01

    The reproducibility of some thermometric fixed points and the accuracy of four platinum resistance thermometers (PRTs) were studied. It was found that the fixed points of aluminium (Al), zinc (Zn), tin (Sn), indium (In) and gallium (Ga) were realized reproducibly within {+-}0.17 mK; {+-}0.11 mK; {+-}0.10 mK; {+-}0.13 mK and {+-}0.12 mK, respectively. Because the actual impurities and their concentration in our samples (of 99.9999 % or 99.999 99 % purity) are unknown, the systematic uncertainly due to impurities cannot be estimated. However, any of the samples of Ga, In, Sn, Zn and Al is consistent with the rest within {+-}0.2 mK, using a cubic or quadratic deviation function, in the temperature range 0 deg C to 660 deg C. This indicates that the effect of impurities is negligible. Four PRTs were selected at random. They were calibrated repeatedly, first up to the Zn point and then up to the Al point. The resistance of each PRT drifted. From time to time, for each PRT, a seemingly well-established resistance drift suddenly and unpredictably changed to a different rate of drift. Occasionally, the resistance of the PRTs shifted. Such unpredictable changes obviously limit the accuracy of temperature measurements using PRTs no matter what the accuracy of their calibrations. In the case of our four PRTs, the uncertainty of temperature measurements near 660 deg C ranged from about {+-}1 mK to about {+-}2,5 mK even though they were all calibrated at all fixed points well within {+-}0.25 mK uncertainty. Possible explanations are offered for the apparently permanent drifts and the erratic shifts in the resistance of the PRTs. Some comments are made concerning the ambiguity of 'immersion tests' in general. The furnaces of the National Research Council of Canada used in this work are high-temperature adiabatic calorimeters. (authors)

  7. Prospective comparison of liver stiffness measurements between two point wave elastography methods: Virtual ouch quantification and elastography point quantification

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Hyun Suk; Lee, Jeong Min; Yoon, Jeong Hee; Lee, Dong Ho; Chang, Won; Han, Joon Koo [Seoul National University Hospital, Seoul (Korea, Republic of)

    2016-09-15

    To prospectively compare technical success rate and reliable measurements of virtual touch quantification (VTQ) elastography and elastography point quantification (ElastPQ), and to correlate liver stiffness (LS) measurements obtained by the two elastography techniques. Our study included 85 patients, 80 of whom were previously diagnosed with chronic liver disease. The technical success rate and reliable measurements of the two kinds of point shear wave elastography (pSWE) techniques were compared by χ{sup 2} analysis. LS values measured using the two techniques were compared and correlated via Wilcoxon signed-rank test, Spearman correlation coefficient, and 95% Bland-Altman limit of agreement. The intraobserver reproducibility of ElastPQ was determined by 95% Bland-Altman limit of agreement and intraclass correlation coefficient (ICC). The two pSWE techniques showed similar technical success rate (98.8% for VTQ vs. 95.3% for ElastPQ, p = 0.823) and reliable LS measurements (95.3% for VTQ vs. 90.6% for ElastPQ, p = 0.509). The mean LS measurements obtained by VTQ (1.71 ± 0.47 m/s) and ElastPQ (1.66 ± 0.41 m/s) were not significantly different (p = 0.209). The LS measurements obtained by the two techniques showed strong correlation (r = 0.820); in addition, the 95% limit of agreement of the two methods was 27.5% of the mean. Finally, the ICC of repeat ElastPQ measurements was 0.991. Virtual touch quantification and ElastPQ showed similar technical success rate and reliable measurements, with strongly correlated LS measurements. However, the two methods are not interchangeable due to the large limit of agreement.

  8. Modified mean generation time parameter in the neutron point kinetics equations

    Energy Technology Data Exchange (ETDEWEB)

    Diniz, Rodrigo C.; Gonçalves, Alessandro C.; Rosa, Felipe S.S., E-mail: alessandro@nuclear.ufrj.br, E-mail: frosa@if.ufrj.br [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    This paper proposes an approximation for the modified point kinetics equations proposed by NUNES et. al, 2015, through the adjustment of a kinetic parameter. This approximation consists of analyzing the terms of the modified point kinetics equations in order to identify the least important ones for the solution, resulting in a modification of the mean generation time parameter that incorporates all influences of the additional terms of the modified kinetics. This approximation is applied on the inverse kinetics, to compare the results with the inverse kinetics from the modified kinetics in order to validate the proposed model. (author)

  9. Modified mean generation time parameter in the neutron point kinetics equations

    International Nuclear Information System (INIS)

    Diniz, Rodrigo C.; Gonçalves, Alessandro C.; Rosa, Felipe S.S.

    2017-01-01

    This paper proposes an approximation for the modified point kinetics equations proposed by NUNES et. al, 2015, through the adjustment of a kinetic parameter. This approximation consists of analyzing the terms of the modified point kinetics equations in order to identify the least important ones for the solution, resulting in a modification of the mean generation time parameter that incorporates all influences of the additional terms of the modified kinetics. This approximation is applied on the inverse kinetics, to compare the results with the inverse kinetics from the modified kinetics in order to validate the proposed model. (author)

  10. 'Stutter timing' for charge decay time measurement

    International Nuclear Information System (INIS)

    Chubb, John; Harbour, John; Pavey, Ian

    2011-01-01

    The paper describes the approach of 'stutter timing' that has been developed to improve the accuracy of measuring charge decay times in the presence of noise in compact and portable charge decay test instrumentation. The approach involves starting and stopping the timing clock as the noisy signal rises above and falls below the target threshold voltage level.

  11. New look at displacement factor and point of measurement corrections in ionization chamber dosimetry

    International Nuclear Information System (INIS)

    Awschalom, M.; Rosenberg, I.; Ten Haken, R.K.

    1983-01-01

    A new technique is presented for determination of the effective point of measurement when cavity ionization chambers are used to measure the absorbed dose due to ionizing radiation in a dense medium. An algorithm is derived relating the effective point of measurement to the displacement correction factor. This algorithm relates variations of the displacement factor to the radiation field gradient. The technique is applied to derive the magnitudes of the corrections for several chambers in a p(66)Be(49) neutron therapy beam. 30 references, 4 figures, 1 table

  12. The relative timing between eye and hand rapid sequential pointing is affected by time pressure, but not by advance knowledge

    NARCIS (Netherlands)

    Deconinck, F.; van Polanen, V.; Savelsbergh, G.J.P.; Bennett, S.

    2011-01-01

    The present study examined the effect of timing constraints and advance knowledge on eye-hand coordination strategy in a sequential pointing task. Participants were required to point at two successively appearing targets on a screen while the inter-stimulus interval (ISI) and the trial order were

  13. Boiling point measurement of a small amount of brake fluid by thermocouple and its application.

    Science.gov (United States)

    Mogami, Kazunari

    2002-09-01

    This study describes a new method for measuring the boiling point of a small amount of brake fluid using a thermocouple and a pear shaped flask. The boiling point of brake fluid was directly measured with an accuracy that was within approximately 3 C of that determined by the Japanese Industrial Standards method, even though the sample volume was only a few milliliters. The method was applied to measure the boiling points of brake fluid samples from automobiles. It was clear that the boiling points of brake fluid from some automobiles dropped to approximately 140 C from about 230 C, and that one of the samples from the wheel cylinder was approximately 45 C lower than brake fluid from the reserve tank. It is essential to take samples from the wheel cylinder, as this is most easily subjected to heating.

  14. On a Use Case Points Measurement Tool for Effective Project Management

    OpenAIRE

    Inoue, Katsuro; Kusumoto, Shinji; Tsuda, Michio

    2007-01-01

    Use case point (UCP) method has been proposed to estimate software development effort in early phase of software project and used in a lot of software organizations. This paper briefly describes an automatic use case measurement tool, called U-EST.

  15. A novel method of measuring the concentration of anaesthetic vapours using a dew-point hygrometer.

    Science.gov (United States)

    Wilkes, A R; Mapleson, W W; Mecklenburgh, J S

    1994-02-01

    The Antoine equation relates the saturated vapour pressure of a volatile substance, such as an anaesthetic agent, to the temperature. The measurement of the 'dew-point' of a dry gas mixture containing a volatile anaesthetic agent by a dew-point hygrometer permits the determination of the partial pressure of the anaesthetic agent. The accuracy of this technique is limited only by the accuracy of the Antoine coefficients and of the temperature measurement. Comparing measurements by the dew-point method with measurements by refractometry showed systematic discrepancies up to 0.2% and random discrepancies with SDS up to 0.07% concentration in the 1% to 5% range for three volatile anaesthetics. The systematic discrepancies may be due to errors in available data for the vapour pressures and/or the refractive indices of the anaesthetics.

  16. Analyzing survival curves at a fixed point in time for paired and clustered right-censored data

    Science.gov (United States)

    Su, Pei-Fang; Chi, Yunchan; Lee, Chun-Yi; Shyr, Yu; Liao, Yi-De

    2018-01-01

    In clinical trials, information about certain time points may be of interest in making decisions about treatment effectiveness. Rather than comparing entire survival curves, researchers can focus on the comparison at fixed time points that may have a clinical utility for patients. For two independent samples of right-censored data, Klein et al. (2007) compared survival probabilities at a fixed time point by studying a number of tests based on some transformations of the Kaplan-Meier estimators of the survival function. However, to compare the survival probabilities at a fixed time point for paired right-censored data or clustered right-censored data, their approach would need to be modified. In this paper, we extend the statistics to accommodate the possible within-paired correlation and within-clustered correlation, respectively. We use simulation studies to present comparative results. Finally, we illustrate the implementation of these methods using two real data sets. PMID:29456280

  17. EMPLOYEE COMMITMENT ACROSS COUNTRIES AND TIMES - MEASUREMENT INVARIANCE

    Directory of Open Access Journals (Sweden)

    Dana Mesner Andolšek

    2015-01-01

    Full Text Available Employee organisational commitment has been long and extensively studied until now (Meyer & Allen, 1997; Jaussi, 2007.An emphasis of current analysis was to verify its measurement characteristics, for the purpose of comparisons of levels of commitment across time and countries. A limited set of countries was chosen among those available in a sample from the data on Work Orientations II, ISSP 1997, purpose fully selected to reflect cultural and structural differences that was expected to affect change in levels of organisational commitment. With the use of structural equations models we first confirmed that a model for configural invariance for two factors measuring conceptually distinct components of Affective commitment (AC and Continuance commitment (CC respectively has better support than of one factor model. Metric and error term invariance was subsequently confirmed. Scalar equivalence, needed for valid comparison of mean levels of both components of commitment, was confirmed as well, with the exception of two country specific Tau coefficient. Finally, a model thus established was applied additionally on data from2005 ISSP. Acceptable fit was achieved for a common model containing both points in time and all countries, which allowed making more firm conclusions about the changes in AC and CC in different countries.

  18. Organic scintillators response function modeling for Monte Carlo simulation of Time-of-Flight measurements

    Energy Technology Data Exchange (ETDEWEB)

    Carasco, C., E-mail: cedric.carasco@cea.fr [CEA, DEN, Cadarache, Nuclear Measurement Laboratory, F-13108 Saint-Paul-lez-Durance (France)

    2012-07-15

    In neutron Time-of-Flight (TOF) measurements performed with fast organic scintillation detectors, both pulse arrival time and amplitude are relevant. Monte Carlo simulation can be used to calculate the time-energy dependant neutron flux at the detector position. To convert the flux into a pulse height spectrum, one must calculate the detector response function for mono-energetic neutrons. MCNP can be used to design TOF systems, but standard MCNP versions cannot reliably calculate the energy deposited by fast neutrons in the detector since multiple scattering effects must be taken into account in an analog way, the individual recoil particles energy deposit being summed with the appropriate scintillation efficiency. In this paper, the energy response function of 2 Double-Prime Multiplication-Sign 2 Double-Prime and 5 Double-Prime Multiplication-Sign 5 Double-Prime liquid scintillation BC-501 A (Bicron) detectors to fast neutrons ranging from 20 keV to 5.0 MeV is computed with GEANT4 to be coupled with MCNPX through the 'MCNP Output Data Analysis' software developed under ROOT (). - Highlights: Black-Right-Pointing-Pointer GEANT4 has been used to model organic scintillators response to neutrons up to 5 MeV. Black-Right-Pointing-Pointer The response of 2 Double-Prime Multiplication-Sign 2 Double-Prime and 5 Double-Prime Multiplication-Sign 5 Double-Prime BC501A detectors has been parameterized with simple functions. Black-Right-Pointing-Pointer Parameterization will allow the modeling of neutron Time of Flight measurements with MCNP using tools based on CERN's ROOT.

  19. Prospects for direct neutron capture measurements on s-process branching point isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, C.; Lerendegui-Marco, J.; Quesada, J.M. [Universidad de Sevilla, Dept. de Fisica Atomica, Molecular y Nuclear, Sevilla (Spain); Domingo-Pardo, C. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Kaeppeler, F. [Karlsruhe Institute of Technology, Institut fuer Kernphysik, Karlsruhe (Germany); Palomo, F.R. [Universidad de Sevilla, Dept. de Ingenieria Electronica, Sevilla (Spain); Reifarth, R. [Goethe-Universitaet Frankfurt am Main, Frankfurt am Main (Germany)

    2017-05-15

    The neutron capture cross sections of several unstable key isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure directly due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n, γ) measurement, where high neutron fluxes and effective background rejection capabilities are required. At present there are about 21 relevant s-process branching point isotopes whose cross section could not be measured yet over the neutron energy range of interest for astrophysics. However, the situation is changing with some very recent developments and upcoming technologies. This work introduces three techniques that will change the current paradigm in the field: the use of γ-ray imaging techniques in (n, γ) experiments, the production of moderated neutron beams using high-power lasers, and double capture experiments in Maxwellian neutron beams. (orig.)

  20. Applied measuring techniques for the investigation of time-dependent flow phenomena in centrifugal compressors

    International Nuclear Information System (INIS)

    Hass, U.; Haupt, U.; Jansen, M.; Kassens, K.; Knapp, P.; Rautenberg, M.

    1978-01-01

    During the past 10 years new measuring techniques have been developed for the experimental investigation of highly loaded centrifugal compressors. These measuring techniques take into account the time dependency of the fluctuating physical quantities such as pressure, temperature, and velocity. Some key points of these experimental techniques are shown and explained in this paper. An important basis for such measurements is the accurate dynamic calibration of the measuring apparatus. In addition, some problems involved analyzing measured signals are dealt with and pressure measurements and their interpretation are shown. Finally optical, acoustical and vibrational measuring procedures are described which are additionally used for the investigation of non-stationary flow phenomena. (orig.) [de

  1. Proof of Concept: Design and Initial Evaluation of a Device to Measure Gastrointestinal Transit Time.

    Science.gov (United States)

    Wagner, Robert H; Savir-Baruch, Bital; Halama, James R; Venu, Mukund; Gabriel, Medhat S; Bova, Davide

    2017-09-01

    Chronic constipation and gastrointestinal motility disorders constitute a large part of a gastroenterology practice and have a significant impact on a patient's quality of life and lifestyle. In most cases, medications are prescribed to alleviate symptoms without there being an objective measurement of response. Commonly used investigations of gastrointestinal transit times are currently limited to radiopaque markers or electronic capsules. Repeated use of these techniques is limited because of the radiation exposure and the significant cost of the devices. We present the proof of concept for a new device to measure gastrointestinal transit time using commonly available and inexpensive materials with only a small amount of radiotracer. Methods: We assembled gelatin capsules containing a 67 Ga-citrate-radiolabeled grain of rice embedded in paraffin for use as a point-source transit device. It was tested for stability in vitro and subsequently was given orally to 4 healthy volunteers and 10 patients with constipation or diarrhea. Imaging was performed at regular intervals until the device was excreted. Results: The device remained intact and visible as a point source in all subjects until excretion. When used along with a diary of bowel movement times and dates, the device could determine the total transit time. The device could be visualized either alone or in combination with a barium small-bowel follow-through study or a gastric emptying study. Conclusion: The use of a point-source transit device for the determination of gastrointestinal transit time is a feasible alternative to other methods. The device is inexpensive and easy to assemble, requires only a small amount of radiotracer, and remains inert throughout the gastrointestinal tract, allowing for accurate determination of gastrointestinal transit time. Further investigation of the device is required to establish optimum imaging parameters and reference values. Measurements of gastrointestinal transit time

  2. Instantaneous local wave vector estimation from multi-spacecraft measurements using few spatial points

    Directory of Open Access Journals (Sweden)

    T. D. Carozzi

    2004-07-01

    Full Text Available We introduce a technique to determine instantaneous local properties of waves based on discrete-time sampled, real-valued measurements from 4 or more spatial points. The technique is a generalisation to the spatial domain of the notion of instantaneous frequency used in signal processing. The quantities derived by our technique are closely related to those used in geometrical optics, namely the local wave vector and instantaneous phase velocity. Thus, this experimental technique complements ray-tracing. We provide example applications of the technique to electric field and potential data from the EFW instrument on Cluster. Cluster is the first space mission for which direct determination of the full 3-dimensional local wave vector is possible, as described here.

  3. Radiation effects in polyolefins below the gel point as measured by torque rheometry

    International Nuclear Information System (INIS)

    Markovic, V.; Babic, D.; Silverman, J.

    1981-01-01

    Torque rheometry is used to obtain information about radiation effects on polymers (crosslinking, degradation) below the gel point. It is shown that rheometric melt viscosity measurements at different shear rates are related changes in the relaxation spectrum. In particular there is a significant radiation effect on low shear rate viscosities but a negligible effect on high shear rate viscosities. The fact that the shear rate in the torque rheometer oscillates about a mean value is utilized to relate torque amplitude measurements to entanglements at zero dose and to crosslink density at absorbed doses below or close to the gel point. (author)

  4. Numerical instability of time-discretized one-point kinetic equations

    International Nuclear Information System (INIS)

    Hashimoto, Kengo; Ikeda, Hideaki; Takeda, Toshikazu

    2000-01-01

    The one-point kinetic equations with numerical errors induced by the explicit, implicit and Crank-Nicolson integration methods are derived. The zero-power transfer functions based on the present equations are demonstrated to investigate the numerical stability of the discretized systems. These demonstrations indicate unconditional stability for the implicit and Crank-Nicolson methods but present the possibility of numerical instability for the explicit method. An upper limit of time mesh spacing for the stability is formulated and several numerical calculations are made to confirm the validity of this formula

  5. Estimation and prediction of convection-diffusion-reaction systems from point measurement

    NARCIS (Netherlands)

    Vries, D.

    2008-01-01

    Different procedures with respect to estimation and prediction of systems characterized by convection, diffusion and reactions on the basis of point measurement data, have been studied. Two applications of these convection-diffusion-reaction (CDR) systems have been used as a case study of the

  6. ASIC for time-of-flight measurements with picosecond timing resolution

    Energy Technology Data Exchange (ETDEWEB)

    Stankova, Vera; Shen, Wei; Harion, Tobias [Kirchhoff-Institute for Physics, Heidelberg Univ. (Germany)

    2015-07-01

    The Positron Emission Tomography (PET) images are especially affected by a high level of noise. This noise affects the potential to detect and discriminate the tumor in relation to the background. Including Time-of-Flight information, with picosecond time resolution, within the conventional PET scanners will improve the signal-to-noise ratio (SNR) and in sequence the quality of the medical images. A mix-mode ASIC (STIC3) has been developed for high precision timing measurements with Silicon Photomultipliers (SiPM). The STiC3 is 64-channel chip, with fully differential analog front-end for crosstalk and electronic noise immunity. It integrates Time to Digital Converters (TDC) with time binning of 50.2 ps for time and energy measurements. Measurements of the of the analog front-end show a time jitter less than 20 ps and jitter of the TDC together with the digital part is around 37 ps. Further the timing of a channel has been tested by injecting a pulse into two channels and measuring the time difference of the recorded timestamps. A Coincidence Time Resolution (CTR) of 215 ps FWHM has been obtained with 3.1 x 3.1 x 15 mm{sup 2} LYSO:Ce scintillator crystals and Hamamatsu SiPM matric (S12643-050CN(x)). Characterization measurements with the chip and its performances are presented.

  7. Flow speed measurement using two-point collective light scattering

    International Nuclear Information System (INIS)

    Heinemeier, N.P.

    1998-09-01

    Measurements of turbulence in plasmas and fluids using the technique of collective light scattering have always been plagued by very poor spatial resolution. In 1994, a novel two-point collective light scattering system for the measurement of transport in a fusion plasma was proposed. This diagnostic method was design for a great improvement of the spatial resolution, without sacrificing accuracy in the velocity measurement. The system was installed at the W7-AS steallartor in Garching, Germany, in 1996, and has been operating since. This master thesis is an investigation of the possible application of this new method to the measurement of flow speeds in normal fluids, in particular air, although the results presented in this work have significance for the plasma measurements as well. The main goal of the project was the experimental verification of previous theoretical predictions. However, the theoretical considerations presented in the thesis show that the method can only be hoped to work for flows that are almost laminar and shearless, which makes it of very small practical interest. Furthermore, this result also implies that the diagnostic at W7-AS cannot be expected to give the results originally hoped for. (au)

  8. Quantification of regional cerebral blood flow (rCBF) measurement with one point sampling by sup 123 I-IMP SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Munaka, Masahiro [University of Occupational and Enviromental Health, Kitakyushu (Japan); Iida, Hidehiro; Murakami, Matsutaro

    1992-02-01

    A handy method of quantifying regional cerebral blood flow (rCBF) measurement by {sup 123}I-IMP SPECT was designed. A standard input function was made and the sampling time to calibrate this standard input function by one point sampling was optimized. An average standard input function was obtained from continuous arterial samplings of 12 healthy adults. The best sampling time was the minimum differential value between the integral calculus value of the standard input function calibrated by one point sampling and the input funciton by continuous arterial samplings. This time was 8 minutes after an intravenous injection of {sup 123}I-IMP and an error was estimated to be {+-}4.1%. The rCBF values by this method were evaluated by comparing them with the rCBF values of the input function with continuous arterial samplings in 2 healthy adults and a patient with cerebral infarction. A significant correlation (r=0.764, p<0.001) was obtained between both. (author).

  9. Displacement correction factor versus effective point of measurement in depth dose curve measurements at {sup 60}Co gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Bruna, A [Universidad Nacional, Cordoba (Argentina). Facultad de Matematica, Astronomia y Fisica; Velez, G R [Hospital San Roque, Cordoba (Argentina). Dept. de Radioterapia; Brunetto, M [Centro Medico Rivado Dean Funes, Cordoba (Argentina)

    1996-08-01

    The discrepancies in data sets of values of the Displacement Factor p{sub d} recommended by different codes of practices for calibration purpose still demand further investigation to clarify this point. In this paper, we propose an experimental method to determine the displacement factor for cylindrical ionization chambers (thimble chambers) in photon beams. Measurements of p{sub d} for several depths were performed for {sup 60}Co gamma rays. From these results we calculated the shift of the effective point of measurement (z-z{sub eff}) for different depths. The results obtained in this work shown: (a) there is no significant change in p{sub d} from 2 cm to 17 cm of depth in water; (b) the value of p{sub d} for a ion-chamber Farmer type (inner radius r = 3.15 cm) is p{sub d} 0.988; (c) the shift of the effective point of measurement has a smooth variation with depth; (d) the value of (z-z{sub eff}) at the recommended calibration depth for {sup 60}Co beams (5 cm) is 0.6r (with r: inner radius of the chamber). The result (b) confirms the value of p{sub d} suggested by the SEFM and NACP protocols and differs with that of the AAPM. The value obtained for (z - z{sub eff}) (d) is very closed to that recommended by the IAEA TRS-277. Finally, the results (a) and (c) suggest that it should be preferable to use the displacement factor instead of effective point of measurement to perform measurements of depth dose curves, since the use of z{sub eff} should take into account its dependence on depth. (author). 7 refs, 4 figs.

  10. Turbulent Statistics From Time-Resolved PIV Measurements of a Jet Using Empirical Mode Decomposition

    Science.gov (United States)

    Dahl, Milo D.

    2013-01-01

    Empirical mode decomposition is an adaptive signal processing method that when applied to a broadband signal, such as that generated by turbulence, acts as a set of band-pass filters. This process was applied to data from time-resolved, particle image velocimetry measurements of subsonic jets prior to computing the second-order, two-point, space-time correlations from which turbulent phase velocities and length and time scales could be determined. The application of this method to large sets of simultaneous time histories is new. In this initial study, the results are relevant to acoustic analogy source models for jet noise prediction. The high frequency portion of the results could provide the turbulent values for subgrid scale models for noise that is missed in large-eddy simulations. The results are also used to infer that the cross-correlations between different components of the decomposed signals at two points in space, neglected in this initial study, are important.

  11. Time-resolved measurements of luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Collier, Bradley B. [Department of Biomedical Engineering, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States); McShane, Michael J., E-mail: mcshane@tamu.edu [Department of Biomedical Engineering, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States); Materials Science and Engineering Program, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States)

    2013-12-15

    Luminescence sensing and imaging has become more widespread in recent years in a variety of industries including the biomedical and environmental fields. Measurements of luminescence lifetime hold inherent advantages over intensity-based response measurements, and advances in both technology and methods have enabled their use in a broader spectrum of applications including real-time medical diagnostics. This review will focus on recent advances in analytical methods, particularly calculation techniques, including time- and frequency-domain lifetime approaches as well as other time-resolved measurements of luminescence. -- Highlights: • Developments in technology have led to widespread use of luminescence lifetime. • Growing interest for sensing and imaging applications. • Recent advances in approaches to lifetime calculations are reviewed. • Advantages and disadvantages of various methods are weighed. • Other methods for measurement of luminescence lifetime also described.

  12. Time-resolved measurements of luminescence

    International Nuclear Information System (INIS)

    Collier, Bradley B.; McShane, Michael J.

    2013-01-01

    Luminescence sensing and imaging has become more widespread in recent years in a variety of industries including the biomedical and environmental fields. Measurements of luminescence lifetime hold inherent advantages over intensity-based response measurements, and advances in both technology and methods have enabled their use in a broader spectrum of applications including real-time medical diagnostics. This review will focus on recent advances in analytical methods, particularly calculation techniques, including time- and frequency-domain lifetime approaches as well as other time-resolved measurements of luminescence. -- Highlights: • Developments in technology have led to widespread use of luminescence lifetime. • Growing interest for sensing and imaging applications. • Recent advances in approaches to lifetime calculations are reviewed. • Advantages and disadvantages of various methods are weighed. • Other methods for measurement of luminescence lifetime also described

  13. Effect of Anisotropy on Shape Measurement Accuracy of Silicon Wafer Using Three-Point-Support Inverting Method

    Science.gov (United States)

    Ito, Yukihiro; Natsu, Wataru; Kunieda, Masanori

    This paper describes the influences of anisotropy found in the elastic modulus of monocrystalline silicon wafers on the measurement accuracy of the three-point-support inverting method which can measure the warp and thickness of thin large panels simultaneously. Deflection due to gravity depends on the crystal orientation relative to the positions of the three-point-supports. Thus the deviation of actual crystal orientation from the direction indicated by the notch fabricated on the wafer causes measurement errors. Numerical analysis of the deflection confirmed that the uncertainty of thickness measurement increases from 0.168µm to 0.524µm due to this measurement error. In addition, experimental results showed that the rotation of crystal orientation relative to the three-point-supports is effective for preventing wafer vibration excited by disturbance vibration because the resonance frequency of wafers can be changed. Thus, surface shape measurement accuracy was improved by preventing resonant vibration during measurement.

  14. Terrestrial laser scanning point clouds time series for the monitoring of slope movements: displacement measurement using image correlation and 3D feature tracking

    Science.gov (United States)

    Bornemann, Pierrick; Jean-Philippe, Malet; André, Stumpf; Anne, Puissant; Julien, Travelletti

    2016-04-01

    Dense multi-temporal point clouds acquired with terrestrial laser scanning (TLS) have proved useful for the study of structure and kinematics of slope movements. Most of the existing deformation analysis methods rely on the use of interpolated data. Approaches that use multiscale image correlation provide a precise and robust estimation of the observed movements; however, for non-rigid motion patterns, these methods tend to underestimate all the components of the movement. Further, for rugged surface topography, interpolated data introduce a bias and a loss of information in some local places where the point cloud information is not sufficiently dense. Those limits can be overcome by using deformation analysis exploiting directly the original 3D point clouds assuming some hypotheses on the deformation (e.g. the classic ICP algorithm requires an initial guess by the user of the expected displacement patterns). The objective of this work is therefore to propose a deformation analysis method applied to a series of 20 3D point clouds covering the period October 2007 - October 2015 at the Super-Sauze landslide (South East French Alps). The dense point clouds have been acquired with a terrestrial long-range Optech ILRIS-3D laser scanning device from the same base station. The time series are analyzed using two approaches: 1) a method of correlation of gradient images, and 2) a method of feature tracking in the raw 3D point clouds. The estimated surface displacements are then compared with GNSS surveys on reference targets. Preliminary results tend to show that the image correlation method provides a good estimation of the displacement fields at first order, but shows limitations such as the inability to track some deformation patterns, and the use of a perspective projection that does not maintain original angles and distances in the correlated images. Results obtained with 3D point clouds comparison algorithms (C2C, ICP, M3C2) bring additional information on the

  15. Period, epoch, and prediction errors of ephemerides from continuous sets of timing measurements

    Science.gov (United States)

    Deeg, H. J.

    2015-06-01

    Space missions such as Kepler and CoRoT have led to large numbers of eclipse or transit measurements in nearly continuous time series. This paper shows how to obtain the period error in such measurements from a basic linear least-squares fit, and how to correctly derive the timing error in the prediction of future transit or eclipse events. Assuming strict periodicity, a formula for the period error of these time series is derived, σP = σT (12 / (N3-N))1 / 2, where σP is the period error, σT the timing error of a single measurement, and N the number of measurements. Compared to the iterative method for period error estimation by Mighell & Plavchan (2013), this much simpler formula leads to smaller period errors, whose correctness has been verified through simulations. For the prediction of times of future periodic events, usual linear ephemeris were epoch errors are quoted for the first time measurement, are prone to an overestimation of the error of that prediction. This may be avoided by a correction for the duration of the time series. An alternative is the derivation of ephemerides whose reference epoch and epoch error are given for the centre of the time series. For long continuous or near-continuous time series whose acquisition is completed, such central epochs should be the preferred way for the quotation of linear ephemerides. While this work was motivated from the analysis of eclipse timing measures in space-based light curves, it should be applicable to any other problem with an uninterrupted sequence of discrete timings for which the determination of a zero point, of a constant period and of the associated errors is needed.

  16. Investigation of potential factors affecting the measurement of dew point temperature in oil-soaked transformers

    Science.gov (United States)

    Kraus, Adam H.

    Moisture within a transformer's insulation system has been proven to degrade its dielectric strength. When installing a transformer in situ, one method used to calculate the moisture content of the transformer insulation is to measure the dew point temperature of the internal gas volume of the transformer tank. There are two instruments commercially available that are designed for dew point temperature measurement: the Alnor Model 7000 Dewpointer and the Vaisala DRYCAPRTM Hand-Held Dewpoint Meter DM70. Although these instruments perform an identical task, the design technology behind each instrument is vastly different. When the Alnor Dewpointer and Vaisala DM70 instruments are used to measure the dew point of the internal gas volume simultaneously from a pressurized transformer, their differences in dew point measurement have been observed to vary as much as 30 °F. There is minimal scientific research available that focuses on the process of measuring dew point of a gas inside a pressurized transformer, let alone this observed phenomenon. The primary objective of this work was to determine what effect certain factors potentially have on dew point measurements of a transformer's internal gas volume, in hopes of understanding the root cause of this phenomenon. Three factors that were studied include (1) human error, (2) the use of calibrated and out-of-calibration instruments, and (3) the presence of oil vapor gases in the dry air sample, and their subsequent effects on the Q-value of the sampled gas. After completing this portion of testing, none of the selected variables proved to be a direct cause of the observed discrepancies between the two instruments. The secondary objective was to validate the accuracy of each instrument as compared to its respective published range by testing against a known dew point temperature produced by a humidity generator. In a select operating range of -22 °F to -4 °F, both instruments were found to be accurate and within their

  17. MLAOS: A Multi-Point Linear Array of Optical Sensors for Coniferous Foliage Clumping Index Measurement

    Directory of Open Access Journals (Sweden)

    Yonghua Qu

    2014-05-01

    Full Text Available The canopy foliage clumping effect is primarily caused by the non-random distribution of canopy foliage. Currently, measurements of clumping index (CI by handheld instruments is typically time- and labor-intensive. We propose a low-cost and low-power automatic measurement system called Multi-point Linear Array of Optical Sensors (MLAOS, which consists of three above-canopy and nine below-canopy optical sensors that capture plant transmittance at different times of the day. Data communication between the MLAOS node is facilitated by using a ZigBee network, and the data are transmitted from the field MLAOS to a remote data server using the Internet. The choice of the electronic element and design of the MLAOS software is aimed at reducing costs and power consumption. A power consumption test showed that, when a 4000 mAH Li-ion battery is used, a maximum of 8–10 months of work can be achieved. A field experiment on a coniferous forest revealed that the CI of MLAOS may reveal a clumping effect that occurs within the canopy. In further work, measurement of the multi-scale clumping effect can be achieved by utilizing a greater number of MLAOS devices to capture the heterogeneity of the plant canopy.

  18. Usefulness of measurement of circulation time using MgSO4 : correlation with time-density curve using electron beam computed tomography

    International Nuclear Information System (INIS)

    Kim, Byung Ki; Lee, Hui Joong; Lee, Jong Min; Kim, Yong Joo; Kang, Duck Sik

    1999-01-01

    To determine the usefulness of MgSO 4 for measuring the systemic circulation time. Systemic circulation time, defined as elapsed time from the injection of MgSO 4 solution to the point of pharyngeal burning sensation, was measured in 63 volunteers. MgSO 4 was injected into a superficial vein of an upper extremity. Using dynamic electron beam computed tomography at the level of the abdominal aorta and celiac axis, a time-intensity curve was plotted, and for these two locations, maximal enhancement time was compared. For 60 of the 63 subjects, both systemic circulation time and maximal enhancement time were determined. Average systemic circulation time was 17.4 (SD:3.6) secs. and average maximal enhancement times at the level of the abdominal aorta and celiac axis were 17.5 (SD:3.0) secs. and 18.5 (SD:3.2) secs., respectively. Correlation coefficients between systemic circulation time and maximal enhancement time for the abdominal aorta and celiac axis were 0.73 (p 4 injection and maximal enhancement time for the abdominal aorta showed significant correlation. Thus, to determine the appropriate scanning time in contrast-enhanced radiological studies, MgSO 4 can be used instead of a test bolus study

  19. Current algebras, measures quasi-invariant under diffeomorphism groups, and infinite quantum systems with accumulation points

    Science.gov (United States)

    Sakuraba, Takao

    The approach to quantum physics via current algebra and unitary representations of the diffeomorphism group is established. This thesis studies possible infinite Bose gas systems using this approach. Systems of locally finite configurations and systems of configurations with accumulation points are considered, with the main emphasis on the latter. In Chapter 2, canonical quantization, quantization via current algebra and unitary representations of the diffeomorphism group are reviewed. In Chapter 3, a new definition of the space of configurations is proposed and an axiom for general configuration spaces is abstracted. Various subsets of the configuration space, including those specifying the number of points in a Borel set and those specifying the number of accumulation points in a Borel set are proved to be measurable using this axiom. In Chapter 4, known results on the space of locally finite configurations and Poisson measure are reviewed in the light of the approach developed in Chapter 3, including the approach to current algebra in the Poisson space by Albeverio, Kondratiev, and Rockner. Goldin and Moschella considered unitary representations of the group of diffeomorphisms of the line based on self-similar random processes, which may describe infinite quantum gas systems with clusters. In Chapter 5, the Goldin-Moschella theory is developed further. Their construction of measures quasi-invariant under diffeomorphisms is reviewed, and a rigorous proof of their conjectures is given. It is proved that their measures with distinct correlation parameters are mutually singular. A quasi-invariant measure constructed by Ismagilov on the space of configurations with accumulation points on the circle is proved to be singular with respect to the Goldin-Moschella measures. Finally a generalization of the Goldin-Moschella measures to the higher-dimensional case is studied, where the notion of covariance matrix and the notion of condition number play important roles. A

  20. Continuous Real-time Measurements of Vertical Distribution of Magnetic Susceptibility In Soils

    Science.gov (United States)

    Petrovsky, E.; Hulka, Z.; Kapicka, A.; Magprox Team

    Measurements of top-soil magnetic susceptibility are used in approximative outlining polluted areas. However, one of the serious limitations of the method is discrimina- tion between top-soil layers enhanced by atmospherically deposited anthropogenic particles from those dominated by natural particles migrating from magnetically-rich basement rocks. For this purpose, measurements of vertical distribution of magnetic susceptibility along soil profiles is one of the most effective ways in estimating the effect of lithogenic contribution. Up to now, in most cases soil cores have to be mea- sured in laboratory. This method is quite time consuming and does not allow flexible decision about the suitability of the measured site for surface magnetic mapping. In our contribution we will present a new device enabling continuous real-time measure- ments of vertical distribution of magnetic susceptibility directly in field, performed in holes after soil coring. The method is fast, yielding smooth curves (6 data points per 1 mm dept), at least as sensitive as laboratory methods available until now, and at- tached notebook enables direct, on-line control of the lithogenic versus anthropogenic contributions.

  1. High Response Dew Point Measurement System for a Supersonic Wind Tunnel

    Science.gov (United States)

    Blumenthal, Philip Z.

    1996-01-01

    A new high response on-line measurement system has been developed to continuously display and record the air stream dew point in the NASA Lewis 10 x 10 supersonic wind tunnel. Previous instruments suffered from such problems as very slow response, erratic readings, and high susceptibility to contamination. The system operates over the entire pressure level range of the 10 x 10 SWT, from less than 2 psia to 45 psia, without the need for a vacuum pump to provide sample flow. The system speeds up tunnel testing, provides large savings in tunnel power costs and provides the dew point input for the data-reduction subroutines which calculate test section conditions.

  2. A solution for measuring accurate reaction time to visual stimuli realized with a programmable microcontroller.

    Science.gov (United States)

    Ohyanagi, Toshio; Sengoku, Yasuhito

    2010-02-01

    This article presents a new solution for measuring accurate reaction time (SMART) to visual stimuli. The SMART is a USB device realized with a Cypress Programmable System-on-Chip (PSoC) mixed-signal array programmable microcontroller. A brief overview of the hardware and firmware of the PSoC is provided, together with the results of three experiments. In Experiment 1, we investigated the timing accuracy of the SMART in measuring reaction time (RT) under different conditions of operating systems (OSs; Windows XP or Vista) and monitor displays (a CRT or an LCD). The results indicated that the timing error in measuring RT by the SMART was less than 2 msec, on average, under all combinations of OS and display and that the SMART was tolerant to jitter and noise. In Experiment 2, we tested the SMART with 8 participants. The results indicated that there was no significant difference among RTs obtained with the SMART under the different conditions of OS and display. In Experiment 3, we used Microsoft (MS) PowerPoint to present visual stimuli on the display. We found no significant difference in RTs obtained using MS DirectX technology versus using the PowerPoint file with the SMART. We are certain that the SMART is a simple and practical solution for measuring RTs accurately. Although there are some restrictions in using the SMART with RT paradigms, the SMART is capable of providing both researchers and health professionals working in clinical settings with new ways of using RT paradigms in their work.

  3. A complementary metal-oxide-semiconductor compatible monocantilever 12-point probe for conductivity measurements on the nanoscale

    DEFF Research Database (Denmark)

    Gammelgaard, Lauge; Bøggild, Peter; Wells, J.W.

    2008-01-01

    and a probe pitch of 500 nm. In-air four-point measurements have been performed on indium tin oxide, ruthenium, and titanium-tungsten, showing good agreement with values obtained by other four-point probes. In-vacuum four-point resistance measurements have been performed on clean Bi(111) using different probe...... spacings. The results show the expected behavior for bulk Bi, indicating that the contribution of electronic surface states to the transport properties is very small. (C) 2008 American Institute of Physics....

  4. Technical aspects of acid dew point measurement in furnace exhaust. Messtechnik fuer die Saeuretaupunktmessung in Feuerungsabgasen

    Energy Technology Data Exchange (ETDEWEB)

    Struschka, M.; Baumbach, G.

    1986-01-01

    SO/sub 3/ formation in flue gases and the effect of furnace parameters, furnace type and design on the efficiency of SO/sub 2/ conversion were investigated in a detailed bibliographic study. Phase equilibrium data for the binary system H/sub 2/SO/sub 4//H/sub 2/O and equations for calculating the acid dew point are presented, and the available wet chemical methods for SO/sub 3/ concentration measurements in flue gases are reviewed. The SM1 acid dew point measuring instrument availabe at the authors' institute was modified by installing a new measuring probe, an external thermoelement intensifier, and a new PD control element for temperature control in the measuring surfaces. Acid dew point measurements were carried out in two different furnaces, i.e. a domestic boiler for light fuel oil and an industrial furnace fuelled with heavy oil at the Stuttgart University heat- and power plant. The measurements are compared with data from relevant publications. (orig./RB) With 80 figs., 7 tabs.

  5. Flow speed measurement using two-point collective light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Heinemeier, N.P

    1998-09-01

    Measurements of turbulence in plasmas and fluids using the technique of collective light scattering have always been plagued by very poor spatial resolution. In 1994, a novel two-point collective light scattering system for the measurement of transport in a fusion plasma was proposed. This diagnostic method was design for a great improvement of the spatial resolution, without sacrificing accuracy in the velocity measurement. The system was installed at the W7-AS steallartor in Garching, Germany, in 1996, and has been operating since. This master thesis is an investigation of the possible application of this new method to the measurement of flow speeds in normal fluids, in particular air, although the results presented in this work have significance for the plasma measurements as well. The main goal of the project was the experimental verification of previous theoretical predictions. However, the theoretical considerations presented in the thesis show that the method can only be hoped to work for flows that are almost laminar and shearless, which makes it of very small practical interest. Furthermore, this result also implies that the diagnostic at W7-AS cannot be expected to give the results originally hoped for. (au) 1 tab., 51 ills., 29 refs.

  6. REAL-TIME STABILITY AND PROFILE COMPARISON MEASUREMENTS BETWEEN TWO DIFFERENT LTPS

    International Nuclear Information System (INIS)

    2005-01-01

    The Long Trace Profiler (LTP) is a precise angle measurement instrument, with a sensitivity and accuracy that can be in the sub-micron radian range. LTP characteristics depend on the particular LTP system schematic design, and the quality of components and assembly. The conditions of temperature, alignment, and mirror support during the measurement process vary between different laboratories, which influences significantly the test repeatability and accuracy. In this paper we introduce a direct comparison method to test the same object at the same point in the same environment at the same time by using two LTPs, which significantly increases the reliability of the comparison. A compact, portable LTP (PTLTP), which can be carried to different laboratories around the world, is used for comparison testing. Stability Comparison experiments between the LTP II at the National Synchrotron Radiation Research Center (NSRRC), and the PTLTP of Brookhaven National Laboratory (BNL) reveal significant differences in performance between the instruments. The experiment is set up so that each optical head simultaneously records both its own sample probe beam and also the probe beam from the other optical head. The two probe beams are reflected from same point on the mirror. Tests show that the stability of the PTLTP with a monolithic beam splitter is 10 times better than the stability of the LTP II which has a separated beam splitter unit. A scheme for comparing scanning measurements of a mirror is introduced. Experimental results show a significant difference between the two LTPs due mainly to distortions in the optical components inside the optical head. A new scheme is proposed for further mirror comparison scanning tests

  7. Real-time measurement of dynamic structure for Pd-D system in heavy-water electrolysis cell

    International Nuclear Information System (INIS)

    Wang Jun; Zeng Xianxin; Yang Jilian; Zhang Baisheng; Ruan Jinghui

    1993-01-01

    The real-time dynamic structure of Pd-D system in D 2 O electrolysis cell is measured on neutron powder diffractometer in CIAE. Diffraction patterns in 2 θ range of 34 degree-95 degree are obtained under the conditions of electrolysing for 0, 3 and 48 A ·h respectively, and the gradual transition of Pd-D system from α-phase to β-phase is observed. The real-time measurements of β peak of (220) reflection show that intensity of β peak almost reaches the saturation point after electrolysing for 0.65 A · h and increases slowly with further electrolysis afterwards

  8. A point implicit time integration technique for slow transient flow problems

    Energy Technology Data Exchange (ETDEWEB)

    Kadioglu, Samet Y., E-mail: kadioglu@yildiz.edu.tr [Department of Mathematical Engineering, Yildiz Technical University, 34210 Davutpasa-Esenler, Istanbul (Turkey); Berry, Ray A., E-mail: ray.berry@inl.gov [Idaho National Laboratory, P.O. Box 1625, MS 3840, Idaho Falls, ID 83415 (United States); Martineau, Richard C. [Idaho National Laboratory, P.O. Box 1625, MS 3840, Idaho Falls, ID 83415 (United States)

    2015-05-15

    Highlights: • This new method does not require implicit iteration; instead it time advances the solutions in a similar spirit to explicit methods. • It is unconditionally stable, as a fully implicit method would be. • It exhibits the simplicity of implementation of an explicit method. • It is specifically designed for slow transient flow problems of long duration such as can occur inside nuclear reactor coolant systems. • Our findings indicate the new method can integrate slow transient problems very efficiently; and its implementation is very robust. - Abstract: We introduce a point implicit time integration technique for slow transient flow problems. The method treats the solution variables of interest (that can be located at cell centers, cell edges, or cell nodes) implicitly and the rest of the information related to same or other variables are handled explicitly. The method does not require implicit iteration; instead it time advances the solutions in a similar spirit to explicit methods, except it involves a few additional function(s) evaluation steps. Moreover, the method is unconditionally stable, as a fully implicit method would be. This new approach exhibits the simplicity of implementation of explicit methods and the stability of implicit methods. It is specifically designed for slow transient flow problems of long duration wherein one would like to perform time integrations with very large time steps. Because the method can be time inaccurate for fast transient problems, particularly with larger time steps, an appropriate solution strategy for a problem that evolves from a fast to a slow transient would be to integrate the fast transient with an explicit or semi-implicit technique and then switch to this point implicit method as soon as the time variation slows sufficiently. We have solved several test problems that result from scalar or systems of flow equations. Our findings indicate the new method can integrate slow transient problems very

  9. A point implicit time integration technique for slow transient flow problems

    International Nuclear Information System (INIS)

    Kadioglu, Samet Y.; Berry, Ray A.; Martineau, Richard C.

    2015-01-01

    Highlights: • This new method does not require implicit iteration; instead it time advances the solutions in a similar spirit to explicit methods. • It is unconditionally stable, as a fully implicit method would be. • It exhibits the simplicity of implementation of an explicit method. • It is specifically designed for slow transient flow problems of long duration such as can occur inside nuclear reactor coolant systems. • Our findings indicate the new method can integrate slow transient problems very efficiently; and its implementation is very robust. - Abstract: We introduce a point implicit time integration technique for slow transient flow problems. The method treats the solution variables of interest (that can be located at cell centers, cell edges, or cell nodes) implicitly and the rest of the information related to same or other variables are handled explicitly. The method does not require implicit iteration; instead it time advances the solutions in a similar spirit to explicit methods, except it involves a few additional function(s) evaluation steps. Moreover, the method is unconditionally stable, as a fully implicit method would be. This new approach exhibits the simplicity of implementation of explicit methods and the stability of implicit methods. It is specifically designed for slow transient flow problems of long duration wherein one would like to perform time integrations with very large time steps. Because the method can be time inaccurate for fast transient problems, particularly with larger time steps, an appropriate solution strategy for a problem that evolves from a fast to a slow transient would be to integrate the fast transient with an explicit or semi-implicit technique and then switch to this point implicit method as soon as the time variation slows sufficiently. We have solved several test problems that result from scalar or systems of flow equations. Our findings indicate the new method can integrate slow transient problems very

  10. Monitoring hillslope moisture dynamics with surface ERT for enhancing spatial significance of hydrometric point measurements

    Science.gov (United States)

    Hübner, R.; Heller, K.; Günther, T.; Kleber, A.

    2015-01-01

    Besides floodplains, hillslopes are basic units that mainly control water movement and flow pathways within catchments of subdued mountain ranges. The structure of their shallow subsurface affects water balance, e.g. infiltration, retention, and runoff. Nevertheless, there is still a gap in the knowledge of the hydrological dynamics on hillslopes, notably due to the lack of generalization and transferability. This study presents a robust multi-method framework of electrical resistivity tomography (ERT) in addition to hydrometric point measurements, transferring hydrometric data into higher spatial scales to obtain additional patterns of distribution and dynamics of soil moisture on a hillslope. A geoelectrical monitoring in a small catchment in the eastern Ore Mountains was carried out at weekly intervals from May to December 2008 to image seasonal moisture dynamics on the hillslope scale. To link water content and electrical resistivity, the parameters of Archie's law were determined using different core samples. To optimize inversion parameters and methods, the derived spatial and temporal water content distribution was compared to tensiometer data. The results from ERT measurements show a strong correlation with the hydrometric data. The response is congruent to the soil tension data. Water content calculated from the ERT profile shows similar variations as that of water content from soil moisture sensors. Consequently, soil moisture dynamics on the hillslope scale may be determined not only by expensive invasive punctual hydrometric measurements, but also by minimally invasive time-lapse ERT, provided that pedo-/petrophysical relationships are known. Since ERT integrates larger spatial scales, a combination with hydrometric point measurements improves the understanding of the ongoing hydrological processes and better suits identification of heterogeneities.

  11. Continuous acid dew point measurement in coal-fired power plants; Kontinuierliche Saeuretaupunktmessung in Braunkohlekraftwerken

    Energy Technology Data Exchange (ETDEWEB)

    Foedisch, Holger; Schulz, Joerg; Schengber, Petra; Dietrich, Gabriele [Dr. Foedisch Umweltmesstechnik AG, Markranstaedt (Germany)

    2009-07-01

    The reduction of flue gas losses is one option to increase power plant efficiency. The target is the optimised low waste gas temperature. When applying lignite and other high-sulphur fuels the temperature of the flue gas is mainly determined by the acid dew point. Temperature of the flue gas system is to amount some 10 to 20 K above the assumed acid dew point. The acid dew point measuring system AMD 08 is able to detect the real acid dew point in a quasi-continuous way. Thus, it is possible to deliberately decrease waste gas temperature. (orig.)

  12. New Bounds of Ostrowski–Gruss Type Inequality for (k + 1 Points on Time Scales

    Directory of Open Access Journals (Sweden)

    Eze R. Nwaeze

    2017-11-01

    Full Text Available The aim of this paper is to present three new bounds of the Ostrowski--Gr\\"uss type inequality for points $x_0,x_1,x_2,\\cdots,x_k$ on time scales. Our results generalize result of Ng\\^o and Liu, and extend results of Ujevi\\'c to time scales with $(k+1$ points. We apply our results to the continuous, discrete, and quantum calculus to obtain many new interesting inequalities. An example is also considered. The estimates obtained in this paper will be very useful in numerical integration especially for the continuous case.

  13. A robust real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenyang [Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); Cheung, Yam [Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas 75390 (United States); Sawant, Amit [Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas, 75390 and Department of Radiation Oncology, University of Maryland, College Park, Maryland 20742 (United States); Ruan, Dan, E-mail: druan@mednet.ucla.edu [Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095 and Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, California 90095 (United States)

    2016-05-15

    Purpose: To develop a robust and real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system. Methods: The authors have developed a robust and fast surface reconstruction method on point clouds acquired by the photogrammetry system, without explicitly solving the partial differential equation required by a typical variational approach. Taking advantage of the overcomplete nature of the acquired point clouds, their method solves and propagates a sparse linear relationship from the point cloud manifold to the surface manifold, assuming both manifolds share similar local geometry. With relatively consistent point cloud acquisitions, the authors propose a sparse regression (SR) model to directly approximate the target point cloud as a sparse linear combination from the training set, assuming that the point correspondences built by the iterative closest point (ICP) is reasonably accurate and have residual errors following a Gaussian distribution. To accommodate changing noise levels and/or presence of inconsistent occlusions during the acquisition, the authors further propose a modified sparse regression (MSR) model to model the potentially large and sparse error built by ICP with a Laplacian prior. The authors evaluated the proposed method on both clinical point clouds acquired under consistent acquisition conditions and on point clouds with inconsistent occlusions. The authors quantitatively evaluated the reconstruction performance with respect to root-mean-squared-error, by comparing its reconstruction results against that from the variational method. Results: On clinical point clouds, both the SR and MSR models have achieved sub-millimeter reconstruction accuracy and reduced the reconstruction time by two orders of magnitude to a subsecond reconstruction time. On point clouds with inconsistent occlusions, the MSR model has demonstrated its advantage in achieving consistent and robust performance despite the introduced

  14. A robust real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system.

    Science.gov (United States)

    Liu, Wenyang; Cheung, Yam; Sawant, Amit; Ruan, Dan

    2016-05-01

    To develop a robust and real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system. The authors have developed a robust and fast surface reconstruction method on point clouds acquired by the photogrammetry system, without explicitly solving the partial differential equation required by a typical variational approach. Taking advantage of the overcomplete nature of the acquired point clouds, their method solves and propagates a sparse linear relationship from the point cloud manifold to the surface manifold, assuming both manifolds share similar local geometry. With relatively consistent point cloud acquisitions, the authors propose a sparse regression (SR) model to directly approximate the target point cloud as a sparse linear combination from the training set, assuming that the point correspondences built by the iterative closest point (ICP) is reasonably accurate and have residual errors following a Gaussian distribution. To accommodate changing noise levels and/or presence of inconsistent occlusions during the acquisition, the authors further propose a modified sparse regression (MSR) model to model the potentially large and sparse error built by ICP with a Laplacian prior. The authors evaluated the proposed method on both clinical point clouds acquired under consistent acquisition conditions and on point clouds with inconsistent occlusions. The authors quantitatively evaluated the reconstruction performance with respect to root-mean-squared-error, by comparing its reconstruction results against that from the variational method. On clinical point clouds, both the SR and MSR models have achieved sub-millimeter reconstruction accuracy and reduced the reconstruction time by two orders of magnitude to a subsecond reconstruction time. On point clouds with inconsistent occlusions, the MSR model has demonstrated its advantage in achieving consistent and robust performance despite the introduced occlusions. The authors have

  15. A robust real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system

    International Nuclear Information System (INIS)

    Liu, Wenyang; Cheung, Yam; Sawant, Amit; Ruan, Dan

    2016-01-01

    Purpose: To develop a robust and real-time surface reconstruction method on point clouds captured from a 3D surface photogrammetry system. Methods: The authors have developed a robust and fast surface reconstruction method on point clouds acquired by the photogrammetry system, without explicitly solving the partial differential equation required by a typical variational approach. Taking advantage of the overcomplete nature of the acquired point clouds, their method solves and propagates a sparse linear relationship from the point cloud manifold to the surface manifold, assuming both manifolds share similar local geometry. With relatively consistent point cloud acquisitions, the authors propose a sparse regression (SR) model to directly approximate the target point cloud as a sparse linear combination from the training set, assuming that the point correspondences built by the iterative closest point (ICP) is reasonably accurate and have residual errors following a Gaussian distribution. To accommodate changing noise levels and/or presence of inconsistent occlusions during the acquisition, the authors further propose a modified sparse regression (MSR) model to model the potentially large and sparse error built by ICP with a Laplacian prior. The authors evaluated the proposed method on both clinical point clouds acquired under consistent acquisition conditions and on point clouds with inconsistent occlusions. The authors quantitatively evaluated the reconstruction performance with respect to root-mean-squared-error, by comparing its reconstruction results against that from the variational method. Results: On clinical point clouds, both the SR and MSR models have achieved sub-millimeter reconstruction accuracy and reduced the reconstruction time by two orders of magnitude to a subsecond reconstruction time. On point clouds with inconsistent occlusions, the MSR model has demonstrated its advantage in achieving consistent and robust performance despite the introduced

  16. The software design of multi-branch, multi-point remote monitoring system for temperature measurement based on MSP430 and DS18B20

    International Nuclear Information System (INIS)

    Yu Jun; Yan Yu

    2009-01-01

    This paper present that the system can acquire the remote temperature measurement data of 40 monitoring points, through the RS-232 serial port and the Intranet. System's hardware is consist of TI's MSP430F149 mixed-signal processor and UA7000A network module. Using digital temperature sensor DS18B20, the structure is simple and easy to expand, the sensors directly send out the temperature data, MSP430F149 has the advantage of ultra-low-power and high degree of integration. Using msp430F149, the multi-branch multi-point temperature measurement system is powerful, simple structure, high reliability, strong anti-interference capability. The client software is user-friendly and easy to use, it is designed in Microsoft Visual C+ +6.0 environment. The monitoring system is able to complete a total of 4 branches of the 40-point temperature measurements in real-time remote monitoring. (authors)

  17. Contactless measurement of muscles fatigue by tracking facial feature points in a video

    DEFF Research Database (Denmark)

    Irani, Ramin; Nasrollahi, Kamal; Moeslund, Thomas B.

    2014-01-01

    their exercises when the level of the fatigue might be dangerous for the patients. The current technology for measuring tiredness, like Electromyography (EMG), requires installing some sensors on the body. In some applications, like remote patient monitoring, this however might not be possible. To deal...... with such cases, in this paper we present a contactless method based on computer vision techniques to measure tiredness by detecting, tracking, and analyzing some facial feature points during the exercise. Experimental results on several test subjects and comparing them against ground truth data show...... that the proposed system can properly find the temporal point of tiredness of the muscles when the test subjects are doing physical exercises....

  18. Measuring device for control rod driving time

    International Nuclear Information System (INIS)

    Tanaka, Kazuhiko; Hanabusa, Masatoshi.

    1993-01-01

    The present invention concerns a measuring device for control driving time having a function capable of measuring a selected control rod driving time and measuring an entire control rod driving time simultaneously. A calculation means and a store means for the selected rod control rod driving time, and a calculation means and a store means for the entire control rod driving time are disposed individually. Each of them measures the driving time and stores the data independent of each other based on a selected control rod insert ion signal and an entire control rod insertion signal. Even if insertion of selected and entire control rods overlaps, each of the control rod driving times can be measured reliably to provide an advantageous effect capable of more accurately conducting safety evaluation for the nuclear reactor based on the result of the measurement. (N.H.)

  19. Textural features and SUV-based variables assessed by dual time point 18F-FDG PET/CT in locally advanced breast cancer.

    Science.gov (United States)

    Garcia-Vicente, Ana María; Molina, David; Pérez-Beteta, Julián; Amo-Salas, Mariano; Martínez-González, Alicia; Bueno, Gloria; Tello-Galán, María Jesús; Soriano-Castrejón, Ángel

    2017-12-01

    To study the influence of dual time point 18F-FDG PET/CT in textural features and SUV-based variables and their relation among them. Fifty-six patients with locally advanced breast cancer (LABC) were prospectively included. All of them underwent a standard 18F-FDG PET/CT (PET-1) and a delayed acquisition (PET-2). After segmentation, SUV variables (SUVmax, SUVmean, and SUVpeak), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were obtained. Eighteen three-dimensional (3D) textural measures were computed including: run-length matrices (RLM) features, co-occurrence matrices (CM) features, and energies. Differences between all PET-derived variables obtained in PET-1 and PET-2 were studied. Significant differences were found between the SUV-based parameters and MTV obtained in the dual time point PET/CT, with higher values of SUV-based variables and lower MTV in the PET-2 with respect to the PET-1. In relation with the textural parameters obtained in dual time point acquisition, significant differences were found for the short run emphasis, low gray-level run emphasis, short run high gray-level emphasis, run percentage, long run emphasis, gray-level non-uniformity, homogeneity, and dissimilarity. Textural variables showed relations with MTV and TLG. Significant differences of textural features were found in dual time point 18F-FDG PET/CT. Thus, a dynamic behavior of metabolic characteristics should be expected, with higher heterogeneity in delayed PET acquisition compared with the standard PET. A greater heterogeneity was found in bigger tumors.

  20. Just-In-Time Inventory: Proceed with caution exclamation point

    International Nuclear Information System (INIS)

    Katterhenry, W.E.

    1995-01-01

    Today's economic climate, the emerging of independent power producers, pending deregulation, and environmental restraints are forcing the utility industry to adopt cost cutting measures in an effort to be more competitive and survive in tomorrow's market place. The cost cutting measure addressed in this paper is ''Just-In-Time Inventory'' of coal for fossil fueled power plants

  1. EBT time-dependent point model code: description and user's guide

    International Nuclear Information System (INIS)

    Roberts, J.F.; Uckan, N.A.

    1977-07-01

    A D-T time-dependent point model has been developed to assess the energy balance in an EBT reactor plasma. Flexibility is retained in the model to permit more recent data to be incorporated as they become available from the theoretical and experimental studies. This report includes the physics models involved, the program logic, and a description of the variables and routines used. All the files necessary for execution are listed, and the code, including a post-execution plotting routine, is discussed

  2. Surface electronic transport measurements: A micro multi-point probe approach

    DEFF Research Database (Denmark)

    Barreto, Lucas

    2014-01-01

    This work is mostly focused on the study of electronic transport properties of two-dimensional materials, in particular graphene and topological insulators. To study these, we have improved a unique micro multi-point probe instrument used to perform transport measurements. Not only the experimental...... quantities are extracted, such as conductivity, carrier density and carrier mobility. • A method to insulate electrically epitaxial graphene grown on metals, based on a stepwise intercalation methodology, is developed and transport measurements are performed in order to test the insulation. • We show...... a direct measurement of the surface electronic transport on a bulk topological insulator. The surface state conductivity and mobility are obtained. Apart from transport properties, we also investigate the atomic structure of the Bi2Se3(111) surface via surface x-ray diraction and low-energy electron...

  3. Simultaneous comparisons of treatments at multiple time points

    DEFF Research Database (Denmark)

    Pallmann, Philip; Pretorius, Mias; Ritz, Christian

    2017-01-01

    that is measured repeatedly over time and contrast two basic modeling strategies: fitting a joint model across all occasions (with random effects and/or some residual covariance structure to account for heteroscedasticity and serial dependence), and a novel approach combining a set of simple marginal, i...

  4. Studying the potential of point detectors in time-resolved dose verification of dynamic radiotherapy

    International Nuclear Information System (INIS)

    Beierholm, A.R.; Behrens, C.F.; Andersen, C.E.

    2015-01-01

    Modern megavoltage x-ray radiotherapy with high spatial and temporal dose gradients puts high demands on the entire delivery system, including not just the linear accelerator and the multi-leaf collimator, but also algorithms used for optimization and dose calculations, and detectors used for quality assurance and dose verification. In this context, traceable in-phantom dosimetry using a well-characterized point detector is often an important supplement to 2D-based quality assurance methods based on radiochromic film or detector arrays. In this study, an in-house developed dosimetry system based on fiber-coupled plastic scintillator detectors was evaluated and compared with a Farmer-type ionization chamber and a small-volume ionization chamber. An important feature of scintillator detectors is that the sensitive volume of the detector can easily be scaled, and five scintillator detectors of different scintillator length were thus employed to quantify volume averaging effects by direct measurement. The dosimetric evaluation comprised several complex-shape static fields as well as simplified dynamic deliveries using RapidArc, a volumetric-modulated arc therapy modality often used at the participating clinic. The static field experiments showed that the smallest scintillator detectors were in the best agreement with dose calculations, while needing the smallest volume averaging corrections. Concerning total dose measured during RapidArc, all detectors agreed with dose calculations within 1.1 ± 0.7% when positioned in regions of high homogenous dose. Larger differences were observed for high dose gradient and organ at risk locations, were differences between measured and calculated dose were as large as 8.0 ± 5.5%. The smallest differences were generally seen for the small-volume ionization chamber and the smallest scintillators. The time-resolved RapidArc dose profiles revealed volume-dependent discrepancies between scintillator and ionization chamber response

  5. Accuracy and optimal timing of activity measurements in estimating the absorbed dose of radioiodine in the treatment of Graves' disease

    Science.gov (United States)

    Merrill, S.; Horowitz, J.; Traino, A. C.; Chipkin, S. R.; Hollot, C. V.; Chait, Y.

    2011-02-01

    Calculation of the therapeutic activity of radioiodine 131I for individualized dosimetry in the treatment of Graves' disease requires an accurate estimate of the thyroid absorbed radiation dose based on a tracer activity administration of 131I. Common approaches (Marinelli-Quimby formula, MIRD algorithm) use, respectively, the effective half-life of radioiodine in the thyroid and the time-integrated activity. Many physicians perform one, two, or at most three tracer dose activity measurements at various times and calculate the required therapeutic activity by ad hoc methods. In this paper, we study the accuracy of estimates of four 'target variables': time-integrated activity coefficient, time of maximum activity, maximum activity, and effective half-life in the gland. Clinical data from 41 patients who underwent 131I therapy for Graves' disease at the University Hospital in Pisa, Italy, are used for analysis. The radioiodine kinetics are described using a nonlinear mixed-effects model. The distributions of the target variables in the patient population are characterized. Using minimum root mean squared error as the criterion, optimal 1-, 2-, and 3-point sampling schedules are determined for estimation of the target variables, and probabilistic bounds are given for the errors under the optimal times. An algorithm is developed for computing the optimal 1-, 2-, and 3-point sampling schedules for the target variables. This algorithm is implemented in a freely available software tool. Taking into consideration 131I effective half-life in the thyroid and measurement noise, the optimal 1-point time for time-integrated activity coefficient is a measurement 1 week following the tracer dose. Additional measurements give only a slight improvement in accuracy.

  6. Analytical expressions for correction factors for noise measurements with a four-point probe

    NARCIS (Netherlands)

    Vandamme, L.K.J.; Leroy, G.

    2006-01-01

    The linear four-point probe method is useful to measure the resistivity, by passing a current I14 through the outer probes and by measuring the voltage V23 between the inner probes. The contacts are on a line and denoted by 1, 2, 3, 4, respectively. The sheet resistance for thin layers with

  7. Program to make remote time measurement on the new precise clock system on totem

    CERN Document Server

    Martin, David

    2016-01-01

    For my project at CERN, I worked in the TOTEM team with Michele Quinto and Francesco Cafagna as supervisors. Their team is currently working on an update on TOTEM that includes a module able to measure precisely the time of flight of particles emitted from the collision at CMS. With this additional data, TOTEM will be able to reconstruct precisely the point of the collision in CMS. The main problem posed for this new module is to provide a precise synchronized clock signal to both the TOTEM detectors situated 200 meters after and before CMS. In fact, due to some external parameters, as temperature, the length of the optical fiber guiding the clock signal can vary yielding thus a unwanted phase difference of the clock between the two detectors. The idea is to get rid of the noisy phase difference to make very precise time of flight measurement of the order of the picosecond. This is achieved by continuously measuring the phase difference and correcting the time measurements according to the current phase diffe...

  8. Automated and continuously operating acid dew point measuring instrument for flue gases

    Energy Technology Data Exchange (ETDEWEB)

    Reckmann, D.; Naundorf, G.

    1986-06-01

    Design and operation is explained for a sulfuric acid dew point indicator for continuous flue gas temperature control. The indicator operated successfully in trial tests over several years with brown coal, gas and oil combustion in a measurement range of 60 to 180 C. The design is regarded as uncomplicated and easy to manufacture. Its operating principle is based on electric conductivity measurement on a surface on which sulfuric acid vapor has condensed. A ring electrode and a PtRh/Pt thermal element as central electrode are employed. A scheme of the equipment design is provided. Accuracy of the indicator was compared to manual dew point sondes manufactured by Degussa and showed a maximum deviation of 5 C. Manual cleaning after a number of weeks of operation is required. Fly ash with a high lime content increases dust buildup and requires more frequent cleaning cycles.

  9. Time measurement - technical importance of most exact clocks

    International Nuclear Information System (INIS)

    Goebel, E.O.; Riehle, F.

    2004-01-01

    The exactness of the best atomic clocks currently shows a temporal variation of 1 second in 30 million years. This means that we have reached the point of the most exact frequency and time measurement ever. In the past, there was a trend towards increasing the exactness in an increasingly fast sequence. Will this trend continue? And who will profit from it? This article is meant to give answers to these questions. This is done by presenting first the level reached currently with the best atomic clocks and describing the research activities running worldwide with the aim of achieving even more exact clocks. In the second part, we present examples of various areas of technical subjects and research in which the most exact clocks are being applied presently and even more exact ones will be needed in the future [de

  10. Fast and direct measurements of the electrical properties of graphene using micro four-point probes

    International Nuclear Information System (INIS)

    Klarskov, M B; Dam, H F; Petersen, D H; Hansen, T M; Loewenborg, A; Booth, T J; Schmidt, M S; Boeggild, P; Lin, R; Nielsen, P F

    2011-01-01

    We present measurements of the electronic properties of graphene using a repositionable micro four-point probe system, which we show here to have unique advantages over measurements made on lithographically defined devices; namely speed, simplicity and lack of a need to pattern graphene. Measurements are performed in ambient, vacuum and controlled environmental conditions using an environmental scanning electron microscope (SEM). The results are comparable to previous results for microcleaved graphene on silicon dioxide (SiO 2 ). We observe a pronounced hysteresis of the charge neutrality point, dependent on the sweep rate of the gate voltage; and environmental measurements provide insight into the sensor application prospects of graphene. The method offers a fast, local and non-destructive technique for electronic measurements on graphene, which can be positioned freely on a graphene flake.

  11. Analysis of the effective point of measurement of a thimble chamber dosimeter set parallel to the X-ray beam axis

    International Nuclear Information System (INIS)

    Shimono, Tetsunori; Nanbu, Hidekazu; Koshida, Kichiro; Kikuchi, Yuzo

    2007-01-01

    To measure the narrow beam used in stereotactic irradiation, installation of the ionization chamber parallel to the X-ray beam axis has been used instead of perpendicular installation. However, the definition of the effective point is a major problem in the parallel installation. In this study, we analyzed the effective point in parallel installation, and considered the prediction and evaluation of measurement point displacement. Relative dosimetry was carried out by installing the thimble ionization chamber in both perpendicular and parallel configurations. We then searched for the measurement point that coincided with the percentage depth dose (PDD) of the perpendicular installation by using the displacement of the measurement point of the parallel installation. We found that the effective point of measurement for relative photon beam dosimetry depends on every detail of the chamber design, including the cavity length and the cavity radius. Moreover, the effective point of measurement also depends on the beam quality and the field size. The amount of effective point displacement for the parallel installation was quantified with the linear expression of tissue peak ratio (TPR) 20, 10 . Our results showed that the amount of effective point displacement can be estimated by the ionization volume of the dosimeter and the energy used. (author)

  12. Possible impact of fixed point sources of SO2 in NSW to the secondary sulphate measurements at Richmond and the dependence of the background secondary sulphate on meteorological variables

    International Nuclear Information System (INIS)

    Crawford, C.; Cohen, D.D.; Stelcer, E.

    2010-01-01

    The contribution to secondary sulfate measurements at Richmond, Australia, from known point sources of SOz is investigated using air mass back trajectories. The conditional probability function (CPF) shows that contribution for days of high sulfur is from areas north east of the site. This is an area where known point sources of SOz, such as coal fired power stations, are located. The meteorological conditions associated with high sulfur days are examined and an artificial neural network is employed to determine the relationship between meteorological variables and sulfur measurements after the influence of known point sources was removed. It is shown that temperature and humidity have a nonlinear positive correlation with sulphate measurements, while wind speed, mixing layer depth and rainfall have a negative nonlinear correlation. In addition, the time of day at which air masses reach Richmond from the eastern and western power stations varies, and so thus the altitude at which the power stations are crossed. The time of day, as well as the altitude at which an SOz point source was passed, show an impact to the measured sulfate at Richmond, although the extent of this remains to be fully investigated

  13. What measurable zero point fluctuations can(not) tell us about dark energy

    International Nuclear Information System (INIS)

    Doran, M.

    2006-05-01

    We show that laboratory experiments cannot measure the absolute value of dark energy. All known experiments rely on electromagnetic interactions. They are thus insensitive to particles and fields that interact only weakly with ordinary matter. In addition, Josephson junction experiments only measure differences in vacuum energy similar to Casimir force measurements. Gravity, however, couples to the absolute value. Finally we note that Casimir force measurements have tested zero point fluctuations up to energies of ∝ 10 eV, well above the dark energy scale of ∝ 0.01 eV. Hence, the proposed cut-off in the fluctuation spectrum is ruled out experimentally. (Orig.)

  14. Reliable clinical serum analysis with reusable electrochemical sensor: Toward point-of-care measurement of the antipsychotic medication clozapine.

    Science.gov (United States)

    Kang, Mijeong; Kim, Eunkyoung; Winkler, Thomas E; Banis, George; Liu, Yi; Kitchen, Christopher A; Kelly, Deanna L; Ghodssi, Reza; Payne, Gregory F

    2017-09-15

    Clozapine is one of the most promising medications for managing schizophrenia but it is under-utilized because of the challenges of maintaining serum levels in a safe therapeutic range (1-3μM). Timely measurement of serum clozapine levels has been identified as a barrier to the broader use of clozapine, which is however challenging due to the complexity of serum samples. We demonstrate a robust and reusable electrochemical sensor with graphene-chitosan composite for rapidly measuring serum levels of clozapine. Our electrochemical measurements in clinical serum from clozapine-treated and clozapine-untreated schizophrenia groups are well correlated to centralized laboratory analysis for the readily detected uric acid and for the clozapine which is present at 100-fold lower concentration. The benefits of our electrochemical measurement approach for serum clozapine monitoring are: (i) rapid measurement (≈20min) without serum pretreatment; (ii) appropriate selectivity and sensitivity (limit of detection 0.7μM); (iii) reusability of an electrode over several weeks; and (iv) rapid reliability testing to detect common error-causing problems. This simple and rapid electrochemical approach for serum clozapine measurements should provide clinicians with the timely point-of-care information required to adjust dosages and personalize the management of schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Machine scheduling to minimize weighted completion times the use of the α-point

    CERN Document Server

    Gusmeroli, Nicoló

    2018-01-01

    This work reviews the most important results regarding the use of the α-point in Scheduling Theory. It provides a number of different LP-relaxations for scheduling problems and seeks to explain their polyhedral consequences. It also explains the concept of the α-point and how the conversion algorithm works, pointing out the relations to the sum of the weighted completion times. Lastly, the book explores the latest techniques used for many scheduling problems with different constraints, such as release dates, precedences, and parallel machines. This reference book is intended for advanced undergraduate and postgraduate students who are interested in scheduling theory. It is also inspiring for researchers wanting to learn about sophisticated techniques and open problems of the field.

  16. Measurement of the point spread function of a pixelated detector array

    Energy Technology Data Exchange (ETDEWEB)

    Ritzer, Christian; Hallen, Patrick; Schug, David; Schulz, Volkmar [Department of Physics of Molecular Imaging Systems, Institute for Experimental Molecular Imaging, RWTH Aachen University, Aachen (Germany)

    2015-05-18

    In order to further understand the PET/MRI scanner of our group, we measured the point spread function of a preclinical scintillation crystal array with a pitch of 1 mm and a total size of 30 mm ~ 30 mm ~ 12 mm. It is coupled via a lightguide to a dSiPM from Philips Digital Photon Counting, used on the TEK-setup. Crystal identification is done with a centre of gravity algorithm and the whole data analysis is performed with the same processing software as for the PET insert, giving comparable results. The beam is created with a 22 NA-Point-Source and a lead collimator, with 0.5 mm bore diameter. The algorithm sorted 62 % of the coincidences into the correct crystal.

  17. Measurement of the point spread function of a pixelated detector array

    International Nuclear Information System (INIS)

    Ritzer, Christian; Hallen, Patrick; Schug, David; Schulz, Volkmar

    2015-01-01

    In order to further understand the PET/MRI scanner of our group, we measured the point spread function of a preclinical scintillation crystal array with a pitch of 1 mm and a total size of 30 mm ~ 30 mm ~ 12 mm. It is coupled via a lightguide to a dSiPM from Philips Digital Photon Counting, used on the TEK-setup. Crystal identification is done with a centre of gravity algorithm and the whole data analysis is performed with the same processing software as for the PET insert, giving comparable results. The beam is created with a 22 NA-Point-Source and a lead collimator, with 0.5 mm bore diameter. The algorithm sorted 62 % of the coincidences into the correct crystal.

  18. Additive measures of travel time variability

    DEFF Research Database (Denmark)

    Engelson, Leonid; Fosgerau, Mogens

    2011-01-01

    This paper derives a measure of travel time variability for travellers equipped with scheduling preferences defined in terms of time-varying utility rates, and who choose departure time optimally. The corresponding value of travel time variability is a constant that depends only on preference...... parameters. The measure is unique in being additive with respect to independent parts of a trip. It has the variance of travel time as a special case. Extension is provided to the case of travellers who use a scheduled service with fixed headway....

  19. Comparative study of size dependent four-point probe sheet resistance measurement on laser annealed ultra-shallow junctions

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Lin, Rong; Hansen, Torben Mikael

    2008-01-01

    have been used to characterize the sheet resistance uniformity of millisecond laser annealed USJs. They verify, both experimentally and theoretically, that the probe pitch of a four-point probe can strongly affect the measured sheet resistance. Such effect arises from the sensitivity (or "spot size......In this comparative study, the authors demonstrate the relationship/correlation between macroscopic and microscopic four-point sheet resistance measurements on laser annealed ultra-shallow junctions (USJs). Microfabricated cantilever four-point probes with probe pitch ranging from 1.5 to 500 mu m......") of an in-line four-point probe. Their study shows the benefit of the spatial resolution of the micro four-point probe technique to characterize stitching effects resulting from the laser annealing process....

  20. Initial response of an automatic dew-point hygrometer using [beta]-ray backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Shigeaki (Saitama Univ., Urawa (Japan). Faculty of Engineering)

    1992-05-01

    This paper describes the initial response of an automatic dew-point hygrometer using [beta]-ray backscattering. The response time after starting of measurement was evaluated in which the dew point measured with the hygrometer reached a value of 90 percent of the correct dew point in its response. Theoretical calculation was made by means of the loop transfer function of a control system employed in the hygrometer. The response times ranged from 1.7 min to 16 min corresponding to the dew point of 47.5degC and -6degC, respectively, and agreed well with experimental ones. (author).

  1. Time discretization of the point kinetic equations using matrix exponential method and First-Order Hold

    International Nuclear Information System (INIS)

    Park, Yujin; Kazantzis, Nikolaos; Parlos, Alexander G.; Chong, Kil To

    2013-01-01

    Highlights: • Numerical solution for stiff differential equations using matrix exponential method. • The approximation is based on First Order Hold assumption. • Various input examples applied to the point kinetics equations. • The method shows superior useful and effective activity. - Abstract: A system of nonlinear differential equations is derived to model the dynamics of neutron density and the delayed neutron precursors within a point kinetics equation modeling framework for a nuclear reactor. The point kinetic equations are mathematically characterized as stiff, occasionally nonlinear, ordinary differential equations, posing significant challenges when numerical solutions are sought and traditionally resulting in the need for smaller time step intervals within various computational schemes. In light of the above realization, the present paper proposes a new discretization method inspired by system-theoretic notions and technically based on a combination of the matrix exponential method (MEM) and the First-Order Hold (FOH) assumption. Under the proposed time discretization structure, the sampled-data representation of the nonlinear point kinetic system of equations is derived. The performance of the proposed time discretization procedure is evaluated using several case studies with sinusoidal reactivity profiles and multiple input examples (reactivity and neutron source function). It is shown, that by applying the proposed method under a First-Order Hold for the neutron density and the precursor concentrations at each time step interval, the stiffness problem associated with the point kinetic equations can be adequately addressed and resolved. Finally, as evidenced by the aforementioned detailed simulation studies, the proposed method retains its validity and accuracy for a wide range of reactor operating conditions, including large sampling periods dictated by physical and/or technical limitations associated with the current state of sensor and

  2. On the Limitations of Taylor’s Hypothesis in Parker Solar Probe’s Measurements near the Alfvén Critical Point

    Science.gov (United States)

    Bourouaine, Sofiane; Perez, Jean C.

    2018-05-01

    In this Letter, we present an analysis of two-point, two-time correlation functions from high-resolution numerical simulations of Reflection-driven Alfvén Turbulence near the Alfvén critical point r c. The simulations model the turbulence in a prescribed background solar wind model chosen to match observational constraints. This analysis allows us to investigate the temporal decorrelation of solar wind turbulence and the validity of Taylor’s approximation near the heliocentric distance r c, which Parker Solar Probe (PSP) is expected to explore in the coming years. The simulations show that the temporal decay of the Fourier-transformed turbulence decorrelation function is better described by a Gaussian model rather than a pure exponential time decay, and that the decorrelation frequency is almost linear with perpendicular wave number k ⊥ (perpendicular with respect to the background magnetic field {{\\boldsymbol{B}}}0). Based on the simulations, we conclude that Taylor’s approximation cannot be used in this instance to provide a connection between the frequency ω of the time signal (measured in the probe frame) and the wavevector k ⊥ of the fluctuations because the frequency k ⊥ V sc (V sc is the spacecraft speed) near r c is comparable to the estimated decorrelation frequency. However, the use of Taylor’s approximation still leads to the correct spectral indices of the power spectra measured at the spacecraft frame. In this Letter, based on a Gaussian model, we suggest a modified relationship between ω and k ⊥, which might be useful in the interpretation of future PSP measurements.

  3. Measuring multiscaling in financial time-series

    International Nuclear Information System (INIS)

    Buonocore, R.J.; Aste, T.; Di Matteo, T.

    2016-01-01

    We discuss the origin of multiscaling in financial time-series and investigate how to best quantify it. Our methodology consists in separating the different sources of measured multifractality by analyzing the multi/uni-scaling behavior of synthetic time-series with known properties. We use the results from the synthetic time-series to interpret the measure of multifractality of real log-returns time-series. The main finding is that the aggregation horizon of the returns can introduce a strong bias effect on the measure of multifractality. This effect can become especially important when returns distributions have power law tails with exponents in the range (2, 5). We discuss the right aggregation horizon to mitigate this bias.

  4. An USB-based time measurement system

    International Nuclear Information System (INIS)

    Qin Xi; Liu Shubin; An Qi

    2010-01-01

    In this paper,we report the electronics of a timing measurement system of PTB(portable TDC board), which is a handy tool based on USB interface, customized for high precision time measurements without any crates. The time digitization is based on the High Performance TDC Chip (HPTDC). The real-time compensation for HPTDC outputs and the USB master logic are implemented in an ALTERA's Cyclone FPGA. The architecture design and logic design are described in detail. Test of the system showed a time resolution of 13.3 ps. (authors)

  5. At the Tipping Point

    Energy Technology Data Exchange (ETDEWEB)

    Wiley, H. S.

    2011-02-28

    There comes a time in every field of science when things suddenly change. While it might not be immediately apparent that things are different, a tipping point has occurred. Biology is now at such a point. The reason is the introduction of high-throughput genomics-based technologies. I am not talking about the consequences of the sequencing of the human genome (and every other genome within reach). The change is due to new technologies that generate an enormous amount of data about the molecular composition of cells. These include proteomics, transcriptional profiling by sequencing, and the ability to globally measure microRNAs and post-translational modifications of proteins. These mountains of digital data can be mapped to a common frame of reference: the organism’s genome. With the new high-throughput technologies, we can generate tens of thousands of data points from each sample. Data are now measured in terabytes and the time necessary to analyze data can now require years. Obviously, we can’t wait to interpret the data fully before the next experiment. In fact, we might never be able to even look at all of it, much less understand it. This volume of data requires sophisticated computational and statistical methods for its analysis and is forcing biologists to approach data interpretation as a collaborative venture.

  6. Temporal multiplexing for economical measurement of power versus time on NIF

    International Nuclear Information System (INIS)

    Thomas, S.; Boyd, B.; Davis, D.T.; Hall, B.

    1996-10-01

    The researchers have designed an economical device to measure the power time history in the National Ignition Facility's (NIF) 192 beam laser. The heart of the system is a commercial, high-speed, four-channel digitizer with a 15,000 point record length. Samples of several beams are taken with fiberoptic pickoffs, separated in time with appropriate fiberoptic delays and presented to high-speed vacuum photodiodes, which convert the samples to electrical signals for the digitizer. Amplitude and time multiplexing are used to cover the required dynamic range and to record 12 samples on the digitizer, making the cost per sample competitive with alternative approaches. Forty-eight digitizers can record the required three samples from each of the 192 beams. An additional similar but lower bandwidth system is used to record the backreflected light from the main laser amplifiers and elsewhere. The recording electronics are discussed in detail

  7. Temporal multiplexing for economical measurement of power versus time on NIF

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.; Boyd, B.; Davis, D.T.; Hall, B.

    1996-10-01

    The researchers have designed an economical device to measure the power time history in the National Ignition Facility`s (NIF) 192 beam laser. The heart of the system is a commercial, high-speed, four-channel digitizer with a 15,000 point record length. Samples of several beams are taken with fiberoptic pickoffs, separated in time with appropriate fiberoptic delays and presented to high-speed vacuum photodiodes, which convert the samples to electrical signals for the digitizer. Amplitude and time multiplexing are used to cover the required dynamic range and to record 12 samples on the digitizer, making the cost per sample competitive with alternative approaches. Forty-eight digitizers can record the required three samples from each of the 192 beams. An additional similar but lower bandwidth system is used to record the backreflected light from the main laser amplifiers and elsewhere. The recording electronics are discussed in detail.

  8. Numerical study and ex vivo assessment of HIFU treatment time reduction through optimization of focal point trajectory

    Science.gov (United States)

    Grisey, A.; Yon, S.; Pechoux, T.; Letort, V.; Lafitte, P.

    2017-03-01

    Treatment time reduction is a key issue to expand the use of high intensity focused ultrasound (HIFU) surgery, especially for benign pathologies. This study aims at quantitatively assessing the potential reduction of the treatment time arising from moving the focal point during long pulses. In this context, the optimization of the focal point trajectory is crucial to achieve a uniform thermal dose repartition and avoid boiling. At first, a numerical optimization algorithm was used to generate efficient trajectories. Thermal conduction was simulated in 3D with a finite difference code and damages to the tissue were modeled using the thermal dose formula. Given an initial trajectory, the thermal dose field was first computed, then, making use of Pontryagin's maximum principle, the trajectory was iteratively refined. Several initial trajectories were tested. Then, an ex vivo study was conducted in order to validate the efficicency of the resulting optimized strategies. Single pulses were performed at 3MHz on fresh veal liver samples with an Echopulse and the size of each unitary lesion was assessed by cutting each sample along three orthogonal planes and measuring the dimension of the whitened area based on photographs. We propose a promising approach to significantly shorten HIFU treatment time: the numerical optimization algorithm was shown to provide a reliable insight on trajectories that can improve treatment strategies. The model must now be improved in order to take in vivo conditions into account and extensively validated.

  9. Life-course occupational social class and health in later life: the importance of frequency and timing of measures.

    Science.gov (United States)

    Stone, Juliet; Netuveli, Gopalakrishnan; Blane, David

    2014-09-01

    Research investigating associations between social class over the life-course and later health relies primarily on secondary analysis of existing data, limiting the number and timing of available measurements. This paper aims to examine the impact of these constraints on the measurement of life-course occupational social class and subsequent explanatory analyses predicting health in later life. Participants of the UK Boyd Orr Lifegrid Subsample ( n  = 294), aged an average of 68 years, provided retrospective information on their life-course occupational social class, coded at 6-month intervals. This was used to simulate two types of life-course data: (1) Theoretical: Life stage (four data-points at key life stages); (2) A-theoretical: Panel data (data-points at regular intervals of varying length). The percentage of life time in disadvantage and the predictive value for limiting longstanding illness (LLI) in later life using the full life-course and simulated data was compared. The presence of 'critical periods' of exposure and the role of trajectories of social class were also investigated. Compared with the full data, the life stage approach estimated a higher percentage of life time in disadvantage and emphasised 'transient' periods in disadvantage (e.g. labour market entry). With varying intervals using the a-theoretical approach, there was no clear pattern. Percentage of life time in manual class was a significant predictor of LLI only when using the four-point life stage approach. Occupational social class at labour market entry was a predictor of LLI in later life, suggesting a 'critical period'. Comparison of trajectories of social class further emphasised the importance of the sequence and timing of exposures to disadvantage in determining later health. We conclude that producing a valid summary of life-course occupational social class does not necessarily require a large number of data-points, particularly if guided by relevant theory, and that such

  10. Measures and Metrics for Feasibility of Proof-of-Concept Studies With Human Immunodeficiency Virus Rapid Point-of-Care Technologies

    Science.gov (United States)

    Pant Pai, Nitika; Chiavegatti, Tiago; Vijh, Rohit; Karatzas, Nicolaos; Daher, Jana; Smallwood, Megan; Wong, Tom; Engel, Nora

    2017-01-01

    Objective Pilot (feasibility) studies form a vast majority of diagnostic studies with point-of-care technologies but often lack use of clear measures/metrics and a consistent framework for reporting and evaluation. To fill this gap, we systematically reviewed data to (a) catalog feasibility measures/metrics and (b) propose a framework. Methods For the period January 2000 to March 2014, 2 reviewers searched 4 databases (MEDLINE, EMBASE, CINAHL, Scopus), retrieved 1441 citations, and abstracted data from 81 studies. We observed 2 major categories of measures, that is, implementation centered and patient centered, and 4 subcategories of measures, that is, feasibility, acceptability, preference, and patient experience. We defined and delineated metrics and measures for a feasibility framework. We documented impact measures for a comparison. Findings We observed heterogeneity in reporting of metrics as well as misclassification and misuse of metrics within measures. Although we observed poorly defined measures and metrics for feasibility, preference, and patient experience, in contrast, acceptability measure was the best defined. For example, within feasibility, metrics such as consent, completion, new infection, linkage rates, and turnaround times were misclassified and reported. Similarly, patient experience was variously reported as test convenience, comfort, pain, and/or satisfaction. In contrast, within impact measures, all the metrics were well documented, thus serving as a good baseline comparator. With our framework, we classified, delineated, and defined quantitative measures and metrics for feasibility. Conclusions Our framework, with its defined measures/metrics, could reduce misclassification and improve the overall quality of reporting for monitoring and evaluation of rapid point-of-care technology strategies and their context-driven optimization. PMID:29333105

  11. Accuracy of micro four-point probe measurements on inhomogeneous samples: A probe spacing dependence study

    DEFF Research Database (Denmark)

    Wang, Fei; Petersen, Dirch Hjorth; Østerberg, Frederik Westergaard

    2009-01-01

    In this paper, we discuss a probe spacing dependence study in order to estimate the accuracy of micro four-point probe measurements on inhomogeneous samples. Based on sensitivity calculations, both sheet resistance and Hall effect measurements are studied for samples (e.g. laser annealed samples...... the probe spacing is smaller than 1/40 of the variation wavelength, micro four-point probes can provide an accurate record of local properties with less than 1% measurement error. All the calculations agree well with previous experimental results.......) with periodic variations of sheet resistance, sheet carrier density, and carrier mobility. With a variation wavelength of ¿, probe spacings from 0.0012 to 1002 have been applied to characterize the local variations. The calculations show that the measurement error is highly dependent on the probe spacing. When...

  12. Direct measurement of surface-state conductance by microscopic four-point probe method

    DEFF Research Database (Denmark)

    Hasegawa, S.; Shiraki, I.; Tanikawa, T.

    2002-01-01

    For in situ measurements of local electrical conductivity of well defined crystal surfaces in ultrahigh vacuum, we have developed microscopic four-point probes with a probe spacing of several micrometres, installed in a scanning-electron - microscope/electron-diffraction chamber. The probe...... is precisely positioned on targeted areas of the sample surface by using piezoactuators. This apparatus enables conductivity measurement with extremely high surface sensitivity, resulting in direct access to surface-state conductivity of the surface superstructures, and clarifying the influence of atomic steps...

  13. Travel Time Estimation Using Freeway Point Detector Data Based on Evolving Fuzzy Neural Inference System.

    Directory of Open Access Journals (Sweden)

    Jinjun Tang

    Full Text Available Travel time is an important measurement used to evaluate the extent of congestion within road networks. This paper presents a new method to estimate the travel time based on an evolving fuzzy neural inference system. The input variables in the system are traffic flow data (volume, occupancy, and speed collected from loop detectors located at points both upstream and downstream of a given link, and the output variable is the link travel time. A first order Takagi-Sugeno fuzzy rule set is used to complete the inference. For training the evolving fuzzy neural network (EFNN, two learning processes are proposed: (1 a K-means method is employed to partition input samples into different clusters, and a Gaussian fuzzy membership function is designed for each cluster to measure the membership degree of samples to the cluster centers. As the number of input samples increases, the cluster centers are modified and membership functions are also updated; (2 a weighted recursive least squares estimator is used to optimize the parameters of the linear functions in the Takagi-Sugeno type fuzzy rules. Testing datasets consisting of actual and simulated data are used to test the proposed method. Three common criteria including mean absolute error (MAE, root mean square error (RMSE, and mean absolute relative error (MARE are utilized to evaluate the estimation performance. Estimation results demonstrate the accuracy and effectiveness of the EFNN method through comparison with existing methods including: multiple linear regression (MLR, instantaneous model (IM, linear model (LM, neural network (NN, and cumulative plots (CP.

  14. Travel Time Estimation Using Freeway Point Detector Data Based on Evolving Fuzzy Neural Inference System.

    Science.gov (United States)

    Tang, Jinjun; Zou, Yajie; Ash, John; Zhang, Shen; Liu, Fang; Wang, Yinhai

    2016-01-01

    Travel time is an important measurement used to evaluate the extent of congestion within road networks. This paper presents a new method to estimate the travel time based on an evolving fuzzy neural inference system. The input variables in the system are traffic flow data (volume, occupancy, and speed) collected from loop detectors located at points both upstream and downstream of a given link, and the output variable is the link travel time. A first order Takagi-Sugeno fuzzy rule set is used to complete the inference. For training the evolving fuzzy neural network (EFNN), two learning processes are proposed: (1) a K-means method is employed to partition input samples into different clusters, and a Gaussian fuzzy membership function is designed for each cluster to measure the membership degree of samples to the cluster centers. As the number of input samples increases, the cluster centers are modified and membership functions are also updated; (2) a weighted recursive least squares estimator is used to optimize the parameters of the linear functions in the Takagi-Sugeno type fuzzy rules. Testing datasets consisting of actual and simulated data are used to test the proposed method. Three common criteria including mean absolute error (MAE), root mean square error (RMSE), and mean absolute relative error (MARE) are utilized to evaluate the estimation performance. Estimation results demonstrate the accuracy and effectiveness of the EFNN method through comparison with existing methods including: multiple linear regression (MLR), instantaneous model (IM), linear model (LM), neural network (NN), and cumulative plots (CP).

  15. GPU-accelerated Modeling and Element-free Reverse-time Migration with Gauss Points Partition

    Science.gov (United States)

    Zhen, Z.; Jia, X.

    2014-12-01

    Element-free method (EFM) has been applied to seismic modeling and migration. Compared with finite element method (FEM) and finite difference method (FDM), it is much cheaper and more flexible because only the information of the nodes and the boundary of the study area are required in computation. In the EFM, the number of Gauss points should be consistent with the number of model nodes; otherwise the accuracy of the intermediate coefficient matrices would be harmed. Thus when we increase the nodes of velocity model in order to obtain higher resolution, we find that the size of the computer's memory will be a bottleneck. The original EFM can deal with at most 81×81 nodes in the case of 2G memory, as tested by Jia and Hu (2006). In order to solve the problem of storage and computation efficiency, we propose a concept of Gauss points partition (GPP), and utilize the GPUs to improve the computation efficiency. Considering the characteristics of the Gaussian points, the GPP method doesn't influence the propagation of seismic wave in the velocity model. To overcome the time-consuming computation of the stiffness matrix (K) and the mass matrix (M), we also use the GPUs in our computation program. We employ the compressed sparse row (CSR) format to compress the intermediate sparse matrices and try to simplify the operations by solving the linear equations with the CULA Sparse's Conjugate Gradient (CG) solver instead of the linear sparse solver 'PARDISO'. It is observed that our strategy can significantly reduce the computational time of K and Mcompared with the algorithm based on CPU. The model tested is Marmousi model. The length of the model is 7425m and the depth is 2990m. We discretize the model with 595x298 nodes, 300x300 Gauss cells and 3x3 Gauss points in each cell. In contrast to the computational time of the conventional EFM, the GPUs-GPP approach can substantially improve the efficiency. The speedup ratio of time consumption of computing K, M is 120 and the

  16. The laboratory information float, time-based competition, and point-of-care testing.

    Science.gov (United States)

    Friedman, B A

    1994-01-01

    A new term, the laboratory information float, should be substituted for turnaround-time when evaluating the performance of the clinical laboratory because it includes the time necessary to make test results both available (ready to use) and accessible (easy to use) to clinicians ordering tests. The laboratory information float can be greatly reduced simply by telescoping the analytic phase of laboratory testing into the preanalytic phase. Significant costs are incurred by such a change, some of which can be reduced by developing a mobile clinical laboratory (sometimes referred to as a "lab-on-a-slab" or "rolling thunder") to transport the analytic devices directly to patient care units. The mobile clinical laboratory should be equipped with an integrated personal computer that can communicate continuously with the host laboratory information system and achieve some semblance of continuous flow processing despite test performance in point-of-care venues. Equipping clinicians with palmtop computers will allow the mobile clinician to access test results and order tests on the run. Such devices can be easily configured to operate in a passive mode, accessing relevant information automatically instead of forcing clinicians to query the laboratory information system periodically for the test results necessary to render care to their patients. The laboratory information float of the year 2,000 will surely be measured in minutes through the judicious deployment of relevant technology such as mobile clinical laboratories and palmtop computers.

  17. Statistical MOSFET Parameter Extraction with Parameter Selection for Minimal Point Measurement

    Directory of Open Access Journals (Sweden)

    Marga Alisjahbana

    2013-11-01

    Full Text Available A method to statistically extract MOSFET model parameters from a minimal number of transistor I(V characteristic curve measurements, taken during fabrication process monitoring. It includes a sensitivity analysis of the model, test/measurement point selection, and a parameter extraction experiment on the process data. The actual extraction is based on a linear error model, the sensitivity of the MOSFET model with respect to the parameters, and Newton-Raphson iterations. Simulated results showed good accuracy of parameter extraction and I(V curve fit for parameter deviations of up 20% from nominal values, including for a process shift of 10% from nominal.

  18. Measurement Uncertainty of Dew-Point Temperature in a Two-Pressure Humidity Generator

    Science.gov (United States)

    Martins, L. Lages; Ribeiro, A. Silva; Alves e Sousa, J.; Forbes, Alistair B.

    2012-09-01

    This article describes the measurement uncertainty evaluation of the dew-point temperature when using a two-pressure humidity generator as a reference standard. The estimation of the dew-point temperature involves the solution of a non-linear equation for which iterative solution techniques, such as the Newton-Raphson method, are required. Previous studies have already been carried out using the GUM method and the Monte Carlo method but have not discussed the impact of the approximate numerical method used to provide the temperature estimation. One of the aims of this article is to take this approximation into account. Following the guidelines presented in the GUM Supplement 1, two alternative approaches can be developed: the forward measurement uncertainty propagation by the Monte Carlo method when using the Newton-Raphson numerical procedure; and the inverse measurement uncertainty propagation by Bayesian inference, based on prior available information regarding the usual dispersion of values obtained by the calibration process. The measurement uncertainties obtained using these two methods can be compared with previous results. Other relevant issues concerning this research are the broad application to measurements that require hygrometric conditions obtained from two-pressure humidity generators and, also, the ability to provide a solution that can be applied to similar iterative models. The research also studied the factors influencing both the use of the Monte Carlo method (such as the seed value and the convergence parameter) and the inverse uncertainty propagation using Bayesian inference (such as the pre-assigned tolerance, prior estimate, and standard deviation) in terms of their accuracy and adequacy.

  19. Double threshold discriminator for timing measurements

    International Nuclear Information System (INIS)

    Frolov, A.R.; Oslopova, T.V.; Pestov, Yu.N.

    1995-01-01

    The new type of a discriminator is based on the idea of simultaneous time measurements at two different thresholds for each pulse. Instead of using two independent electronic TDC channels this discriminator produces an output pulse with the timing taking into account the information from two time measurements ''on-line''. The operation principle, analytical calculations and experimental results are presented. The time walk of the discriminator at the level of 10 ps in the range of the input pulse height of 0.2-1.5 V has been obtained. ((orig.))

  20. 'Stutter timing' for charge decay time measurement

    Energy Technology Data Exchange (ETDEWEB)

    Chubb, John [Infostatic, 2 Monica Drive, Pittville, Cheltenham, GL50 4NQ (United Kingdom); Harbour, John [Hawthorne Technical Design, The Hawthornes, Startley, Chippenham, SN15 5HG,UK (United Kingdom); Pavey, Ian, E-mail: jchubb@infostatic.co.uk [Chilworth Technology Ltd, Beta House, Southampton Science Park, Southampton, SO16 7NS (United Kingdom)

    2011-06-23

    The paper describes the approach of 'stutter timing' that has been developed to improve the accuracy of measuring charge decay times in the presence of noise in compact and portable charge decay test instrumentation. The approach involves starting and stopping the timing clock as the noisy signal rises above and falls below the target threshold voltage level.

  1. Measurement and analysis of pressure tube elongation in the Douglas Point reactor

    International Nuclear Information System (INIS)

    Causey, A.R.; MacEwan, S.R.; Jamieson, H.C.; Mitchell, A.B.

    1980-02-01

    Elongations of zirconium alloy pressure tubes in CANDU reactors, which occur as a result of neutron-irradiation-induced creep and growth, have been measured over the past 6 years, and the consequences of thses elongations have recently been analysed. Elongation rates, previously deduced from extensive measurements of elongations of cold-worked Zircaloy-2 pressure tubes in the Pickering reactors, have been modified to apply to the pressure tubes in the Douglas Point (DP) reactor by taking into account measured diffences in texture and dislocation density. Using these elongation rates, and structural data unique to the DP reactor, the analysis predicts elongation behaviour which is in good agreement with pressure tube elongations measured during the ten years of reactor operation. (Auth)

  2. Farey Statistics in Time n^{2/3} and Counting Primitive Lattice Points in Polygons

    OpenAIRE

    Patrascu, Mihai

    2007-01-01

    We present algorithms for computing ranks and order statistics in the Farey sequence, taking time O (n^{2/3}). This improves on the recent algorithms of Pawlewicz [European Symp. Alg. 2007], running in time O (n^{3/4}). We also initiate the study of a more general algorithmic problem: counting primitive lattice points in planar shapes.

  3. Measurement of Voice Onset Time in Maxillectomy Patients

    OpenAIRE

    Hattori, Mariko; Sumita, Yuka I.; Taniguchi, Hisashi

    2014-01-01

    Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients ...

  4. Comparability of Results between Point-of-Care and Automated Instruments to Measure B-type Natriuretic Peptide

    OpenAIRE

    Shah, Kevin; Terracciano, Garrett J.; Jiang, Kevin; Maisel, Alan S.; Fitzgerald, Robert L.

    2010-01-01

    Objectives: Heart failure is one of the leading causes of death in the U.S. The incorporation of B-type natriuretic peptide (BNP) measurements when triaging patients presenting with shortness of breath has improved the diagnostic and prognostic ability of physicians. Currently, there are no point-of-care systems for quantifying BNP that can be used without sacrificing accuracy. We compared the analytical performance of the Abbott i-STAT analyzer, a handheld point-of-care system for measuring ...

  5. Measurement of voice onset time in maxillectomy patients.

    Science.gov (United States)

    Hattori, Mariko; Sumita, Yuka I; Taniguchi, Hisashi

    2014-01-01

    Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients for objective speech evaluation. We examined voice onset time for /ka/ and /ta/ in 13 maxillectomy patients by calculating the number of valid measurements of voice onset time out of three trials for each syllable. Wilcoxon's signed rank test showed that voice onset time measurements were more successful for /ka/ and /ta/ when a prosthesis was used (Z = -2.232, P = 0.026 and Z = -2.401, P = 0.016, resp.) than when a prosthesis was not used. These results indicate a prosthesis affected voice onset measurement in these patients. Although more research in this area is needed, measurement of voice onset time has the potential to be used to evaluate consonant production in maxillectomy patients wearing a prosthesis.

  6. Measurement of Voice Onset Time in Maxillectomy Patients

    Directory of Open Access Journals (Sweden)

    Mariko Hattori

    2014-01-01

    Full Text Available Objective speech evaluation using acoustic measurement is needed for the proper rehabilitation of maxillectomy patients. For digital evaluation of consonants, measurement of voice onset time is one option. However, voice onset time has not been measured in maxillectomy patients as their consonant sound spectra exhibit unique characteristics that make the measurement of voice onset time challenging. In this study, we established criteria for measuring voice onset time in maxillectomy patients for objective speech evaluation. We examined voice onset time for /ka/ and /ta/ in 13 maxillectomy patients by calculating the number of valid measurements of voice onset time out of three trials for each syllable. Wilcoxon’s signed rank test showed that voice onset time measurements were more successful for /ka/ and /ta/ when a prosthesis was used (Z=−2.232, P=0.026 and Z=−2.401, P=0.016, resp. than when a prosthesis was not used. These results indicate a prosthesis affected voice onset measurement in these patients. Although more research in this area is needed, measurement of voice onset time has the potential to be used to evaluate consonant production in maxillectomy patients wearing a prosthesis.

  7. Freezing Point Depressions of Aqueous MEA, MDEA, and MEA−MDEA Measured with a New Apparatus

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Pedersen, Mikkel Gielsager; Thomsen, Kaj

    2011-01-01

    Freezing points for aqueous monoethanolamine (MEA), methyl diethanolamine (MDEA), and MEA−MDEA solutions were measured in the concentration range from 0 to 0.4 mass fractions of the alkanolamines. For the aqueous MEA−MDEA system, freezing points for 1:4, 1:2, 1:1, 2:1, and 4:1 molar ratios of MEA....../MDEA were determined. The experimental values indicate that the MDEA−water interaction is stronger than the MEA−water interaction. Measurements were carried out by a new modified Beckmann apparatus, which has not previously been described. The apparatus and method proved to have good repeatability...

  8. Estimating envelope thermal characteristics from single point in time thermal images

    Science.gov (United States)

    Alshatshati, Salahaldin Faraj

    Energy efficiency programs implemented nationally in the U.S. by utilities have rendered savings which have cost on average 0.03/kWh. This cost is still well below generation costs. However, as the lowest cost energy efficiency measures are adopted, this the cost effectiveness of further investment declines. Thus there is a need to more effectively find the most opportunities for savings regionally and nationally, so that the greatest cost effectiveness in implementing energy efficiency can be achieved. Integral to this process. are at scale energy audits. However, on-site building energy audits process are expensive, in the range of US1.29/m2-$5.37/m2 and there are an insufficient number of professionals to perform the audits. Energy audits that can be conducted at-scale and at low cost are needed. Research is presented that addresses at community-wide scales characterization of building envelope thermal characteristics via drive-by and fly-over GPS linked thermal imaging. A central question drives this research: Can single point-in-time thermal images be used to infer U-values and thermal capacitances of walls and roofs? Previous efforts to use thermal images to estimate U-values have been limited to rare steady exterior weather conditions. The approaches posed here are based upon the development two models first is a dynamic model of a building envelope component with unknown U-value and thermal capacitance. The weather conditions prior to the thermal image are used as inputs to the model. The model is solved to determine the exterior surface temperature, ultimately predicted the temperature at the thermal measurement time. The model U-value and thermal capacitance are tuned in order to force the error between the predicted surface temperature and the measured surface temperature from thermal imaging to be near zero. This model is developed simply to show that such a model cannot be relied upon to accurately estimate the U-value. The second is a data

  9. Interesting Interest Points

    DEFF Research Database (Denmark)

    Aanæs, Henrik; Dahl, Anders Lindbjerg; Pedersen, Kim Steenstrup

    2012-01-01

    on spatial invariance of interest points under changing acquisition parameters by measuring the spatial recall rate. The scope of this paper is to investigate the performance of a number of existing well-established interest point detection methods. Automatic performance evaluation of interest points is hard......Not all interest points are equally interesting. The most valuable interest points lead to optimal performance of the computer vision method in which they are employed. But a measure of this kind will be dependent on the chosen vision application. We propose a more general performance measure based...... position. The LED illumination provides the option for artificially relighting the scene from a range of light directions. This data set has given us the ability to systematically evaluate the performance of a number of interest point detectors. The highlights of the conclusions are that the fixed scale...

  10. Characterization of positional errors and their influence on micro four-point probe measurements on a 100 nm Ru film

    DEFF Research Database (Denmark)

    Kjær, Daniel; Hansen, Ole; Østerberg, Frederik Westergaard

    2015-01-01

    Thin-film sheet resistance measurements at high spatial resolution and on small pads are important and can be realized with micrometer-scale four-point probes. As a result of the small scale the measurements are affected by electrode position errors. We have characterized the electrode position...... errors in measurements on Ru thin film using an Au-coated 12-point probe. We show that the standard deviation of the static electrode position error is on the order of 5 nm, which significantly affects the results of single configuration measurements. Position-error-corrected dual......-configuration measurements, however, are shown to eliminate the effect of position errors to a level limited either by electrical measurement noise or dynamic position errors. We show that the probe contact points remain almost static on the surface during the measurements (measured on an atomic scale) with a standard...

  11. Incorporation of Time Delayed Measurements in a Discrete-time Kalman Filter

    DEFF Research Database (Denmark)

    Larsen, Thomas Dall; Andersen, Nils Axel; Ravn, Ole

    1998-01-01

    In many practical systems there is a delay in some of the sensor devices, for instance vision measurements that may have a long processing time. How to fuse these measurements in a Kalman filter is not a trivial problem if the computational delay is critical. Depending on how much time...... using past and present estimates of the Kalman filter and calculating an optimal gain for this extrapolated measurement...... there is at hand, the designer has to make trade offs between optimality and computational burden of the filter. In this paper various methods in the literature along with a new method proposed by the authors will be presented and compared. The new method is based on “extrapolating” the measurement to present time...

  12. The IPERMOB System for Effective Real-Time Road Travel Time Measurement and Prediction

    OpenAIRE

    Martelli, Francesca; Renda, Maria Elena; Santi, Paolo

    2010-01-01

    Accurate, real-time measurement and estimation of road travel time is considered a central problem in the design of advanced Intelligent Transportation Systems. In particular, whether eective, real-time collection of travel time measurements in a urban area is possible is, to the best of our knowledge, still an open problem. In this paper, we introduce the IPERMOB system for efficient, real-time collection of travel time measurements in urban areas through vehicular networks. We demonstrate t...

  13. A test of alternative estimators for volume at time 1 from remeasured point samples

    Science.gov (United States)

    Francis A. Roesch; Edwin J. Green; Charles T. Scott

    1993-01-01

    Two estimators for volume at time 1 for use with permanent horizontal point samples are evaluated. One estimator, used traditionally, uses only the trees sampled at time 1, while the second estimator, originally presented by Roesch and coauthors (F.A. Roesch, Jr., E.J. Green, and C.T. Scott. 1989. For. Sci. 35(2):281-293). takes advantage of additional sample...

  14. Dual time point 2-deoxy-2-[18F]fluoro-D-glucose PET/CT: nodal staging in locally advanced breast cancer.

    Science.gov (United States)

    García Vicente, A M; Soriano Castrejón, A; Cruz Mora, M Á; Ortega Ruiperez, C; Espinosa Aunión, R; León Martín, A; González Ageitos, A; Van Gómez López, O

    2014-01-01

    To assess dual time point 2-deoxy-2-[(18)F]fluoro-D-glucose (18)(F)FDG PET-CT accuracy in nodal staging and in detection of extra-axillary involvement. Dual time point [(18)F] FDG PET/CT scan was performed in 75 patients. Visual and semiquantitative assessment of lymph nodes was performed. Semiquantitative measurement of SUV and ROC-analysis were carried out to calculate SUV(max) cut-off value with the best diagnostic performance. Axillary and extra-axillary lymph node chains were evaluated. Sensitivity and specificity of visual assessment was 87.3% and 75%, respectively. SUV(max) values with the best sensitivity were 0.90 and 0.95 for early and delayed PET, respectively. SUV(max) values with the best specificity were 1.95 and 2.75, respectively. Extra-axillary lymph node involvement was detected in 26.7%. FDG PET/CT detected extra-axillary lymph node involvement in one-fourth of the patients. Semiquantitative lymph node analysis did not show any advantage over the visual evaluation. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  15. Measuring Total Column Water Vapor by Pointing an Infrared Thermometer at the Sky

    Science.gov (United States)

    Mims, Forrest M., III; Chambers, Lin H.; Brooks, David R.

    2011-01-01

    A 2-year study affirms that the temperature (Tz) indicated by an inexpensive ($20 to $60) IR thermometer pointed at the cloud-free zenith sky provides an approximate indication of the total column water vapor (precipitable water or PW). PW was measured by a MICROTOPS II sun photometer. The coefficient of correlation (r2) of the PW and Tz was 0.90, and the rms difference was 3.2 mm. A comparison of the Tz data with the PW provided by a GPS site 31 km NNE yielded an r2 of 0.79, and an rms difference of 5.8 mm. An expanded study compared Tz from eight IR thermometers with PW at various times during the day and night from 17 May to 18 October 2010, mainly at the Texas site and 10 days at Hawaii's Mauna Loa Observatory (MLO). The best results of this comparison were provided by two IR thermometers models that yielded an r2 of 0.96 and an rms difference with the PW of 2.7 mm. The results of both the ongoing 2-year study and the 5-month instrument comparison show that IR thermometers can measure PW with an accuracy (rms difference/mean PW) approaching 10%, the accuracy typically ascribed to sun photometers.

  16. The role of socioeconomic factors in Black-White health inequities across the life course: Point-in-time measures, long-term exposures, and differential health returns.

    Science.gov (United States)

    Boen, Courtney

    2016-12-01

    Research links Black-White health disparities to racial differences in socioeconomic status (SES), but understanding of the role of SES in racial health gaps has been restricted by reliance on static measures of health and socioeconomic well-being that mask the dynamic quality of these processes and ignore the racialized nature of the SES-health connection. Utilizing twenty-three years of longitudinal data from the Panel Study of Income Dynamics (1984-2007), this study uses multilevel growth curve models to examine how multiple dimensions of socioeconomic well-being-including long-term economic history and differential returns to SES-contribute to the life course patterning of Black-White health disparities across two critical markers of well-being: body mass index (N = 9057) and self-rated health (N = 11,329). Findings indicate that long-term SES exerts a significant influence on both body mass index and self-rated health, net of point-in-time measures, and that Black-White health gaps are smallest in models that adjust for both long-term and current SES. I also find that Blacks and Whites receive differential health returns to increases in SES, which suggests that other factors-such as neighborhood segregation and exposure racial discrimination-may restrict Blacks from converting increases in SES into health improvements in the same way as Whites. Together, these processes contribute to the life course patterning of Black-White health gaps and raise concerns about previous misestimation of the role of SES in racial health disparities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Undergraduate Consent Form Reading in Relation to Conscientiousness, Procrastination, and the Point-of-Time Effect.

    Science.gov (United States)

    Theiss, Justin D; Hobbs, William B; Giordano, Peter J; Brunson, Olivia M

    2014-07-01

    Informed consent is central to conducting ethical research with human participants. The present study investigated differences in consent form reading in relation to conscientiousness, procrastination, and the point-of-time (PT) effect among undergraduate participants at a U.S. university. As hypothesized, conscientious participants and those who signed up to participate in a research study more days in advance and for earlier sessions (PT effect) read the consent form more thoroughly. However, procrastination was not related to consent form reading. Most importantly, consent form reading in general was poor, with 80% of participants demonstrating that they had not read the consent form. Conscientious participants were more likely to self-report reading the consent form, irrespective of their measured consent form reading. The article closes with suggestions to improve the process of obtaining informed consent with undergraduate participants. © The Author(s) 2014.

  18. Technical Note: Experimental determination of the effective point of measurement of two cylindrical ionization chambers in a clinical proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, Yuya, E-mail: yuya.sugama@gmail.com [Proton Therapy Center, Aizawa Hospital, Nagano 390-0821, Japan and Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 409-3898 (Japan); Nishio, Teiji [Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551 (Japan); Onishi, Hiroshi [Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi 409-3898 (Japan)

    2015-07-15

    Purpose: IAEA TRS-398 notes that cylindrical ionization chambers are preferred for reference proton dosimetry. If a cylindrical ionization chamber is used in a phantom to measure the dose as a function of depth, the effective point of measurement (EPOM) must be taken into account. IAEA TRS-398 recommends a displacement of 0.75 times the inner cavity radius (0.75R) for heavy ion beams. Theoretical models by Palmans and by Bhullar and Watchman confirmed this value. However, the experimental results vary from author to author. The purpose of this study is to accurately measure the displacement and explain the past experimental discrepancies. Methods: In this work, we measured the EPOM of cylindrical ionization chambers with high accuracy by comparing the Bragg-peak position obtained with cylindrical ionization chambers (PTW 30013, PTW 31016) to that obtained using a plane-parallel ionization chamber (PTW 34045). Results: The EPOMs of PTW 30013 and 31016 were shifted by 0.92 ± 0.07 R with R = 3.05 mm and 0.90 ± 0.14 R with R = 1.45 mm, respectively, from the reference point toward the source. Conclusions: The EPOMs obtained were greater than the value of 0.75R proposed by the IAEA TRS-398 and the analytical results.

  19. Measuring space-time fuzziness with high energy γ-ray detectors

    Directory of Open Access Journals (Sweden)

    Cattaneo Paolo Walter

    2017-01-01

    Full Text Available There are several suggestions to probe space-time fuzziness (also known as space-time foam due to the quantum mechanics nature of space-time. These effects are predicted to be very small, being related to the Planck length, so that the only hope to experimentally detect them is to look at particles propagating along cosmological distances. Some phenomenological approaches suggest that photons originating from pointlike sources at cosmological distance experience path length fluctuation that could be detected. Also the direction of flight of such photons may be subject to a dispersion such that the image of a point-like source is blurred and detected as a disk. An experimentally accessible signature may be images of point-like sources larger that the size due to the Point Spread Function of the instrument. This additional broadening should increase with distance and photon energy. Some concrete examples that can be studied with the AGILE and FERMI-LAT γ -ray satellite experiments are discussed.

  20. ISOL yield predictions from holdup-time measurements

    International Nuclear Information System (INIS)

    Spejewski, Eugene H.; Carter, H Kennon; Mervin, Brenden T.; Prettyman, Emily S.; Kronenberg, Andreas; Stracener, Daniel W

    2008-01-01

    A formalism based on a simple model is derived to predict ISOL yields for all isotopes of a given element based on a holdup-time measurement of a single isotope of that element. Model predictions, based on parameters obtained from holdup-time measurements, are compared to independently-measured experimental values

  1. A point-of-care chemistry test for reduction of turnaround and clinical decision time.

    Science.gov (United States)

    Lee, Eui Jung; Shin, Sang Do; Song, Kyoung Jun; Kim, Seong Chun; Cho, Jin Seong; Lee, Seung Chul; Park, Ju Ok; Cha, Won Chul

    2011-06-01

    Our study compared clinical decision time between patients managed with a point-of-care chemistry test (POCT) and patients managed with the traditional central laboratory test (CLT). This was a randomized controlled multicenter trial in the emergency departments (EDs) of 5 academic teaching hospitals. We randomly assigned patients to POCT or CLT stratified by the Emergency Severity Index. A POCT chemistry analyzer (Piccolo; Abaxis, Inc, Union City, Calif), which is able to test liver panel, renal panel, pancreas enzymes, lipid panel, electrolytes, and blood gases, was set up in each ED. Primary and secondary end point was turnaround time and door-to-clinical-decision time. The total 2323 patients were randomly assigned to the POCT group (n = 1167) or to the CLT group (n = 1156). All of the basic characteristics were similar in the 2 groups. The turnaround time (median, interquartile range [IQR]) of the POCT group was shorter than that of the CLT group (14, 12-19 versus 55, 45-69 minutes; P CLT group (46, 33-61 versus 86, 68-107 minutes; P CLT group (P CLT. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Statistical process control: A feasibility study of the application of time-series measurement in early neurorehabilitation after acquired brain injury.

    Science.gov (United States)

    Markovic, Gabriela; Schult, Marie-Louise; Bartfai, Aniko; Elg, Mattias

    2017-01-31

    Progress in early cognitive recovery after acquired brain injury is uneven and unpredictable, and thus the evaluation of rehabilitation is complex. The use of time-series measurements is susceptible to statistical change due to process variation. To evaluate the feasibility of using a time-series method, statistical process control, in early cognitive rehabilitation. Participants were 27 patients with acquired brain injury undergoing interdisciplinary rehabilitation of attention within 4 months post-injury. The outcome measure, the Paced Auditory Serial Addition Test, was analysed using statistical process control. Statistical process control identifies if and when change occurs in the process according to 3 patterns: rapid, steady or stationary performers. The statistical process control method was adjusted, in terms of constructing the baseline and the total number of measurement points, in order to measure a process in change. Statistical process control methodology is feasible for use in early cognitive rehabilitation, since it provides information about change in a process, thus enabling adjustment of the individual treatment response. Together with the results indicating discernible subgroups that respond differently to rehabilitation, statistical process control could be a valid tool in clinical decision-making. This study is a starting-point in understanding the rehabilitation process using a real-time-measurements approach.

  3. Carrier accumulation and depletion in point-contact capacitance-voltage measurements

    Science.gov (United States)

    Naitou, Yuichi

    2017-11-01

    Scanning capacitance microscopy (SCM) is a variation of atomic force microscopy in which a conductive probe tip detects the bias modulated capacitance for the purpose of measuring the nanoscale semiconductor carrier concentration. SCM can be regarded as a point-contact capacitance-voltage system, and its capacitance-voltage properties are different from those of a conventional parallel-plate capacitor. In this study, the charge accumulation and depletion behavior of a semiconductor sample were closely investigated by SCM. By analyzing the tip-sample approach curve, the effective probe tip area and charge depletion depth could be quantitatively determined.

  4. Accuracy enhancement of point triangulation probes for linear displacement measurement

    Science.gov (United States)

    Kim, Kyung-Chan; Kim, Jong-Ahn; Oh, SeBaek; Kim, Soo Hyun; Kwak, Yoon Keun

    2000-03-01

    Point triangulation probes (PTBs) fall into a general category of noncontact height or displacement measurement devices. PTBs are widely used for their simple structure, high resolution, and long operating range. However, there are several factors that must be taken into account in order to obtain high accuracy and reliability; measurement errors from inclinations of an object surface, probe signal fluctuations generated by speckle effects, power variation of a light source, electronic noises, and so on. In this paper, we propose a novel signal processing algorithm, named as EASDF (expanded average square difference function), for a newly designed PTB which is composed of an incoherent source (LED), a line scan array detector, a specially selected diffuse reflecting surface, and several optical components. The EASDF, which is a modified correlation function, is able to calculate displacement between the probe and the object surface effectively even if there are inclinations, power fluctuations, and noises.

  5. Heterogeneous dynamics of ionic liquids: A four-point time correlation function approach

    Science.gov (United States)

    Liu, Jiannan; Willcox, Jon A. L.; Kim, Hyung J.

    2018-05-01

    Many ionic liquids show behavior similar to that of glassy systems, e.g., large and long-lasted deviations from Gaussian dynamics and clustering of "mobile" and "immobile" groups of ions. Herein a time-dependent four-point density correlation function—typically used to characterize glassy systems—is implemented for the ionic liquids, choline acetate, and 1-butyl-3-methylimidazolium acetate. Dynamic correlation beyond the first ionic solvation shell on the time scale of nanoseconds is found in the ionic liquids, revealing the cooperative nature of ion motions. The traditional solvent, acetonitrile, on the other hand, shows a much shorter length-scale that decays after a few picoseconds.

  6. Improving Gastric Cancer Outcome Prediction Using Single Time-Point Artificial Neural Network Models

    Science.gov (United States)

    Nilsaz-Dezfouli, Hamid; Abu-Bakar, Mohd Rizam; Arasan, Jayanthi; Adam, Mohd Bakri; Pourhoseingholi, Mohamad Amin

    2017-01-01

    In cancer studies, the prediction of cancer outcome based on a set of prognostic variables has been a long-standing topic of interest. Current statistical methods for survival analysis offer the possibility of modelling cancer survivability but require unrealistic assumptions about the survival time distribution or proportionality of hazard. Therefore, attention must be paid in developing nonlinear models with less restrictive assumptions. Artificial neural network (ANN) models are primarily useful in prediction when nonlinear approaches are required to sift through the plethora of available information. The applications of ANN models for prognostic and diagnostic classification in medicine have attracted a lot of interest. The applications of ANN models in modelling the survival of patients with gastric cancer have been discussed in some studies without completely considering the censored data. This study proposes an ANN model for predicting gastric cancer survivability, considering the censored data. Five separate single time-point ANN models were developed to predict the outcome of patients after 1, 2, 3, 4, and 5 years. The performance of ANN model in predicting the probabilities of death is consistently high for all time points according to the accuracy and the area under the receiver operating characteristic curve. PMID:28469384

  7. Cloud-point measurement for (sulphate salts + polyethylene glycol 15000 + water) systems by the particle counting method

    International Nuclear Information System (INIS)

    Imani, A.; Modarress, H.; Eliassi, A.; Abdous, M.

    2009-01-01

    The phase separation of (water + salt + polyethylene glycol 15000) systems was studied by cloud-point measurements using the particle counting method. The effect of three kinds of sulphate salt (Na 2 SO 4 , K 2 SO 4 , (NH 4 ) 2 SO 4 ) concentration, polyethylene glycol 15000 concentration, mass ratio of polymer to salt on the cloud-point temperature of these systems have been investigated. The results obtained indicate that the cloud-point temperatures decrease linearly with increase in polyethylene glycol concentrations for different salts. Also, the cloud points decrease with an increase in mass ratio of salt to polymer.

  8. Point-splitting in a curved space-time background. 1 -gravitational contribution to the axial anomaly

    International Nuclear Information System (INIS)

    Liggatt, P.A.J.; Macfarlane, A.J.

    1978-01-01

    A prescription is given for point-splitting in a curved space-time background which is a natural generalization of that familiar in quantum electrodynamics and Yang-Mills theory. It is applied (to establish its validity) to the verification of the gravitational anomaly in the divergence of a fermion axial current. Notable features of the prescription are that it defines a point-split current which can be differentiated straightforwardly, and that it involves a natural way of averaging (four dimensionally) over the directions of point splitting. The method can extend directly from the spin-1/2 fermion case treated to other cases, e.g. to spin -3/2 Rarita-Schwinger fermions. (author)

  9. Bridging the gap between a stationary point process and its Palm distribution

    NARCIS (Netherlands)

    Nieuwenhuis, G.

    1994-01-01

    In the context of stationary point processes measurements are usually made from a time point chosen at random or from an occurrence chosen at random. That is, either the stationary distribution P or its Palm distribution P° is the ruling probability measure. In this paper an approach is presented to

  10. CANDU pressure tube leak detection by annulus gas dew point measurement. A critical review

    International Nuclear Information System (INIS)

    Greening, F.R.

    2017-01-01

    In the event of a pressure tube leak from a small through-wall crack during CANDU reactor operations, there is a regulatory requirement - referred to as Leak Before Break (LBB) - for the licensee to demonstrate that there will be sufficient time for the leak to be detected and the reactor shut down before the crack grows to the critical size for fast-uncontrolled rupture. In all currently operating CANDU reactors, worldwide, this LBB requirement is met via continuous dew point measurements of the CO_2 gas circulating in the reactor's Annulus Gas System (AGS). In this paper the historical development and current status of this leak detection capability is reviewed and the use of moisture injection tests as a verification procedure is critiqued. It is concluded that these tests do not represent AGS conditions that are to be expected in the event of a real pressure tube leak.

  11. CANDU pressure tube leak detection by annulus gas dew point measurement. A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Greening, F.R. [CTS-NA, Tiverton, ON (Canada)

    2017-03-15

    In the event of a pressure tube leak from a small through-wall crack during CANDU reactor operations, there is a regulatory requirement - referred to as Leak Before Break (LBB) - for the licensee to demonstrate that there will be sufficient time for the leak to be detected and the reactor shut down before the crack grows to the critical size for fast-uncontrolled rupture. In all currently operating CANDU reactors, worldwide, this LBB requirement is met via continuous dew point measurements of the CO{sub 2} gas circulating in the reactor's Annulus Gas System (AGS). In this paper the historical development and current status of this leak detection capability is reviewed and the use of moisture injection tests as a verification procedure is critiqued. It is concluded that these tests do not represent AGS conditions that are to be expected in the event of a real pressure tube leak.

  12. A sensorless method for measuring the point mobility of mechanical structures

    Science.gov (United States)

    Boulandet, R.; Michau, M.; Herzog, P.; Micheau, P.; Berry, A.

    2016-09-01

    This paper presents a convenient and cost-effective experimental tool for measuring the mobility characteristics of a mechanical structure. The objective is to demonstrate that the point mobility measurement can be performed using only an electrodynamic inertial exciter. Unlike previous work based on voice coil actuators, no load cell or accelerometer is needed. Instead, it is theoretically shown that the mobility characteristics of the structure can be estimated from variations in the electrical input impedance of the actuator fixed onto it, provided that the electromechanical parameters of the actuator are known. The proof of concept is made experimentally using a cheap commercially available actuator on a simply supported plate, leading to a good dynamic range from 100 Hz to 1 kHz. The methodology to assess the basic parameters of the actuator is also given. Measured data are compared to a standard shaker testing and the strengths and weaknesses of the sensorless mobility measuring device are discussed. It is believed that this sensorless mobility measuring device can be a convenient experimental tool to determine the dynamic characteristics of a wide range of mechanical structures.

  13. Correction of measured Gamma-Knife output factors for angular dependence of diode detectors and PinPoint ionization chamber.

    Science.gov (United States)

    Hršak, Hrvoje; Majer, Marija; Grego, Timor; Bibić, Juraj; Heinrich, Zdravko

    2014-12-01

    Dosimetry for Gamma-Knife requires detectors with high spatial resolution and minimal angular dependence of response. Angular dependence and end effect time for p-type silicon detectors (PTW Diode P and Diode E) and PTW PinPoint ionization chamber were measured with Gamma-Knife beams. Weighted angular dependence correction factors were calculated for each detector. The Gamma-Knife output factors were corrected for angular dependence and end effect time. For Gamma-Knife beams angle range of 84°-54°. Diode P shows considerable angular dependence of 9% and 8% for the 18 mm and 14, 8, 4 mm collimator, respectively. For Diode E this dependence is about 4% for all collimators. PinPoint ionization chamber shows angular dependence of less than 3% for 18, 14 and 8 mm helmet and 10% for 4 mm collimator due to volumetric averaging effect in a small photon beam. Corrected output factors for 14 mm helmet are in very good agreement (within ±0.3%) with published data and values recommended by vendor (Elekta AB, Stockholm, Sweden). For the 8 mm collimator diodes are still in good agreement with recommended values (within ±0.6%), while PinPoint gives 3% less value. For the 4 mm helmet Diodes P and E show over-response of 2.8% and 1.8%, respectively. For PinPoint chamber output factor of 4 mm collimator is 25% lower than Elekta value which is generally not consequence of angular dependence, but of volumetric averaging effect and lack of lateral electronic equilibrium. Diodes P and E represent good choice for Gamma-Knife dosimetry. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  14. Polar coordinated fuzzy controller based real-time maximum-power point control of photovoltaic system

    Energy Technology Data Exchange (ETDEWEB)

    Syafaruddin; Hiyama, Takashi [Department of Computer Science and Electrical Engineering of Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Karatepe, Engin [Department of Electrical and Electronics Engineering of Ege University, 35100 Bornova-Izmir (Turkey)

    2009-12-15

    It is crucial to improve the photovoltaic (PV) system efficiency and to develop the reliability of PV generation control systems. There are two ways to increase the efficiency of PV power generation system. The first is to develop materials offering high conversion efficiency at low cost. The second is to operate PV systems optimally. However, the PV system can be optimally operated only at a specific output voltage and its output power fluctuates under intermittent weather conditions. Moreover, it is very difficult to test the performance of a maximum-power point tracking (MPPT) controller under the same weather condition during the development process and also the field testing is costly and time consuming. This paper presents a novel real-time simulation technique of PV generation system by using dSPACE real-time interface system. The proposed system includes Artificial Neural Network (ANN) and fuzzy logic controller scheme using polar information. This type of fuzzy logic rules is implemented for the first time to operate the PV module at optimum operating point. ANN is utilized to determine the optimum operating voltage for monocrystalline silicon, thin-film cadmium telluride and triple junction amorphous silicon solar cells. The verification of availability and stability of the proposed system through the real-time simulator shows that the proposed system can respond accurately for different scenarios and different solar cell technologies. (author)

  15. Impacts of Satellite Orbit and Clock on Real-Time GPS Point and Relative Positioning.

    Science.gov (United States)

    Shi, Junbo; Wang, Gaojing; Han, Xianquan; Guo, Jiming

    2017-06-12

    Satellite orbit and clock corrections are always treated as known quantities in GPS positioning models. Therefore, any error in the satellite orbit and clock products will probably cause significant consequences for GPS positioning, especially for real-time applications. Currently three types of satellite products have been made available for real-time positioning, including the broadcast ephemeris, the International GNSS Service (IGS) predicted ultra-rapid product, and the real-time product. In this study, these three predicted/real-time satellite orbit and clock products are first evaluated with respect to the post-mission IGS final product, which demonstrates cm to m level orbit accuracies and sub-ns to ns level clock accuracies. Impacts of real-time satellite orbit and clock products on GPS point and relative positioning are then investigated using the P3 and GAMIT software packages, respectively. Numerical results show that the real-time satellite clock corrections affect the point positioning more significantly than the orbit corrections. On the contrary, only the real-time orbit corrections impact the relative positioning. Compared with the positioning solution using the IGS final product with the nominal orbit accuracy of ~2.5 cm, the real-time broadcast ephemeris with ~2 m orbit accuracy provided <2 cm relative positioning error for baselines no longer than 216 km. As for the baselines ranging from 574 to 2982 km, the cm-dm level positioning error was identified for the relative positioning solution using the broadcast ephemeris. The real-time product could result in <5 mm relative positioning accuracy for baselines within 2982 km, slightly better than the predicted ultra-rapid product.

  16. Impacts of Satellite Orbit and Clock on Real-Time GPS Point and Relative Positioning

    Directory of Open Access Journals (Sweden)

    Junbo Shi

    2017-06-01

    Full Text Available Satellite orbit and clock corrections are always treated as known quantities in GPS positioning models. Therefore, any error in the satellite orbit and clock products will probably cause significant consequences for GPS positioning, especially for real-time applications. Currently three types of satellite products have been made available for real-time positioning, including the broadcast ephemeris, the International GNSS Service (IGS predicted ultra-rapid product, and the real-time product. In this study, these three predicted/real-time satellite orbit and clock products are first evaluated with respect to the post-mission IGS final product, which demonstrates cm to m level orbit accuracies and sub-ns to ns level clock accuracies. Impacts of real-time satellite orbit and clock products on GPS point and relative positioning are then investigated using the P3 and GAMIT software packages, respectively. Numerical results show that the real-time satellite clock corrections affect the point positioning more significantly than the orbit corrections. On the contrary, only the real-time orbit corrections impact the relative positioning. Compared with the positioning solution using the IGS final product with the nominal orbit accuracy of ~2.5 cm, the real-time broadcast ephemeris with ~2 m orbit accuracy provided <2 cm relative positioning error for baselines no longer than 216 km. As for the baselines ranging from 574 to 2982 km, the cm–dm level positioning error was identified for the relative positioning solution using the broadcast ephemeris. The real-time product could result in <5 mm relative positioning accuracy for baselines within 2982 km, slightly better than the predicted ultra-rapid product.

  17. Drift-time measurement electronics

    International Nuclear Information System (INIS)

    Pernicka, M.

    1978-01-01

    The aim of the construction was to improve the time resolution without using the facility of time stretching, to have a fast read-out possibility, and to be still cheaper in price in comparison to other systems. A possibility was thus foreseen for using the firm Fairchild. These integrated circuits (IC) have, for example, a propagation delay of 0.75 ns for a gate. One can expect therefore less time jitter and less time difference between the different inputs. Furthermore this IC offers a greater flexibility and therefore the number of ICs decreases and distances become smaller. Working with clock frequencies up to 166.6 MHz is easily possible without running into timing problems. On the other hand, to make full use of the advantages of this IC, it was necessary to build the print as a multilayer. The only risk could be in the use of a completely new product. A further aim was to build for this system a second type of drift-time module with a short time range for measuring drift time and pulse length in rotated multiwire proportional chambers. A brief outline of the specifications of the different modules is given in table 1. (Auth.)

  18. Application of fluorescent tracer agent technology to point-of-care gastrointestinal permeability measurement

    Science.gov (United States)

    Dorshow, Richard B.; Shieh, Jeng-Jong; Rogers, Thomas E.; Hall-Moore, Carla; Shaikh, Nurmohammad; Talcott, Michael; Tarr, Phillip I.

    2016-03-01

    Gut dysfunction, often accompanied by increased mucosal permeability to gut contents, frequently accompanies a variety of human intestinal inflammatory conditions. These disorders include inflammatory bowel diseases (e.g., Crohn's Disease) and environmental enteropathy and enteric dysfunction, a condition strongly associated with childhood malnutrition and stunting in resource poor areas of the world. The most widely used diagnostic assay for gastrointestinal permeability is the lactulose to mannitol ratio (L:M) measurement. These sugars are administered orally, differentially absorbed by the gut, and then cleared from the body by glomerular filtration in the kidney. The amount of each sugar excreted in the urine is measured. The larger sugar, lactulose, is minimally absorbed through a healthy gut. The smaller sugar, mannitol, in contrast, is readily absorbed through both a healthy and injured gut. Thus a higher ratio of lactulose to mannitol reflects increased intestinal permeability. However, several issues prevent widespread use of the L:M ratio in clinical practice. Urine needs to be collected over time intervals of several hours, the specimen then needs to be transported to an analytical laboratory, and sophisticated equipment is required to measure the concentration of each sugar in the urine. In this presentation we show that fluorescent tracer agents with molecular weights similar to those of the sugars, selected from our portfolio of biocompatible renally cleared fluorophores, mimic the L:M ratio test for gut permeability. This fluorescent tracer agent detection technology can be used to overcome the limitations of the L:M assay, and is amenable to point-of-care clinical use.

  19. Visitor’s Guide to Oliktok Point Atmospheric Radiation Measurement Climate Research Facility, North Slope of Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Desilets, Darin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Helsel, Fred M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bendure, Al O. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lucero, Daniel A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ivey, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dexheimer, Danielle N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-04-01

    The importance of Oliktok Point, Alaska, as a focal point for climate research in the Arctic continues to grow with the addition of a U.S. Department of Energy (DOE) Atmospheric Radiation Monitoring (ARM) Climate Research Facility Mobile Facility (AMF) and the expansion of infrastructure to support airborne measurements. The site hosts a suite of instruments for making multi-year, high-fidelity atmospheric measurements; serves as a base of operations for field campaigns; and contains the only Restricted Airspace and Warning Area in the U.S. Arctic, which enables the use of unmanned aircraft systems. The use of this site by climate researchers involves several considerations, including its remoteness, harsh climate, and location amid the North Slope oilfields. This guide is intended to help visitors to Oliktok Point navigate this unique physical and administrative environment, and thereby facilitate safe and productive operations.

  20. EXAMINATION ABOUT INFLUENCE FOR PRECISION OF 3D IMAGE MEASUREMENT FROM THE GROUND CONTROL POINT MEASUREMENT AND SURFACE MATCHING

    Directory of Open Access Journals (Sweden)

    T. Anai

    2015-05-01

    Full Text Available As the 3D image measurement software is now widely used with the recent development of computer-vision technology, the 3D measurement from the image is now has acquired the application field from desktop objects as wide as the topography survey in large geographical areas. Especially, the orientation, which used to be a complicated process in the heretofore image measurement, can be now performed automatically by simply taking many pictures around the object. And in the case of fully textured object, the 3D measurement of surface features is now done all automatically from the orientated images, and greatly facilitated the acquisition of the dense 3D point cloud from images with high precision. With all this development in the background, in the case of small and the middle size objects, we are now furnishing the all-around 3D measurement by a single digital camera sold on the market. And we have also developed the technology of the topographical measurement with the air-borne images taken by a small UAV [1~5]. In this present study, in the case of the small size objects, we examine the accuracy of surface measurement (Matching by the data of the experiments. And as to the topographic measurement, we examine the influence of GCP distribution on the accuracy by the data of the experiments. Besides, we examined the difference of the analytical results in each of the 3D image measurement software. This document reviews the processing flow of orientation and the 3D measurement of each software and explains the feature of the each software. And as to the verification of the precision of stereo-matching, we measured the test plane and the test sphere of the known form and assessed the result. As to the topography measurement, we used the air-borne image data photographed at the test field in Yadorigi of Matsuda City, Kanagawa Prefecture JAPAN. We have constructed Ground Control Point which measured by RTK-GPS and Total Station. And we show the results

  1. Examination about Influence for Precision of 3d Image Measurement from the Ground Control Point Measurement and Surface Matching

    Science.gov (United States)

    Anai, T.; Kochi, N.; Yamada, M.; Sasaki, T.; Otani, H.; Sasaki, D.; Nishimura, S.; Kimoto, K.; Yasui, N.

    2015-05-01

    As the 3D image measurement software is now widely used with the recent development of computer-vision technology, the 3D measurement from the image is now has acquired the application field from desktop objects as wide as the topography survey in large geographical areas. Especially, the orientation, which used to be a complicated process in the heretofore image measurement, can be now performed automatically by simply taking many pictures around the object. And in the case of fully textured object, the 3D measurement of surface features is now done all automatically from the orientated images, and greatly facilitated the acquisition of the dense 3D point cloud from images with high precision. With all this development in the background, in the case of small and the middle size objects, we are now furnishing the all-around 3D measurement by a single digital camera sold on the market. And we have also developed the technology of the topographical measurement with the air-borne images taken by a small UAV [1~5]. In this present study, in the case of the small size objects, we examine the accuracy of surface measurement (Matching) by the data of the experiments. And as to the topographic measurement, we examine the influence of GCP distribution on the accuracy by the data of the experiments. Besides, we examined the difference of the analytical results in each of the 3D image measurement software. This document reviews the processing flow of orientation and the 3D measurement of each software and explains the feature of the each software. And as to the verification of the precision of stereo-matching, we measured the test plane and the test sphere of the known form and assessed the result. As to the topography measurement, we used the air-borne image data photographed at the test field in Yadorigi of Matsuda City, Kanagawa Prefecture JAPAN. We have constructed Ground Control Point which measured by RTK-GPS and Total Station. And we show the results of analysis made

  2. Experimental determination of the effective point of measurement for various detectors used in photon and electron beam dosimetry.

    Science.gov (United States)

    Looe, Hui Khee; Harder, Dietrich; Poppe, Björn

    2011-07-21

    The subject of this study is the 'shift of the effective point of measurement', Δz, well known as a method of correction compensating for the 'displacement effect' in photon and electron beam dosimetry. Radiochromic EBT 1 films have been used to measure the 'true' TPR curves of 6 and 15 MV photons and 6 and 9 MeV electrons in the solid water-equivalent material RW3. For the Roos and Markus chambers, the cylindrical 'PinPoint', 'Semiflex' and 'Rigid-Stem' chambers, the 2D-Array and the E-type silicon diode (all from PTW-Freiburg), the positions of the effective points of measurement have been determined by direct or indirect comparison between their TPR curves and those of the EBT 1 film. Both for the Roos and Markus chambers, we found Δz = (0.4 ± 0.1) mm, which confirms earlier experimental and Monte Carlo results, but means a shortcoming of the 'water-equivalent window thickness' formula. For the cylindrical chambers, the ratio Δz/r was observed to increase with r, confirming a recent Monte Carlo prediction by Tessier (2010 E2-CN-182, Paper no 147, IDOS, Vienna) as well as the experimental observations by Johansson et al (1978 IAEA Symp. Proc. (Vienna) IAEA-SM-222/35 pp 243-70). According to a theoretical consideration, the shift of the effective point of measurement from the reference point of the detector is caused by a gradient of the fluence of the ionizing particles. As the experiments have shown, the value of Δz depends on the construction of the detector, but remains invariant under changes of radiation quality and depth. Other disturbances, which do not belong to the class of 'gradient effects', are not corrected by shifting the effective point of measurement.

  3. Time measurements for thermalequilibrium in spodumene crystals

    International Nuclear Information System (INIS)

    Fujii, A.T.; Isotani, S.

    1982-01-01

    Experiments for measurement of time taken to reach thermal equilibrium in Spodumene crystals - 2mm to 5,4mm thick - in the temperature range 100 0 to 250 0 C are described. The measurements indicate a linear relationship between time and thickenes for heating as well as for cooling. Difference in thermal equilibrium time for heating and for cooling is about of 20 seconds. (author) [pt

  4. Dead time effects in laser Doppler anemometry measurements

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Buchhave, Preben; George, William K.

    2014-01-01

    frequency range, starting around the cutoff frequency due to the finite size of the MV. Using computer-generated data mimicking the LDA data, these effects have previously been shown to appear due to the effect of dead time, i.e., the finite time during which the system is not able to acquire new...... measurements. These dead times can be traced back to the fact that the burst-mode LDA cannot measure more than one signal burst at a time. Since the dead time is approximately equal to the residence time for a particle traversing a measurement volume, we are dealing with widely varying dead times, which...

  5. Optimal distribution of temperature points in μSR measurement of local field

    International Nuclear Information System (INIS)

    Pełka, R.; Zieliński, P.M.; Konieczny, P.; Wasiutyński, T.

    2013-01-01

    Three possible distributions of temperature points in the μSR measurement of local field (order parameter) are discussed. The least square method is applied to estimate the scale of the deviations of the fitted parameters from the true values. It indicates that the distribution corresponding to a uniform section of the order parameter values (uniform-in-signal) incurs the smallest errors. The distribution constructed on the basis of the zeros of the Chebyshev polynomials yields comparable uncertainties, while the uniform-in-temperature distribution turns out to be least effective incurring considerably larger errors. These findings can be useful while planning an order parameter measurement in the μSR experiment

  6. The reliability of point-of-care prothrombin time testing. A comparison of CoaguChek S and XS INR measurements with hospital laboratory monitoring.

    LENUS (Irish Health Repository)

    Ryan, F

    2010-02-01

    The development of point-of-care (POC) testing devices enables patients to test their own international normalized ratio (INR) at home. However, previous studies have shown that when compared with clinical laboratory values, statistically significant differences may occur between the two methods of INR measurement. The aim of this study was to evaluate the accuracy of the CoaguChek S and XS POC meters relative to clinical laboratory measurements. As part of a randomized, crossover patient self-testing (PST) study at Cork University Hospital, patients were randomized to 6 months PST or 6 months routine care by the anticoagulation management service. During the PST arm of the study, patients measured their INR at home using the CoaguChek S or XS POC meter. External quality control was performed at enrollment, 2 months and 4 months by comparing the POC measured INR with the laboratory determined value. One hundred and fifty-one patients provided 673 paired samples. Good correlation was shown between the two methods of determination (r = 0.91), however, statistically significant differences did occur. A Bland-Altman plot illustrated good agreement of INR values between 2.0 and 3.5 INR units but there was increasing disagreement as the INR rose above 3.5. Eighty-seven per cent of all dual measurements were within the recommended 0.5 INR units of each other. This study adds to the growing evidence that POC testing is a reliable and safe alternative to hospital laboratory monitoring but highlights the importance of external quality control when these devices are used for monitoring oral anticoagulation.

  7. Nanosecond time measurements of single pulse

    International Nuclear Information System (INIS)

    Xing Jingyuan; Cheng Shiyuan

    1986-01-01

    This report mainly describes the principle specification of circuit design and time-interval calibrations of model SHS 500 time-to-digital converter. Its range is 12 to 500 ns, with six ranges: 50, 100, 200, 300, 400 and 500 ns. The precision of measured time-interval is 0.3% of full scale and time resolution is 0.1% of full scale

  8. An Energy-Based Similarity Measure for Time Series

    Directory of Open Access Journals (Sweden)

    Pierre Brunagel

    2007-11-01

    Full Text Available A new similarity measure, called SimilB, for time series analysis, based on the cross-ΨB-energy operator (2004, is introduced. ΨB is a nonlinear measure which quantifies the interaction between two time series. Compared to Euclidean distance (ED or the Pearson correlation coefficient (CC, SimilB includes the temporal information and relative changes of the time series using the first and second derivatives of the time series. SimilB is well suited for both nonstationary and stationary time series and particularly those presenting discontinuities. Some new properties of ΨB are presented. Particularly, we show that ΨB as similarity measure is robust to both scale and time shift. SimilB is illustrated with synthetic time series and an artificial dataset and compared to the CC and the ED measures.

  9. Validity of the Water Hammer Formula for Determining Regional Aortic Pulse Wave Velocity: Comparison of One-Point and Two-Point (Foot-to-Foot) Measurements Using a Multisensor Catheter in Human.

    Science.gov (United States)

    Hanya, Shizuo

    2013-01-01

    Lack of high-fidelity simultaneous measurements of pressure and flow velocity in the aorta has impeded the direct validation of the water-hammer formula for estimating regional aortic pulse wave velocity (AO-PWV1) and has restricted the study of the change of beat-to-beat AO-PWV1 under varying physiological conditions in man. Aortic pulse wave velocity was derived using two methods in 15 normotensive subjects: 1) the conventional two-point (foot-to-foot) method (AO-PWV2) and 2) a one-point method (AO-PWV1) in which the pressure velocity-loop (PV-loop) was analyzed based on the water hammer formula using simultaneous measurements of flow velocity (Vm) and pressure (Pm) at the same site in the proximal aorta using a multisensor catheter. AO-PWV1 was calculated from the slope of the linear regression line between Pm and Vm where wave reflection (Pb) was at a minimum in early systole in the PV-loop using the water hammer formula, PWV1 = (Pm/Vm)/ρ, where ρ is the blood density. AO-PWV2 was calculated using the conventional two-point measurement method as the distance/traveling time of the wave between 2 sites for measuring P in the proximal aorta. Beat-to-beat alterations of AO-PWV1 in relationship to aortic pressure and linearity of the initial part of the PV-loop during a Valsalva maneuver were also assessed in one subject. The initial part of the loop became steeper in association with the beat-to-beat increase in diastolic pressure in phase 4 during the Valsalva maneuver. The linearity of the initial part of the PV-loop was maintained consistently during the maneuver. Flow velocity vs. pressure in the proximal aorta was highly linear during early systole, with Pearson's coefficients ranging from 0.9954 to 0.9998. The average values of AO-PWV1 and AO-PWV2 were 6.3 ± 1.2 and 6.7 ± 1.3 m/s, respectively. The regression line of AO-PWV1 on AO-PWV2 was y = 0.95x + 0.68 (r = 0.93, p <0.001). This study concluded that the water-hammer formula (one-point method) provides

  10. Prediction uncertainty of plume characteristics derived from a small number of measuring points

    Science.gov (United States)

    French, H. K.; van der Zee, S. E. A. T. M.; Leijnse, A.

    A small number of measuring points may inflict a bias on the characterisation of flow and transport based on field experiments in the unsaturated zone. Simulation of pure advective transport of a Gaussian plume through a setup of 30 regularly placed measuring points revealed regular temporal fluctuations about the real spatial moments. An irregular setup predicted both irregular fluctuations and larger discrepancies from the real value. From these considerations, a regular setup is recommended. Spatial moments were sensitive to the plume size relative to the distance between individual measuring points. To reduce prediction errors of the variance, the distance between the measuring points should be less than twice the standard deviation of the examined plume. The total size of the setup should cover several standard deviations of the plume to avoid mass being lost from the monitored area. Numerical simulations of a dispersing plume (comparing calculations based on 9000 nodes with 30 measuring points) revealed that vertical and horizontal centres of mass were predicted well at all degrees of heterogeneity, and the same was the case for horizontal variances. Vertical variances were more susceptible to prediction errors, but estimates were of the same order of magnitude as the real values. Résumé Lorsque l'on cherche à caractériser l'écoulement et le transport à partir d'expériences de terrain dans la zone saturée, il arrive qu'un petit nombre de points introduisent un biais. La simulation d'un transport purement advectif d'un panache gaussien au travers d'un ensemble de 30 points de mesures espacés régulièrement fait apparaître des variations temporelles régulières autour des moments spatiaux réels. Un ensemble irrégulier conduit à prédire à la fois des variations irrégulières et de plus grandes divergences par rapport à la valeur réelle. A partir de ces constations, un ensemble régulier est recommandé. Les moments spatiaux sont apparus

  11. Three-point method for measuring the geometric error components of linear and rotary axes based on sequential multilateration

    International Nuclear Information System (INIS)

    Zhang, Zhenjiu; Hu, Hong

    2013-01-01

    The linear and rotary axes are fundamental parts of multi-axis machine tools. The geometric error components of the axes must be measured for motion error compensation to improve the accuracy of the machine tools. In this paper, a simple method named the three point method is proposed to measure the geometric error of the linear and rotary axes of the machine tools using a laser tracker. A sequential multilateration method, where uncertainty is verified through simulation, is applied to measure the 3D coordinates. Three noncollinear points fixed on the stage of each axis are selected. The coordinates of these points are simultaneously measured using a laser tracker to obtain their volumetric errors by comparing these coordinates with ideal values. Numerous equations can be established using the geometric error models of each axis. The geometric error components can be obtained by solving these equations. The validity of the proposed method is verified through a series of experiments. The results indicate that the proposed method can measure the geometric error of the axes to compensate for the errors in multi-axis machine tools.

  12. Measurements of the Received Signal Level and Service Coverage Area at the IEEE 802.11 Access Point in the Building

    Science.gov (United States)

    Gunantara, N.; Sudiarta, P. K.; Prasetya, AAN A. I.; Dharma, A.; Gde Antara, I. N.

    2018-04-01

    Access point (AP) is part of a Wireless Local Access Network (WLAN) with its communications using WiFi. AP is used to transmit and receive data to users/clients. The ability of AP to serve users/clients depends on many factors. Moreover, if AP is applied in conditions inside the building. In this study, AP is installed at two points inside the building and then measured in the form of the received signal level (RSL) and service coverage area. One AP measured its performance by 26 measurement points and the other AP measured its performance by 20 measurement points. When AP has measured its performance then another AP position is switched off. Based on the measurement result, the received signal level value is the highest value is about -47 dBm at a distance of 3.2 m, while the lowest is about -79 dBm at a 9.21 m because it is on barrier 2 walls. While based on service coverage area, the area which is far away from the AP then the quality of service becomes bad because the transmitted signal is weakening caused by the distance and the loss of the wall.

  13. Transcutaneous oxygen pressure measurement in diabetic foot ulcers: mean values and cut-point for wound healing.

    Science.gov (United States)

    Yang, Chuan; Weng, Huan; Chen, Lihong; Yang, Haiyun; Luo, Guangming; Mai, Lifang; Jin, Guoshu; Yan, Li

    2013-01-01

    The purpose of this study was to investigate mean values and cut-point of transcutaneous oxygen pressure (TcPO2) measurement in patients with diabetic foot ulcers. Prospective, descriptive study. Sixty-one patients with diabetes mellitus and foot ulcers comprised the sample. The research setting was Sun Yat-sen Memorial Hospital of SunYat-sen University, Guangzhou, China. Participants underwent transcutaneous oxygen (TcPO2) measurement at the dorsum of foot. Patients were classified into 3 groups according to clinical outcomes: (1) ulcers healed with intact skin group, (2) ulcer improved, and (3) ulcer failed to improve. TcPO2 was assessed and cut-points for predicting diabetic foot ulcer healing were calculated. Thirty-six patients healed with intact skin, 8 experienced improvement, and 17 showed no improvement. Mean TcPO2 levels were significantly higher (Pfoot ulcers. In contrast, all patients with TcPO2≥ 40 mmHg achieved wound closure. Measurement of TcPO2 in the supine position revealed a cut-point value of 25 mmHg as the best threshold for predicting diabetic foot ulcer healing; the area under the curve using this cut-point was 0.838 (95% confidence interval = 0.700-0.976). The sensitivity, specificity, positive predictive value, and negative predictive value for TxPO2 were 88.6%, 82.4%, 90.7%, and 72.2%, respectively. TcPO2≥ 40 mmHg was associated with diabetic foot ulcer healing, but a TcPO2≤ 10 mmHg was associated with failure of wound healing. We found that a cut-point of 25 mmHg was most predictive of diabetic foot ulcer healing.

  14. Transit time measurement of Juqueri river waters

    International Nuclear Information System (INIS)

    Plata Bedmar, E.; Garcia A, E.; Albuquerque, A.M. de; Sanchez, W.

    1975-01-01

    The time of travel of the Juqueri River water through the east branch of the Pirapora Reservoir was measured using radioactive tracers (6 Ci 131 I in Kl Solution). The changes in Juqueri River flow rate were also measured during the run. The center of mass of the radioactive cloud was used for the time of travel calculations. Six measurements of the Juqueri River flow rate were perfomed in different days, using the total count method. Fifty, millicuries of 131 I were used in each run. The results of time travel obtained under non-steady conditions, and their correction for steady state are also discussed

  15. Use of dew-point hygrometry, direct sweat collection, and measurement of body water losses to determine sweating rates in exercising horses.

    Science.gov (United States)

    Kingston, J K; Geor, R J; McCutcheon, L J

    1997-02-01

    To compare dew-point hygrometry, direct sweat collection, and measurement of body water loss as methods for determination of sweating rate (SR) in exercising horses. 6 exercise-trained Thoroughbreds. SR was measured in 6 horses exercising at 40% of the speed that elicited maximum oxygen consumption for 45 km, with a 15-minute rest at the end of each 15-km phase. Each horse completed 2 exercise trials. Dew-point hygrometry, as a method of local SR determination, was validated in vitro by measurement of rate of evaporative water loss. During exercise, local SR was determined every 10 minutes by the following 2 methods: (1) dew-point hygrometry on the neck and lateral area of the thorax, and (2) on the basis of the volume of sweat collected from a sealed plastic pouch attached to the lateral area of the thorax. Mean whole body SR was calculated from total body water loss incurred during exercise. Evaporation rate measured by use of dew-point hygrometry was significantly correlated (r2 = 0.92) with the actual rate of evaporative water loss. There was a similar pattern of change in SR measured by dew-point hygrometry on the neck and lateral area of the thorax during exercise, with a significantly higher SR on the neck. The SR measured on the thorax by direct sweat collection and by dew-point hygrometry were of similar magnitude. Mean whole body SR calculated from total body water loss was not significantly different from mean whole body SR estimated from direct sweat collection or dew-point hygrometry measurements on the thorax. Dew-point hygrometry and direct sweat collection are useful methods for determination of local SR in horses during prolonged, steady-state exercise in moderate ambient conditions. Both methods of local SR determination provide an accurate estimated of whole body SR.

  16. Scaling point/plot measurements of greenhouse gas fluxes, balances and intensities to whole-farms and landscapes

    NARCIS (Netherlands)

    Rosenstock, T.S.; Rufino, Mariana; Chirinda, N.; Bussel, van L.G.J.; Reidsma, P.; Butterbach-Bahl, K.

    2015-01-01

    Measurements of nutrient stocks and greenhouse gas (GHG) fluxes are typically collected at very local scales (<1 to 30 m2) and then extrapolated to estimate impacts at larger spatial extents (farms, landscapes, or even countries). Translating point measurements to higher levels of aggregation is

  17. Criticism on Jäntti's Three Point Method on curtailing gas adsorption measurements

    NARCIS (Netherlands)

    Massen, C.H.; Poulis, J.A.; Robens, E.

    2000-01-01

    Jäntti introduced a method to reduce the time required for the stepwise measurement of adsorption isotherms (Jäntti et al., Progress in Vacuum Microbalance Techniques, Vol. 1, Heyden, London, pp. 345–353, 1972). After a pressure change he measured the adsorbed mass three times and calculated its

  18. A consideration of a measuring point of ventricular dilatation on CT scanning

    International Nuclear Information System (INIS)

    Kuno, Koichi; Miyake, Kazuo

    1980-01-01

    Ventricular dilatation has been judged by pneumo-ventricurography, pneumo-encepharography and carotid angiography (CAG), though all these procedures are very uncomfortable for patients. On the other hand, the CT scan is very easy as a follow-up study of ventricular dilatation for a weak patient. We carried out the CT scan (Hitachi CT-H 250 Scanner, NaI detector) and CAG on 84 cases. The ventricular dilatation was judged by the degree of outstretch of the strio-thalamic vein on an AP view of the phrebogram, classified into 3 types. For all three types classified by the phrebogram, we studied various measuring points of the ventricle on the CT scan. The portions measured on the CT scan were: (1) the frontal cerebro-ventricular index (F-CVI), (2) the bicaudate cerebro-ventricular index (Bicaud-CVI), and (3) the maximum Monro's cerebro-ventricular index (M-CVI), the width of the frontal horn, and the thickness of the ventricular body. The following results were obtained: (1) In measuring the ventricular size on the CT scan, the most interrelated point with the ventricular dilatation is the M-CVI - the ratio of the largest width of the body through the Monro foramen to the width of the brain. In this case, however, the width of the frontal horn and of the body should also be considered. (2) Voltage and electric current changed the EMI-number, but did not alter the measuring value. In this case, the width and the level should be kept constant. (3) The group with the marked ventricular dilatation has a larger value of the CT scan than its value of GAG. (4) The normal value of the M-CVI is 24 +- 3%, moreover, the width of the frontal horn is less than 10 mm, and the thickness of the ventricular body is less than 17 mm. (author)

  19. Laser Dew-Point Hygrometer

    Science.gov (United States)

    Matsumoto, Shigeaki; Toyooka, Satoru

    1995-01-01

    A rough-surface-type automatic dew-point hygrometer was developed using a laser diode and an optical fiber cable. A gold plate with 0.8 µ m average surface roughness was used as a surface for deposition of dew to facilitate dew deposition and prevent supersaturation of water vapor at the dew point. It was shown experimentally that the quantity of dew deposited can be controlled to be constant at any predetermined level, and is independent of the dew point to be measured. The dew points were measured in the range from -15° C to 54° C in which the temperature ranged from 0° C to 60° C. The measurement error of the dew point was ±0.5° C which was equal to below ±2% in relative humidity in the above dew-point range.

  20. Measurement of evaporative water loss in small animals by dew-point hygrometry.

    Science.gov (United States)

    Bernstein, M H; Hudson, D M; Stearns, J M; Hoyt, R W

    1977-08-01

    This paper presents the procedures and equations to be utilized for measurement of evaporative water loss (mw), by use of the dew-point hygrometer, in small animals exposed to air containing water vapor in an open-flow system. The system accounted accurately for the water evaporated from a bubble flask. In addition, hygrometric measurements of pulmocutaneous mw in pigeons (Columba livia, mean mass 0.31 kg) agreed closely with simultaneous gravimetric measurements, utilizing a desiccant in the sample stream, in a manner independently of air temperature (Ta, 20 or 40 degrees C), ambient water vapor pressure (PW, 4-16 10(2) Pa), or mw (5-66 mg-min-1). Evaporation in pigeons was independent of PW at 20 degrees C, but increased with decreasing PW at 40 degrees C, suggesting differences in ventilatory adjustments to changes in PW at the two temperatures.

  1. Geospatial exposure to point-of-sale tobacco: real-time craving and smoking-cessation outcomes.

    Science.gov (United States)

    Kirchner, Thomas R; Cantrell, Jennifer; Anesetti-Rothermel, Andrew; Ganz, Ollie; Vallone, Donna M; Abrams, David B

    2013-10-01

    Little is known about the factors that drive the association between point-of-sale marketing and behavior, because methods that directly link individual-level use outcomes to real-world point-of-sale exposure are only now beginning to be developed. Daily outcomes during smoking cessation were examined as a function of both real-time geospatial exposure to point-of-sale tobacco (POST) and subjective craving to smoke. Continuous individual geospatial location data collected over the first month of a smoking-cessation attempt in 2010-2012 (N=475) were overlaid on a POST outlet geodatabase (N=1060). Participants' mobility data were used to quantify the number of times they came into contact with a POST outlet. Participants recorded real-time craving levels and smoking status via ecological momentary assessment (EMA) on cellular telephones. The final data set spanned a total of 12,871 days of EMA and geospatial tracking. Lapsing was significantly more likely on days with any POST contact (OR=1.19, 95% CI=1.18, 1.20), and increasingly likely as the number of daily POST contacts increased (OR=1.07, 95% CI=1.06, 1.08). Overall, daily POST exposure was significantly associated with lapsing when craving was low (OR=1.22, 95% CI=1.20, 1.23); high levels of craving were more directly associated with lapse outcomes. These data shed light on the way mobility patterns drive a dynamic interaction between individuals and the POST environment, demonstrating that quantification of individuals' exposure to POST marketing can be used to identify previously unrecognized patterns of association among individual mobility, the built environment, and behavioral outcomes. © 2013 American Journal of Preventive Medicine.

  2. End-point impedance measurements across dominant and nondominant hands and robotic assistance with directional damping.

    Science.gov (United States)

    Erden, Mustafa Suphi; Billard, Aude

    2015-06-01

    The goal of this paper is to perform end-point impedance measurements across dominant and nondominant hands while doing airbrush painting and to use the results for developing a robotic assistance scheme. We study airbrush painting because it resembles in many ways manual welding, a standard industrial task. The experiments are performed with the 7 degrees of freedom KUKA lightweight robot arm. The robot is controlled in admittance using a force sensor attached at the end-point, so as to act as a free-mass and be passively guided by the human. For impedance measurements, a set of nine subjects perform 12 repetitions of airbrush painting, drawing a straight-line on a cartoon horizontally placed on a table, while passively moving the airbrush mounted on the robot's end-point. We measure hand impedance during the painting task by generating sudden and brief external forces with the robot. The results show that on average the dominant hand displays larger impedance than the nondominant in the directions perpendicular to the painting line. We find the most significant difference in the damping values in these directions. Based on this observation, we develop a "directional damping" scheme for robotic assistance and conduct a pilot study with 12 subjects to contrast airbrush painting with and without robotic assistance. Results show significant improvement in precision with both dominant and nondominant hands when using robotic assistance.

  3. New algorithm using only one variable measurement applied to a maximum power point tracker

    Energy Technology Data Exchange (ETDEWEB)

    Salas, V.; Olias, E.; Lazaro, A.; Barrado, A. [University Carlos III de Madrid (Spain). Dept. of Electronic Technology

    2005-05-01

    A novel algorithm for seeking the maximum power point of a photovoltaic (PV) array for any temperature and solar irradiation level, needing only the PV current value, is proposed. Satisfactory theoretical and experimental results are presented and were obtained when the algorithm was included on a 100 W 24 V PV buck converter prototype, using an inexpensive microcontroller. The load of the system used was a battery and a resistance. The main advantage of this new maximum power point tracking (MPPT), when is compared with others, is that it only uses the measurement of the photovoltaic current, I{sub PV}. (author)

  4. Stationary point of the radiometric control of cesium contamination of agricultural animals

    International Nuclear Information System (INIS)

    1997-01-01

    Stationary point of the radiometric control of cesium contamination of an agricultural animals. Is intended for vital measurements of the contents of radiocesium in muscular tissue of a cattle. Can be used on cattle-breeding farms, providing points, in meat factories and personal facilities. As a base means for accommodation of the control point the motor-car is used. Design of the car allows to automate operations on deployment of the control point on a place and translation of one to a transport mode. Limits of measured specific activity of cesium contamination of a cattle is up 5*10 -9 to 5*10 -6 Ci/kg. The basic error on the bottom limit of measurement at confidence coefficient 0,95 is no more than 30%. Measurement time for the bottom limit of determined specific activity is no more than 30 s. There is automatic measurement mode. Type of a power is 220 V, 50 Hz. Range of working temperatures is up -15 to +35 centigrade. Relative humidity is no more than 98% at 25 centigrade. External gamma background is till 0.035 mR/h. Time of installation and dismantle of stationary control point is no more than 1,5 hours. The direct radiometric control in divo allows to fulfil and to use biotechnological process of removing of cesium isotopes from body of animals for decrease of levels of radioactive contamination

  5. The recovery of a time-dependent point source in a linear transport equation: application to surface water pollution

    International Nuclear Information System (INIS)

    Hamdi, Adel

    2009-01-01

    The aim of this paper is to localize the position of a point source and recover the history of its time-dependent intensity function that is both unknown and constitutes the right-hand side of a 1D linear transport equation. Assuming that the source intensity function vanishes before reaching the final control time, we prove that recording the state with respect to the time at two observation points framing the source region leads to the identification of the source position and the recovery of its intensity function in a unique manner. Note that at least one of the two observation points should be strategic. We establish an identification method that determines quasi-explicitly the source position and transforms the task of recovering its intensity function into solving directly a well-conditioned linear system. Some numerical experiments done on a variant of the water pollution BOD model are presented

  6. Combinations of Epoch Durations and Cut-Points to Estimate Sedentary Time and Physical Activity among Adolescents

    Science.gov (United States)

    Fröberg, Andreas; Berg, Christina; Larsson, Christel; Boldemann, Cecilia; Raustorp, Anders

    2017-01-01

    The purpose of the current study was to investigate how combinations of different epoch durations and cut-points affect the estimations of sedentary time and physical activity in adolescents. Accelerometer data from 101 adolescents were derived and 30 combinations were used to estimate sedentary time, light, moderate, vigorous, and combined…

  7. New definitions of pointing stability - ac and dc effects. [constant and time-dependent pointing error effects on image sensor performance

    Science.gov (United States)

    Lucke, Robert L.; Sirlin, Samuel W.; San Martin, A. M.

    1992-01-01

    For most imaging sensors, a constant (dc) pointing error is unimportant (unless large), but time-dependent (ac) errors degrade performance by either distorting or smearing the image. When properly quantified, the separation of the root-mean-square effects of random line-of-sight motions into dc and ac components can be used to obtain the minimum necessary line-of-sight stability specifications. The relation between stability requirements and sensor resolution is discussed, with a view to improving communication between the data analyst and the control systems engineer.

  8. Measurements of the fuel temperature coefficient of reactivity at Hinkley Point 'B': 1981

    International Nuclear Information System (INIS)

    George, T.A.

    1982-03-01

    Measurements of the fuel temperature coefficient of reactivity made at Hinkley Point 'B' AGR in 1981 are described. These measurements follow earlier tests reported in e.g. RD/B/N4846 and are part of a series of measurements designed to support theoretical estimates of the change of fuel temperature coefficient as a function of core irradiation. Low and high power measurements were made at a mean core irradiation of 1170GWD. As previously, the measurements at both power levels show agreement with theoretical predictions to within the estimated experimental errors. Recent measurements (mean core irradiation >500GWD) show evidence of a small systematic difference between measured and theoretical values with the experimental values being approximately equal to 0.1mN/ 0 C more positive than the theoretical ones. The measured value of αsub(U) at high power was -0.64+-0.10mN/ 0 C and the low power value, corrected theoretically to normal operating conditions, was also -0.64+-0.10mN/ 0 C. (author)

  9. Deformation analyse of the high point field Košická Nová Ves

    Directory of Open Access Journals (Sweden)

    Sedlák Vladimír

    2003-09-01

    Full Text Available From the science point of view the deformation measurements serve to an objective determination of movements and from the technical point of view the deformation measurements serve to a determinantion of the building technologies and the construction procedures. Detrmined movements by means of using the geodetic terrestrial or satellite navigation technologies give informations about displacements in a concrete time information on the base of repeated geodetic measurements in the concrete time intervals (epochs.Level deformation investigation of the point of the monitoring station stabled in the fill slope territory Košická Nová Ves is the main task of the presented paper. Level measurements are realized in autumn 2000 (the epoch 200.9 - it is considered as the first epoch of the deformation measurement, and in spring 2001 (the epoch 2001.3 – it is considered as the second epoch of the deformation measurement.

  10. Inflection point inflation and time dependent potentials in string theory

    International Nuclear Information System (INIS)

    Itzhaki, Nissan; Kovetz, Ely D.

    2007-01-01

    We consider models of inflection point inflation. The main drawback of such models is that they suffer from the overshoot problem. Namely the initial condition should be fine tuned to be near the inflection point for the universe to inflate. We show that stringy realizations of inflection point inflation are common and offer a natural resolution to the overshoot problem

  11. [A new measurement method of time-resolved spectrum].

    Science.gov (United States)

    Shi, Zhi-gang; Huang, Shi-hua; Liang, Chun-jun; Lei, Quan-sheng

    2007-02-01

    A new method for measuring time-resolved spectrum (TRS) is brought forward. Programming with assemble language controlled the micro-control-processor (AT89C51), and a kind of peripheral circuit constituted the drive circuit, which drived the stepping motor to run the monochromator. So the light of different kinds of expected wavelength could be obtained. The optical signal was transformed to electrical signal by optical-to-electrical transform with the help of photomultiplier tube (Hamamatsu 1P28). The electrical signal of spectrum data was transmitted to the oscillograph. Connecting the two serial interfaces of RS232 between the oscillograph and computer, the electrical signal of spectrum data could be transmitted to computer for programming to draw the attenuation curve and time-resolved spectrum (TRS) of the swatch. The method for measuring time-resolved spectrum (TRS) features parallel measurement in time scale but serial measurement in wavelength scale. Time-resolved spectrum (TRS) and integrated emission spectrum of Tb3+ in swatch Tb(o-BBA)3 phen were measured using this method. Compared with the real time-resolved spectrum (TRS). It was validated to be feasible, credible and convenient. The 3D spectra of fluorescence intensity-wavelength-time, and the integrated spectrum of the swatch Tb(o-BBA)3 phen are given.

  12. The design of visible system for improving the measurement accuracy of imaging points

    Science.gov (United States)

    Shan, Qiu-sha; Li, Gang; Zeng, Luan; Liu, Kai; Yan, Pei-pei; Duan, Jing; Jiang, Kai

    2018-02-01

    It has a widely applications in robot vision and 3D measurement for binocular stereoscopic measurement technology. And the measure precision is an very important factor, especially in 3D coordination measurement, high measurement accuracy is more stringent to the distortion of the optical system. In order to improving the measurement accuracy of imaging points, to reducing the distortion of the imaging points, the optical system must be satisfied the requirement of extra low distortion value less than 0.1#65285;, a transmission visible optical lens was design, which has characteristic of telecentric beam path in image space, adopted the imaging model of binocular stereo vision, and imaged the drone at the finity distance. The optical system was adopted complex double Gauss structure, and put the pupil stop on the focal plane of the latter groups, maked the system exit pupil on the infinity distance, and realized telecentric beam path in image space. The system mainly optical parameter as follows: the system spectrum rangement is visible light wave band, the optical effective length is f '=30mm, the relative aperture is 1/3, and the fields of view is 21°. The final design results show that the RMS value of the spread spots of the optical lens in the maximum fields of view is 2.3μm, which is less than one pixel(3.45μm) the distortion value is less than 0.1%, the system has the advantage of extra low distortion value and avoids the latter image distortion correction; the proposed modulation transfer function of the optical lens is 0.58(@145 lp/mm), the imaging quality of the system is closed to the diffraction limited; the system has simply structure, and can satisfies the requirements of the optical indexes. Ultimately, based on the imaging model of binocular stereo vision was achieved to measuring the drone at the finity distance.

  13. The motion of a classical spinning point particle in a Riemann-Cartan space-time

    International Nuclear Information System (INIS)

    Amorim, R.

    1983-01-01

    A consistent set of equations of motion for classical charged point particles with spin and magnetic dipole moment in a Riemann-Cartan space-time is generated from a generalized Lagrangean formalism. The equations avoid the spurius free helicoidal solutions and at the same time conserve the canonical condition of normalization of the 4-velocity. The 4-velocity and the mechanical moment are paralell in this theory, where the condition of orthogonality between the spin and the 4-velocity is treated as a non-holonomic one. (Author) [pt

  14. Beginning SharePoint 2010 Administration Windows SharePoint Foundation 2010 and Microsoft SharePoint Server 2010

    CERN Document Server

    Husman, Göran

    2010-01-01

    Complete coverage on the latest advances in SharePoint 2010 administration. SharePoint 2010 comprises an abundance of new features, and this book shows you how to take advantage of all SharePoint 2010's many improvements. Written by a four-time SharePoint MVP, Beginning SharePoint 2010 Administration begins with a comparison of SharePoint 2010 compared to the previous version and then examines the differences between WSS 4.0 and MSS 2010. Packed with step-by-step instructions, tips and tricks, and real-world examples, this book dives into the basics of how to install, manage, and administrate

  15. Measuring Time to Biochemical Failure in the TROG 96.01 Trial: When Should the Clock Start Ticking?

    International Nuclear Information System (INIS)

    Denham, James W.; Steigler, Allison; Kumar, Mahesh; Lamb, David S.; Joseph, David; Spry, Nigel A.; Tai, Keen-Hun; Atkinson, Chris; Turner, Sandra FRANZCR; Greer, Peter B.; Gleeson, Paul S.; D'Este, Catherine

    2009-01-01

    Purpose: We sought to determine whether short-term neoadjuvant androgen deprivation (STAD) duration influences the optimal time point from which Phoenix fail (time to biochemical failure; TTBF) should be measured. Methods and Materials: In the Trans-Tasman Radiation Oncology Group 96.01 trial, men with locally advanced prostate cancer were randomized to 3 or 6 months STAD before and during prostatic irradiation (XRT) or to XRT alone. The prognostic value of TTBF measured from the end of radiation (ERT) and randomization were compared using Cox models. Results: Between 1996 and 2000, 802 eligible patients were randomized. In 436 men with Phoenix failure, TTBF measured from randomization was a powerful predictor of prostate cancer-specific survival and marginally more accurate than TTBF measured from ERT in Cox models. Insufficient data were available to confirm that TTBF measured from testosterone recovery may also be a suitable option. Conclusions: TTBF measured from randomization (commencement of therapy) performed well in this trial dataset and will be a convenient option if this finding holds in other datasets that include long-term androgen deprivation data.

  16. A dynamic approach to real-time performance measurement in design projects

    DEFF Research Database (Denmark)

    Skec, Stanko; Cash, Philip; Storga, Mario

    2017-01-01

    Recent developments in engineering design management point to the need for more dynamic, fine-grain measurement approaches able to deal with multi-dimensional, cross-level process performance in product design. Thus, this paper proposes a new approach to the measurement and management of individu...

  17. Picosecond time measurement using ultra fast analog memories

    OpenAIRE

    Breton, D.; Delagnes, E.; Maalmi, J.

    2009-01-01

    International audience; The currently existing electronics dedicated to precise time measurement is mainly based on the use of constant fraction discriminators (CFD) associated with Time to Digital Converters (TDC). The constant fraction technique minimizes the time walk effect (dependency of timing on the pulse amplitude). Several attempts have been made to integrate CFD in multi-channel ASICs. But the time resolution measured on the most advanced one is of the order of 30 ps rms. Two main t...

  18. Use of dew-point detection for quantitative measurement of sweating rate

    Science.gov (United States)

    Brengelmann, G. L.; Mckeag, M.; Rowell, L. B.

    1975-01-01

    A method of measuring sweat rate (SR) based on detection of dew point (DP) is proposed which has advantages that may be attractive to other laboratories concerned with recording SR from selected areas of skin. It is similar to other methods in that dry gas is passed through a capsule which isolates several square centimeters of skin surface. The difference is in the means of determining how much gaseous water is carried off in the effluent moist gas. The DP detector used is free of the drawbacks of previous devices. DP is obtained through the fundamental technique of determining the temperature at which condensate forms on a mirror. Variations in DP are tracked rapidly, and accurately (+ or - 0.8 C nominal, sensitivity + or - 0.05 C) over a wide range ( -40 C to +50 C) without measurable hysteresis. The detector asembly is rugged and readily opened for cleaning and inspection.

  19. Alignment of time-resolved data from high throughput experiments.

    Science.gov (United States)

    Abidi, Nada; Franke, Raimo; Findeisen, Peter; Klawonn, Frank

    2016-12-01

    To better understand the dynamics of the underlying processes in cells, it is necessary to take measurements over a time course. Modern high-throughput technologies are often used for this purpose to measure the behavior of cell products like metabolites, peptides, proteins, [Formula: see text]RNA or mRNA at different points in time. Compared to classical time series, the number of time points is usually very limited and the measurements are taken at irregular time intervals. The main reasons for this are the costs of the experiments and the fact that the dynamic behavior usually shows a strong reaction and fast changes shortly after a stimulus and then slowly converges to a certain stable state. Another reason might simply be missing values. It is common to repeat the experiments and to have replicates in order to carry out a more reliable analysis. The ideal assumptions that the initial stimulus really started exactly at the same time for all replicates and that the replicates are perfectly synchronized are seldom satisfied. Therefore, there is a need to first adjust or align the time-resolved data before further analysis is carried out. Dynamic time warping (DTW) is considered as one of the common alignment techniques for time series data with equidistant time points. In this paper, we modified the DTW algorithm so that it can align sequences with measurements at different, non-equidistant time points with large gaps in between. This type of data is usually known as time-resolved data characterized by irregular time intervals between measurements as well as non-identical time points for different replicates. This new algorithm can be easily used to align time-resolved data from high-throughput experiments and to come across existing problems such as time scarcity and existing noise in the measurements. We propose a modified method of DTW to adapt requirements imposed by time-resolved data by use of monotone cubic interpolation splines. Our presented approach

  20. Comparison of real-time BTEX flux measurements to reported emission inventories in the Upper Green River Basin, Wyoming.

    Science.gov (United States)

    Edie, R.; Robertson, A.; Murphy, S. M.; Soltis, J.; Field, R. A.; Zimmerle, D.; Bell, C.

    2017-12-01

    Other Test Method 33a (OTM-33a) is an EPA-developed near-source measurement technique that utilizes a Gaussian plume inversion to calculate the flux of a point source 20 to 200 meters away. In 2014, the University of Wyoming mobile laboratory—equipped with a Picarro methane analyzer and an Ionicon Proton Transfer Reaction Time of Flight Mass Spectrometer—measured methane and BTEX fluxes from oil and gas operations in the Upper Green River Basin (UGRB), Wyoming. In this study, OTM-33a BTEX flux measurements are compared to BTEX emissions reported by operators in the Wyoming Department of Environmental Quality (WY-DEQ) emission inventory. On average, OTM-33a measured BTEX fluxes are almost twice as high as those reported in the emission inventory. To further constrain errors in the OTM-33a method, methane test releases were performed at the Colorado State University Methane Emissions Test and Evaluation Center (METEC) in June of 2017. The METEC facility contains decommissioned oil and gas equipment arranged in realistic well pad layouts. Each piece of equipment has a multitude of possible emission points. A Gaussian fit of measurement error from these 29 test releases indicate the median OTM-33a measurement quantified 55% of the metered flowrate. BTEX results from the UGRB campaign and inventory analysis will be presented, along with a discussion of errors associated with the OTM-33a measurement technique. Real-time BTEX and methane mixing ratios at the measurement locations (which show a lack of correlation between VOC and methane sources in 20% of sites sampled) will also be discussed.

  1. Comparative measurements performed by the IRSN, the ACRO and the CRIIRAD on some points of a pillbox of the Vaujours Fort (77)

    International Nuclear Information System (INIS)

    2014-01-01

    As an association reported a relatively high measurement of radioactivity on the site of the Vaujours Fort, the IRSN, the ACRO and the CRIIRAD have been asked to perform comparative measurements on this site. After having briefly recalled some elements of the site history, described the areas concerned by this control, indicated the expected radioactive elements, this report presents the measurements which were to be performed: dose equivalent rate, beta radiation, hardware used by the IRSN. It presents the measurement protocol: planned protocol and implemented protocol. It comments the measurement performance: noise, selection and measurement of reference points, measurements on different points. It proposes a comparative analysis of results obtained on the different points and on a sample. Measurements are then discussed. Photos and measurement tables are provided in appendix

  2. Stable long-time semiclassical description of zero-point energy in high-dimensional molecular systems.

    Science.gov (United States)

    Garashchuk, Sophya; Rassolov, Vitaly A

    2008-07-14

    Semiclassical implementation of the quantum trajectory formalism [J. Chem. Phys. 120, 1181 (2004)] is further developed to give a stable long-time description of zero-point energy in anharmonic systems of high dimensionality. The method is based on a numerically cheap linearized quantum force approach; stabilizing terms compensating for the linearization errors are added into the time-evolution equations for the classical and nonclassical components of the momentum operator. The wave function normalization and energy are rigorously conserved. Numerical tests are performed for model systems of up to 40 degrees of freedom.

  3. Spatial determination of magnetic avalanche ignition points

    International Nuclear Information System (INIS)

    Jaafar, Reem; McHugh, S.; Suzuki, Yoko; Sarachik, M.P.; Myasoedov, Y.; Zeldov, E.; Shtrikman, H.; Bagai, R.; Christou, G.

    2008-01-01

    Using time-resolved measurements of local magnetization in the molecular magnet Mn 12 -ac, we report studies of magnetic avalanches (fast magnetization reversals) with non-planar propagating fronts, where the curved nature of the magnetic fronts is reflected in the time-of-arrival at micro-Hall sensors placed at the surface of the sample. Assuming that the avalanche interface is a spherical bubble that grows with a radius proportional to time, we are able to locate the approximate ignition point of each avalanche in a two-dimensional cross-section of the crystal. We find that although in most samples the avalanches ignite at the long ends, as found in earlier studies, there are crystals in which ignition points are distributed throughout an entire weak region near the center, with a few avalanches still originating at the ends

  4. Spatial determination of magnetic avalanche ignition points

    Energy Technology Data Exchange (ETDEWEB)

    Jaafar, Reem; McHugh, S.; Suzuki, Yoko [Physics Department, City College of the City University of New York, New York, NY 10031 (United States); Sarachik, M.P. [Physics Department, City College of the City University of New York, New York, NY 10031 (United States)], E-mail: sarachik@sci.ccny.cuny.edu; Myasoedov, Y.; Zeldov, E.; Shtrikman, H. [Department Condensed Matter Physics, Weizmann Institute of Science, Rehovot 76100 (Israel); Bagai, R.; Christou, G. [Department of Chemistry, University of Florida, Gainesville, FL 32611 (United States)

    2008-03-15

    Using time-resolved measurements of local magnetization in the molecular magnet Mn{sub 12}-ac, we report studies of magnetic avalanches (fast magnetization reversals) with non-planar propagating fronts, where the curved nature of the magnetic fronts is reflected in the time-of-arrival at micro-Hall sensors placed at the surface of the sample. Assuming that the avalanche interface is a spherical bubble that grows with a radius proportional to time, we are able to locate the approximate ignition point of each avalanche in a two-dimensional cross-section of the crystal. We find that although in most samples the avalanches ignite at the long ends, as found in earlier studies, there are crystals in which ignition points are distributed throughout an entire weak region near the center, with a few avalanches still originating at the ends.

  5. Study into Point Cloud Geometric Rigidity and Accuracy of TLS-Based Identification of Geometric Bodies

    Science.gov (United States)

    Klapa, Przemyslaw; Mitka, Bartosz; Zygmunt, Mariusz

    2017-12-01

    Capability of obtaining a multimillion point cloud in a very short time has made the Terrestrial Laser Scanning (TLS) a widely used tool in many fields of science and technology. The TLS accuracy matches traditional devices used in land surveying (tacheometry, GNSS - RTK), but like any measurement it is burdened with error which affects the precise identification of objects based on their image in the form of a point cloud. The point’s coordinates are determined indirectly by means of measuring the angles and calculating the time of travel of the electromagnetic wave. Each such component has a measurement error which is translated into the final result. The XYZ coordinates of a measuring point are determined with some uncertainty and the very accuracy of determining these coordinates is reduced as the distance to the instrument increases. The paper presents the results of examination of geometrical stability of a point cloud obtained by means terrestrial laser scanner and accuracy evaluation of solids determined using the cloud. Leica P40 scanner and two different settings of measuring points were used in the tests. The first concept involved placing a few balls in the field and then scanning them from various sides at similar distances. The second part of measurement involved placing balls and scanning them a few times from one side but at varying distances from the instrument to the object. Each measurement encompassed a scan of the object with automatic determination of its position and geometry. The desk studies involved a semiautomatic fitting of solids and measurement of their geometrical elements, and comparison of parameters that determine their geometry and location in space. The differences of measures of geometrical elements of balls and translations vectors of the solids centres indicate the geometrical changes of the point cloud depending on the scanning distance and parameters. The results indicate the changes in the geometry of scanned objects

  6. Interactive Trunk Extraction from Forest Point Cloud

    Directory of Open Access Journals (Sweden)

    T. Mizoguchi

    2014-06-01

    Full Text Available For forest management or monitoring, it is required to constantly measure several parameters of each tree, such as height, diameter at breast height, and trunk volume. Terrestrial laser scanner has been used for this purpose instead of human workers to reduce time and cost for the measurement. In order to use point cloud captured by terrestrial laser scanner in the above applications, it is an important step to extract all trees or their trunks separately. For this purpose, we propose an interactive system in which a user can intuitively and efficiently extract each trunk by a simple editing on the distance image created from the point cloud. We demonstrate the effectiveness of our proposed system from various experiments.

  7. [Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

    Science.gov (United States)

    Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

    2015-07-01

    Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff.

  8. Measuring coseismic displacements with point-like targets offset tracking

    KAUST Repository

    Hu, Xie; Wang, Teng; Liao, Mingsheng

    2014-01-01

    Offset tracking is an important complement to measure large ground displacements in both azimuth and range dimensions where synthetic aperture radar (SAR) interferometry is unfeasible. Subpixel offsets can be obtained by searching for the cross-correlation peak calculated from the match patches uniformly distributed on two SAR images. However, it has its limitations, including redundant computation and incorrect estimations on decorrelated patches. In this letter, we propose a simple strategy that performs offset tracking on detected point-like targets (PT). We first detect image patches within bright PT by using a sinc-like template from a single SAR image and then perform offset tracking on them to obtain the pixel shifts. Compared with the standard method, the application on the 2010 M 7.2 El Mayor-Cucapah earthquake shows that the proposed PT offset tracking can significantly increase the cross-correlation and thus result in both efficiency and reliability improvements. © 2013 IEEE.

  9. Determination of melting point of mixed-oxide fuel irradiated in a fast breeder reactor

    International Nuclear Information System (INIS)

    Tachibana, Toshimichi

    1985-01-01

    The melting point of fuel is important to set its in-reactor maximum temperature in fuel design. The fuel melting point measuring methods are broadly the filament method and the capsule sealing method. The only instance of measuring the melting point of irradiated mixed oxide (U, Pu)O 2 fuel by the filament method is by GE in the United States. The capsule sealing method, while the excellent means, is difficult in weld sealing the irradiated fuel in a capsule within the cell. In the fast reactor development program, the remotely operated melting point measuring apparatus in capsule sealing the mixed (U, Pu)O 2 fuel irradiated in the experimental FBR Joyo was set in the cell and the melting point was measured, for the first time in the world. (Mori, K.)

  10. Measurement of the Dead-Time in a Multichannel Analyser

    DEFF Research Database (Denmark)

    Mortensen, L.; Olsen, J.

    1973-01-01

    By means of two simple measurements three different dead-times are determined: the normal dead-time, a dead-time coming from the pile-up, and a dead-time due to the finite width of the timing pulses.......By means of two simple measurements three different dead-times are determined: the normal dead-time, a dead-time coming from the pile-up, and a dead-time due to the finite width of the timing pulses....

  11. Wall shear stress fixed points in cardiovascular fluid mechanics.

    Science.gov (United States)

    Arzani, Amirhossein; Shadden, Shawn C

    2018-05-17

    Complex blood flow in large arteries creates rich wall shear stress (WSS) vectorial features. WSS acts as a link between blood flow dynamics and the biology of various cardiovascular diseases. WSS has been of great interest in a wide range of studies and has been the most popular measure to correlate blood flow to cardiovascular disease. Recent studies have emphasized different vectorial features of WSS. However, fixed points in the WSS vector field have not received much attention. A WSS fixed point is a point on the vessel wall where the WSS vector vanishes. In this article, WSS fixed points are classified and the aspects by which they could influence cardiovascular disease are reviewed. First, the connection between WSS fixed points and the flow topology away from the vessel wall is discussed. Second, the potential role of time-averaged WSS fixed points in biochemical mass transport is demonstrated using the recent concept of Lagrangian WSS structures. Finally, simple measures are proposed to quantify the exposure of the endothelial cells to WSS fixed points. Examples from various arterial flow applications are demonstrated. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Value of dual-time-point 18FDG PET-CT imaging on involved-field radiotherapy for hilar and mediastinal metastatic lymph nodes in non-small cell lung cancer

    International Nuclear Information System (INIS)

    Hu Man; Sun Xindong; Liu Ningbo; Gong Heyi; Fu Zheng; Ma Li; Li Xinke; Xu Xiaoqing; Yu Jinming

    2008-01-01

    Objective: To discuss the value of dual-time-point 18 FDG PET-CT imaging on involved-field radiotherapy for hilar and mediastinal metastatic lymph nodes in patients with non-small cell lung cancer (NSCLC). Methods: Fifty-four patients with NSCLC were included in this analysis, including 34 men and 20 women with mean age of 59 (34-76) years. Two sequential PET-CT scans given 3-5 days before surgery were standard single-time-point imaging for the whole body and delayed imaging for the thorax. The pathologic data were used as golden standard to determine the difference between the standard single-time-point and dual-time-point PET-CT imaging in the definition of gross target volume (GTV) of involved-field radiotherapy for metastatic lymph nodes. Results: For hilar metastatic lymph nodes, the GTV defined by single-time-point imaging was consistent with pathologic GTV in 21 patients (39%), comparing with 31 patients (57%) by dual-time-point imaging. Using pathologic data as golden standard, GTV alteration defined by single-time-point imaging had statistically significant difference comparing with that defined by dual-time-point imaging( =519.00, P=0.023). For mediastinal metastatic lymph nodes, the GTV defined by single-time-point imaging was consistent with pathologic GTV in 30 patients (56%), comparing with 36 patients (67%) by dual-time-point imaging. Using pathologic data as golden standard, GTV alteration defined by single-time-point imaging had no statistically significant difference comparing with that defined by dual-time-point imaging (u= 397.50, P=0.616). Conclusions: For patients with NSCLC receiving involved-field radiotherapy, GTV definition for hilar and mediastinal metastatic lymph nodes by dual-time-point imaging is more consistent with that by pathologic data. Dual-time-point imaging has a larger value in terms of target delineation for hilar and mediastinal metastatic lymph nodes. (authors)

  13. Locating single-point sources from arrival times containing large picking errors (LPEs): the virtual field optimization method (VFOM)

    Science.gov (United States)

    Li, Xi-Bing; Wang, Ze-Wei; Dong, Long-Jun

    2016-01-01

    Microseismic monitoring systems using local location techniques tend to be timely, automatic and stable. One basic requirement of these systems is the automatic picking of arrival times. However, arrival times generated by automated techniques always contain large picking errors (LPEs), which may make the location solution unreliable and cause the integrated system to be unstable. To overcome the LPE issue, we propose the virtual field optimization method (VFOM) for locating single-point sources. In contrast to existing approaches, the VFOM optimizes a continuous and virtually established objective function to search the space for the common intersection of the hyperboloids, which is determined by sensor pairs other than the least residual between the model-calculated and measured arrivals. The results of numerical examples and in-site blasts show that the VFOM can obtain more precise and stable solutions than traditional methods when the input data contain LPEs. Furthermore, we discuss the impact of LPEs on objective functions to determine the LPE-tolerant mechanism, velocity sensitivity and stopping criteria of the VFOM. The proposed method is also capable of locating acoustic sources using passive techniques such as passive sonar detection and acoustic emission.

  14. The study of transit time measurement for flow through the central and southern canals of MADA using I-131 radioisotope technique

    International Nuclear Information System (INIS)

    Roslan Mohd Ali; Md Shahid Ayub; Zainuddin Othman; Juhari Yusof; Mohd Asri Ramli; Eow Boon Tiak

    1996-01-01

    The measurement of breakthrough and transit time through the central and southern canals of Lembaga Kemajuan Pertanian Muda (MADA) by using radiotracer technique is discussed An estimated of 1700 cusec water was released from Pelubang regulator through central canal. The water is then distributed through several regulators down stream and finally ended through the SCD1 and SCD1a secondary canals. Radiotracer 1-131 with the activity of 250 mCi and 500 mCi were injected at several identified injection points by using glass breaker technique. The measurement of breakthrough and transit time were observed respectively at several measurement station. Results of the study indicated that the time travel from Pelubang regulator to SCD1a secondary canal would take about 3 days during normal operation. Detail of breakthrough and transit time at every regulators and other measurement stations were also presented

  15. Development of Precise Point Positioning Method Using Global Positioning System Measurements

    Directory of Open Access Journals (Sweden)

    Byung-Kyu Choi

    2011-09-01

    Full Text Available Precise point positioning (PPP is increasingly used in several parts such as monitoring of crustal movement and maintaining an international terrestrial reference frame using global positioning system (GPS measurements. An accuracy of PPP data processing has been increased due to the use of the more precise satellite orbit/clock products. In this study we developed PPP algorithm that utilizes data collected by a GPS receiver. The measurement error modelling including the tropospheric error and the tidal model in data processing was considered to improve the positioning accuracy. The extended Kalman filter has been also employed to estimate the state parameters such as positioning information and float ambiguities. For the verification, we compared our results to other of International GNSS Service analysis center. As a result, the mean errors of the estimated position on the East-West, North-South and Up-Down direction for the five days were 0.9 cm, 0.32 cm, and 1.14 cm in 95% confidence level.

  16. Chiral measurements with the Fixed-Point Dirac operator and construction of chiral currents

    International Nuclear Information System (INIS)

    Hasenfratz, P.; Hauswirth, S.; Holland, K.; Joerg, T.; Niedermayer, F.

    2002-01-01

    In this preliminary study, we examine the chiral properties of the parametrized Fixed-Point Dirac operator D FP , see how to improve its chirality via the Overlap construction, measure the renormalized quark condensate Σ-circumflex and the topological susceptibility χ t , and investigate local chirality of near zero modes of the Dirac operator. We also give a general construction of chiral currents and densities for chiral lattice actions

  17. Hypovitamininosis D in Childhood Cancer Survivors: Importance of Vitamin D Supplementation and Measurement Over Different Points of Time.

    Science.gov (United States)

    Fouda, Ashraf; Kandil, Shaimaa; Boujettif, Khadijah; Fayea, Najwa

    2018-03-01

    This observational retrospective cross-sectional and case-controlled study measures levels of 25-hydroxy-vitamin D (25-OH-VD) in pediatric cancer survivors at different intervals and assesses the effect of 2 supplementation regimens over a period of 12 months. Sixty-eight patients were included in this quasi-experimental study, of which 32 were boys and 36 were girls. A control group of 30 healthy children were included. It was found that initial 25-OH-VD levels were insufficient (vitamin D during the 12 months in comparison with patients supplemented with 1000 IU/day. Our findings indicate that pediatric cancer survivors who require frequent monitoring of their 25-OH-VD levels yielded better results when supplemented with higher doses of vitamin D over longer periods of time. A course of oral vitamin D supplementation regimen of 50,000 IU/month gave effective results with excellent compliance and no reports of any adverse or harmful effects.

  18. Fast and direct measurements of the electrical properties of graphene using micro four-point probes

    DEFF Research Database (Denmark)

    Klarskov, Mikkel Buster; Dam, Henrik Friis; Petersen, Dirch Hjorth

    2011-01-01

    . Measurements are performed in ambient, vacuum and controlled environmental conditions using an environmental scanning electron microscope (SEM). The results are comparable to previous results for microcleaved graphene on silicon dioxide (SiO2). We observe a pronounced hysteresis of the charge neutrality point...

  19. Derivation of Pal-Bell equations for two-point reactors, and its application to correlation measurements at KUCA

    International Nuclear Information System (INIS)

    Murata, Naoyuki; Yamane, Yoshihiro; Nishina, Kojiro; Shiroya, Seiji; Kanda, Keiji.

    1980-01-01

    A probability is defined for an event in which m neutrons exist at time t sub(f) in core I of a coupled-core system, originating from a neutron injected into the core I at an earlier time t; we call it P sub(I,I,m)(t sub(f)/t). Similarly, P sub(I,II,m)(t sub(f)/t) is defined as the probability for m neutrons to exist in core II of the system at time t sub(f), originating from a neutron injected into the core I at time t. Then a system of coupled equations are derived for the generating functions G sub(Ij)(z, t sub(f)/t) = μP sub(Ijm)(t sub(f)/t).z sup(m), where j = I, II. By similar procedures equations are derived for the generating functions associated with joint probability of the following events: a given combination of numbers of neutrons are detected during given series of detection time intervals by a detector inserted in one of the cores. The above two kinds of systems of equations can be regarded as a two-point version of Pal-Bell's equations. As the application of these formulations, analyzing formula for correlation measurements, namely (1) Feynman-alpha experiment and (2) Rossi-alpha experiment of Orndoff-type, are derived, and their feasibility is verified by experiments carried out at KUCA. (author)

  20. Gene expression pattern at different time points following ALA-PDT

    International Nuclear Information System (INIS)

    Verwanger, T.; Sanovic, R.; Ruhdorfer, S.; Aberger, F.; Frischauf, A.; Krammer, B.

    2003-01-01

    Full text: The photo sensitizer protoporphyrin IX, endogenously accumulated from the precursor aminolevulinic acid (ALA), is a successful agent in photodynamic tumor therapy. In spite of encouraging clinical results, the basic mechanisms leading to cell death are not fully understood. We therefore set out to analyze the alteration of the gene expression pattern in the squamous cell carcinoma cell line A-431 at different time points after photodynamic treatment with endogenous protoporphyrin IX by cDNA-array technique. Cells were incubated for 16 hours with 100 μg/ml ALA and irradiated with a fluence of 3.5 J/cm 2 resulting in 50 % survival until 8 hours post treatment. RNA was isolated at 1.5, 3, 5 and 8 hours post treatment as well as of 3 controls (untreated, light only and dark), radioactively labelled by reverse transcription with 33P-dCTP and hybridized onto macroarray PCR filters containing PCR products of 2135 genes, which were selected for relevance in tumors, stress response and signal transduction. Verification of observed expression changes was carried out by real time PCR. We found a strong induction of expression of immediate early genes like c-fos as well as decreased expression of genes involved in proliferation like myc and the proliferating cell nuclear antigen (PCNA). (author)

  1. Point of care creatinine measurement for diagnosis of renal disease using a disposable microchip

    NARCIS (Netherlands)

    Ávila Muñoz, Mónica; Floris, J.; Staal, S.S.; Ríos, Ángel; Eijkel, Jan C.T.; van den Berg, Albert

    2013-01-01

    A point-of-care device for the determination of elevated creatinine levels in blood is reported. This device potentially offers a new and simple clinical regime for the determination of creatinine that will give huge time savings and removal of several steps of determination. The test employs a

  2. A new algorithm combining geostatistics with the surrogate data approach to increase the accuracy of comparisons of point radiation measurements with cloud measurements

    Science.gov (United States)

    Venema, V. K. C.; Lindau, R.; Varnai, T.; Simmer, C.

    2009-04-01

    Two main groups of statistical methods used in the Earth sciences are geostatistics and stochastic modelling. Geostatistical methods, such as various kriging algorithms, aim at estimating the mean value for every point as well as possible. In case of sparse measurements, such fields have less variability at small scales and a narrower distribution as the true field. This can lead to biases if a nonlinear process is simulated on such a kriged field. Stochastic modelling aims at reproducing the structure of the data. One of the stochastic modelling methods, the so-called surrogate data approach, replicates the value distribution and power spectrum of a certain data set. However, while stochastic methods reproduce the statistical properties of the data, the location of the measurement is not considered. Because radiative transfer through clouds is a highly nonlinear process it is essential to model the distribution (e.g. of optical depth, extinction, liquid water content or liquid water path) accurately as well as the correlations in the cloud field because of horizontal photon transport. This explains the success of surrogate cloud fields for use in 3D radiative transfer studies. However, up to now we could only achieve good results for the radiative properties averaged over the field, but not for a radiation measurement located at a certain position. Therefore we have developed a new algorithm that combines the accuracy of stochastic (surrogate) modelling with the positioning capabilities of kriging. In this way, we can automatically profit from the large geostatistical literature and software. The algorithm is tested on cloud fields from large eddy simulations (LES). On these clouds a measurement is simulated. From the pseudo-measurement we estimated the distribution and power spectrum. Furthermore, the pseudo-measurement is kriged to a field the size of the final surrogate cloud. The distribution, spectrum and the kriged field are the inputs to the algorithm. This

  3. Time Frame Affects Vantage Point in Episodic and Semantic Autobiographical Memory: Evidence from Response Latencies

    Directory of Open Access Journals (Sweden)

    Jerzy J. Karylowski

    2017-04-01

    Full Text Available Previous research suggests that, with the passage of time, representations of self in episodic memory become less dependent on their initial (internal vantage point and shift toward an external perspective that is normally characteristic of how other people are represented. The present experiment examined this phenomenon in both episodic and semantic autobiographical memory using latency of self-judgments as a measure of accessibility of the internal vs. the external perspective. Results confirmed that in the case of representations of the self retrieved from recent autobiographical memories, trait-judgments regarding unobservable self-aspects (internal perspective were faster than trait judgments regarding observable self-aspects (external perspective. Yet, in the case of self-representations retrieved from memories of a more distant past, judgments regarding observable self-aspects were faster. Those results occurred for both self-representations retrieved from episodic memory and for representations retrieved from the semantic memory. In addition, regardless of the effect of time, greater accessibility of unobservable (vs. observable self-aspects was associated with the episodic rather than semantic autobiographical memory. Those results were modified by neither declared trait’s self-descriptiveness (yes vs. no responses nor by its desirability (highly desirable vs. moderately desirable traits. Implications for compatibility between how self and others are represented and for the role of self in social perception are discussed.

  4. Time Frame Affects Vantage Point in Episodic and Semantic Autobiographical Memory: Evidence from Response Latencies.

    Science.gov (United States)

    Karylowski, Jerzy J; Mrozinski, Blazej

    2017-01-01

    Previous research suggests that, with the passage of time, representations of self in episodic memory become less dependent on their initial (internal) vantage point and shift toward an external perspective that is normally characteristic of how other people are represented. The present experiment examined this phenomenon in both episodic and semantic autobiographical memory using latency of self-judgments as a measure of accessibility of the internal vs. the external perspective. Results confirmed that in the case of representations of the self retrieved from recent autobiographical memories, trait-judgments regarding unobservable self-aspects (internal perspective) were faster than trait judgments regarding observable self-aspects (external perspective). Yet, in the case of self-representations retrieved from memories of a more distant past, judgments regarding observable self-aspects were faster. Those results occurred for both self-representations retrieved from episodic memory and for representations retrieved from the semantic memory. In addition, regardless of the effect of time, greater accessibility of unobservable (vs. observable) self-aspects was associated with the episodic rather than semantic autobiographical memory. Those results were modified by neither declared trait's self-descriptiveness ( yes vs. no responses) nor by its desirability (highly desirable vs. moderately desirable traits). Implications for compatibility between how self and others are represented and for the role of self in social perception are discussed.

  5. Is the timed loaded standing test a valid measure of back muscle endurance in people with vertebral osteoporosis?

    Science.gov (United States)

    Newman, M; Newman, R; Hughes, T; Vadher, K; Barker, K L

    2018-04-01

    Timed loaded standing (TLS) is a suggested measure of back muscle endurance for people with vertebral osteoporosis. Surface electromyography revealed back muscles work harder and fatigue during TLS. The test end-point and total time were associated with back fatigue. The findings help demonstrate the concurrent validity of the TLS test. The TLS test is suggested as a measure of back muscle endurance for patients with vertebral osteoporosis. However, to date, no study has demonstrated that TLS does measure back extensor or erector spinae (ES) muscle endurance. We used surface electromyography (sEMG) to investigate the performance of the thoracic ES muscles during TLS. Thirty-six people with vertebral osteoporosis with a mean age of 71.6 (range 45-86) years participated. sEMG recordings were made of the ES at T3 and T12 bilaterally during quiet standing (QS) and TLS. The relative (%) change in sEMG amplitude between conditions was compared. Fatigue was evaluated by analysing the change in median frequency (MF) of the sEMG signal during TLS, and the correlation between maximal TLS time and rate of MF decline was examined. Activity in the ES increased significantly during TLS at all electrode locations. During TLS, the MF declined at a mean rate of -24.2% per minute (95% C.I. -26.5 to -21.9%). The MF slope and test time were strongly correlated (r 2  = 0.71), and at test end, the final MF dropped to an average 89% (95% C.I. 85 to 93%) of initial MF. Twenty-eight participants (78%) reported fatigue was the main reason for stopping, and for eight (22%), it was pain. This study demonstrates that TLS challenges the ES muscles in the thoracic region and results in ES fatigue. Endurance time and the point at which the TLS test ends are strongly related to ES fatigue.

  6. Distance of Sample Measurement Points to Prototype Catalog Curve

    DEFF Research Database (Denmark)

    Hjorth, Poul G.; Karamehmedovic, Mirza; Perram, John

    2006-01-01

    We discuss strategies for comparing discrete data points to a catalog (reference) curve by means of the Euclidean distance from each point to the curve in a pump's head H vs. flow Qdiagram. In particular we find that a method currently in use is inaccurate. We propose several alternatives...

  7. Verification for the disagreement between effective point and geometrical center of thimble ionization chamber

    International Nuclear Information System (INIS)

    Shimomura, K.; Tabushi, K.

    2005-01-01

    In radiotherapy, it is certainly necessary to grasp the quantity and the distribution of the radiation administered to the human body. To measure these correctly, the standard measurement method of the absorbed dose of water is recommended by AAPM, IAEA, and JSPM. The standard method also recommends that absolute measurements should be performed using the thimble ionization chamber (TIC). The absorbed dose of water measured by TIC should be corrected for diverse effects. There is the definition of measurement point for TIC based on these effects. Because TIC is cylindrical form and has finite volume, the measurement point differs from the geometrical center of TIC. In the standard definitions, the point is called the effective point and recommended that its location is a shift equal to 0.6 times of the inner radius of TIC from the geometrical center. In this work, we examined the accuracy of the definitions of the effective point for TIC by simulation with EGS4. (author)

  8. Experimental study of influence characteristics of flue gas fly ash on acid dew point

    Science.gov (United States)

    Song, Jinhui; Li, Jiahu; Wang, Shuai; Yuan, Hui; Ren, Zhongqiang

    2017-12-01

    The long-term operation experience of a large number of utility boilers shows that the measured value of acid dew point is generally lower than estimated value. This is because the influence of CaO and MgO on acid dew point in flue gas fly ash is not considered in the estimation formula of acid dew point. On the basis of previous studies, the experimental device for acid dew point measurement was designed and constructed, and the acid dew point under different smoke conditions was measured. The results show that the CaO and MgO in the flue gas fly ash have an obvious influence on the acid dew point, and the content of the fly ash is negatively correlated with the temperature of acid dew point At the same time, the concentration of H2SO4 in flue gas is different, and the acid dew point of flue gas is different, and positively correlated with the acid dew point.

  9. A method for untriggered time-dependent searches for multiple flares from neutrino point sources

    International Nuclear Information System (INIS)

    Gora, D.; Bernardini, E.; Cruz Silva, A.H.

    2011-04-01

    A method for a time-dependent search for flaring astrophysical sources which can be potentially detected by large neutrino experiments is presented. The method uses a time-clustering algorithm combined with an unbinned likelihood procedure. By including in the likelihood function a signal term which describes the contribution of many small clusters of signal-like events, this method provides an effective way for looking for weak neutrino flares over different time-scales. The method is sensitive to an overall excess of events distributed over several flares which are not individually detectable. For standard cases (one flare) the discovery potential of the method is worse than a standard time-dependent point source analysis with unknown duration of the flare by a factor depending on the signal-to-background level. However, for flares sufficiently shorter than the total observation period, the method is more sensitive than a time-integrated analysis. (orig.)

  10. A method for untriggered time-dependent searches for multiple flares from neutrino point sources

    Energy Technology Data Exchange (ETDEWEB)

    Gora, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Institute of Nuclear Physics PAN, Cracow (Poland); Bernardini, E.; Cruz Silva, A.H. [Institute of Nuclear Physics PAN, Cracow (Poland)

    2011-04-15

    A method for a time-dependent search for flaring astrophysical sources which can be potentially detected by large neutrino experiments is presented. The method uses a time-clustering algorithm combined with an unbinned likelihood procedure. By including in the likelihood function a signal term which describes the contribution of many small clusters of signal-like events, this method provides an effective way for looking for weak neutrino flares over different time-scales. The method is sensitive to an overall excess of events distributed over several flares which are not individually detectable. For standard cases (one flare) the discovery potential of the method is worse than a standard time-dependent point source analysis with unknown duration of the flare by a factor depending on the signal-to-background level. However, for flares sufficiently shorter than the total observation period, the method is more sensitive than a time-integrated analysis. (orig.)

  11. Exact analytical solution of time-independent neutron transport equation, and its applications to systems with a point source

    International Nuclear Information System (INIS)

    Mikata, Y.

    2014-01-01

    Highlights: • An exact solution for the one-speed neutron transport equation is obtained. • This solution as well as its derivation are believed to be new. • Neutron flux for a purely absorbing material with a point neutron source off the origin is obtained. • Spherically as well as cylindrically piecewise constant cross sections are studied. • Neutron flux expressions for a point neutron source off the origin are believed to be new. - Abstract: An exact analytical solution of the time-independent monoenergetic neutron transport equation is obtained in this paper. The solution is applied to systems with a point source. Systematic analysis of the solution of the time-independent neutron transport equation, and its applications represent the primary goal of this paper. To the best of the author’s knowledge, certain key results on the scalar neutron flux as well as their derivations are new. As an application of these results, a scalar neutron flux for a purely absorbing medium with a spherically piecewise constant cross section and an isotropic point neutron source off the origin as well as that for a cylindrically piecewise constant cross section with a point neutron source off the origin are obtained. Both of these results are believed to be new

  12. The cost of travel time variability: three measures with properties

    DEFF Research Database (Denmark)

    Engelson, Leonid; Fosgerau, Mogens

    2016-01-01

    This paper explores the relationships between three types of measures of the cost of travel time variability: measures based on scheduling preferences and implicit departure time choice, Bernoulli type measures based on a univariate function of travel time, and mean-dispersion measures. We...

  13. Measuring health inequalities over time

    Directory of Open Access Journals (Sweden)

    Gustavo Bergonzoli

    2007-11-01

    Full Text Available Background: several methodologies have been used to measure health inequalities. Most of them do so in a cross- sectional fashion, causing significant loss of information. None of them measure health inequalities in social territories over time. Methods: this article presents two approaches measure health inequalities: one approach consists of a refinement of cross-sectional study, by using the analysis of ANOVA variance (ANOVA procedure to explore whether the gap between social territories is real or due to chance. Several adjustments were made to limit errors inevitably found in multiple comparisons. Polynomial procedures were then applied to identify and evaluate any trends. The second sociales se utilizó approach measures the health gap between social territories or strata (as defined in this study over time using the Poisson regression. These approaches were applied using life expectancy and maternal mortality data from Venezuela. Results: a positive relationship between tendenterritories and life expectancy was found, with a significant cia linal trend. The relation between maternal mortality and materna y territorios sociales fue cuadrática. La medición desocial territories was quadratic. The measurement of the la brecha, gap between least developed social territory and the most, a developed territory showed a gap reduction from the first to the second decade, mainly because of an increase of territorio social maternal mortality in the more developed area, rather than a real improvement in the least developed. Conclusions: study helps to clarify the impact that public policies and interventions have in reducing the health gap. Knowledge that a health gap between social territories can decrease without showing improvement in the least developed sector , is an important finding for monitoring and evaluating health interventions for improving living and health conditions in the population.

  14. Are anomalously short tunnelling times measurable?

    International Nuclear Information System (INIS)

    Delgado, V.; Muga, J.G.

    1996-01-01

    Low and Mende have analyzed the conditions that would make possible an actual measurement of an anomalously short traversal time through a potential barrier concluding that such a measurement cannot be made because it is not possible to describe the tunnelling of a wave packet initially close to the barrier by the open-quote open-quote usual wave packet space time analysis close-quote close-quote. We complement this work in several ways: It is argued that the described failure of the usual formalism occurs under a set of too restrictive conditions, some of them not physically motivated, so it does not necessarily imply the impossibility of such a measurement. However, by retaining only conditions well motivated on physical grounds we have performed a systematic numerical check which shows that the conclusion by Low and Mende is indeed generally valid. It is shown that, as speculated by Low and Mende, the process is dominated by over the barrier transmission. Copyright copyright 1996 Academic Press, Inc

  15. Uncertainties for pressure-time efficiency measurements

    OpenAIRE

    Ramdal, Jørgen; Jonsson, Pontus; Dahlhaug, Ole Gunnar; Nielsen, Torbjørn; Cervantes, Michel

    2010-01-01

     In connection with the pressure-time project at the Norwegian University of Science and Technology and Luleå University of Technology, a number of tests with the pressure-time method have been performed at the Waterpower Laboratory in Trondheim, Norway. The aim is to lower the uncertainty and improve usability of the method. Also a field test at the Anundsjoe power plant in Sweden has been performed. The pressure-time measurement is affected by random uncertainty. To minimize the effect of t...

  16. Structural evolution in the isothermal crystallization process of the molten nylon 10/10 traced by time-resolved infrared spectral measurements and synchrotron SAXS/WAXD measurements

    International Nuclear Information System (INIS)

    Tashiro, Kohji; Nishiyama, Asami; Tsuji, Sawako; Hashida, Tomoko; Hanesaka, Makoto; Takeda, Shinichi; Weiyu, Cao; Reddy, Kummetha Raghunatha; Masunaga, Hiroyasu; Sasaki, Sono; Takata, Masaki; Ito, Kazuki

    2009-01-01

    The structural evolution in the isothermal crystallization process of nylon 10/10 from the melt has been clarified concretely on the basis of the time-resolved infrared spectral measurement as well as the synchrotron wide-angle and small-angle X-ray scattering measurements. Immediately after the temperature jump from the melt to the crystallization point, the isolated domains consisting of the hydrogen-bonded random coils were formed in the melt, as revealed by Guinier plot of SAXS data and the infrared spectral data. With the passage of time these domains approached each other with stronger correlation as analyzed by Debye-Bueche equation. These domains transformed finally to the stacked crystalline lamellae, in which the conformationally-regularized methylene segments of the CO sides were connected each other by stronger intermolecular hydrogen bonds to form the crystal lattice.

  17. Comparability of Results Between a Point-of-Care and an Automated Instrument for Measurement of B-Type Natriuretic Peptide

    OpenAIRE

    Shah, Kevin; Terracciano, Garrett J; Jiang, Kevin; Maisel, Alan S; Fitzgerald, Robert L

    2010-01-01

    Objectives: Heart failure is one of the leading causes of death in the U.S. The incorporation of B-type natriuretic peptide (BNP) measurements when triaging patients presenting with shortness of breath has improved the diagnostic and prognostic ability of physicians. Currently, there are no point-of-care systems for quantifying BNP that can be used without sacrificing accuracy. We compared the analytical performance of the Abbott i-STAT analyzer, a handheld point-of-care system for measuring ...

  18. Measures and Metrics for Feasibility of Proof-of-Concept Studies With Human Immunodeficiency Virus Rapid Point-of-Care Technologies: The Evidence and the Framework.

    Science.gov (United States)

    Pant Pai, Nitika; Chiavegatti, Tiago; Vijh, Rohit; Karatzas, Nicolaos; Daher, Jana; Smallwood, Megan; Wong, Tom; Engel, Nora

    2017-12-01

    Pilot (feasibility) studies form a vast majority of diagnostic studies with point-of-care technologies but often lack use of clear measures/metrics and a consistent framework for reporting and evaluation. To fill this gap, we systematically reviewed data to ( a ) catalog feasibility measures/metrics and ( b ) propose a framework. For the period January 2000 to March 2014, 2 reviewers searched 4 databases (MEDLINE, EMBASE, CINAHL, Scopus), retrieved 1441 citations, and abstracted data from 81 studies. We observed 2 major categories of measures, that is, implementation centered and patient centered, and 4 subcategories of measures, that is, feasibility, acceptability, preference, and patient experience. We defined and delineated metrics and measures for a feasibility framework. We documented impact measures for a comparison. We observed heterogeneity in reporting of metrics as well as misclassification and misuse of metrics within measures. Although we observed poorly defined measures and metrics for feasibility, preference, and patient experience, in contrast, acceptability measure was the best defined. For example, within feasibility, metrics such as consent, completion, new infection, linkage rates, and turnaround times were misclassified and reported. Similarly, patient experience was variously reported as test convenience, comfort, pain, and/or satisfaction. In contrast, within impact measures, all the metrics were well documented, thus serving as a good baseline comparator. With our framework, we classified, delineated, and defined quantitative measures and metrics for feasibility. Our framework, with its defined measures/metrics, could reduce misclassification and improve the overall quality of reporting for monitoring and evaluation of rapid point-of-care technology strategies and their context-driven optimization.

  19. Development of a Multi-Point Microwave Interferometry (MPMI) Method

    Energy Technology Data Exchange (ETDEWEB)

    Specht, Paul Elliott [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cooper, Marcia A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jilek, Brook Anton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    A multi-point microwave interferometer (MPMI) concept was developed for non-invasively tracking a shock, reaction, or detonation front in energetic media. Initially, a single-point, heterodyne microwave interferometry capability was established. The design, construction, and verification of the single-point interferometer provided a knowledge base for the creation of the MPMI concept. The MPMI concept uses an electro-optic (EO) crystal to impart a time-varying phase lag onto a laser at the microwave frequency. Polarization optics converts this phase lag into an amplitude modulation, which is analyzed in a heterodyne interfer- ometer to detect Doppler shifts in the microwave frequency. A version of the MPMI was constructed to experimentally measure the frequency of a microwave source through the EO modulation of a laser. The successful extraction of the microwave frequency proved the underlying physical concept of the MPMI design, and highlighted the challenges associated with the longer microwave wavelength. The frequency measurements made with the current equipment contained too much uncertainty for an accurate velocity measurement. Potential alterations to the current construction are presented to improve the quality of the measured signal and enable multiple accurate velocity measurements.

  20. A microwave resonance dew-point hygrometer

    Science.gov (United States)

    Underwood, R. J.; Cuccaro, R.; Bell, S.; Gavioso, R. M.; Madonna Ripa, D.; Stevens, M.; de Podesta, M.

    2012-08-01

    We report the first measurements of a quasi-spherical microwave resonator used as a dew-point hygrometer. In conventional dew-point hygrometers, the condensation of water from humid gas flowing over a mirror is detected optically, and the mirror surface is then temperature-controlled to yield a stable condensed layer. In our experiments we flowed moist air from a humidity generator through a quasi-spherical resonator and detected the onset of condensation by measuring the frequency ratio of selected microwave modes. We verified the basic operation of the device over the dew-point range 9.5-13.5 °C by comparison with calibrated chilled-mirror hygrometers. These tests indicate that the microwave method may allow a quantitative estimation of the volume and thickness of the water layer which is condensed on the inner surface of the resonator. The experiments reported here are preliminary due to the limited time available for the work, but show the potential of the method for detecting not only water but a variety of other liquid or solid condensates. The robust all-metal construction should make the device appropriate for use in industrial applications over a wide range of temperatures and pressures.

  1. A microwave resonance dew-point hygrometer

    International Nuclear Information System (INIS)

    Underwood, R J; Bell, S; Stevens, M; De Podesta, M; Cuccaro, R; Gavioso, R M; Ripa, D Madonna

    2012-01-01

    We report the first measurements of a quasi-spherical microwave resonator used as a dew-point hygrometer. In conventional dew-point hygrometers, the condensation of water from humid gas flowing over a mirror is detected optically, and the mirror surface is then temperature-controlled to yield a stable condensed layer. In our experiments we flowed moist air from a humidity generator through a quasi-spherical resonator and detected the onset of condensation by measuring the frequency ratio of selected microwave modes. We verified the basic operation of the device over the dew-point range 9.5–13.5 °C by comparison with calibrated chilled-mirror hygrometers. These tests indicate that the microwave method may allow a quantitative estimation of the volume and thickness of the water layer which is condensed on the inner surface of the resonator. The experiments reported here are preliminary due to the limited time available for the work, but show the potential of the method for detecting not only water but a variety of other liquid or solid condensates. The robust all-metal construction should make the device appropriate for use in industrial applications over a wide range of temperatures and pressures. (paper)

  2. Direct measurement of α2F in normal metals using point-contacts: noble metals

    International Nuclear Information System (INIS)

    Jansen, A.G.M.; Mueller, F.M.; Wyder, P.

    1976-01-01

    A new technique of forming tiny point junctions, first discussed by Sharvin, is described. By measuring the second derivative of voltage with respect to current, using techniques similar to tunnel junction spectroscopy, structure is found which is consistent with bulk phonon densities of states derived from neutron scattering. The same results were reported at LT 14 by Yanson using a shorted film technique

  3. SHORT COMMUNICATION: Time measurement device with four femtosecond stability

    Science.gov (United States)

    Panek, Petr; Prochazka, Ivan; Kodet, Jan

    2010-10-01

    We present the experimental results of extremely precise timing in the sense of time-of-arrival measurements in a local time scale. The timing device designed and constructed in our laboratory is based on a new concept using a surface acoustic wave filter as a time interpolator. Construction of the device is briefly described. The experiments described were focused on evaluating the timing precision and stability. Low-jitter test pulses with a repetition frequency of 763 Hz were generated synchronously to the local time base and their times of arrival were measured. The resulting precision of a single measurement was typically 900 fs RMS, and a timing stability TDEV of 4 fs was achieved for time intervals in the range from 300 s to 2 h. To our knowledge this is the best value reported to date for the stability of a timing device. The experimental results are discussed and possible improvements are proposed.

  4. Decreasing Computational Time for VBBinaryLensing by Point Source Approximation

    Science.gov (United States)

    Tirrell, Bethany M.; Visgaitis, Tiffany A.; Bozza, Valerio

    2018-01-01

    The gravitational lens of a binary system produces a magnification map that is more intricate than a single object lens. This map cannot be calculated analytically and one must rely on computational methods to resolve. There are generally two methods of computing the microlensed flux of a source. One is based on ray-shooting maps (Kayser, Refsdal, & Stabell 1986), while the other method is based on an application of Green’s theorem. This second method finds the area of an image by calculating a Riemann integral along the image contour. VBBinaryLensing is a C++ contour integration code developed by Valerio Bozza, which utilizes this method. The parameters at which the source object could be treated as a point source, or in other words, when the source is far enough from the caustic, was of interest to substantially decrease the computational time. The maximum and minimum values of the caustic curves produced, were examined to determine the boundaries for which this simplification could be made. The code was then run for a number of different maps, with separation values and accuracies ranging from 10-1 to 10-3, to test the theoretical model and determine a safe buffer for which minimal error could be made for the approximation. The determined buffer was 1.5+5q, with q being the mass ratio. The theoretical model and the calculated points worked for all combinations of the separation values and different accuracies except the map with accuracy and separation equal to 10-3 for y1 max. An alternative approach has to be found in order to accommodate a wider range of parameters.

  5. A comparison of the real-time and the imaginary-time formalisms of finite temperature field theory for 2,3, and 4-point Green's functions

    International Nuclear Information System (INIS)

    Aurenche, P.; Becherrawy, T.

    1991-07-01

    The predictions of the real-time and the imaginary-time formalisms of Finite Temperature Field Theory is compared. Retarded and advanced amplitudes are constructed in the real-time formalism which are linear combinations of the usual time-ordered thermo-field dynamics amplitudes. These amplitudes can be easily compared to the various analytically continued amplitudes of the imaginary-time formalism. Explicit calculation of the 2,3 and 4-point Green's functions in φ 3 field theory is done in the one and two-loop approximations, and the compatibility of the two formalisms is shown. (author) 17 refs., 12 figs

  6. Experience of Dual Time Point Brain F-18 FDG PET/CT Imaging in Patients with Infections Disease

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Weung; Kim, Chang Guhn; Park, Soon Ah; Jung, Sang Ah [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

    2010-06-15

    Dual time point FDG PET imaging (DTPI) has been considered helpful for discrimination of benign and malignant disease, and staging lymph node status in patients with pulmonary malignancy. However, DTPI for benign disease has been rarely reported, and it may show a better description of metabolic status and extent of benign infection disease than early imaging only. The authors report on the use F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) imaging with additional delayed imaging on a 52-year-old man with sparganosis and a 70-year-old man with tuberculous meningitis. To the best of our knowledge, this is the first report on dual time point PET/CT imaging in patients with cerebral sparganosis and tuberculous meningitis.

  7. Measurement of total acid number (TAN) and TAN boiling point distribution in petroleum products by electrospray ionization mass spectrometry.

    Science.gov (United States)

    Qian, Kuangnan; Edwards, Kathleen E; Dechert, Gary J; Jaffe, Stephen B; Green, Larry A; Olmstead, William N

    2008-02-01

    We report a new method for rapid measurement of total acid number (TAN) and TAN boiling point (BP) distribution for petroleum crude and products. The technology is based on negative ion electrospray ionization mass spectrometry (ESI-MS) for selective ionization of petroleum acid and quantification of acid structures and molecular weight distributions. A chip-based nanoelectrospray system enables microscale (boiling point distributions of TAN values can be calculated from the composition. The rapid measurement of TAN BP distributions by ESI is demonstrated for a series of high-TAN crudes and distillation cuts. TAN values determined by the technique agree well with those by the titration method. The distributed properties compare favorably with those measured by distillation and measurement of TAN of corresponding cuts.

  8. Perceived Time as a Measure of Mental Workload

    DEFF Research Database (Denmark)

    Hertzum, Morten; Holmegaard, Kristin Due

    2013-01-01

    The mental workload imposed by systems is important to their operation and usability. Consequently, researchers and practitioners need reliable, valid, and easy-to-administer methods for measuring mental workload. The ratio of perceived time to clock time appears to be such a method, yet mental...... is a performance-related rather than task-related dimension of mental workload. We find a higher perceived time ratio for timed than untimed tasks. According to subjective workload ratings and pupil-diameter measurements the timed tasks impose higher mental workload. This finding contradicts the prospective...... paradigm, which asserts that perceived time decreases with increasing mental workload. We also find a higher perceived time ratio for solved than unsolved tasks, while subjective workload ratings indicate lower mental workload for the solved tasks. This finding shows that the relationship between...

  9. Cluster magnetic field observations in the magnetosheath: four-point measurements of mirror structures

    Directory of Open Access Journals (Sweden)

    E. A. Lucek

    2001-09-01

    Full Text Available The Cluster spacecraft have returned the first simultaneous four-point measurements of the magnetosheath. We present an analysis of data recorded on 10 November 2000, when the four spacecrafts observed an interval of strong mirrorlike activity. Correlation analysis between spacecraft pairs is used to examine the scale size of the mirror structures in three dimensions. Two examples are presented which suggest that the scale size of mirror structures is ~ 1500–3000 km along the flow direction, and shortest along the magnetopause normal (< 600 km, which, in this case, is approximately perpendicular to both the mean magnetic field and the magnetosheath flow vector. Variations on scales of ~ 750–1000 km are found along the maximum variance direction. The level of correlation in this direction, however, and the time lag observed, are found to be variable. These first results suggest that variations occur on scales of the order of the spacecraft separation ( ~ 1000 km in at least two directions, but analysis of further examples and a statistical survey of structures observed with different magnetic field orientations and tetrahedral configurations will enable us to describe more fully the size and orientation of mirror structures.Key words. Magnetosphenic physics (magnetosheath; plasma waves and instabilities

  10. Cluster magnetic field observations in the magnetosheath: four-point measurements of mirror structures

    Directory of Open Access Journals (Sweden)

    E. A. Lucek

    Full Text Available The Cluster spacecraft have returned the first simultaneous four-point measurements of the magnetosheath. We present an analysis of data recorded on 10 November 2000, when the four spacecrafts observed an interval of strong mirrorlike activity. Correlation analysis between spacecraft pairs is used to examine the scale size of the mirror structures in three dimensions. Two examples are presented which suggest that the scale size of mirror structures is ~ 1500–3000 km along the flow direction, and shortest along the magnetopause normal (< 600 km, which, in this case, is approximately perpendicular to both the mean magnetic field and the magnetosheath flow vector. Variations on scales of ~ 750–1000 km are found along the maximum variance direction. The level of correlation in this direction, however, and the time lag observed, are found to be variable. These first results suggest that variations occur on scales of the order of the spacecraft separation ( ~ 1000 km in at least two directions, but analysis of further examples and a statistical survey of structures observed with different magnetic field orientations and tetrahedral configurations will enable us to describe more fully the size and orientation of mirror structures.

    Key words. Magnetosphenic physics (magnetosheath; plasma waves and instabilities

  11. The Bs0: measurement of the life time and study of the oscillations with the ALEPH experiment

    International Nuclear Information System (INIS)

    Schune, M.H.

    1997-01-01

    This work describes first the theoretical motivations for the study of the life time and the oscillation frequency of the B s 0 meson. After a brief presentation of the Cabbibo-Kobayashi-Maskawa matrix, the oscillation formalism is presented and the importance of the Δm d and Δm s pointed out in the frame of the Standard Model. The author explains the importance of measuring the B s 0 life time and the ΔΓ s , the width difference between the two states of B s 0 . The second chapter is devoted to the selection of events and the measurement of the proper time, taking the time resolution into account. The third chapter deals with the measurement of the life time and the analytical convolution used for this measurement and for the study of the oscillations. This chapter gives also the experimental result obtained for the measurement of ΔΓ s . The fourth chapter states the tagging method, the variables used for it and the systematic checking. Rapid simulations are presented in the fifth chapter as well as the procedure used to give a lower limit for Δm s . Finally, the last chapter shows the analysis of the B s 0 oscillation frequency, states the obtained limit in comparison to other results. The influence of this limit and a limit obtained by combining the results of the ALEPH and DELPHI collaborations are discussed with respect to the determination of the Standard Model parameters. (N.T.)

  12. Point-of-care estimation of haemoglobin concentration in all age ...

    African Journals Online (AJOL)

    Point-of-care estimation of haemoglobin concentration in all age groups in clinical ... and the results were compared using standard scatter and difference plots. ... Hb measurements with a smaller sample volume, improved turnaround time, ...

  13. Use of Response Time for Measuring Cognitive Ability

    Directory of Open Access Journals (Sweden)

    Patrick C. Kyllonen

    2016-11-01

    Full Text Available The purpose of this paper is to review some of the key literature on response time as it has played a role in cognitive ability measurement, providing a historical perspective as well as covering current research. We discuss the speed-level distinction, dimensions of speed and level in cognitive abilities frameworks, speed–accuracy tradeoff, approaches to addressing speed–accuracy tradeoff, analysis methods, particularly item response theory-based, response time models from cognitive psychology (ex-Gaussian function, and the diffusion model, and other uses of response time in testing besides ability measurement. We discuss several new methods that can be used to provide greater insight into the speed and level aspects of cognitive ability and speed–accuracy tradeoff decisions. These include item-level time limits, the use of feedback (e.g., CUSUMs, explicit scoring rules that combine speed and accuracy information (e.g., count down timing, and cognitive psychology models. We also review some of the key psychometric advances in modeling speed and level, which combine speed and ability measurement, address speed–accuracy tradeoff, allow for distinctions between response times on items responded to correctly and incorrectly, and integrate psychometrics with information-processing modeling. We suggest that the application of these models and tools is likely to advance both the science and measurement of human abilities for theory and applications.

  14. Broad frequency band full field measurements for advanced applications: Point-wise comparisons between optical technologies

    Science.gov (United States)

    Zanarini, Alessandro

    2018-01-01

    The progress of optical systems gives nowadays at disposal on lightweight structures complex dynamic measurements and modal tests, each with its own advantages, drawbacks and preferred usage domains. It is thus more easy than before to obtain highly spatially defined vibration patterns for many applications in vibration engineering, testing and general product development. The potential of three completely different technologies is here benchmarked on a common test rig and advanced applications. SLDV, dynamic ESPI and hi-speed DIC are here first deployed in a complex and unique test on the estimation of FRFs with high spatial accuracy from a thin vibrating plate. The latter exhibits a broad band dynamics and high modal density in the common frequency domain where the techniques can find an operative intersection. A peculiar point-wise comparison is here addressed by means of discrete geometry transforms to put all the three technologies on trial at each physical point of the surface. Full field measurement technologies cannot estimate only displacement fields on a refined grid, but can exploit the spatial consistency of the results through neighbouring locations by means of numerical differentiation operators in the spatial domain to obtain rotational degrees of freedom and superficial dynamic strain distributions, with enhanced quality, compared to other technologies in literature. Approaching the task with the aid of superior quality receptance maps from the three different full field gears, this work calculates and compares rotational and dynamic strain FRFs. Dynamic stress FRFs can be modelled directly from the latter, by means of a constitutive model, avoiding the costly and time-consuming steps of building and tuning a numerical dynamic model of a flexible component or a structure in real life conditions. Once dynamic stress FRFs are obtained, spectral fatigue approaches can try to predict the life of a component in many excitation conditions. Different

  15. Atmospheric plume progression as a function of time and distance from the release point for radioactive isotopes.

    Science.gov (United States)

    Eslinger, Paul W; Bowyer, Ted W; Cameron, Ian M; Hayes, James C; Miley, Harry S

    2015-10-01

    The radionuclide network of the International Monitoring System comprises up to 80 stations around the world that have aerosol and xenon monitoring systems designed to detect releases of radioactive materials to the atmosphere from nuclear explosions. A rule of thumb description of plume concentration and duration versus time and distance from the release point is useful when designing and deploying new sample collection systems. This paper uses plume development from atmospheric transport modeling to provide a power-law rule describing atmospheric dilution factors as a function of distance from the release point. Consider the plume center-line concentration seen by a ground-level sampler as a function of time based on a short-duration ground-level release of a nondepositing radioactive tracer. The concentration C (Bq m(-3)) near the ground varies with distance from the source with the relationship C=R×A(D,C) ×e (-λ(-1.552+0.0405×D)) × 5.37×10(-8) × D(-2.35) where R is the release magnitude (Bq), D is the separation distance (km) from the ground level release to the measurement location, λ is the decay constant (h(-1)) for the radionuclide of interest and AD,C is an attenuation factor that depends on the length of the sample collection period. This relationship is based on the median concentration for 10 release locations with different geographic characteristics and 365 days of releases at each location, and it has an R(2) of 0.99 for 32 distances from 100 to 3000 km. In addition, 90 percent of the modeled plumes fall within approximately one order of magnitude of this curve for all distances. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Comparison of Single-Point and Continuous Sampling Methods for Estimating Residential Indoor Temperature and Humidity.

    Science.gov (United States)

    Johnston, James D; Magnusson, Brianna M; Eggett, Dennis; Collingwood, Scott C; Bernhardt, Scott A

    2015-01-01

    Residential temperature and humidity are associated with multiple health effects. Studies commonly use single-point measures to estimate indoor temperature and humidity exposures, but there is little evidence to support this sampling strategy. This study evaluated the relationship between single-point and continuous monitoring of air temperature, apparent temperature, relative humidity, and absolute humidity over four exposure intervals (5-min, 30-min, 24-hr, and 12-days) in 9 northern Utah homes, from March-June 2012. Three homes were sampled twice, for a total of 12 observation periods. Continuous data-logged sampling was conducted in homes for 2-3 wks, and simultaneous single-point measures (n = 114) were collected using handheld thermo-hygrometers. Time-centered single-point measures were moderately correlated with short-term (30-min) data logger mean air temperature (r = 0.76, β = 0.74), apparent temperature (r = 0.79, β = 0.79), relative humidity (r = 0.70, β = 0.63), and absolute humidity (r = 0.80, β = 0.80). Data logger 12-day means were also moderately correlated with single-point air temperature (r = 0.64, β = 0.43) and apparent temperature (r = 0.64, β = 0.44), but were weakly correlated with single-point relative humidity (r = 0.53, β = 0.35) and absolute humidity (r = 0.52, β = 0.39). Of the single-point RH measures, 59 (51.8%) deviated more than ±5%, 21 (18.4%) deviated more than ±10%, and 6 (5.3%) deviated more than ±15% from data logger 12-day means. Where continuous indoor monitoring is not feasible, single-point sampling strategies should include multiple measures collected at prescribed time points based on local conditions.

  17. A Point Kinetics Model for Estimating Neutron Multiplication of Bare Uranium Metal in Tagged Neutron Measurements

    Science.gov (United States)

    Tweardy, Matthew C.; McConchie, Seth; Hayward, Jason P.

    2017-07-01

    An extension of the point kinetics model is developed to describe the neutron multiplicity response of a bare uranium object under interrogation by an associated particle imaging deuterium-tritium (D-T) measurement system. This extended model is used to estimate the total neutron multiplication of the uranium. Both MCNPX-PoliMi simulations and data from active interrogation measurements of highly enriched and depleted uranium geometries are used to evaluate the potential of this method and to identify the sources of systematic error. The detection efficiency correction for measured coincidence response is identified as a large source of systematic error. If the detection process is not considered, results suggest that the method can estimate total multiplication to within 13% of the simulated value. Values for multiplicity constants in the point kinetics equations are sensitive to enrichment due to (n, xn) interactions by D-T neutrons and can introduce another significant source of systematic bias. This can theoretically be corrected if isotopic composition is known a priori. The spatial dependence of multiplication is also suspected of introducing further systematic bias for high multiplication uranium objects.

  18. Time Resolved Deposition Measurements in NSTX

    International Nuclear Information System (INIS)

    Skinner, C.H.; Kugel, H.; Roquemore, A.L.; Hogan, J.; Wampler, W.R.

    2004-01-01

    Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 (micro)g/cm 2 of deposition, however surprisingly, 15.9 (micro)g/cm 2 of material loss occurred at 7 discharges. The net deposited mass of 13.3 (micro)g/cm 2 matched the mass of 13.5 (micro)g/cm 2 measured independently by ion beam analysis. Monte Carlo modeling suggests that transient processes are likely to dominate the deposition

  19. Economic Order Quality Model for Determining the Sales Prices of Fresh Goods at Various Points in Time

    Directory of Open Access Journals (Sweden)

    Po-Yu Chen

    2017-01-01

    Full Text Available Although the safe consumption of goods such as food products, medicine, and vaccines is related to their freshness, consumers frequently understand less than suppliers about the freshness of goods when they purchase them. Because of this lack of information, apart from sales prices, consumers refer only to the manufacturing and expiration dates when deciding whether to purchase and how many of these goods to buy. If dealers could determine the sales price at each point in time and customers’ intention to buy goods of varying freshness, then dealers could set an optimal inventory cycle and allocate a weekly sales price for each point in time, thereby maximizing the profit per unit time. Therefore, in this study, an economic order quality model was established to enable discussion of the optimal control of sales prices. The technique for identifying the optimal solution for the model was determined, the characteristics of the optimal solution were demonstrated, and the implications of the solution’s sensitivity analysis were explained.

  20. The succinonitrile triple-point standard: a fixed point to improve the accuracy of temperature measurements in the clinical laboratory.

    Science.gov (United States)

    Mangum, B W

    1983-07-01

    In an investigation of the melting and freezing behavior of succinonitrile, the triple-point temperature was determined to be 58.0805 degrees C, with an estimated uncertainty of +/- 0.0015 degrees C relative to the International Practical Temperature Scale of 1968 (IPTS-68). The triple-point temperature of this material is evaluated as a temperature-fixed point, and some clinical laboratory applications of this fixed point are proposed. In conjunction with the gallium and ice points, the availability of succinonitrile permits thermistor thermometers to be calibrated accurately and easily on the IPTS-68.

  1. Using a space filling curve approach for the management of dynamic point clouds

    NARCIS (Netherlands)

    Psomadaki, S; van Oosterom, P.J.M.; Tijssen, T.P.M.; Baart, F.

    2016-01-01

    Point cloud usage has increased over the years. The development of low-cost sensors makes it now possible to acquire frequent point cloud measurements on a short time period (day, hour, second). Based on the requirements coming from the coastal monitoring domain, we have developed, implemented and

  2. Evaluation of point-of-care analyzers' ability to reduce bias in conductivity-based hematocrit measurement during cardiopulmonary bypass

    NARCIS (Netherlands)

    Teerenstra, S.; Steinfelder-Visscher, J.; Gunnewiek, J.K.; Weerwind, P.W.

    2014-01-01

    Most point-of-care testing analyzers use the conductivity method to measure hematocrit (hct). During open-heart surgery, blood-conductivity is influenced by shifts in electrolyte and colloid concentrations caused by infusion media used, and this may lead to considerable bias in the hct measurement.

  3. Quantum trajectories and measurements in continuous time. The diffusive case

    International Nuclear Information System (INIS)

    Barchielli, Alberto; Gregoratti, Matteo

    2009-01-01

    This course-based monograph introduces the reader to the theory of continuous measurements in quantum mechanics and provides some benchmark applications. The approach chosen, quantum trajectory theory, is based on the stochastic Schroedinger and master equations, which determine the evolution of the a-posteriori state of a continuously observed quantum system and give the distribution of the measurement output. The present introduction is restricted to finite-dimensional quantum systems and diffusive outputs. Two appendices introduce the tools of probability theory and quantum measurement theory which are needed for the theoretical developments in the first part of the book. First, the basic equations of quantum trajectory theory are introduced, with all their mathematical properties, starting from the existence and uniqueness of their solutions. This makes the text also suitable for other applications of the same stochastic differential equations in different fields such as simulations of master equations or dynamical reduction theories. In the next step the equivalence between the stochastic approach and the theory of continuous measurements is demonstrated. To conclude the theoretical exposition, the properties of the output of the continuous measurement are analyzed in detail. This is a stochastic process with its own distribution, and the reader will learn how to compute physical quantities such as its moments and its spectrum. In particular this last concept is introduced with clear and explicit reference to the measurement process. The two-level atom is used as the basic prototype to illustrate the theory in a concrete application. Quantum phenomena appearing in the spectrum of the fluorescence light, such as Mollow's triplet structure, squeezing of the fluorescence light, and the linewidth narrowing, are presented. Last but not least, the theory of quantum continuous measurements is the natural starting point to develop a feedback control theory in

  4. X-points in the spectral emissivity of solid and liquid refractory transition metals measured by multichannel pyrometry. Discussion of the experimental method and physical interpretation

    International Nuclear Information System (INIS)

    Ronchi, C.; Hiernaut, J.P.; Hyland, G.J.

    1993-01-01

    The spectral emissivities of some refractory Transition metals (Hf, Mo, Nb, Re, V, W and Zr) have been measured from about 2500 K up to temperatures above the melting point T m . The experimental method adopted is based on multiwavelength pyrometric measurements, where the determination of the spectral emissivity is implicitly related to the evaluation of temperature through the radiation emission law and an assumed relationship between the spectral emissivity ε and the wavelength λ. Heating was produced with a pulsed laser in times of the order of 100 ms. A specially constructed pyrometer was used which enabled measurements at six different wavelengths to be carried out at time intervals of the order of 0.1 ms. A model for the evaluation of temperature and spectral emissivities has been developed and its limitations due to statistical and systematic errors are discussed. Our experiments confirm the existence of a unique wavelength, λ-x for each metal to which different ε λ -isotherms converge for λ x and from which they diverge for λ>λ x and at which ε λ is independent of T, and thus equal, in particular, to its value at T m , indicate that λ x is preserved through T m and reveal that at T m these metals are effectively 'grey'. Detailed theoretical investigations reveal that the occurrence of the λ x points is intimately connected with the particular T and λ dependences of the interband contribution to the imaginary part of the complex dielectric function entailed by specific features of the electronic band-structure of the Transition metals concerned. Finally, in connection with the 'grey' phenomenon at T m , it should be stressed that this is not found in the case of the Noble metals, although, like Transition metals, they exhibit λ x points, despite their quite different band-structures. (author). 56 refs., 8 figs., 5 tabs

  5. Industrial point source CO2 emission strength estimation with aircraft measurements and dispersion modelling.

    Science.gov (United States)

    Carotenuto, Federico; Gualtieri, Giovanni; Miglietta, Franco; Riccio, Angelo; Toscano, Piero; Wohlfahrt, Georg; Gioli, Beniamino

    2018-02-22

    CO 2 remains the greenhouse gas that contributes most to anthropogenic global warming, and the evaluation of its emissions is of major interest to both research and regulatory purposes. Emission inventories generally provide quite reliable estimates of CO 2 emissions. However, because of intrinsic uncertainties associated with these estimates, it is of great importance to validate emission inventories against independent estimates. This paper describes an integrated approach combining aircraft measurements and a puff dispersion modelling framework by considering a CO 2 industrial point source, located in Biganos, France. CO 2 density measurements were obtained by applying the mass balance method, while CO 2 emission estimates were derived by implementing the CALMET/CALPUFF model chain. For the latter, three meteorological initializations were used: (i) WRF-modelled outputs initialized by ECMWF reanalyses; (ii) WRF-modelled outputs initialized by CFSR reanalyses and (iii) local in situ observations. Governmental inventorial data were used as reference for all applications. The strengths and weaknesses of the different approaches and how they affect emission estimation uncertainty were investigated. The mass balance based on aircraft measurements was quite succesful in capturing the point source emission strength (at worst with a 16% bias), while the accuracy of the dispersion modelling, markedly when using ECMWF initialization through the WRF model, was only slightly lower (estimation with an 18% bias). The analysis will help in highlighting some methodological best practices that can be used as guidelines for future experiments.

  6. Some thermophysical properties of ruthenium in the neighbourhood of the melting point

    International Nuclear Information System (INIS)

    Sheindlin, A.E.; Kats, S.A.; Berezin, B.Ya.; Chekhovskoy, V.Ya.; Kenisarin, M.M.

    1975-01-01

    The technique of levitation calorimetry has been used to study for the first time thermophysical properties of ruthenium in the neighbourhood of the melting point. To measure enthalpy a copper block calorimeter with an istohermal jacket has been used. Basing on the values measured the equations for enthalpy of solid and liquid ruthenium within the temperature ranges of 2,270-2,607 K and 2,607-2,760 K respectively have been obtained by the least squares method. In addition the melting temperature of ruthenium and its brightness temperature at the melting point, the wavelength being 0.65 micron, have been measured. The results of the measurements have been used to calculate the heat and entropy of fusion, the specific heat of solid and that of liquid ruthenium and its normal spectral emissivity at the melting point

  7. Real time refractive index measurement by ESPI

    International Nuclear Information System (INIS)

    Torroba, R.; Joenathan, C.

    1991-01-01

    In this paper a method to measure refractive index variations in real time is reported. A technique to introduce reference fringes in real time is discussed. Both the theoretical and experimental results are presented and an example with phase shifting is given. (author). 8 refs, 5 figs

  8. Improved Dynamic Planar Point Location

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Arge, Lars; Georgiadis, Loukas

    2006-01-01

    We develop the first linear-space data structures for dynamic planar point location in general subdivisions that achieve logarithmic query time and poly-logarithmic update time.......We develop the first linear-space data structures for dynamic planar point location in general subdivisions that achieve logarithmic query time and poly-logarithmic update time....

  9. Timely resolved measurements on CdSe nanoparticles

    International Nuclear Information System (INIS)

    Holt, B.E. von

    2006-01-01

    By means of infrared spectroscopy the influence of the organic cover on structure and dynamics of CdSe nanoparticles was studied. First a procedure was developed, which allows to get from the static infrared spectrum informations on the quality of the organic cover and the binding behaviour of the ligands. On qualitatively high-grade and well characterized samples thereafter the dynamics of the lowest-energy electron level 1S e was time-resolvedly meausred in thew visible range. As reference served CdSe TOPO, which was supplemented by samples with the ligands octanthiole, octanic acid, octylamine, naphthoquinone, benzoquinone, and pyridine. The studied nanoparticles had a diameter of 4.86 nm. By means of the excitation-scanning or pump=probe procedure first measurements in the picosecond range were performed. The excitation wavelengths were thereby spectrally confined and so chosen that selectively the transitions 1S 3/2 -1S-e and 1P 3/2 -1P e but not the intermediately lyingt transition 2S 3/2 -1S e were excited. The excitation energies were kept so low that the excitation of several excitons in one crystal could be avoided. The scanning wavelength in the infrared corresponded to the energy difference between the electron levels 1S e and 1P e . The transients in the picosecond range are marked by a steep increasement of the signal, on which a multi-exponential decay follows. The increasement, which reproduces the popiulation of the excited state, isa inependent on the choice of the ligands. The influence of the organic cover is first visible in the different decay times of the excited electron levels. the decay of the measurement signal of CdSe TOPO can be approximatively described by three time constants: a decay constant in the early picosecond region, a time constant around hundert picoseconds, and a time constant of some nanoseconds. At increasing scanning wavelength the decay constants become longer. By directed excitation of the 1S 3/2 -1S e and the 1P 3

  10. Real-time database for high resolution neutron monitor measurements

    Energy Technology Data Exchange (ETDEWEB)

    Steigies, Christian T.; Rother, Oliver M.; Wimmer-Schweingruber, Robert F.; Heber, Bernd [IEAP, Christian-Albrechts-Universitaet zu Kiel (Germany)

    2008-07-01

    The worldwide network of standardised neutron monitors is, after 50 years, still the state-of-the-art instrumentation to measure spectral variations of the primary cosmic ray component. These measurements are an ideal complement to space based cosmic ray measurements. Data from the approximately 50 IGY and NM64 neutron monitors is stored locally but also available through data collections sites like the World Data Center (WDC) or the IZMIRAN ftp server. The data from the WDC is in a standard format, but only hourly values are available. IZMIRAN collects the data in the best available time resolution, but the data arrives on the ftp server only hours, sometimes days, after the measurements. Also, the high time-resolution measurements of the different stations do not have a common format, a conversion routine for each station is needed before they can be used for scientific analysis. Supported by the 7th framework program of the European Commission, we are setting up a real-time database where high resolution cosmic ray measurements will be stored and accessible immediately after the measurement. Stations that do not have 1-minute resolution measurements will be upgraded to 1-minute or better resolution with an affordable standard registration system, that will submit the measurements to the database via the internet in real-time.

  11. Methane and CO2 fluxes of moving point sources - Beyond or within the limits of eddy covariance measurements

    Science.gov (United States)

    Felber, Raphael; Neftel, Albrecht; Münger, Andreas; Ammann, Christof

    2014-05-01

    The eddy covariance (EC) technique has been extensively used for CO2 and energy exchange measurements over different ecosystems. For some years, it has been also becoming widely used to investigate CH4 and N2O exchange over ecosystems including grazing systems. EC measurements represent a spatially integrated flux over an upwind area (footprint). Whereas for extended homogenous areas EC measurements work well, the animals in a grazing system are a challenge as they represent moving point sources that create inhomogeneous conditions in space and time. The main issues which have to be taken into account when applying EC flux measurements over a grazed system are: i) In the presence of animals the high time resolution concentration measurements show large spikes in the signal. These spikes may be filtered/reduced by standard quality control software in order to avoid wrong measurements. ii) Data on the position of the animals relative to the flux footprint is needed to quantify the contribution of the grazing animals to the measured flux. For one grazing season we investigated the ability of EC flux measurements to reliably quantify the contribution of the grazing animals to the CH4 and CO2 exchange over pasture systems. For this purpose, a field experiment with a herd of twenty dairy cows in a full-day rotational grazing system was carried out on the Swiss central plateau. Net CH4 and CO2 exchange of the pasture system was measured continuously by the eddy covariance technique (Sonic Anemometer HS-50, Gill Instruments Ltd; FGGA, Los Gatos Research Inc.). To quantify the contribution of the animals to the net flux, the position of the individual cows was recorded using GPS (5 s time resolution) on each animal. An existing footprint calculation tool (ART footprint tool) was adapted and CH4 emissions of the cows were calculated. CH4 emissions from cows could be used as a tracer to investigate the quality of the evaluation of the EC data, since the background exchange of

  12. Does the Timing of Measurement Alter Session-RPE in Boxers?

    Science.gov (United States)

    Uchida, Marco C; Teixeira, Luis F M; Godoi, Vladmir J; Marchetti, Paulo H; Conte, Marcelo; Coutts, Aaron J; Bacurau, Reury F P

    2014-01-01

    The purpose of this study was to compare the influence of measuring the overall session rating of perceived exertion (session-RPE) at 10 vs. 30 minutes following exercise. Eight boxers completed three different standardized training sessions of different intensities (easy, moderate and hard) in a matchedpairs, randomized research design. Exercise intensity was assessed during each bout by measuring heart rate, blood lactate concentration and session-RPE. To assess the effect of measurement timing on session-RPE, RPE data were collected either 10 or 30 minutes post-exercise. There was no significant effect of measurement time on session-RPE values following easy (10 minutes: session-RPE = 1.3 ± 1.0 Arbitrary Unit (AU), %Heart Rate Reserve (HRR) = 49.5 ± 11.1, and ∆Blood lactate = -2.3 ± 16.3%; 30 minutes: session-RPE = 1.7 ± 1.0 AU, %HRR = 51.3 ± 10.8, and ∆Blood lactate = 0.7 ± 25.2%), moderate (10 minutes: session-RPE = 2.7 ± 1.6 AU, %HRR = 67.2 ± 10.8, and ∆Blood lactate = 2.2 ± 19%; 30 minutes: session-RPE = 2.5 ± 0.9 AU, %HRR = 67.2 ± 5.9, and ∆Blood lactate = 24.5 ± 17.1%) and hard (10 minutes: session-RPE = 5.7 ± 1.0 AU, %HRR = 88.1 ± 6.3, and ∆Blood lactate = 146.3 ± 87.9%; 30 minutes: session-RPE = 5.8 ± 1.9 AU, %HRR> = 83.3 ± 8.0, and ∆Blood lactate = 91.6 ± 39%) sessions. In conclusion, our findings suggest that session-RPE can be used in boxing training routines across a range of intensities and accurate measurements can be determined as early as 10 minutes after exercise. Key PointsIt is difficult to quantify and monitoring the external training load in martial arts (e.g. Aikido, Kung Fu, Judo) and physical combat sports (e.g. Boxing, Muay Thai), session RPE method appears to be a reliable method to quantifying training load in those sports.For many athletes it is impractical to wait 30 minutes after training session to provide a session-RPE. The present findings show that collecting ses-sion-RPE measures at 10 min

  13. Discrete time interval measurement system: fundamentals, resolution and errors in the measurement of angular vibrations

    International Nuclear Information System (INIS)

    Gómez de León, F C; Meroño Pérez, P A

    2010-01-01

    The traditional method for measuring the velocity and the angular vibration in the shaft of rotating machines using incremental encoders is based on counting the pulses at given time intervals. This method is generically called the time interval measurement system (TIMS). A variant of this method that we have developed in this work consists of measuring the corresponding time of each pulse from the encoder and sampling the signal by means of an A/D converter as if it were an analog signal, that is to say, in discrete time. For this reason, we have denominated this method as the discrete time interval measurement system (DTIMS). This measurement system provides a substantial improvement in the precision and frequency resolution compared with the traditional method of counting pulses. In addition, this method permits modification of the width of some pulses in order to obtain a mark-phase on every lap. This paper explains the theoretical fundamentals of the DTIMS and its application for measuring the angular vibrations of rotating machines. It also displays the required relationship between the sampling rate of the signal, the number of pulses of the encoder and the rotating velocity in order to obtain the required resolution and to delimit the methodological errors in the measurement

  14. Micro-four-point probes in a UHV scanning electron microscope for in-situ surface-conductivity measurements

    DEFF Research Database (Denmark)

    Shiraki, I.; Nagao, T.; Hasegawa, S.

    2000-01-01

    For in-situ measurements of surface conductivity in ultrahigh vacuum (UHV), we have installed micro-four-point probes (probe spacings down to 4 mum) in a UHV scanning electron microscope (SEM) combined with scanning reflection-high-energy electron diffraction (RHEED). With the aid of piezoactuators...

  15. Standard Test Method for Measuring Extreme Heat-Transfer Rates from High-Energy Environments Using a Transient, Null-Point Calorimeter

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers the measurement of the heat-transfer rate or the heat flux to the surface of a solid body (test sample) using the measured transient temperature rise of a thermocouple located at the null point of a calorimeter that is installed in the body and is configured to simulate a semi-infinite solid. By definition the null point is a unique position on the axial centerline of a disturbed body which experiences the same transient temperature history as that on the surface of a solid body in the absence of the physical disturbance (hole) for the same heat-flux input. 1.2 Null-point calorimeters have been used to measure high convective or radiant heat-transfer rates to bodies immersed in both flowing and static environments of air, nitrogen, carbon dioxide, helium, hydrogen, and mixtures of these and other gases. Flow velocities have ranged from zero (static) through subsonic to hypersonic, total flow enthalpies from 1.16 to greater than 4.65 × 101 MJ/kg (5 × 102 to greater than 2 × 104 ...

  16. Georeferenced Point Clouds: A Survey of Features and Point Cloud Management

    Directory of Open Access Journals (Sweden)

    Johannes Otepka

    2013-10-01

    Full Text Available This paper presents a survey of georeferenced point clouds. Concentration is, on the one hand, put on features, which originate in the measurement process themselves, and features derived by processing the point cloud. On the other hand, approaches for the processing of georeferenced point clouds are reviewed. This includes the data structures, but also spatial processing concepts. We suggest a categorization of features into levels that reflect the amount of processing. Point clouds are found across many disciplines, which is reflected in the versatility of the literature suggesting specific features.

  17. Boltzmann babies in the proper time measure

    Energy Technology Data Exchange (ETDEWEB)

    Bousso, Raphael; Bousso, Raphael; Freivogel, Ben; Yang, I-Sheng

    2007-12-20

    After commenting briefly on the role of the typicality assumption in science, we advocate a phenomenological approach to the cosmological measure problem. Like any other theory, a measure should be simple, general, well defined, and consistent with observation. This allows us to proceed by elimination. As an example, we consider the proper time cutoff on a geodesic congruence. It predicts that typical observers are quantum fluctuations in the early universe, or Boltzmann babies. We sharpen this well-known youngness problem by taking into account the expansion and open spatial geometry of pocket universes. Moreover, we relate the youngness problem directly to the probability distribution for observables, such as the temperature of the cosmic background radiation. We consider a number of modifications of the proper time measure, but find none that would make it compatible with observation.

  18. Study on the effect of measurement points upon reduced added mass matrix; Shukusho fuka shitsuryo matrix ni okeru kansokuten no eikyo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Funaki, T.; Hayashi, S. [Osaka University, Osaka (Japan). Faculty of engineering

    1996-12-31

    It is known in estimating vibration characteristics of a ship that fluid range affects largely a structure. A parameter calculation was performed on node vibration in the vertical direction of a rotating elliptic body such as a ship to investigate the effect of an arranging method of the measurement points upon the result of the analysis. As a result, it is thought that equivalent interval arrangement of 21 measurement points would be sufficient in a lower order side mode of vibrations with less than four nodes. An analysis of calculations performed by arranging measurement points in experimental measurement points revealed that analysis accuracy would not increase even if the number of measurement points is increased if it is done so without considering rotation vector. An experiment was carried out with the number of measurement points increased to verify the above fact, with which the analysis was verified correct. Therefore, as has been forecasted in the previous report, the cause for the analysis accuracy deterioration in a high order mode may be estimated as the effect of the rotation vector. However, since it is not the situation that an analysis considering the rotation vector has been conducted, it cannot be concluded yet that the effect of the rotation vector is the sole cause. 4 refs., 14 figs., 7 tabs.

  19. Study on the effect of measurement points upon reduced added mass matrix; Shukusho fuka shitsuryo matrix ni okeru kansokuten no eikyo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Funaki, T; Hayashi, S [Osaka University, Osaka (Japan). Faculty of engineering

    1997-12-31

    It is known in estimating vibration characteristics of a ship that fluid range affects largely a structure. A parameter calculation was performed on node vibration in the vertical direction of a rotating elliptic body such as a ship to investigate the effect of an arranging method of the measurement points upon the result of the analysis. As a result, it is thought that equivalent interval arrangement of 21 measurement points would be sufficient in a lower order side mode of vibrations with less than four nodes. An analysis of calculations performed by arranging measurement points in experimental measurement points revealed that analysis accuracy would not increase even if the number of measurement points is increased if it is done so without considering rotation vector. An experiment was carried out with the number of measurement points increased to verify the above fact, with which the analysis was verified correct. Therefore, as has been forecasted in the previous report, the cause for the analysis accuracy deterioration in a high order mode may be estimated as the effect of the rotation vector. However, since it is not the situation that an analysis considering the rotation vector has been conducted, it cannot be concluded yet that the effect of the rotation vector is the sole cause. 4 refs., 14 figs., 7 tabs.

  20. Transient Point Infiltration In The Unsaturated Zone

    Science.gov (United States)

    Buecker-Gittel, M.; Mohrlok, U.

    The risk assessment of leaking sewer pipes gets more and more important due to urban groundwater management and environmental as well as health safety. This requires the quantification and balancing of transport and transformation processes based on the water flow in the unsaturated zone. The water flow from a single sewer leakage could be described as a point infiltration with time varying hydraulic conditions externally and internally. External variations are caused by the discharge in the sewer pipe as well as the state of the leakage itself. Internal variations are the results of microbiological clogging effects associated with the transformation processes. Technical as well as small scale laboratory experiments were conducted in order to investigate the water transport from an transient point infiltration. From the technical scale experiment there was evidence that the water flow takes place under transient conditions when sewage infiltrates into an unsaturated soil. Whereas the small scale experiments investigated the hydraulics of the water transport and the associated so- lute and particle transport in unsaturated soils in detail. The small scale experiment was a two-dimensional representation of such a point infiltration source where the distributed water transport could be measured by several tensiometers in the soil as well as by a selective measurement of the discharge at the bottom of the experimental setup. Several series of experiments were conducted varying the boundary and initial con- ditions in order to derive the important parameters controlling the infiltration of pure water from the point source. The results showed that there is a significant difference between the infiltration rate in the point source and the discharge rate at the bottom, that could be explained by storage processes due to an outflow resistance at the bottom. This effect is overlayn by a decreasing water content decreases over time correlated with a decreasing infiltration

  1. Application of a two-sinker densimeter for phase-equilibrium measurements: A new technique for the detection of dew points and measurements on the (methane + propane) system

    International Nuclear Information System (INIS)

    McLinden, Mark O.; Richter, Markus

    2016-01-01

    Highlights: • A new technique for detecting dew points in fluid mixtures is described. • The method makes use of a two-sinker densimeter. • The technique is based on a quantitative measurement of sample mass adsorbed onto the surface of the densimeter sinkers. • The dew-point density and dew-point pressure are determined with low uncertainty. • The method is applied to the (methane + propane) system and compared to traditional methods. - Abstract: We explore a novel method for determining the dew-point density and dew-point pressure of fluid mixtures and compare it to traditional methods. The (p, ρ, T, x) behavior of three (methane + propane) mixtures was investigated with a two-sinker magnetic suspension densimeter over the temperature range of (248.15–293.15) K; the measurements extended from low pressures into the two-phase region. The compositions of the gravimetrically prepared mixtures were (0.74977, 0.50688, and 0.26579) mole fraction methane. We analyzed isothermal data by: (1) a “traditional” analysis of the intersection of a virial fit of the (p vs. ρ) data in the single-phase region with a linear fit of the data in the two-phase region; and (2) an analysis of the adsorbed mass on the sinker surfaces. We compared these to a traditional isochoric experiment. We conclude that the “adsorbed mass” analysis of an isothermal experiment provides an accurate determination of the dew-point temperature, pressure, and density. However, a two-sinker densimeter is required.

  2. Comparison of soil water measurement using the neutron scattering, time domain reflectometry and capacitance methods. Results of a consultants meeting

    International Nuclear Information System (INIS)

    2000-02-01

    Soil water measurement based on neutron scattering has been a valuable tool for the past 40 years because it possesses many of the above mentioned qualities. However, licensing, training of users and safety regulations pertaining to the radioactive source in these devices make their use preventive and expensive in some situations such as unattended monitoring. Disposal of gauges is also increasingly expensive. In past years, the high dielectric constant property of water at high frequencies has been used as the basis to estimate the soil water content. The two major techniques that make use of this property are the capacitance sensors and time domain reflectometry (TDR). The capacitance approach makes use of radio frequencies for determining soil dielectric constant and thus its water content. Significant progress has been made in this approach, with the ability to carry out profile measurement in recent improvement. However, poor precision, dependant on soil types, salinity and temperature are some of the concern relating to the method, making its use difficult for routine soil water measurements. The TDR measures the propagation of an electromagnetic pulse along the transmission lines (wave guides). By measuring the travel time, the velocity and hence the apparent dielectric constant of the soil can be estimated. This then allows the water content of the soil to be determined. Major advances in TDR equipment, probe configurations, data logging and multiplexing, make this a promising technique for point specific monitoring of soil water. In view of the restrictive use of neutron probes, the rapid advancement and the decreasing cost of the non-nuclear methods in recent years, there is a need to compare these methodologies in order to formulate recommendations and establish guidelines for future uses. The objectives of the consultants meeting, as defined by the IAEA in agreement with its mandate, were: To compare the advantages and disadvantages in the various soil

  3. Measurement of gamma quantum interaction point in plastic scintillator with WLS strips

    Energy Technology Data Exchange (ETDEWEB)

    Smyrski, J., E-mail: smyrski@if.uj.edu.pl [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Alfs, D.; Bednarski, T.; Białas, P.; Czerwiński, E.; Dulski, K.; Gajos, A.; Głowacz, B.; Gupta-Sharma, N. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Gorgol, M.; Jasińska, B. [Department of Nuclear Methods, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin (Poland); Kajetanowicz, M.; Kamińska, D.; Korcyl, G. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); Kowalski, P. [Świerk Computing Centre, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Krzemień, W. [High Energy Department, National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Krawczyk, N.; Kubicz, E.; Mohammed, M.; Niedźwiecki, Sz. [Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, S. Łojasiewicza 11, 30-348 Cracow (Poland); and others

    2017-04-11

    The feasibility of measuring the aśxial coordinate of a gamma quantum interaction point in a plastic scintillator bar via the detection of scintillation photons escaping from the scintillator with an array of wavelength-shifting (WLS) strips is demonstrated. Using a test set-up comprising a BC-420 scintillator bar and an array of sixteen BC-482A WLS strips we achieved a spatial resolution of 5 mm (σ) for annihilation photons from a {sup 22}Na isotope. The studied method can be used to improve the spatial resolution of a plastic-scintillator-based PET scanner which is being developed by the J-PET collaboration.

  4. Real time estimation of photovoltaic modules characteristics and its application to maximum power point operation

    Energy Technology Data Exchange (ETDEWEB)

    Garrigos, Ausias; Blanes, Jose M.; Carrasco, Jose A. [Area de Tecnologia Electronica, Universidad Miguel Hernandez de Elche, Avda. de la Universidad s/n, 03202 Elche, Alicante (Spain); Ejea, Juan B. [Departamento de Ingenieria Electronica, Universidad de Valencia, Avda. Dr Moliner 50, 46100 Valencia, Valencia (Spain)

    2007-05-15

    In this paper, an approximate curve fitting method for photovoltaic modules is presented. The operation is based on solving a simple solar cell electrical model by a microcontroller in real time. Only four voltage and current coordinates are needed to obtain the solar module parameters and set its operation at maximum power in any conditions of illumination and temperature. Despite its simplicity, this method is suitable for low cost real time applications, as control loop reference generator in photovoltaic maximum power point circuits. The theory that supports the estimator together with simulations and experimental results are presented. (author)

  5. A Point Kinetics Model for Estimating Neutron Multiplication of Bare Uranium Metal in Tagged Neutron Measurements

    International Nuclear Information System (INIS)

    Tweardy, Matthew C.; McConchie, Seth; Hayward, Jason P.

    2017-01-01

    An extension of the point kinetics model is developed in this paper to describe the neutron multiplicity response of a bare uranium object under interrogation by an associated particle imaging deuterium-tritium (D-T) measurement system. This extended model is used to estimate the total neutron multiplication of the uranium. Both MCNPX-PoliMi simulations and data from active interrogation measurements of highly enriched and depleted uranium geometries are used to evaluate the potential of this method and to identify the sources of systematic error. The detection efficiency correction for measured coincidence response is identified as a large source of systematic error. If the detection process is not considered, results suggest that the method can estimate total multiplication to within 13% of the simulated value. Values for multiplicity constants in the point kinetics equations are sensitive to enrichment due to (n, xn) interactions by D-T neutrons and can introduce another significant source of systematic bias. This can theoretically be corrected if isotopic composition is known a priori. Finally, the spatial dependence of multiplication is also suspected of introducing further systematic bias for high multiplication uranium objects.

  6. Measuring Time in Sporting Competitions with the Domain-Specific Language EasyTime

    OpenAIRE

    Fister Jr., Iztok; Fister, Iztok

    2012-01-01

    Measuring time in mass sporting competitions is unthinkable manually today because of their long duration and unreliability. Besides, automatic timing devices based on the RFID technology have become cheaper. However, these devices cannot operate stand-alone. To work efficiently, they need a computer timing system for monitoring results. Such system should be capable of processing the incoming events, encoding and assigning results to a individual competitor, sorting results according to the ...

  7. Effects of barium concentration on oropharyngeal swallow timing measures.

    Science.gov (United States)

    Stokely, Shauna L; Molfenter, Sonja M; Steele, Catriona M

    2014-02-01

    Videofluoroscopy is commonly used for evaluating oropharyngeal swallowing but requires radiopaque contrast (typically barium). Prior studies suggest that some aspects of swallowing, including timing measures of oral and pharyngeal bolus transit, vary depending on barium concentration. The aim of our study was to identify timing differences in healthy swallowing between "thin" (40 % w/v concentration) and "ultrathin" (22 % w/v concentration) barium solutions. Twenty healthy adults (Ten women; mean age = 31 years) each performed a series of three noncued 5-ml swallows each of ultrathin and thin liquid barium solutions in videofluoroscopy. Timing measures were compared between barium concentrations using a mixed-model ANOVA. The measures of interest were stage transition duration, pharyngeal transit time, and duration of upper esophageal sphincter opening. Significant differences were observed in the timing measures of swallowing with respect to barium concentration. In all cases, longer durations were seen with the higher barium concentration. Barium concentration influences timing parameters in healthy swallowing, even between ultrathin and thin concentrations. Clinicians need to understand and control for the impact of different barium stimuli on swallowing physiology.

  8. Tunneling Time and Weak Measurement in Strong Field Ionization.

    Science.gov (United States)

    Zimmermann, Tomáš; Mishra, Siddhartha; Doran, Brent R; Gordon, Daniel F; Landsman, Alexandra S

    2016-06-10

    Tunneling delays represent a hotly debated topic, with many conflicting definitions and little consensus on when and if such definitions accurately describe the physical observables. Here, we relate these different definitions to distinct experimental observables in strong field ionization, finding that two definitions, Larmor time and Bohmian time, are compatible with the attoclock observable and the resonance lifetime of a bound state, respectively. Both of these definitions are closely connected to the theory of weak measurement, with Larmor time being the weak measurement value of tunneling time and Bohmian trajectory corresponding to the average particle trajectory, which has been recently reconstructed using weak measurement in a two-slit experiment [S. Kocsis, B. Braverman, S. Ravets, M. J. Stevens, R. P. Mirin, L. K. Shalm, and A. M. Steinberg, Science 332, 1170 (2011)]. We demonstrate a big discrepancy in strong field ionization between the Bohmian and weak measurement values of tunneling time, and we suggest this arises because the tunneling time is calculated for a small probability postselected ensemble of electrons. Our results have important implications for the interpretation of experiments in attosecond science, suggesting that tunneling is unlikely to be an instantaneous process.

  9. First Direct Mass Measurements of Nuclides around Z =100 with a Multireflection Time-of-Flight Mass Spectrograph

    Science.gov (United States)

    Ito, Y.; Schury, P.; Wada, M.; Arai, F.; Haba, H.; Hirayama, Y.; Ishizawa, S.; Kaji, D.; Kimura, S.; Koura, H.; MacCormick, M.; Miyatake, H.; Moon, J. Y.; Morimoto, K.; Morita, K.; Mukai, M.; Murray, I.; Niwase, T.; Okada, K.; Ozawa, A.; Rosenbusch, M.; Takamine, A.; Tanaka, T.; Watanabe, Y. X.; Wollnik, H.; Yamaki, S.

    2018-04-01

    The masses of 246Es, 251Fm, and the transfermium nuclei Md-252249 and 254No, produced by hot- and cold-fusion reactions, in the vicinity of the deformed N =152 neutron shell closure, have been directly measured using a multireflection time-of-flight mass spectrograph. The masses of 246Es and 249,250,252Md were measured for the first time. Using the masses of Md,250249 as anchor points for α decay chains, the masses of heavier nuclei, up to 261Bh and 266Mt, were determined. These new masses were compared with theoretical global mass models and demonstrated to be in good agreement with macroscopic-microscopic models in this region. The empirical shell gap parameter δ2 n derived from three isotopic masses was updated with the new masses and corroborates the existence of the deformed N =152 neutron shell closure for Md and Lr.

  10. Timing jitter measurements at the SLC electron source

    International Nuclear Information System (INIS)

    Sodja, J.; Browne, M.J.; Clendenin, J.E.

    1989-03-01

    The SLC thermionic gun and electron source produce a beam of up to 15 /times/ 10 10 /sub e//minus/ in a single S-band bunch. A 170 keV, 2 ns FWHM pulse out of the gun is compressed by means of two subharmonic buncher cavities followed by an S-band buncher and a standard SLAC accelerating section. Ceramic gaps in the beam pipe at the output of the gun allow a measure of the beam intensity and timing. A measurement at these gaps of the timing jitter, with a resolution of <10 ps, is described. 3 refs., 5 figs

  11. Parcellation of the Healthy Neonatal Brain into 107 Regions Using Atlas Propagation through Intermediate Time Points in Childhood.

    Science.gov (United States)

    Blesa, Manuel; Serag, Ahmed; Wilkinson, Alastair G; Anblagan, Devasuda; Telford, Emma J; Pataky, Rozalia; Sparrow, Sarah A; Macnaught, Gillian; Semple, Scott I; Bastin, Mark E; Boardman, James P

    2016-01-01

    Neuroimage analysis pipelines rely on parcellated atlases generated from healthy individuals to provide anatomic context to structural and diffusion MRI data. Atlases constructed using adult data introduce bias into studies of early brain development. We aimed to create a neonatal brain atlas of healthy subjects that can be applied to multi-modal MRI data. Structural and diffusion 3T MRI scans were acquired soon after birth from 33 typically developing neonates born at term (mean postmenstrual age at birth 39(+5) weeks, range 37(+2)-41(+6)). An adult brain atlas (SRI24/TZO) was propagated to the neonatal data using temporal registration via childhood templates with dense temporal samples (NIH Pediatric Database), with the final atlas (Edinburgh Neonatal Atlas, ENA33) constructed using the Symmetric Group Normalization (SyGN) method. After this step, the computed final transformations were applied to T2-weighted data, and fractional anisotropy, mean diffusivity, and tissue segmentations to provide a multi-modal atlas with 107 anatomical regions; a symmetric version was also created to facilitate studies of laterality. Volumes of each region of interest were measured to provide reference data from normal subjects. Because this atlas is generated from step-wise propagation of adult labels through intermediate time points in childhood, it may serve as a useful starting point for modeling brain growth during development.

  12. Parcellation of the healthy neonatal brain into 107 regions using atlas propagation through intermediate time points in childhood

    Directory of Open Access Journals (Sweden)

    Manuel eBlesa Cabez

    2016-05-01

    Full Text Available Neuroimage analysis pipelines rely on parcellated atlases generated from healthy individuals to provide anatomic context to structural and diffusion MRI data. Atlases constructed using adult data introduce bias into studies of early brain development. We aimed to create a neonatal brain atlas of healthy subjects that can be applied to multi-modal MRI data. Structural and diffusion 3T MRI scans were acquired soon after birth from 33 typically developing neonates born at term (mean postmenstrual age at birth 39+5 weeks, range 37+2-41+6. An adult brain atlas (SRI24/TZO was propagated to the neonatal data using temporal registration via childhood templates with dense temporal samples (NIH Pediatric Database, with the final atlas (Edinburgh Neonatal Atlas, ENA33 constructed using the Symmetric Group Normalization method. After this step, the computed final transformations were applied to T2-weighted data, and fractional anisotropy, mean diffusivity, and tissue segmentations to provide a multi-modal atlas with 107 anatomical regions; a symmetric version was also created to facilitate studies of laterality. Volumes of each region of interest were measured to provide reference data from normal subjects. Because this atlas is generated from step-wise propagation of adult labels through intermediate time points in childhood, it may serve as a useful starting point for modelling brain growth during development.

  13. Measurement of the Retention Time of Different Ophthalmic Formulations with Ultrahigh-Resolution Optical Coherence Tomography.

    Science.gov (United States)

    Gagliano, Caterina; Papa, Vincenzo; Amato, Roberta; Malaguarnera, Giulia; Avitabile, Teresio

    2018-04-01

    Purpose/aim of the study: The purpose of this study was to measure the pre-corneal retention time of two marketed formulations (eye drops and eye gel) of a steroid-antibiotic fixed combination (FC) containing 0.1% dexamethasone and 0.3% netilmicin. Pre-corneal retention time was evaluated in 16 healthy subjects using an ultrahigh-resolution anterior segment spectral domain optical coherence tomography (OCT). All subjects randomly received both formulations of the FC (Netildex, SIFI, Italy). Central tear film thickness (CTFT) was measured before instillation (time 0) and then after 1, 10, 20, 30, 40 50, 60 and 120 min. The pre-corneal retention time was calculated by plotting CTFT as a function of time. Differences between time points and groups were analyzed by Student's t-test. CTFT increased significantly after the instillation of the eye gel formulation (p < 0.001). CTFT reached its maximum value 1 min after instillation and returned to baseline after 60 min. No effect on CTFT was observed after the instillation of eye drops. The difference between the two formulations was statistically significant at time 1 min (p < 0.0001), 10 min (p < 0.001) and 20 min (p < 0.01). The FC formulated as eye gel was retained on the ocular surface longer than the corresponding eye drop solution. Consequently, the use of the eye gel might extend the interval between instillations and decrease the frequency of administration.

  14. Multiple Positive Solutions of a Nonlinear Four-Point Singular Boundary Value Problem with a p-Laplacian Operator on Time Scales

    Directory of Open Access Journals (Sweden)

    Shihuang Hong

    2009-01-01

    Full Text Available We present sufficient conditions for the existence of at least twin or triple positive solutions of a nonlinear four-point singular boundary value problem with a p-Laplacian dynamic equation on a time scale. Our results are obtained via some new multiple fixed point theorems.

  15. On the design of a radix-10 online floating-point multiplier

    Science.gov (United States)

    McIlhenny, Robert D.; Ercegovac, Milos D.

    2009-08-01

    This paper describes an approach to design and implement a radix-10 online floating-point multiplier. An online approach is considered because it offers computational flexibility not available with conventional arithmetic. The design was coded in VHDL and compiled, synthesized, and mapped onto a Virtex 5 FPGA to measure cost in terms of LUTs (look-up-tables) as well as the cycle time and total latency. The routing delay which was not optimized is the major component in the cycle time. For a rough estimate of the cost/latency characteristics, our design was compared to a standard radix-2 floating-point multiplier of equivalent precision. The results demonstrate that even an unoptimized radix-10 online design is an attractive implementation alternative for FPGA floating-point multiplication.

  16. Drop size distribution measured by imaging: determination of the measurement volume by the calibration of the point spread function

    International Nuclear Information System (INIS)

    Fdida, Nicolas; Blaisot, Jean-Bernard

    2010-01-01

    Measurement of drop size distributions in a spray depends on the definition of the control volume for drop counting. For image-based techniques, this implies the definition of a depth-of-field (DOF) criterion. A sizing procedure based on an imaging model and associated with a calibration procedure is presented. Relations between image parameters and object properties are used to provide a measure of the size of the droplets, whatever the distance from the in-focus plane. A DOF criterion independent of the size of the drops and based on the determination of the width of the point spread function (PSF) is proposed. It allows to extend the measurement volume to defocused droplets and, due to the calibration of the PSF, to clearly define the depth of the measurement volume. Calibrated opaque discs, calibrated pinholes and an optical edge are used for this calibration. A comparison of the technique with a phase Doppler particle analyser and a laser diffraction granulometer is performed on an application to an industrial spray. Good agreement is found between the techniques when particular care is given to the sampling of droplets. The determination of the measurement volume is used to determine the drop concentration in the spray and the maximum drop concentration that imaging can support

  17. Interevent Time Distribution of Renewal Point Process, Case Study: Extreme Rainfall in South Sulawesi

    Science.gov (United States)

    Sunusi, Nurtiti

    2018-03-01

    The study of time distribution of occurrences of extreme rain phenomena plays a very important role in the analysis and weather forecast in an area. The timing of extreme rainfall is difficult to predict because its occurrence is random. This paper aims to determine the inter event time distribution of extreme rain events and minimum waiting time until the occurrence of next extreme event through a point process approach. The phenomenon of extreme rain events over a given period of time is following a renewal process in which the time for events is a random variable τ. The distribution of random variable τ is assumed to be a Pareto, Log Normal, and Gamma. To estimate model parameters, a moment method is used. Consider Rt as the time of the last extreme rain event at one location is the time difference since the last extreme rainfall event. if there are no extreme rain events up to t 0, there will be an opportunity for extreme rainfall events at (t 0, t 0 + δt 0). Furthermore from the three models reviewed, the minimum waiting time until the next extreme rainfall will be determined. The result shows that Log Nrmal model is better than Pareto and Gamma model for predicting the next extreme rainfall in South Sulawesi while the Pareto model can not be used.

  18. Approaching time is important for assessment of endoscopic surgical skills.

    Science.gov (United States)

    Tokunaga, Masakazu; Egi, Hiroyuki; Hattori, Minoru; Yoshimitsu, Masanori; Sumitani, Daisuke; Kawahara, Tomohiro; Okajima, Masazumi; Ohdan, Hideki

    2012-05-01

    This study aimed to verify whether the approaching time (the time taken to reach the target point from another point, a short distance apart, during point-to-point movement in endoscopic surgery), assessed using the Hiroshima University Endoscopic Surgical Assessment Device (HUESAD), could distinguish the skill level of surgeons. Expert surgeons (who had performed more than 50 endoscopic surgeries) and novice surgeons (who had no experience in performing endoscopic surgery) were tested using the HUESAD. The approaching time, total time, and intermediate time (total time--approaching time) were measured and analyzed using the trajectory of the tip of the instrument. The approaching time and total time were significantly shorter in the expert group than in the novice group (p time did not significantly differ between the groups (p > 0.05). The approaching time, which is a component of the total time, is very mportant in the measurement of the total time to assess endoscopic surgical skills. Further, the approaching time was useful for skill assessment by the HUESAD for evaluating the skill of surgeons performing endoscopic surgery.

  19. Real-time measurement and control at JET signal processing and physics analysis for diagnostics

    International Nuclear Information System (INIS)

    Felton, R.; Joffrin, E.; Murari, A.

    2005-01-01

    To meet the requirements of the scientific programme, the EFDA JET real-time measurement and control project has developed an integrated set of real-time plasma measurements, experiment control and communication facilities. Traditional experiments collected instrument data during the plasma pulse and calculated physics data after the pulse. The challenge for continuous tokamak operation is to calculate the physics data in real-time, keeping up with the evolution of the plasma. In JET, many plasma diagnostics have been augmented with extra data acquisition and signal-processing systems so that they can both capture instrument data for conventional post-pulse analysis and calculate calibrated, validated physics results in real-time. During the pulse, the systems send sampled data sets into a network, which distributes the data to several destinations. The receiving systems may do further analysis, integrating data from several measurements, or may control the plasma scenario by heating or fuelling. The simplest real-time diagnostic systems apply scale factors to the signals, as with the electron cyclotron emission (ECE) diagnostic's 96 tuned radiometer channels, giving the electron temperature profile. In various spectroscopy diagnostics, spectral features are least-squares-fitted to measure spectra from several lines of sight, within 50 ms. Ion temperatures and rotation speed can be calculated from the line widths and shifts. For diagnostics using modulation techniques, the systems implement digital-signal processing phase trackers, lock-in amplifiers and filters, e.g., the far infrared (FIR) interferometer samples 15 channels at 400 kHz for 30 s, i.e., six million samples per second. Diagnostics have specific lines of sight, spatial channels, and various sampling rates. The heating/fuelling systems have relatively coarse spatial localisation. Analysis systems have been developed to integrate the basic physics data into smaller sets of controllable parameters on a

  20. NOTE ON TRAVEL TIME SHIFTS DUE TO AMPLITUDE MODULATION IN TIME-DISTANCE HELIOSEISMOLOGY MEASUREMENTS

    International Nuclear Information System (INIS)

    Nigam, R.; Kosovichev, A. G.

    2010-01-01

    Correct interpretation of acoustic travel times measured by time-distance helioseismology is essential to get an accurate understanding of the solar properties that are inferred from them. It has long been observed that sunspots suppress p-mode amplitude, but its implications on travel times have not been fully investigated so far. It has been found in test measurements using a 'masking' procedure, in which the solar Doppler signal in a localized quiet region of the Sun is artificially suppressed by a spatial function, and using numerical simulations that the amplitude modulations in combination with the phase-speed filtering may cause systematic shifts of acoustic travel times. To understand the properties of this procedure, we derive an analytical expression for the cross-covariance of a signal that has been modulated locally by a spatial function that has azimuthal symmetry and then filtered by a phase-speed filter typically used in time-distance helioseismology. Comparing this expression to the Gabor wavelet fitting formula without this effect, we find that there is a shift in the travel times that is introduced by the amplitude modulation. The analytical model presented in this paper can be useful also for interpretation of travel time measurements for the non-uniform distribution of oscillation amplitude due to observational effects.

  1. Evaluation of articular cartilage in patients with femoroacetabular impingement (FAI) using T2* mapping at different time points at 3.0 Tesla MRI: a feasibility study

    International Nuclear Information System (INIS)

    Apprich, S.; Mamisch, T.C.; Welsch, G.H.; Bonel, H.; Siebenrock, K.A.; Dudda, M.; Kim, Y.J.; Trattnig, S.

    2012-01-01

    To define the feasibility of utilizing T2* mapping for assessment of early cartilage degeneration prior to surgery in patients with symptomatic femoroacetabular impingement (FAI), we compared cartilage of the hip joint in patients with FAI and healthy volunteers using T2* mapping at 3.0 Tesla over time. Twenty-two patients (13 females and 9 males; mean age 28.1 years) with clinical signs of FAI and Toennis grade ≤ 1 on anterior-posterior x-ray and 35 healthy age-matched volunteers were examined at a 3 T MRI using a flexible body coil. T2* maps were calculated from sagittal- and coronal-oriented gradient-multi-echo sequences using six echoes (TR 125, TE 4.41/8.49/12.57/16.65/20.73/24.81, scan time 4.02 min), both measured at beginning and end of the scan (45 min time span between measurements). Region of interest analysis was manually performed on four consecutive slices for superior and anterior cartilage. Mean T2* values were compared among patients and volunteers, as well as over time using analysis of variance and Student's t-test. Whereas quantitative T2* values for the first measurement did not reveal significant differences between patients and volunteers, either for sagittal (p = 0.644) or coronal images (p = 0.987), at the first measurement, a highly significant difference (p ≤ 0.004) was found for both measurements with time after unloading of the joint. Over time we found decreasing mean T2* values for patients, in contrast to increasing mean T2* relaxation times in volunteers. The study proved the feasibility of utilizing T2* mapping for assessment of early cartilage degeneration in the hip joint in FAI patients at 3 Tesla to predict possible success of joint-preserving surgery. However, we suggest the time point for measuring T2* as an MR biomarker for cartilage and the changes in T2* over time to be of crucial importance for designing an MR protocol in patients with FAI. (orig.)

  2. Automatic dew-point temperature sensor.

    Science.gov (United States)

    Graichen, H; Rascati, R; Gonzalez, R R

    1982-06-01

    A device is described for measuring dew-point temperature and water vapor pressure in small confined areas. The method is based on the deposition of water on a cooled surface when at dew-point temperature. A small Peltier module lowers the temperature of two electrically conductive plates. At dew point the insulating gap separating the plates becomes conductive as water vapor condenses. Sensors based on this principle can be made small and rugged and can be used for measuring directly the local water vapor pressure. They may be installed within a conventional ventilated sweat capsule used for measuring water vapor loss from the skin surface. A novel application is the measurement of the water vapor pressure gradients across layers of clothing worn by an exercising subject.

  3. Real-time diamagnetic flux measurements on ASDEX Upgrade.

    Science.gov (United States)

    Giannone, L; Geiger, B; Bilato, R; Maraschek, M; Odstrčil, T; Fischer, R; Fuchs, J C; McCarthy, P J; Mertens, V; Schuhbeck, K H

    2016-05-01

    Real-time diamagnetic flux measurements are now available on ASDEX Upgrade. In contrast to the majority of diamagnetic flux measurements on other tokamaks, no analog summation of signals is necessary for measuring the change in toroidal flux or for removing contributions arising from unwanted coupling to the plasma and poloidal field coil currents. To achieve the highest possible sensitivity, the diamagnetic measurement and compensation coil integrators are triggered shortly before plasma initiation when the toroidal field coil current is close to its maximum. In this way, the integration time can be chosen to measure only the small changes in flux due to the presence of plasma. Two identical plasma discharges with positive and negative magnetic field have shown that the alignment error with respect to the plasma current is negligible. The measured diamagnetic flux is compared to that predicted by TRANSP simulations. The poloidal beta inferred from the diamagnetic flux measurement is compared to the values calculated from magnetic equilibrium reconstruction codes. The diamagnetic flux measurement and TRANSP simulation can be used together to estimate the coupled power in discharges with dominant ion cyclotron resonance heating.

  4. Modeling and measurement of boiling point elevation during water vaporization from aqueous urea for SCR applications

    International Nuclear Information System (INIS)

    Dan, Ho Jin; Lee, Joon Sik

    2016-01-01

    Understanding of water vaporization is the first step to anticipate the conversion process of urea into ammonia in the exhaust stream. As aqueous urea is a mixture and the urea in the mixture acts as a non-volatile solute, its colligative properties should be considered during water vaporization. The elevation of boiling point for urea water solution is measured with respect to urea mole fraction. With the boiling-point elevation relation, a model for water vaporization is proposed underlining the correction of the heat of vaporization of water in the urea water mixture due to the enthalpy of urea dissolution in water. The model is verified by the experiments of water vaporization as well. Finally, the water vaporization model is applied to the water vaporization of aqueous urea droplets. It is shown that urea decomposition can begin before water evaporation finishes due to the boiling-point elevation

  5. Modeling and measurement of boiling point elevation during water vaporization from aqueous urea for SCR applications

    Energy Technology Data Exchange (ETDEWEB)

    Dan, Ho Jin; Lee, Joon Sik [Seoul National University, Seoul (Korea, Republic of)

    2016-03-15

    Understanding of water vaporization is the first step to anticipate the conversion process of urea into ammonia in the exhaust stream. As aqueous urea is a mixture and the urea in the mixture acts as a non-volatile solute, its colligative properties should be considered during water vaporization. The elevation of boiling point for urea water solution is measured with respect to urea mole fraction. With the boiling-point elevation relation, a model for water vaporization is proposed underlining the correction of the heat of vaporization of water in the urea water mixture due to the enthalpy of urea dissolution in water. The model is verified by the experiments of water vaporization as well. Finally, the water vaporization model is applied to the water vaporization of aqueous urea droplets. It is shown that urea decomposition can begin before water evaporation finishes due to the boiling-point elevation.

  6. Time optimization of 90Sr measurements: Sequential measurement of multiple samples during ingrowth of 90Y

    International Nuclear Information System (INIS)

    Holmgren, Stina; Tovedal, Annika; Björnham, Oscar; Ramebäck, Henrik

    2016-01-01

    The aim of this paper is to contribute to a more rapid determination of a series of samples containing 90 Sr by making the Cherenkov measurement of the daughter nuclide 90 Y more time efficient. There are many instances when an optimization of the measurement method might be favorable, such as; situations requiring rapid results in order to make urgent decisions or, on the other hand, to maximize the throughput of samples in a limited available time span. In order to minimize the total analysis time, a mathematical model was developed which calculates the time of ingrowth as well as individual measurement times for n samples in a series. This work is focused on the measurement of 90 Y during ingrowth, after an initial chemical separation of strontium, in which it is assumed that no other radioactive strontium isotopes are present. By using a fixed minimum detectable activity (MDA) and iterating the measurement time for each consecutive sample the total analysis time will be less, compared to using the same measurement time for all samples. It was found that by optimization, the total analysis time for 10 samples can be decreased greatly, from 21 h to 6.5 h, when assuming a MDA of 1 Bq/L and at a background count rate of approximately 0.8 cpm. - Highlights: • An approach roughly a factor of three more efficient than an un-optimized method. • The optimization gives a more efficient use of instrument time. • The efficiency increase ranges from a factor of three to 10, for 10 to 40 samples.

  7. Measurement-theoretic foundations of time discounting in economics

    OpenAIRE

    Conrad Heilmann

    2008-01-01

    In economics, the concept of time discounting introduces weights on future goods to make these less valuable. Yet, both the conceptual motivation for time discounting and its specic functional form remain contested. To address these problems, this paper provides a measurement-theoretic framework of representation for time discounting. The representation theorem characterises time discounting factors by representations of time dierences. This general result can be interpreted with existing the...

  8. A point of application study to determine the accuracy, precision and reliability of a low-cost balance plate for center of pressure measurement.

    Science.gov (United States)

    Goble, Daniel J; Khan, Ehran; Baweja, Harsimran S; O'Connor, Shawn M

    2018-04-11

    Changes in postural sway measured via force plate center of pressure have been associated with many aspects of human motor ability. A previous study validated the accuracy and precision of a relatively new, low-cost and portable force plate called the Balance Tracking System (BTrackS). This work compared a laboratory-grade force plate versus BTrackS during human-like dynamic sway conditions generated by an inverted pendulum device. The present study sought to extend previous validation attempts for BTrackS using a more traditional point of application (POA) approach. Computer numerical control (CNC) guided application of ∼155 N of force was applied five times to each of 21 points on five different BTrackS Balance Plate (BBP) devices with a hex-nose plunger. Results showed excellent agreement (ICC > 0.999) between the POAs and measured COP by the BBP devices, as well as high accuracy ( 0.999) providing evidence of almost perfect inter-device reliability. Taken together, these results provide an important, static corollary to the previously obtained dynamic COP results from inverted pendulum testing of the BBP. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Time-resolved brightness measurements by streaking

    Science.gov (United States)

    Torrance, Joshua S.; Speirs, Rory W.; McCulloch, Andrew J.; Scholten, Robert E.

    2018-03-01

    Brightness is a key figure of merit for charged particle beams, and time-resolved brightness measurements can elucidate the processes involved in beam creation and manipulation. Here we report on a simple, robust, and widely applicable method for the measurement of beam brightness with temporal resolution by streaking one-dimensional pepperpots, and demonstrate the technique to characterize electron bunches produced from a cold-atom electron source. We demonstrate brightness measurements with 145 ps temporal resolution and a minimum resolvable emittance of 40 nm rad. This technique provides an efficient method of exploring source parameters and will prove useful for examining the efficacy of techniques to counter space-charge expansion, a critical hurdle to achieving single-shot imaging of atomic scale targets.

  10. Change Points in the Population Trends of Aerial-Insectivorous Birds in North America: Synchronized in Time across Species and Regions.

    Directory of Open Access Journals (Sweden)

    Adam C Smith

    Full Text Available North American populations of aerial insectivorous birds are in steep decline. Aerial insectivores (AI are a group of bird species that feed almost exclusively on insects in flight, and include swallows, swifts, nightjars, and flycatchers. The causes of the declines are not well understood. Indeed, it is not clear when the declines began, or whether the declines are shared across all species in the group (e.g., caused by changes in flying insect populations or specific to each species (e.g., caused by changes in species' breeding habitat. A recent study suggested that population trends of aerial insectivores changed for the worse in the 1980s. If there was such a change point in trends of the group, understanding its timing and geographic pattern could help identify potential causes of the decline. We used a hierarchical Bayesian, penalized regression spline, change point model to estimate group-level change points in the trends of 22 species of AI, across 153 geographic strata of North America. We found evidence for group-level change points in 85% of the strata. Change points for flycatchers (FC were distinct from those for swallows, swifts and nightjars (SSN across North America, except in the Northeast, where all AI shared the same group-level change points. During the 1980s, there was a negative change point across most of North America, in the trends of SSN. For FC, the group-level change points were more geographically variable, and in many regions there were two: a positive change point followed by a negative change point. This group-level synchrony in AI population trends is likely evidence of a response to a common environmental factor(s with similar effects on many species across broad spatial extents. The timing and geographic patterns of the change points that we identify here should provide a spring-board for research into the causes behind aerial insectivore declines.

  11. Guidelines for time-to-event end point definitions in sarcomas and gastrointestinal stromal tumors (GIST) trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†.

    Science.gov (United States)

    Bellera, C A; Penel, N; Ouali, M; Bonvalot, S; Casali, P G; Nielsen, O S; Delannes, M; Litière, S; Bonnetain, F; Dabakuyo, T S; Benjamin, R S; Blay, J-Y; Bui, B N; Collin, F; Delaney, T F; Duffaud, F; Filleron, T; Fiore, M; Gelderblom, H; George, S; Grimer, R; Grosclaude, P; Gronchi, A; Haas, R; Hohenberger, P; Issels, R; Italiano, A; Jooste, V; Krarup-Hansen, A; Le Péchoux, C; Mussi, C; Oberlin, O; Patel, S; Piperno-Neumann, S; Raut, C; Ray-Coquard, I; Rutkowski, P; Schuetze, S; Sleijfer, S; Stoeckle, E; Van Glabbeke, M; Woll, P; Gourgou-Bourgade, S; Mathoulin-Pélissier, S

    2015-05-01

    The use of potential surrogate end points for overall survival, such as disease-free survival (DFS) or time-to-treatment failure (TTF) is increasingly common in randomized controlled trials (RCTs) in cancer. However, the definition of time-to-event (TTE) end points is rarely precise and lacks uniformity across trials. End point definition can impact trial results by affecting estimation of treatment effect and statistical power. The DATECAN initiative (Definition for the Assessment of Time-to-event End points in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for RCT in sarcomas and gastrointestinal stromal tumors (GIST). We first carried out a literature review to identify TTE end points (primary or secondary) reported in publications of RCT. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points. Recommendations were developed through a validated consensus method formalizing the degree of agreement among experts. Recommended guidelines for the definition of TTE end points commonly used in RCT for sarcomas and GIST are provided for adjuvant and metastatic settings, including DFS, TTF, time to progression and others. Use of standardized definitions should facilitate comparison of trials' results, and improve the quality of trial design and reporting. These guidelines could be of particular interest to research scientists involved in the design, conduct, reporting or assessment of RCT such as investigators, statisticians, reviewers, editors or regulatory authorities. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. Time-resolved absorption measurements on OMEGA

    International Nuclear Information System (INIS)

    Jaanimagi, P.A.; DaSilva, L.; Delettrez, J.; Gregory, G.G.; Richardson, M.C.

    1986-01-01

    Time-resolved measurements of the incident laser light that is scattered and/or refracted from targets irradiated by the 24 uv-beam OMEGA laser at LLE, have provided some interesting features related to time-resolved absorption. The decrease in laser absorption characteristic of irradiating a target that implodes during the laser pulse has been observed. The increase in absorption expected as the critical density surface moves from a low to a high Z material in the target has also been noted. The detailed interpretation of these results is made through comparisons with simulation using the code LILAC, as well as with streak data from time-resolved x-ray imaging and spectroscopy. In addition, time and space-resolved imaging of the scattered light yields information on laser irradiation uniformity conditions on the target. The report consists of viewgraphs

  13. Dual-time-point O-(2-[18F]fluoroethyl)-L-tyrosine PET for grading of cerebral gliomas

    International Nuclear Information System (INIS)

    Lohmann, Philipp; Herzog, Hans; Rota Kops, Elena; Stoffels, Gabriele; Judov, Natalie; Filss, Christian; Tellmann, Lutz; Galldiks, Norbert; Weiss, Carolin; Sabel, Michael; Coenen, Heinz Hubert; Shah, Nadim Jon; Langen, Karl-Josef

    2015-01-01

    We aimed to evaluate the diagnostic potential of dual-time-point imaging with positron emission tomography (PET) using O-(2-[ 18 F]fluoroethyl)-L-tyrosine ( 18 F-FET) for non-invasive grading of cerebral gliomas compared with a dynamic approach. Thirty-six patients with histologically confirmed cerebral gliomas (21 primary, 15 recurrent; 24 high-grade, 12 low-grade) underwent dynamic PET from 0 to 50 min post-injection (p.i.) of 18 F-FET, and additionally from 70 to 90 min p.i. Mean tumour-to-brain ratios (TBR mean ) of 18 F-FET uptake were determined in early (20-40 min p.i.) and late (70-90 min p.i.) examinations. Time-activity curves (TAC) of the tumours from 0 to 50 min after injection were assigned to different patterns. The diagnostic accuracy of changes of 18 F-FET uptake between early and late examinations for tumour grading was compared to that of curve pattern analysis from 0 to 50 min p.i. of 18 F-FET. The diagnostic accuracy of changes of the TBR mean of 18 F-FET PET uptake between early and late examinations for the identification of HGG was 81 % (sensitivity 83 %; specificity 75 %; cutoff - 8 %; p < 0.001), and 83 % for curve pattern analysis (sensitivity 88 %; specificity 75 %; p < 0.001). Dual-time-point imaging of 18 F-FET uptake in gliomas achieves diagnostic accuracy for tumour grading that is similar to the more time-consuming dynamic data acquisition protocol. (orig.)

  14. Observers' measurements in premetric electrodynamics: Time and radar length

    Science.gov (United States)

    Gürlebeck, Norman; Pfeifer, Christian

    2018-04-01

    The description of an observer's measurement in general relativity and the standard model of particle physics is closely related to the spacetime metric. In order to understand and interpret measurements, which test the metric structure of the spacetime, like the classical Michelson-Morley, Ives-Stilwell, Kennedy-Thorndike experiments or frequency comparison experiments in general, it is necessary to describe them in theories, which go beyond the Lorentzian metric structure. However, this requires a description of an observer's measurement without relying on a metric. We provide such a description of an observer's measurement of the fundamental quantities time and length derived from a premetric perturbation of Maxwell's electrodynamics and a discussion on how these measurements influence classical relativistic observables like time dilation and length contraction. Most importantly, we find that the modification of electrodynamics influences the measurements at two instances: the propagation of light is altered as well as the observer's proper time normalization. When interpreting the results of a specific experiment, both effects cannot be disentangled, in general, and have to be taken into account.

  15. Measuring sensitivity in pharmacoeconomic studies. Refining point sensitivity and range sensitivity by incorporating probability distributions.

    Science.gov (United States)

    Nuijten, M J

    1999-07-01

    The aim of the present study is to describe a refinement of a previously presented method, based on the concept of point sensitivity, to deal with uncertainty in economic studies. The original method was refined by the incorporation of probability distributions which allow a more accurate assessment of the level of uncertainty in the model. In addition, a bootstrap method was used to create a probability distribution for a fixed input variable based on a limited number of data points. The original method was limited in that the sensitivity measurement was based on a uniform distribution of the variables and that the overall sensitivity measure was based on a subjectively chosen range which excludes the impact of values outside the range on the overall sensitivity. The concepts of the refined method were illustrated using a Markov model of depression. The application of the refined method substantially changed the ranking of the most sensitive variables compared with the original method. The response rate became the most sensitive variable instead of the 'per diem' for hospitalisation. The refinement of the original method yields sensitivity outcomes, which greater reflect the real uncertainty in economic studies.

  16. Individual Test Point Fluctuations of Macular Sensitivity in Healthy Eyes and Eyes With Age-Related Macular Degeneration Measured With Microperimetry.

    Science.gov (United States)

    Barboni, Mirella Telles Salgueiro; Szepessy, Zsuzsanna; Ventura, Dora Fix; Németh, János

    2018-04-01

    To establish fluctuation limits, it was considered that not only overall macular sensitivity but also fluctuations of individual test points in the macula might have clinical value. Three repeated measurements of microperimetry were performed using the Standard Expert test of Macular Integrity Assessment (MAIA) in healthy subjects ( N = 12, age = 23.8 ± 1.5 years old) and in patients with age-related macular degeneration (AMD) ( N = 11, age = 68.5 ± 7.4 years old). A total of 37 macular points arranged in four concentric rings and in four quadrants were analyzed individually and in groups. The data show low fluctuation of macular sensitivity of individual test points in healthy subjects (average = 1.38 ± 0.28 dB) and AMD patients (average = 2.12 ± 0.60 dB). Lower sensitivity points are more related to higher fluctuation than to the distance from the central point. Fixation stability showed no effect on the sensitivity fluctuation. The 95th percentile of the standard deviations of healthy subjects was, on average, 2.7 dB, ranging from 1.2 to 4 dB, depending on the point tested. Point analysis and regional analysis might be considered prior to evaluating macular sensitivity fluctuation in order to distinguish between normal variation and a clinical change. S tatistical methods were used to compare repeated microperimetry measurements and to establish fluctuation limits of the macular sensitivity. This analysis could add information regarding the integrity of different macular areas and provide new insights into fixation points prior to the biofeedback fixation training.

  17. Measurement of the Rise-Time in a Single Sided Ladder Detector

    International Nuclear Information System (INIS)

    Gerber, C.E.

    1997-01-01

    In this note we report on the measurement of the preamplifier output rise time for a SVXII chip mounted on a D0 single sided ladder. The measurements were performed on the ladder 001-883-L, using the laser test stand of Lab D. The rise time was measured for different values of the response (or bandwidth) of the preamplifier. As a bigger bandwidth results in longer rise times and therefore in less noise, the largest possible bandwidth consistent with the time between bunch crossings should be chosen to operate the detectors. The rise time is defined as the time elapsed between 10% and 90% of the charge is collected. It is also interesting to measure the time for full charge collection and the percentage of charge collected in 132 ns and 396 ns. The results are shown in table 1, for bandwidths between 2 and 63 (binary numbers). The uncertainty on the time measurement is considered to be ∼ 10 ns. Figure 1 schematically defines the four quantities measured: rise time, time of full charge collection, and percentage of charge collected in 132 ns and 396 ns. Figures 2 to 8 are the actual measurements for bandwidths of 2, 4, 8, 12, 24, 32 and 63. Figure 9 is a second measurement for BW=24, used as a consistency check of the system and the time measurement performed on the plots. The data indicate that the single sided ladders can be operated at BW=63 for 396 ns and BW=12 for 132 ns, achieving full charge collection. This will result in smaller noise than originally anticipated.

  18. Material Classification Using Raw Time-of-Flight Measurements

    KAUST Repository

    Su, Shuochen; Heide, Felix; Swanson, Robin J.; Klein, Jonathan; Callenberg, Clara; Hullin, Matthias; Heidrich, Wolfgang

    2016-01-01

    We propose a material classification method using raw time-of-flight (ToF) measurements. ToF cameras capture the correlation between a reference signal and the temporal response of material to incident illumination. Such measurements encode unique

  19. Improved pointing information for SCIAMACHY from in-flight measurements of the viewing directions towards sun and moon

    Science.gov (United States)

    Bramstedt, Klaus; Stone, Thomas C.; Gottwald, Manfred; Noël, Stefan; Bovensmann, Heinrich; Burrows, John P.

    2017-07-01

    The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) on Envisat (2002-2012) performed nadir, limb, solar/lunar occultation and various monitoring measurements. The pointing information of the instrument is determined by the attitude information of the Envisat platform with its star trackers together with the encoder readouts of both the azimuth and the elevation scanner of SCIAMACHY. In this work, we present additional sources of attitude information from the SCIAMACHY measurements itself. The basic principle is the same as used by the star tracker: we measure the viewing direction towards celestial objects, i.e. sun and moon, to detect possible mispointings. In sun over limb port observations, we utilise the vertical scans over the solar disk. In horizontal direction, SCIAMACHY's sun follower device (SFD) is used to adjust the viewing direction. Moon over limb port measurements use for both the vertical and the horizontal direction the adjustment by the SFD. The viewing direction is steered towards the intensity centroid of the illuminated part of the lunar disk. We use reference images from the USGS Robotic Lunar Observatory (ROLO) to take into account the inhomogeneous surface and the variations by lunar libration and phase to parameterise the location of the intensity centroid from the observation geometry. Solar observations through SCIAMACHY's so-called sub-solar port (with a viewing direction closely to zenith) also use the SFD in the vertical direction. In the horizontal direction the geometry of the port defines the viewing direction. Using these three type of measurements, we fit improved mispointing parameters by minimising the pointing offsets in elevation and azimuth. The geolocation of all retrieved products will benefit from this; the tangent heights are especially improved. The altitudes assigned to SCIAMACHY's solar occultation measurements are changed in the range of -130 to -330 m, the lunar occultation

  20. Improved pointing information for SCIAMACHY from in-flight measurements of the viewing directions towards sun and moon

    Directory of Open Access Journals (Sweden)

    K. Bramstedt

    2017-07-01

    Full Text Available The SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY on Envisat (2002–2012 performed nadir, limb, solar/lunar occultation and various monitoring measurements. The pointing information of the instrument is determined by the attitude information of the Envisat platform with its star trackers together with the encoder readouts of both the azimuth and the elevation scanner of SCIAMACHY. In this work, we present additional sources of attitude information from the SCIAMACHY measurements itself. The basic principle is the same as used by the star tracker: we measure the viewing direction towards celestial objects, i.e. sun and moon, to detect possible mispointings. In sun over limb port observations, we utilise the vertical scans over the solar disk. In horizontal direction, SCIAMACHY's sun follower device (SFD is used to adjust the viewing direction. Moon over limb port measurements use for both the vertical and the horizontal direction the adjustment by the SFD. The viewing direction is steered towards the intensity centroid of the illuminated part of the lunar disk. We use reference images from the USGS Robotic Lunar Observatory (ROLO to take into account the inhomogeneous surface and the variations by lunar libration and phase to parameterise the location of the intensity centroid from the observation geometry. Solar observations through SCIAMACHY's so-called sub-solar port (with a viewing direction closely to zenith also use the SFD in the vertical direction. In the horizontal direction the geometry of the port defines the viewing direction. Using these three type of measurements, we fit improved mispointing parameters by minimising the pointing offsets in elevation and azimuth. The geolocation of all retrieved products will benefit from this; the tangent heights are especially improved. The altitudes assigned to SCIAMACHY's solar occultation measurements are changed in the range of −130 to −330 m, the lunar

  1. Potential barrier classification by short-time measurement

    International Nuclear Information System (INIS)

    Granot, Er'el; Marchewka, Avi

    2006-01-01

    We investigate the short-time dynamics of a delta-function potential barrier on an initially confined wave packet. There are mainly two conclusions: (A) At short times the probability density of the first particles that passed through the barrier is unaffected by it. (B) When the barrier is absorptive (i.e., its potential is imaginary) it affects the transmitted wave function at shorter times than a real potential barrier. Therefore, it is possible to distinguish between an imaginary and a real potential barrier by measuring its effect at short times only on the transmitting wave function

  2. Potential barrier classification by short-time measurement

    Science.gov (United States)

    Granot, Er'El; Marchewka, Avi

    2006-03-01

    We investigate the short-time dynamics of a delta-function potential barrier on an initially confined wave packet. There are mainly two conclusions: (A) At short times the probability density of the first particles that passed through the barrier is unaffected by it. (B) When the barrier is absorptive (i.e., its potential is imaginary) it affects the transmitted wave function at shorter times than a real potential barrier. Therefore, it is possible to distinguish between an imaginary and a real potential barrier by measuring its effect at short times only on the transmitting wave function.

  3. Comparison of Objectively Measured and Self-reported Time Spent Sitting

    DEFF Research Database (Denmark)

    Lagersted-Olsen, Julie; Korshøj, M; Skotte, J

    2014-01-01

    Until recently, methods for objective quantification of sitting time have been lacking. The aim of this study was to validate self-reported measures against objectively measured total sitting time and longest continuous time with uninterrupted sitting during working hours, leisure time on workday...... a retrospective 7-day questionnaire. A generalized linear model showed the difference between the methods. No significant correlations were found between objective and self-reported sitting time (r...

  4. Measurement of time processing ability and daily time management in children with disabilities.

    Science.gov (United States)

    Janeslätt, Gunnel; Granlund, Mats; Kottorp, Anders

    2009-01-01

    Improvement is needed in methods for planning and evaluating interventions designed to facilitate daily time management for children with intellectual disability, Asperger syndrome, or other developmental disorders. The aim of this study was to empirically investigate the hypothesized relation between children's time processing ability (TPA), daily time management, and self-rated autonomy. Such a relationship between daily time management and TPA may support the idea that TPA is important for daily time management and that children with difficulties in TPA might benefit from intervention aimed at improving daily time management. Participants were children aged 6 to 11 years with dysfunctions such as attention-deficit/hyperactivity disorder, autism, or physical or intellectual disabilities (N = 118). TPA was measured with the instrument KaTid. All data were transformed to interval measures using applications of Rasch models and then further analysed with correlation and regression analysis. The results demonstrate a moderate significant relation between the parents' ratings of daily time management and TPA of the children, and between the self-rating of autonomy and TPA. There was also a significant relation between self-ratings of autonomy and the parents' rating of the children's daily time management. Parents' ratings of their children's daily time management explain 25% of the variation in TPA, age of the children explains 22%, while the child's self-rating of autonomy can explain 9% of the variation in TPA. The three variables together explain 38% of the variation in TPA. The results indicate the viability of the instrument for assessing TPA also in children with disabilities and that the ability measured by KaTid is relevant for daily time management. TPA seems to be a factor for children's daily time management that needs to be taken into consideration when planning and evaluating interventions designed to facilitate everyday functioning for children with

  5. Time-dependent Taylor–Aris dispersion of an initial point concentration

    DEFF Research Database (Denmark)

    Vedel, Søren; Hovad, Emil; Bruus, Henrik

    2014-01-01

    -specific theoretical results, and furthermore predict new phenomena. In particular, for the transient phase before the well-described steady Taylor–Aris limit is reached, we find anomalous diffusion with a dependence of the temporal scaling exponent on the initial release point, generalizing this finding in specific...... cases. During this transient we furthermore identify maxima in the values of the dispersion coefficient which exceed the Taylor–Aris value by amounts that depend on channel geometry, initial point release position, velocity profile and Péclet number. We show that these effects are caused by a difference...

  6. Efficient Algorithms for Segmentation of Item-Set Time Series

    Science.gov (United States)

    Chundi, Parvathi; Rosenkrantz, Daniel J.

    We propose a special type of time series, which we call an item-set time series, to facilitate the temporal analysis of software version histories, email logs, stock market data, etc. In an item-set time series, each observed data value is a set of discrete items. We formalize the concept of an item-set time series and present efficient algorithms for segmenting a given item-set time series. Segmentation of a time series partitions the time series into a sequence of segments where each segment is constructed by combining consecutive time points of the time series. Each segment is associated with an item set that is computed from the item sets of the time points in that segment, using a function which we call a measure function. We then define a concept called the segment difference, which measures the difference between the item set of a segment and the item sets of the time points in that segment. The segment difference values are required to construct an optimal segmentation of the time series. We describe novel and efficient algorithms to compute segment difference values for each of the measure functions described in the paper. We outline a dynamic programming based scheme to construct an optimal segmentation of the given item-set time series. We use the item-set time series segmentation techniques to analyze the temporal content of three different data sets—Enron email, stock market data, and a synthetic data set. The experimental results show that an optimal segmentation of item-set time series data captures much more temporal content than a segmentation constructed based on the number of time points in each segment, without examining the item set data at the time points, and can be used to analyze different types of temporal data.

  7. Measurements to determine the sulfuric acid dew point and the SO sub 3 concentration in flue gas of power plant vessels. Messungen zur Bestimmung des Saeuretaupunktes und der SO sub 3 -Konzentration im Rauchgas von Kraftwerkskesseln

    Energy Technology Data Exchange (ETDEWEB)

    Derichs, W.; Menden, W. (RWE Energie AG, Bergheim (Germany)); Ebel, P.K. (Apparatebau Hundsbach GmbH, Baden-Baden (Germany))

    1990-01-01

    Among the customary methods of dew point determination, the technique of recording the increase in conductivity between two electrodes at the moment of acid condensing onto them, and measuring at the same time the temperature of the sensor, is appropriate to determine the sulfuric acid dew point in dust-laden flue gas. By means of the sensitivity of a newly developed sensor, the accuracy of the measurement method could be improved to such an extent that also low acid dew points and rapid changes can be recorded reliably. Measurements have shown that the acid dew point primarily depends on the SO{sub 3} content which is substantially determined by the sulfur content of the fuel and the type of flue gas ducts. Further influential quantities include flue gas humidity, air surplus, other gaseous flue gas components such as HCl and HF, as well as the quantity, composition and temperature-dependent adsorption capability of the flue dusts. (orig./BBR).

  8. Method of Measuring the Coupled Lattice Functions at the Interaction Point in e sup + e sup - Storage Rings

    CERN Document Server

    Cai, Y

    2003-01-01

    We have investigate a method of measuring the complete lattice functions including the coupling parameters at any azimuthal position in a periodic an symplectic system. In particular, the method is applied to measure the lattice functions at the interaction point where the beams collide. It has been demonstrate that a complete set of lattice functions can be accurately measured with two adjacent beam position monitors and the known transformation matrix between them. As a by-product, the method also automatically measures the complete one-turn matrix.

  9. Sensitivity of the breastfeeding motivational measurement scale: a known group analysis of first time mothers.

    Science.gov (United States)

    Stockdale, Janine; Sinclair, Marlene; Kernohan, George; McCrum-Gardner, Evie; Keller, John

    2013-01-01

    Breastfeeding has immense public health value for mothers, babies, and society. But there is an undesirably large gap between the number of new mothers who undertake and persist in breastfeeding compared to what would be a preferred level of accomplishment. This gap is a reflection of the many obstacles, both physical and psychological, that confront new mothers. Previous research has illuminated many of these concerns, but research on this problem is limited in part by the unavailability of a research instrument that can measure the key differences between first-time mothers and experienced mothers, with regard to the challenges they face when breastfeeding and the instructional advice they require. An instrument was designed to measure motivational complexity associated with sustained breast feeding behaviour; the Breastfeeding Motivational Measurement Scale. It contains 51 self-report items (7 point Likert scale) that cluster into four categories related to perceived value of breast-feeding, confidence to succeed, factors that influence success or failure, and strength of intentions, or goal. However, this scale has not been validated in terms of its sensitivity to profile the motivation of new mothers and experienced mothers. This issue was investigated by having 202 breastfeeding mothers (100 first time mothers) fill out the scale. The analysis reported in this paper is a three factor solution consisting of value, midwife support, and expectancies for success that explained the characteristics of first time mothers as a known group. These results support the validity of the BMM scale as a diagnostic tool for research on first time mothers who are learning to breastfeed. Further research studies are required to further test the validity of the scale in additional subgroups.

  10. Gradient-free determination of isoelectric points of proteins on chip.

    Science.gov (United States)

    Łapińska, Urszula; Saar, Kadi L; Yates, Emma V; Herling, Therese W; Müller, Thomas; Challa, Pavan K; Dobson, Christopher M; Knowles, Tuomas P J

    2017-08-30

    The isoelectric point (pI) of a protein is a key characteristic that influences its overall electrostatic behaviour. The majority of conventional methods for the determination of the isoelectric point of a molecule rely on the use of spatial gradients in pH, although significant practical challenges are associated with such techniques, notably the difficulty in generating a stable and well controlled pH gradient. Here, we introduce a gradient-free approach, exploiting a microfluidic platform which allows us to perform rapid pH change on chip and probe the electrophoretic mobility of species in a controlled field. In particular, in this approach, the pH of the electrolyte solution is modulated in time rather than in space, as in the case for conventional determinations of the isoelectric point. To demonstrate the general approachability of this platform, we have measured the isoelectric points of representative set of seven proteins, bovine serum albumin, β-lactoglobulin, ribonuclease A, ovalbumin, human transferrin, ubiquitin and myoglobin in microlitre sample volumes. The ability to conduct measurements in free solution thus provides the basis for the rapid determination of isoelectric points of proteins under a wide variety of solution conditions and in small volumes.

  11. Life satisfaction set point: stability and change.

    Science.gov (United States)

    Fujita, Frank; Diener, Ed

    2005-01-01

    Using data from 17 years of a large and nationally representative panel study from Germany, the authors examined whether there is a set point for life satisfaction (LS)--stability across time, even though it can be perturbed for short periods by life events. The authors found that 24% of respondents changed significantly in LS from the first 5 years to the last 5 years and that stability declined as the period between measurements increased. Average LS in the first 5 years correlated .51 with the 5-year average of LS during the last 5 years. Height, weight, body mass index, systolic and diastolic blood pressure, and personality traits were all more stable than LS, whereas income was about as stable as LS. Almost 9% of the sample changed an average of 3 or more points on a 10-point scale from the first 5 to last 5 years of the study.

  12. Two-sorted Point-Interval Temporal Logics

    DEFF Research Database (Denmark)

    Balbiani, Philippe; Goranko, Valentin; Sciavicco, Guido

    2011-01-01

    There are two natural and well-studied approaches to temporal ontology and reasoning: point-based and interval-based. Usually, interval-based temporal reasoning deals with points as particular, duration-less intervals. Here we develop explicitly two-sorted point-interval temporal logical framework...... whereby time instants (points) and time periods (intervals) are considered on a par, and the perspective can shift between them within the formal discourse. We focus on fragments involving only modal operators that correspond to the inter-sort relations between points and intervals. We analyze...

  13. Effects of orbit and pointing geometry of a spaceborne formation for monostatic-bistatic radargrammetry on terrain elevation measurement accuracy.

    Science.gov (United States)

    Renga, Alfredo; Moccia, Antonio

    2009-01-01

    During the last decade a methodology for the reconstruction of surface relief by Synthetic Aperture Radar (SAR) measurements - SAR interferometry - has become a standard. Different techniques developed before, such as stereo-radargrammetry, have been experienced from space only in very limiting geometries and time series, and, hence, branded as less accurate. However, novel formation flying configurations achievable by modern spacecraft allow fulfillment of SAR missions able to produce pairs of monostatic-bistatic images gathered simultaneously, with programmed looking angles. Hence it is possible to achieve large antenna separations, adequate for exploiting to the utmost the stereoscopic effect, and to make negligible time decorrelation, a strong liming factor for repeat-pass stereo-radargrammetric techniques. This paper reports on design of a monostatic-bistatic mission, in terms of orbit and pointing geometry, and taking into account present generation SAR and technology for accurate relative navigation. Performances of different methods for monostatic-bistatic stereo-radargrammetry are then evaluated, showing the possibility to determine the local surface relief with a metric accuracy over a wide range of Earth latitudes.

  14. Guidelines for time-to-event end point definitions in breast cancer trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†.

    Science.gov (United States)

    Gourgou-Bourgade, S; Cameron, D; Poortmans, P; Asselain, B; Azria, D; Cardoso, F; A'Hern, R; Bliss, J; Bogaerts, J; Bonnefoi, H; Brain, E; Cardoso, M J; Chibaudel, B; Coleman, R; Cufer, T; Dal Lago, L; Dalenc, F; De Azambuja, E; Debled, M; Delaloge, S; Filleron, T; Gligorov, J; Gutowski, M; Jacot, W; Kirkove, C; MacGrogan, G; Michiels, S; Negreiros, I; Offersen, B V; Penault Llorca, F; Pruneri, G; Roche, H; Russell, N S; Schmitt, F; Servent, V; Thürlimann, B; Untch, M; van der Hage, J A; van Tienhoven, G; Wildiers, H; Yarnold, J; Bonnetain, F; Mathoulin-Pélissier, S; Bellera, C; Dabakuyo-Yonli, T S

    2015-05-01

    Using surrogate end points for overall survival, such as disease-free survival, is increasingly common in randomized controlled trials. However, the definitions of several of these time-to-event (TTE) end points are imprecisely which limits interpretation and cross-trial comparisons. The estimation of treatment effects may be directly affected by the definitions of end points. The DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for randomized cancer clinical trials (RCTs) in breast cancer. A literature review was carried out to identify TTE end points (primary or secondary) reported in publications of randomized trials or guidelines. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points based on a validated consensus method that formalize the degree of agreement among experts. Recommended guidelines for the definitions of TTE end points commonly used in RCTs for breast cancer are provided for non-metastatic and metastatic settings. The use of standardized definitions should facilitate comparisons of trial results and improve the quality of trial design and reporting. These guidelines could be of particular interest to those involved in the design, conducting, reporting, or assessment of RCT. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  15. A novel imaging technique to measure capillary-refill time: improving diagnostic accuracy for dehydration in young children with gastroenteritis.

    Science.gov (United States)

    Shavit, Itai; Brant, Rollin; Nijssen-Jordan, Cheri; Galbraith, Roger; Johnson, David W

    2006-12-01

    Assessment of dehydration in young children currently depends on clinical judgment, which is relatively inaccurate. By using digital videography, we developed a way to assess capillary-refill time more objectively. Our goal was to determine whether digitally measured capillary-refill time assesses the presence of significant dehydration (> or = 5%) in young children with gastroenteritis more accurately than conventional capillary refill and overall clinical assessment. We prospectively enrolled children with gastroenteritis, 1 month to 5 years of age, who were evaluated in a tertiary-care pediatric emergency department and judged by a triage nurse to be at least mildly dehydrated. Before any treatment, we measured the weight and digitally measured capillary-refill time of these children. Pediatric emergency physicians determined capillary-refill time by using conventional methods and degree of dehydration by overall clinical assessment by using a 7-point Likert scale. Postillness weight gain was used to estimate fluid deficit; beginning 48 hours after assessment, children were reweighed every 24 hours until 2 sequential weights differed by no more than 2%. We compared the accuracy of digitally measured capillary-refill time with conventional capillary refill and overall clinical assessment by determining sensitivities, specificities, likelihood ratios, and area under the receiver operator characteristic curves. A total of 83 patients were enrolled and had complete follow-up; 13 of these patients had significant dehydration (> or = 5% of body weight). The area under the receiver operator characteristic curves for digitally measured capillary-refill time and overall clinical assessment relative to fluid deficit ( or = 5%) were 0.99 and 0.88, respectively. Positive likelihood ratios were 11.7 for digitally measured capillary-refill time, 4.5 for conventional capillary refill, and 4.1 for overall clinical assessment. Results of this prospective cohort study suggest

  16. Dosimetric system for measurement of radioactive contaminations

    International Nuclear Information System (INIS)

    Litynski, Z.; Pienkos, J.P.; Witkowski, J.; Zadrozny, S.

    1985-01-01

    A dosimetric system for personnel dosimetry and monitoring measuring a contamination without time delay and dead time is described. The system ensures many-point measurement and minimalization of background radiation influence. 1 fig. (A.S.)

  17. Ultra-shallow junction (USJ) sheet resistance measurements with a non-penetrating four point probe

    International Nuclear Information System (INIS)

    Benjamin, M.C.; Hillard, R.J.; Borland, J.O.

    2005-01-01

    An accurate method to measure the four point probe (4PP) sheet resistance (R S ) of ultra shallow junction (USJ) Source-Drain Extension structures is described. The method utilizes Elastic Material probes (EM-probes) to form non-penetrating contacts to the silicon surface [R.J. Hillard, P.Y. Hung, William Chism, C. Win Ye, W.H. Howland, L.C. Tan, C.E. Kalnas, Characterization and Metrology for ULSI Technology, AIP Conference proceedings 683 (2003) 802.]. The probe design is kinematic and the force is controlled to ensure elastic deformation of the probe material. The probe material is such that large direct tunneling currents can flow through the native oxide thereby forming a low impedance contact. Sheet resistance measurements on USJ implanted P+/N structures with Secondary Ion Mass Spectroscopy (SIMS) junction depths less than 15 nm have been measured. The method is demonstrated on implanted USJ structures and found to be consistent with expectations

  18. Measuring work-life balance using time diary data

    OpenAIRE

    Kimberly Fisher; Richard Layte

    2004-01-01

    This paper examines how time diaries facilitate the study of work-life balance. We first compare aggregate time spent in paid work, unpaid work, attending to personal needs, and free time across seven countries using the Multinational Time Use Study. We then measure the overlap of work with other activities in two ways. First, we map the timing of episodes of work over the day, and overlay these maps onto maps of leisure time. A social group can be said to have a work-life balance if their pe...

  19. Developing a Tool Point Control Scheme for a Hydraulic Crane Using Interactive Real-time Dynamic Simulation

    DEFF Research Database (Denmark)

    Pedersen, Mikkel Melters; Hansen, Michael Rygaard; Ballebye, Morten

    2010-01-01

    This paper describes the implementation of an interactive real-time dynamic simulation model of a hydraulic crane. The user input to the model is given continuously via joystick and output is presented continuously in a 3D animation. Using this simulation model, a tool point control scheme...... is developed for the specific crane, considering the saturation phenomena of the system and practical implementation....

  20. Real-time multi-GNSS single-frequency precise point positioning

    NARCIS (Netherlands)

    de Bakker, P.F.; Tiberius, C.C.J.M.

    2017-01-01

    Precise Point Positioning (PPP) is a popular Global Positioning System (GPS) processing strategy, thanks to its high precision without requiring additional GPS infrastructure. Single-Frequency PPP (SF-PPP) takes this one step further by no longer relying on expensive dual-frequency GPS receivers,

  1. Consumers' price awareness at the point-of-selection: What constitutes the most appropriate measure of consumers' price awareness and what determines the differences?

    DEFF Research Database (Denmark)

    Jensen, Birger Boutrup

    This paper focuses on consumers' price information processing at the point-of-selection. Specifically, it updates past results of consumers' price awareness at the point-of-selection - applying both a price-recall and a price-recognition test - and tests hypotheses on potential determinants...... of consumers' price awareness at the point-of-selection. Both price-memory tests resulted in higher measured price awareness than in any of the past studies. Results also indicate that price recognition is not the most appropiate measure. Finally, a discriminant analysis shows that consumers who are aware...

  2. Sodium borocaptate (BSH) for Boron Neutron Capture Therapy (BNCT) in the hamster cheek pouch oral cancer model: boron biodistribution at 9 post administration time-points

    International Nuclear Information System (INIS)

    Garabalino, M.A.; Heber, E.M.; Monti, Hughes A.; Molinari, A.J.; Pozzi, E.C.C.; Trivillin, V.A.; Schwint, Amanda E.

    2011-01-01

    The therapeutic success of Boron Neutron Capture Therapy (BNCT) depends centrally on boron concentration in tumor and healthy tissue. We previously demonstrated the therapeutic efficacy of boronophenylalanine (BPA) and sodium decahydrodecaborate (GB-10) as boron carriers for BNCT in the hamster cheek pouch oral cancer model. Given the clinical relevance of sodium mercaptoundecahydro-closo-dodecaborate (BSH) as a boron carrier, the aim of the present study was to expand the ongoing BSH biodistribution studies in the hamster cheek pouch oral cancer model. In particular, we studied 3 additional post-administration time-points and increased the sample size corresponding to the time-points evaluated previously, to select more accurately the post-administration time at which neutron irradiation would potentially confer the greatest therapeutic advantage. BSH was dissolved in saline solution in anaerobic conditions to avoid the formation of the dimer BSSB and its oxides which are toxic. The solution was injected intravenously at a dose of 50 mg 10 B/kg (88 mg BSH / kg). Different groups of animals were killed humanely at 7, 8, and 10 h after administration of BSH. The sample size corresponding to the time-points 3, 4, 6, 9 and 12 h was increased. Samples of blood, tumor, precancerous tissue, normal pouch tissue, cheek mucosa, parotid gland, palate, skin, tongue, spinal cord marrow, brain, liver, kidney, spleen and lung were processed for boron measurement by Optic Emission Spectroscopy (ICP-OES). Boron concentration in tumor peaked to 24-34 ppm, 3-10 h post-administration of BSH, with a spread in values that resembled that previously reported in other experimental models and human subjects. The boron concentration ratios tumor/normal pouch tissue and tumor/blood ranged from 1.3 to 1.8. No selective tumor uptake was observed at any of the time points evaluated. The times post-administration of BSH that would be therapeutically most useful would be 5, 7 and 9 h. The

  3. Time-resolved beam energy measurements at LAMPF

    International Nuclear Information System (INIS)

    Hudgings, D.W.; Clark, D.A.; Bryant, H.C.

    1979-01-01

    A narrow atomic photodetachment resonance is used to measure the LAMPF beam energy. Energy and time resolution are adequate to permit the use of this method in studying transient changes in accelerated beam energy

  4. Validation and Assessment of Multi-GNSS Real-Time Precise Point Positioning in Simulated Kinematic Mode Using IGS Real-Time Service

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2018-02-01

    Full Text Available Precise Point Positioning (PPP is a popular technology for precise applications based on the Global Navigation Satellite System (GNSS. Multi-GNSS combined PPP has become a hot topic in recent years with the development of multiple GNSSs. Meanwhile, with the operation of the real-time service (RTS of the International GNSS Service (IGS agency that provides satellite orbit and clock corrections to broadcast ephemeris, it is possible to obtain the real-time precise products of satellite orbits and clocks and to conduct real-time PPP. In this contribution, the real-time multi-GNSS orbit and clock corrections of the CLK93 product are applied for real-time multi-GNSS PPP processing, and its orbit and clock qualities are investigated, first with a seven-day experiment by comparing them with the final multi-GNSS precise product ‘GBM’ from GFZ. Then, an experiment involving real-time PPP processing for three stations in the Multi-GNSS Experiment (MGEX network with a testing period of two weeks is conducted in order to evaluate the convergence performance of real-time PPP in a simulated kinematic mode. The experimental result shows that real-time PPP can achieve a convergence performance of less than 15 min for an accuracy level of 20 cm. Finally, the real-time data streams from 12 globally distributed IGS/MGEX stations for one month are used to assess and validate the positioning accuracy of real-time multi-GNSS PPP. The results show that the simulated kinematic positioning accuracy achieved by real-time PPP on different stations is about 3.0 to 4.0 cm for the horizontal direction and 5.0 to 7.0 cm for the three-dimensional (3D direction.

  5. Double point source W-phase inversion: Real-time implementation and automated model selection

    Science.gov (United States)

    Nealy, Jennifer; Hayes, Gavin

    2015-01-01

    Rapid and accurate characterization of an earthquake source is an extremely important and ever evolving field of research. Within this field, source inversion of the W-phase has recently been shown to be an effective technique, which can be efficiently implemented in real-time. An extension to the W-phase source inversion is presented in which two point sources are derived to better characterize complex earthquakes. A single source inversion followed by a double point source inversion with centroid locations fixed at the single source solution location can be efficiently run as part of earthquake monitoring network operational procedures. In order to determine the most appropriate solution, i.e., whether an earthquake is most appropriately described by a single source or a double source, an Akaike information criterion (AIC) test is performed. Analyses of all earthquakes of magnitude 7.5 and greater occurring since January 2000 were performed with extended analyses of the September 29, 2009 magnitude 8.1 Samoa earthquake and the April 19, 2014 magnitude 7.5 Papua New Guinea earthquake. The AIC test is shown to be able to accurately select the most appropriate model and the selected W-phase inversion is shown to yield reliable solutions that match published analyses of the same events.

  6. Time Synchronized Wireless Sensor Network for Vibration Measurement

    Science.gov (United States)

    Uchimura, Yutaka; Nasu, Tadashi; Takahashi, Motoichi

    Network based wireless sensing has become an important area of research and various new applications for remote sensing are expected to emerge. One of the promising applications is structural health monitoring of building or civil engineering structure and it often requires vibration measurement. For the vibration measurement via wireless network, time synchronization is indispensable. In this paper, we introduce a newly developed time synchronized wireless sensor network system. The system employs IEEE 802.11 standard based TSF counter and sends the measured data with the counter value. TSF based synchronization enables consistency on common clock among different wireless nodes. We consider the scale effect on the synchronization accuracy and the effect is evaluated by stochastic analysis and simulation studies. A new wireless sensing system is developed and the hardware and software specifications are shown. The experiments are conducted in a reinforced concrete building and results show good performance enough for vibration measurement purpose.

  7. Stability of continuous-time quantum filters with measurement imperfections

    Science.gov (United States)

    Amini, H.; Pellegrini, C.; Rouchon, P.

    2014-07-01

    The fidelity between the state of a continuously observed quantum system and the state of its associated quantum filter, is shown to be always a submartingale. The observed system is assumed to be governed by a continuous-time Stochastic Master Equation (SME), driven simultaneously by Wiener and Poisson processes and that takes into account incompleteness and errors in measurements. This stability result is the continuous-time counterpart of a similar stability result already established for discrete-time quantum systems and where the measurement imperfections are modelled by a left stochastic matrix.

  8. Hysteresis of Soil Point Water Retention Functions Determined by Neutron Radiography

    Science.gov (United States)

    Perfect, E.; Kang, M.; Bilheux, H.; Willis, K. J.; Horita, J.; Warren, J.; Cheng, C.

    2010-12-01

    Soil point water retention functions are needed for modeling flow and transport in partially-saturated porous media. Such functions are usually determined by inverse modeling of average water retention data measured experimentally on columns of finite length. However, the resulting functions are subject to the appropriateness of the chosen model, as well as the initial and boundary condition assumptions employed. Soil point water retention functions are rarely measured directly and when they are the focus is invariably on the main drying branch. Previous direct measurement methods include time domain reflectometry and gamma beam attenuation. Here we report direct measurements of the main wetting and drying branches of the point water retention function using neutron radiography. The measurements were performed on a coarse sand (Flint #13) packed into 2.6 cm diameter x 4 cm long aluminum cylinders at the NIST BT-2 (50 μm resolution) and ORNL-HFIR CG1D (70 μm resolution) imaging beamlines. The sand columns were saturated with water and then drained and rewetted under quasi-equilibrium conditions using a hanging water column setup. 2048 x 2048 pixel images of the transmitted flux of neutrons through the column were acquired at each imposed suction (~10-15 suction values per experiment). Volumetric water contents were calculated on a pixel by pixel basis using Beer-Lambert’s law in conjunction with beam hardening and geometric corrections. The pixel rows were averaged and combined with information on the known distribution of suctions within the column to give 2048 point drying and wetting functions for each experiment. The point functions exhibited pronounced hysteresis and varied with column height, possibly due to differences in porosity caused by the packing procedure employed. Predicted point functions, extracted from the hanging water column volumetric data using the TrueCell inverse modeling procedure, showed very good agreement with the range of point

  9. Development of a Real-Time Resistance Measurement for Vibrio parahaemolyticus Detection by the Lecithin-Dependent Hemolysin Gene

    Science.gov (United States)

    Xiang, Guiming; Pu, Xiaoyun; Jiang, Dongneng; Liu, Linlin; Liu, Chang; Liu, Xiaobo

    2013-01-01

    The marine bacterium Vibrio parahaemolyticus (V. parahaemolyticus) causes gastroenteritis in humans via the ingestion of raw or undercooked contaminated seafood, and early diagnosis and prompt treatment are important for the prevention of V. parahaemolyticus-related diseases. In this study, a real-time resistance measurement based on loop-mediated isothermal amplification (LAMP), electrochemical ion bonding (Crystal violet and Mg2+), real-time monitoring, and derivative analysis was developed. V. parahaemolyticus DNA was first amplified by LAMP, and the products (DNA and pyrophosphate) represented two types of negative ions that could combine with a positive dye (Crystal violet) and positive ions (Mg2+) to increase the resistance of the reaction liquid. This resistance was measured in real-time using a specially designed resistance electrode, thus permitting the quantitative detection of V. parahaemolyticus. The results were obtained in 1–2 hours, with a minimum bacterial density of 10 CFU.mL−1 and high levels of accuracy (97%), sensitivity (96.08%), and specificity (97.96%) when compared to cultivation methods. Therefore, this simple and rapid method has a potential application in the detection of V. parahaemolyticus on a gene chip or in point-of-care testing. PMID:23991096

  10. Dual-time-point FDG-PET/CT Imaging of Temporal Bone Chondroblastoma: A Report of Two Cases

    Directory of Open Access Journals (Sweden)

    Akira Toriihara

    2015-07-01

    Full Text Available Temporal bone chondroblastoma is an extremely rare benign bone tumor. We encountered two cases showing similar imaging findings on computed tomography (CT, magnetic resonance imaging (MRI, and dual-time-point 18F-fluorodeoxyglucose (18F-FDG positron emission tomography (PET/CT. In both cases, CT images revealed temporal bone defects and sclerotic changes around the tumor. Most parts of the tumor showed low signal intensity on T2- weighted MRI images and non-uniform enhancement on gadolinium contrast-enhanced T1-weighted images. No increase in signal intensity was noted in diffusion-weighted images. Dual-time-point PET/CT showed markedly elevated 18F-FDG uptake, which increased from the early to delayed phase. Nevertheless, immunohistochemical analysis of the resected tumor tissue revealed weak expression of glucose transporter-1 and hexokinase II in both tumors. Temporal bone tumors, showing markedly elevated 18F-FDG uptake, which increases from the early to delayed phase on PET/CT images, may be diagnosed as malignant bone tumors. Therefore, the differential diagnosis should include chondroblastoma in combination with its characteristic findings on CT and MRI.

  11. APD Response Time Measurements for Future TOF-E Systems

    Science.gov (United States)

    Starkey, M. J.; Ogasawara, K.; Dayeh, M. A.; Desai, M. I.

    2017-12-01

    In space physics, the ability to detect ions is crucial to understanding plasma distributions in the solar wind. This usually typically requires the determination of the particle's mass, charge, and total energy. Current ion detection schemes are implemented in three sequential parts; an electrostatic analyzer for energy per charge (E/Q) measurements, a time-of-flight (TOF) for mass per charge (M/Q) measurements, and a solid-state detector (SSD) for total energy (E) measurements. Recent work has suggested the use of avalanche photodiode detectors (APD) for a simultaneous TOF and total energy (TOF-E) measurement system, which would replace traditional SSDs, simplify design, and reduce costs. Although TOF based ion spectrometry typically requires timing resolution of systems.

  12. Three-point phase correlations: A new measure of non-linear large-scale structure

    CERN Document Server

    Wolstenhulme, Richard; Obreschkow, Danail

    2015-01-01

    We derive an analytical expression for a novel large-scale structure observable: the line correlation function. The line correlation function, which is constructed from the three-point correlation function of the phase of the density field, is a robust statistical measure allowing the extraction of information in the non-linear and non-Gaussian regime. We show that, in perturbation theory, the line correlation is sensitive to the coupling kernel F_2, which governs the non-linear gravitational evolution of the density field. We compare our analytical expression with results from numerical simulations and find a very good agreement for separations r>20 Mpc/h. Fitting formulae for the power spectrum and the non-linear coupling kernel at small scales allow us to extend our prediction into the strongly non-linear regime. We discuss the advantages of the line correlation relative to standard statistical measures like the bispectrum. Unlike the latter, the line correlation is independent of the linear bias. Furtherm...

  13. A different outlook on time: visual and auditory month names elicit different mental vantage points for a time-space synaesthete.

    Science.gov (United States)

    Jarick, Michelle; Dixon, Mike J; Stewart, Mark T; Maxwell, Emily C; Smilek, Daniel

    2009-01-01

    Synaesthesia is a fascinating condition whereby individuals report extraordinary experiences when presented with ordinary stimuli. Here we examined an individual (L) who experiences time units (i.e., months of the year and hours of the day) as occupying specific spatial locations (January is 30 degrees to the left of midline). This form of time-space synaesthesia has been recently investigated by Smilek et al. (2007) who demonstrated that synaesthetic time-space associations are highly consistent, occur regardless of intention, and can direct spatial attention. We extended this work by showing that for the synaesthete L, her time-space vantage point changes depending on whether the time units are seen or heard. For example, when L sees the word JANUARY, she reports experiencing January on her left side, however when she hears the word "January" she experiences the month on her right side. L's subjective reports were validated using a spatial cueing paradigm. The names of months were centrally presented followed by targets on the left or right. L was faster at detecting targets in validly cued locations relative to invalidly cued locations both for visually presented cues (January orients attention to the left) and for aurally presented cues (January orients attention to the right). We replicated this difference in visual and aural cueing effects using hour of the day. Our findings support previous research showing that time-space synaesthesia can bias visual spatial attention, and further suggest that for this synaesthete, time-space associations differ depending on whether they are visually or aurally induced.

  14. Magnetic field gradients inferred from multi-point measurements of Cluster FGM and EDI

    Science.gov (United States)

    Teubenbacher, Robert; Nakamura, Rumi; Giner, Lukas; Plaschke, Ferdinand; Baumjohann, Wolfgang; Magnes, Werner; Eichelberger, Hans; Steller, Manfred; Torbert, Roy

    2013-04-01

    We use Cluster data from fluxgate magnetometer (FGM) and electron drift instrument (EDI) to determine the magnetic field gradients in the near-Earth magnetotail. Here we use the magnetic field data from FGM measurements as well as the gyro-time data of electrons determined from the time of flight measurements of EDI. The results are compared with the values estimated from empirical magnetic field models for different magnetospheric conditions. We also estimated the spin axis offset of FGM based on comparison between EDI and FGM data and discuss the possible effect in determining the current sheet characteristics.

  15. Real Time Precise Point Positioning: Preliminary Results for the Brazilian Region

    Science.gov (United States)

    Marques, Haroldo; Monico, João.; Hirokazu Shimabukuro, Milton; Aquino, Marcio

    2010-05-01

    GNSS positioning can be carried out in relative or absolute approach. In the last years, more attention has been driven to the real time precise point positioning (PPP). To achieve centimeter accuracy with this method in real time it is necessary to have available the satellites precise coordinates as well as satellites clocks corrections. The coordinates can be used from the predicted IGU ephemeris, but the satellites clocks must be estimated in a real time. It can be made from a GNSS network as can be seen from EUREF Permanent Network. The infra-structure to realize the PPP in real time is being available in Brazil through the Brazilian Continuous Monitoring Network (RBMC) together with the Sao Paulo State GNSS network which are transmitting GNSS data using NTRIP (Networked Transport of RTCM via Internet Protocol) caster. Based on this information it was proposed a PhD thesis in the Univ. Estadual Paulista (UNESP) aiming to investigate and develop the methodology to estimate the satellites clocks and realize PPP in real time. Then, software is being developed to process GNSS data in the real time PPP mode. A preliminary version of the software was called PPP_RT and is able to process GNSS code and phase data using precise ephemeris and satellites clocks. The PPP processing can be accomplished considering the absolute satellite antenna Phase Center Variation (PCV), Ocean Tide Loading (OTL), Earth Body Tide, among others. The first order ionospheric effects can be eliminated or minimized by ion-free combination or parameterized in the receiver-satellite direction using a stochastic process, e.g. random walk or white noise. In the case of ionosphere estimation, a pseudo-observable is introduced in the mathematical model for each satellite and the initial value can be computed from Klobuchar model or from Global Ionospheric Map (GIM). The adjustment is realized in the recursive mode and the DIA (Detection Identification and Adaptation) is used for quality control. In

  16. Evaluation of articular cartilage in patients with femoroacetabular impingement (FAI) using T2* mapping at different time points at 3.0 Tesla MRI: a feasibility study.

    Science.gov (United States)

    Apprich, S; Mamisch, T C; Welsch, G H; Bonel, H; Siebenrock, K A; Kim, Y-J; Trattnig, S; Dudda, M

    2012-08-01

    To define the feasibility of utilizing T2* mapping for assessment of early cartilage degeneration prior to surgery in patients with symptomatic femoroacetabular impingement (FAI), we compared cartilage of the hip joint in patients with FAI and healthy volunteers using T2* mapping at 3.0 Tesla over time. Twenty-two patients (13 females and 9 males; mean age 28.1 years) with clinical signs of FAI and Tönnis grade ≤ 1 on anterior-posterior x-ray and 35 healthy age-matched volunteers were examined at a 3 T MRI using a flexible body coil. T2* maps were calculated from sagittal- and coronal-oriented gradient-multi-echo sequences using six echoes (TR 125, TE 4.41/8.49/12.57/16.65/20.73/24.81, scan time 4.02 min), both measured at beginning and end of the scan (45 min time span between measurements). Region of interest analysis was manually performed on four consecutive slices for superior and anterior cartilage. Mean T2* values were compared among patients and volunteers, as well as over time using analysis of variance and Student's t-test. Whereas quantitative T2* values for the first measurement did not reveal significant differences between patients and volunteers, either for sagittal (p = 0.644) or coronal images (p = 0.987), at the first measurement, a highly significant difference (p ≤ 0.004) was found for both measurements with time after unloading of the joint. Over time we found decreasing mean T2* values for patients, in contrast to increasing mean T2* relaxation times in volunteers. The study proved the feasibility of utilizing T2* mapping for assessment of early cartilage degeneration in the hip joint in FAI patients at 3 Tesla to predict possible success of joint-preserving surgery. However, we suggest the time point for measuring T2* as an MR biomarker for cartilage and the changes in T2* over time to be of crucial importance for designing an MR protocol in patients with FAI.

  17. Time resolved measurements of triton burnup in JET plasmas

    International Nuclear Information System (INIS)

    Conroy, S.; Jarvis, O.N.; Sadler, G.; Huxtable, G.B.

    1988-01-01

    Triton production from one branch of the deuteron-deuteron fusion reaction is routinely measured at 6 ms time intervals in JET plasma discharges by recording the 2.5 MeV neutrons produced in the other branch using a set of calibrated fission chambers. The burnup of the tritons is measured by detecting the 14 MeV t-d neutrons with a 0.2 cm 3 Si(Li) diode. The 2.5 MeV neutron flux can be used in a simple time dependent calculation based on classical slowing-down theory to predict the 14 MeV neutron flux. The measured flux and the triton slowing-down time are systematically lower than the values estimated from the key plasma parameters but the differences are within the experimental errors. (author). 19 refs, 8 figs

  18. Identifying Time Measurement Tampering in the Traversal Time and Hop Count Analysis (TTHCA Wormhole Detection Algorithm

    Directory of Open Access Journals (Sweden)

    Jonny Karlsson

    2013-05-01

    Full Text Available Traversal time and hop count analysis (TTHCA is a recent wormhole detection algorithm for mobile ad hoc networks (MANET which provides enhanced detection performance against all wormhole attack variants and network types. TTHCA involves each node measuring the processing time of routing packets during the route discovery process and then delivering the measurements to the source node. In a participation mode (PM wormhole where malicious nodes appear in the routing tables as legitimate nodes, the time measurements can potentially be altered so preventing TTHCA from successfully detecting the wormhole. This paper analyses the prevailing conditions for time tampering attacks to succeed for PM wormholes, before introducing an extension to the TTHCA detection algorithm called ∆T Vector which is designed to identify time tampering, while preserving low false positive rates. Simulation results confirm that the ∆T Vector extension is able to effectively detect time tampering attacks, thereby providing an important security enhancement to the TTHCA algorithm.

  19. Stopped-flow technique for transit time measurement in a gas jet

    International Nuclear Information System (INIS)

    Rengan, K.; Lin, J.; Lim, T.; Meyer, R.A.; Harrell, J.

    1985-01-01

    A 'stopped-flow' technique for the measurement of transit time of reaction products in a gas jet is described. The method involved establishing the gas flow through the jet system when the reactor is operating steadily and allowing the pressure to reach equilibrium values. The gas flow is stopped by means of electrically operated valves. The transit-time measurement is achieved by opening the valves and initiating the multiscanning of total activity simultaneously. The value obtained agrees well with the transit time measured by pulsing the reactor. The 'stopped-flow' technique allows on-line measurement of transit time in any gas jet system where the physical transportation time is the major component of the transit time. This technique is especially useful for systems installed in reactors which do not have pulsing capability. (orig.)

  20. Time interval measurement between to emission: a systematics

    International Nuclear Information System (INIS)

    Bizard, G.; Bougault, R.; Brou, R.; Colin, J.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Mahi, M.; Meslin, C.; Steckmeyer, J.C.; Tamain, B.; Wieloch, A.

    1998-01-01

    A systematic study of the evolution of intervals of fragment emission times as a function of the energy deposited in the compound system was performed. Several measurements, Ne at 60 MeV/u, Ar at 30 and 60 MeV/u and two measurements for Kr at 60 MeV/u (central and semi-peripheral collisions) are presented. In all the experiments the target was Au and the mass of the compounds system was around A = 200. The excitation energies per nucleon reached in the case of these heavy systems cover the range of 3 to 5.5 MeV/u. The method used to determine the emission time intervals is based on the correlation functions associated to the relative angle distributions. The gaps between the data and simulations allow to evaluate the emission times. A rapid decrease of these time intervals was observed when the excitation energy increased. This variation starts at 500 fm/c which corresponds to a sequential emission. This relatively long time which indicates a weak interaction between fragments, corresponds practically to the measurement threshold. The shortest intervals (about 50 fm/c) are associated to a spontaneous multifragmentation and were observed in the case of central collisions at Ar+Au and Kr+Au at 60 MeV/u. Two interpretations are possible. The multifragmentation process might be viewed as a sequential process of very short time-separation or else, one can separate two zones heaving in mind that the multifragmentation is predominant from 4,5 MeV/u excitation energy upwards. This question is still open and its study is under way at LPC. An answer could come from the study of the rupture process of an excited nucleus, notably by the determination of its life-time