WorldWideScience

Sample records for reliable side-by-side comparisons

  1. Direct comparison of [18F]FDG PET/CT with PET alone and with side-by-side PET and CT in patients with malignant melanoma

    International Nuclear Information System (INIS)

    Mottaghy, Felix M.; Wohlfart, Petra; Blumstein, Norbert M.; Neumaier, Bernd; Glatting, Gerhard; Buck, Andreas K.; Reske, Sven N.; Sunderkoetter, Cord; Schubert, Roland; Oezdemir, Cueneyt; Scharfetter-Kochanek, Karin

    2007-01-01

    The purpose of this retrospective, blinded study was to evaluate the additional value of [ 18 F]FDG PET/CT in comparison with PET alone and with side-by-side PET and CT in patients with malignant melanoma (MM). A total of 127 consecutive studies of patients with known MM referred for a whole-body PET/CT examination were included in this study. PET alone, side-by-side PET and CT and integrated PET/CT study were independently and separately interpreted without awareness of the clinical information. One score each was applied for certainty of lesion localisation and for certainty of lesion characterisation. Verification of the findings was subsequently performed using all available clinical, pathological (n = 30) and follow-up information. The number of lesions with an uncertain localisation was significantly (p 18 F]FDG. (orig.)

  2. Side-by-side comparison of techniques for analyzing organic acids, total organic carbon, and anions. Final report

    International Nuclear Information System (INIS)

    Byers, W.A.; Richards, J.; Silva, H.; Miller, M.R.; Palino, G.F.; Wall, P.S.

    1986-09-01

    The objective of this project was to compare the organic acids sampling and analysis methods of Westinghouse and NWT Corporation. Sampling was performed at three sites, chosen to represent units with high, intermediate and low levels of organic contamination. To check the precision of each method, concurrent sampling was employed. To check the accuracy of each method, additions of standard organic solutions were made at one of the sites. Inorganic anions were also analyzed at each site by each contractor. Theoretical values of cation conductivity were calculated from organic and inorganic analytical data and compared to values measured onsite at the time of sampling. Total organic carbon (TOC) analyses were performed to evaluate different instruments and sampling techniques, as well as provide additional information on the relationship between TOC and organic acids concentrations. It was concluded that either of the organic acid sampling/analysis techniques used by the contractors can produce reliable results. TOC samples lose organics content with storage time and should be analyzed no later than one week after they are taken; if at all possible, they should be stored in a refrigerated condition. State-of-the art techniques for TOC sampling and analysis can produce results varying by 20 to 50 ppB for levels in the range of 50 to 120 ppB; any proposed limits for TOC should be reviewed in that light. Results of anion analyses are quite sensitive to sampling and analytical techniques. Reasonable agreement between calculated and measured values of cation conductivity suggests that both contractors had accurately determined all major anionic species

  3. Side-by-side comparisons of evacuated compound parabolic concentrator and flat plate solar collector systems at temperatures of 90 to 100C

    Science.gov (United States)

    Allen, J. W.; Schertz, W. W.; Wantroba, A. S.

    1987-03-01

    This collector system study is an extension of a previous system study in which Argonne National Laboratory (ANL) compared the performance of three solar energy systems operated side by side for over a year. In the present system study, four solar energy systems were operated side by side for part of a year. Two of the collector systems used commercially available compound parabolic concentrator (CPC) collectors, one used a commercially available flat plate collector, and one used an experimental CPC collector built by The University of Chicago. The collectors were mounted in fixed positions; they did not track the Sun, and their tilt angles were not seasonally adjusted. All of the collector arrays faced south and were tilted at 42 deg with respect to the horizon (to match the 42 deg N latitude at ANL). All four collector systems started each day with their storage temperatures at 90 C. During the day, each system was operated by its own solar controller. At the end of the day, the tanks were mixed and the temperature changes in the tanks were measured. The change in storage energy was calculated from the temperature change, the heat capacity of the storage system, and the pump energy.

  4. Side-by-Side Comparison of the Biological Characteristics of Human Umbilical Cord and Adipose Tissue-Derived Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Li Hu

    2013-01-01

    Full Text Available Both human adipose tissue-derived mesenchymal stem cells (ASCs and umbilical cord-derived mesenchymal stem cells (UC-MSCs have been explored as attractive mesenchymal stem cells (MSCs sources, but very few parallel comparative studies of these two cell types have been made. We designed a side-by-side comparative study by isolating MSCs from the adipose tissue and umbilical cords from mothers delivering full-term babies and thus compared the various biological aspects of ASCs and UC-MSCs derived from the same individual, in one study. Both types of cells expressed cell surface markers characteristic of MSCs. ASCs and UC-MSCs both could be efficiently induced into adipocytes, osteoblasts, and neuronal phenotypes. While there were no significant differences in their osteogenic differentiation, the adipogenesis of ASCs was more prominent and efficient than UC-MSCs. In the meanwhile, ASCs responded better to neuronal induction methods, exhibiting the higher differentiation rate in a relatively shorter time. In addition, UC-MSCs exhibited a more prominent secretion profile of cytokines than ASCs. These results indicate that although ASCs and UC-MSCs share considerable similarities in their immunological phenotype and pluripotentiality, certain biological differences do exist, which might have different implications for future cell-based therapy.

  5. A Comparison of Bilateral Side-by-Side Metal Stents Deployed Above and Across the Sphincter of Oddi in the Management of Malignant Hilar Biliary Obstruction.

    Science.gov (United States)

    Cosgrove, Natalie; Siddiqui, Ali A; Adler, Douglas G; Shahid, Haroon; Sarkar, Avik; Sharma, Ashish; Kowalski, Thomas E; Loren, David; Warndorf, Matthew; Chennat, Jennifer; Munigala, Satish; Papachristou, Georgios I

    2017-07-01

    The optimal method for endoscopic placement of bilateral self-expanding metal stents (SEMS) for the management of malignant hilar biliary obstruction has not been determined. The aim of this study was to compare the efficacies and complication rates between SEMS placed above and across the sphincter of Oddi (SO) in patients with malignant hilar biliary obstruction. A retrospective review of patients with malignant hilar strictures who underwent bilateral SEMS placement at 3 centers was performed. Patients were divided into 2 groups: group A (above SO, n=52) or B (across SO, n=120). Patient demographics, technical success (successful SEMS placement across the stricture), functional success (decrease in pretreatment bilirubin level), complications, stent occlusion, and patient survival in the 2 groups were evaluated. We identified 172 patients with malignant hilar biliary obstruction (106 males, mean age 67 y). Significantly more early complications (1.9% vs. 11.7%, P=0.04) were seen in group B, mainly post-endoscopic retrograde cholangio-pancreatography pancreatitis. Mean SEMS patency periods were 33 weeks for group A and 29.6 weeks for group B (P=0.3). Occlusion rates were 50% and 45% for groups A and B (P=0.61); occlusion was due to tumor in-growth or overgrowth in all patients. SEMS occlusion was successfully treated endoscopically in 85% (22/26) patients in group A and 96% (52/54) in group B (P=0.24). The median survival time was 26 weeks in the group A and 29 weeks in group B (P=0.49). Bilateral side-by-side SEMS placement above or below the SO results in similar success rates, stent patency duration, and stent occlusion rates. Significantly fewer complications, with a trend toward lower rates of pancreatitis, were observed for SEMS placed above the SO.

  6. Side-by-side comparison of an open-chamber (TM 300) and a closed-chamber (Vapometer™) transepidermal water loss meter.

    Science.gov (United States)

    Steiner, Markus; Aikman-Green, Sylvie; Prescott, Gordon J; Dick, Finlay D

    2011-08-01

    The measurement of transepidermal water loss (TEWL) is used to monitor changes in the stratum corneum's permeability to water vapor. This measurement is widely used in the cosmetics industry and in dermatology research. However, only limited work has been undertaken to assess the comparability of results from different TEWL meters over an extended range of measurements. This study compared the results of TEWL measurements between two commonly used open-chamber and closed-chamber TEWL devices. Five hundred and forty measurements were taken in 17 participants on the dorsum and palm of both hands on two different days and the order of the devices was randomized. The results showed that the open TEWL meter's capacity for measuring high values of TEWL was restricted, and that the closed-chamber TEWL meter was less sensitive to differences in the lower range of measurements. Both devices have their strengths for different applications, but their results cannot be directly compared. We were unable to find a statistical model that would allow us to transform the measurements made on one device for a comparison with the results generated by the other device. © 2011 John Wiley & Sons A/S.

  7. Novel 755-nm diode laser vs. conventional 755-nm scanned alexandrite laser: Side-by-side comparison pilot study for thorax and axillary hair removal.

    Science.gov (United States)

    Paasch, Uwe; Wagner, Justinus A; Paasch, Hartmut W

    2015-01-01

    Alexandrite (755 nm) and diode lasers (800-810 nm) are commonly used for hair removal. The alexandrite laser technology is somewhat cumbersome whereas new diode lasers are more robust. Recently, alexandrite-like 755 nm wavelength diodes became available. To compare the efficacy, tolerability, and subject satisfaction of a 755 nm diode laser operated in conventional (HR) and non-conventional in-motion (SHR) modes with a conventional scanned alexandrite 755 nm laser for chest and axillary hair removal. A prospective, single-center, proof of principle study was designed to evaluate the safety, efficacy and handling of a 755 nm diode laser system in comparison to a standard alexandrite 755 nm scanning hair removal laser. The new 755 nm diode is suitable to be used in SHR and HR mode and has been tested for its safety, efficacy and handling in a volunteer with success. Overall, both systems showed a high efficacy in hair reduction (88.8% 755 nm diode laser vs. 77.7% 755 nm alexandrite laser). Also, during the study period, no severe adverse effects were reported. The new 755 nm diode laser is as effective and safe as the traditional 755 nm alexandrite laser. Additionally, treatment with the 755 nm diode laser with HR and SHR modes was found to be less painful.

  8. Numerical study of two side-by-side cylinders with unequal diameters at low Reynolds number

    International Nuclear Information System (INIS)

    Gao, Y Y; Wang, X K; Tan, S K

    2012-01-01

    Two-dimensional laminar flow about two side-by-side unequal cylinders with different diameter ratios d/D and centre-to-centre spacing ratios T/D at Re=300 (based on the larger cylinder diameter) was simulated using a CFD software. Comparisons of experimental and numerical results were made to elucidate the degree of interference due to d/D and T/D and their effects on the flow patterns and vortex shedding frequencies. The findings showed that the flow patterns behind two unequal cylinders were distinctly different from that behind two equal side-by-side cylinders, with distinct in-phase and anti-phase vortex shedding, and random switching of modes of vortex shedding.

  9. Flapping propulsion with side-by-side pitching foils

    Science.gov (United States)

    Huera-Huarte, Francisco

    2016-11-01

    Fish schools are one of the most common types of collective behaviour observed in nature. One of the reasons why fish swim in groups, is to reduce the cost of transport of the school. In this work we explore the propulsive performance of two foils flapping in a symmetric configuration, i.e. with an out-of-phase flapping motion. Direct thrust measurements and Particle Image Velocimetry (PIV) allowed a detailed examination of the forces and the wake generated by the system, for different kinematics (swept angles and frequencies) and shaft separations. For certain specific cases, volumetric PIV shows major differences on how the different structures in the wake of the system evolve, depending on the imposed kinematics and the side-by-side separation between the foils. Results obtained will be compared against data produced with isolated flapping foils with similar imposed kinematics, with the aim to better understand the interactions between both and the performance of the system as a whole. The author would like to acknowledge the financial support provided by the Spanish Ministerio de Economia y competitividad (MINECO) through Grant DPI2015-71645-P.

  10. Classification of gap flow regimes in two side-by-side circular cylinders

    CSIR Research Space (South Africa)

    Atkins, M

    2014-02-01

    Full Text Available The behavior of the flow around two circular cylinders arranged in a side-by-side configuration strongly depends on the transverse center-to-center gap spacing ratio (T/D) where D is the cylinder diameter. Based on the observed wake structure [13...

  11. Side-by-side determination of workers' exposure to wood dust with IOM and open-faced samplers.

    Science.gov (United States)

    Cavlović, Anka Ozana; Beljo Lučić, Ružica; Jug, Matija; Radmanović, Kristijan; Bešlić, Ivan

    2013-09-01

    Woodworkers' exposure to airborne particles is measured with different sampling techniques throughout the world. Due to a great number of exposure data obtained with different samplers, European countries have aimed over the last ten years to find a conversion factor for mass concentrations that would render these measurements comparable. Following the accepted EU standards and regulations, we replaced a 25 mm open-faced (OF) filter holder with an IOM head to determine woodworkers' exposure to inhalable dust and establish an IOM/OF sampler ratio that might serve as a reliable factor for converting the existing OF data to IOM dust mass concentration in the industrial environment. For this side-by-side sampling we used personal 25 mm OF (N=29) and IOM (N=29) sampling heads over eight working hours. The obtained IOM/OF ratios ranged between 0.7 and 2.3. However, mass concentrations obtained by IOM and OF samplers did not significantly differ. Our findings suggest that there is no need for conversion of the existing OF data for workers exposed to wood dust, provided that dust mass concentrations in the working environment range between 1 mg m-3 and 7 mg m-3. Future side-by-side measurements should also involve environments with low wood dust mass concentrations.

  12. Functionally Graded Ceramics Fabricated with Side-by-Side Tape Casting for Use in Magnetic Refrigeration

    DEFF Research Database (Denmark)

    Bulatova, Regina; Bahl, Christian; Andersen, Kjeld Bøhm

    2015-01-01

    Functionally graded ceramic tapes have been fabricated by a side-by-side tape casting technique. This study shows the possibility and describes the main principles of adjacent coflow of slurries resulting in formation of thin plates of graded ceramic material. Results showed that the small...... variations of solvent and binder system concentrations have a substantial effect on slurry viscosity. Varying these parameters showed that side-by-side tape casting with a well-defined interface area is possible for slurries with viscosities above 3500 mPa s at a casting shear rate of 3.3 s -1...... of developing this graded ceramic tape casting was applications of these specific magnetocaloric properties within the magnetic refrigeration technology....

  13. Vortex interactions in a two side-by-side cylinder near-wake

    International Nuclear Information System (INIS)

    Wang, Z.J.; Zhou, Y.

    2005-01-01

    The flow behind two side-by-side circular cylinders is experimentally investigated based on laser-illuminated flow-visualization, particle image velocimetry and hot-wire measurements. The flow is classified as three regimes: single street (the cylinder center-to-center spacing T/d 2.0). Special attention is given to the regime of 1.2 2.0, the flow structure change from the anti-phase to in-phase mode starts with a phase shift between gap vortices. The dynamical role of gap bleeding between cylinders for L/d < 1.2 is also examined

  14. The Variation of Interface Formation with Slurry Viscosity Change in Side-By-Side Tape Casting

    DEFF Research Database (Denmark)

    Bulatova, Regina; Jabbari, Masoud; Andersen, Kjeld Bøhm

    Homogenous and flexible adjacently graded tapes were produced by casting the organic-based slurries simultaneously. To develop side-by-side tape casing (SBSTC), the material optimization, modernization of the doctor blade design, and parameters control of such processes as casting, drying, de......-bindering and sintering were studied. Solvent and binder concentrations were varied in order to optimize co-casting flow, as well as the drying and sintering shrinkage. Tapes were evaluated in terms of rheological behavior of the slurries, the green and sintered tape microstructure, the quality of the interface area...

  15. Fluid-mediated stability and speed-increase for heaving hydrofoils swimming side-by-side

    Science.gov (United States)

    Newbolt, Joel; Zhang, Jun; Ristroph, Leif

    2017-11-01

    As an example of collective motion in active swimmers we study the fluid-mediated interaction between two heaving hydrofoils that swim with a fixed transverse separation (between the heaving mid-heights) but are free to independently choose their forward swimming speeds and positions. Experiments reveal that out-of-phase foils are attracted to a side-by-side configuration which also increases the swimming speed of the pair (up to 59% faster for our parameters), while in-phase foils are repelled from this configuration. Because this type of swimming is qualitatively similar to that of fish and birds this interaction could be important to schooling and flocking.

  16. Quantitative flow characteristics for side-by-side square cylinders via PIV

    Directory of Open Access Journals (Sweden)

    Dogan Sercan

    2012-04-01

    Full Text Available In this study, instantaneous and time-averaged flow structures downstream of the sharp-edged single and two and three side-by-side square cylinders (SCs immersed in a uniform open channel water flow were studied by a technique of particle image velocimetry (PIV. Experimental results of wake flow structures were presented for gap ratios (G/D in the range of 1.0”G/D”3.0 for Reynolds number values of 1050, 2450 and 3400. Flow structures depending on the square cylinder (SC configurations and Reynolds number were discussed. It has been found that the development of the vortex shedding as well as the flow structure were substantially altered for side-by-side SCs comparing to the single SC. Asymmetrical and biased wake structures were observed because of the jetlike flow between the SCs for two SCs cases for the gap ratio less than 2.0. Depending on the gap spacing between the SCs, the interaction results of time2 averaged vorticity, velocity vector field, Reynolds stress correlations and streamline patterns in the wake region form a distinguished flow structure. Strouhal numbers for the single square cylinder for 1050≤Re≤3400 are found in the range of 0.12-0.13. The present results have supported the previous works by providing detailed quantitative experimental information with PIV in the wake region of the SC and might be helpful for validation of numerical studies and designers.

  17. Flow Features of Three Side-by-side Circular Cylinders at Low Reynolds Number

    Directory of Open Access Journals (Sweden)

    Liu Junkao

    2016-01-01

    Full Text Available In order to study the fluctuation of kinetic parameter of cylinder matrix in incompressible stationary flow, the flow fluid around three side-by-side circular cylinders are simulated using Immersed Boundary–Lattice Boltzmann method (IB-LBM. Drag and lift force of the three cylinders are investigated as the interval between each cylinder varied from zero to five times of the cylinder diameter. Five flow patterns are defined according to the vortices structure in the downstream of the cylinders. Power spectrum analysis of lift force is developed to explain the vortex patterns. Through the research, we find the strength and phase of the gap flow play an important role in the vortex formatting process. The vortices shedding from different cylinders neutralize and combine in the near wake, contributing a lot to the variation of forces.

  18. Interface Oscillation in the Side-by-Side (SBS) Tape Casting of Functionally Graded Ceramics (FGCs)

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Bulatova, Regina; Hattel, Jesper Henri

    2012-01-01

    temperature of the magnetic regenerator varies along the paths. The main goal of this research is to study the multiple material flow in SBS tape casting and analyze its influence on the interface between the stripes. The materials used for the experimental part are La0.85Sr0.15MnO3 and Ce0.9Gd0.1O2ceramic...... is a common process in producing multilayer ceramics, which now is used for producing side-by-side (SBS) functionally graded ceramics (FGCs). These FGCs are mostly used in the magnetic refrigeration sectors due to the varying composition of the magnetocaloric materials so that the magnetic transition...... slurries. The rheological behavior of the slurries are extracted from experiments and used in the ANSYS FLUENT commercial code to develop a fluid flow model for the non-Newtonian ceramic slurries and evaluate the interface oscillation between the stripes in SBS tape casting. The Numerical results show...

  19. [Excimer laser therapy of alopecia areata--side-by-side evaluation of a representative area].

    Science.gov (United States)

    Raulin, Christian; Gündogan, Cüneyt; Greve, Bärbel; Gebert, Susanne

    2005-07-01

    We report for the first time on hair regrowth in alopecia areata of the scalp achieved with the 308-nm xenon-chloride excimer laser in a prospective side-by-side trial. The alopecia areata had shown progression over a period of three years, and various treatments had not been effective. Out of a number of affected areas, one representative lesion was chosen; one half of it was treated, the other half remained untreated. After 27 sessions (200 - 4000 mJ/cm2, cumulative dose 52.6 J/cm2) over 3 months, only the treated area showed hair growth; which suggests that this was most probably not a spontaneous remission.

  20. Audiovisual integration increases the intentional step synchronization of side-by-side walkers.

    Science.gov (United States)

    Noy, Dominic; Mouta, Sandra; Lamas, Joao; Basso, Daniel; Silva, Carlos; Santos, Jorge A

    2017-12-01

    When people walk side-by-side, they often synchronize their steps. To achieve this, individuals might cross-modally match audiovisual signals from the movements of the partner and kinesthetic, cutaneous, visual and auditory signals from their own movements. Because signals from different sensory systems are processed with noise and asynchronously, the challenge of the CNS is to derive the best estimate based on this conflicting information. This is currently thought to be done by a mechanism operating as a Maximum Likelihood Estimator (MLE). The present work investigated whether audiovisual signals from the partner are integrated according to MLE in order to synchronize steps during walking. Three experiments were conducted in which the sensory cues from a walking partner were virtually simulated. In Experiment 1 seven participants were instructed to synchronize with human-sized Point Light Walkers and/or footstep sounds. Results revealed highest synchronization performance with auditory and audiovisual cues. This was quantified by the time to achieve synchronization and by synchronization variability. However, this auditory dominance effect might have been due to artifacts of the setup. Therefore, in Experiment 2 human-sized virtual mannequins were implemented. Also, audiovisual stimuli were rendered in real-time and thus were synchronous and co-localized. All four participants synchronized best with audiovisual cues. For three of the four participants results point toward their optimal integration consistent with the MLE model. Experiment 3 yielded performance decrements for all three participants when the cues were incongruent. Overall, these findings suggest that individuals might optimally integrate audiovisual cues to synchronize steps during side-by-side walking. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Wake structures of two side by side spheres in a tripped boundary layer flow

    Directory of Open Access Journals (Sweden)

    Canli Eyüb

    2014-03-01

    Full Text Available Two independent spheres were placed in a side by side arrangement and flow structure in the wake region of the spheres was investigated with a Particle Image Velocimetry (PIV system when the spheres were in a boundary layer over a flat plate as a special case. Reynolds number was 5000 based on the sphere diameter which was 42.5 mm. Boundary layer was tripped 8mm away from the leading edge of the flat plate with a 5 mm trip wire. The thickness of the hydrodynamically developed boundary layer was determined as 63mm which was larger than the sphere diameter of D=42.5mm. Wake region of the spheres was examined from point of flow physics for the different sphere locations in the ranges of 0≤G/D ≤1.5 and 0≤S/D ≤1.5 where G and S were the distance between the spheres and the distance between the bottom point of the spheres and the flat plate surface, respectively. Depending on the different sphere locations, instantaneous and time averaged vorticity data, scalar values of time-averaged velocity components and their root mean square (rms values and time averaged vorticity data are presented in the study for the evaluation of wake region of the spheres. It is demonstrated that the gap between the two spheres and the interaction between the gap and the boundary layer greatly affects flow pattern, especially when spheres are located near to the flat plate surface, i.e. S/D=0.1 for 0≤G/D ≤1.5. Different distances between the spheres resulted in various flow patterns as the spheres were approached to the flat plate. The distance S/D=0.1 for all gap values has the strongest effect on the wake structures. Beyond G/D=1.0, the sphere wakes tend to be similar to single sphere case. The instantaneous vorticity fields of the side by side arrangements comprised wavy structures in higher level comparing to an individual sphere case. The gap flow intensifies the occurrence of small scale eddies in the wake region. The submersion rate of the spheres

  2. Side-by-side ANFIS as a useful tool for estimating correlated thermophysical properties

    Science.gov (United States)

    Grieu, Stéphane; Faugeroux, Olivier; Traoré, Adama; Claudet, Bernard; Bodnar, Jean-Luc

    2015-12-01

    In the present paper, an artificial intelligence-based approach dealing with the estimation of correlated thermophysical properties is designed and evaluated. This new and "intelligent" approach makes use of photothermal responses obtained when homogeneous materials are subjected to a light flux. Commonly, gradient-based algorithms are used as parameter estimation techniques. Unfortunately, such algorithms show instabilities leading to non-convergence in case of correlated properties to be estimated from a rebuilt impulse response. So, the main objective of the present work was to simultaneously estimate both the thermal diffusivity and conductivity of homogeneous materials, from front-face or rear-face photothermal responses to pseudo random binary signals. To this end, we used side-by-side neuro-fuzzy systems (adaptive network-based fuzzy inference systems) trained with a hybrid algorithm. We focused on the impact on generalization of both the examples used during training and the fuzzification process. In addition, computation time was a key point to consider. That is why the developed algorithm is computationally tractable and allows both the thermal diffusivity and conductivity of homogeneous materials to be simultaneously estimated with very good accuracy (the generalization error ranges between 4.6% and 6.2%).

  3. Lift on side by side intruders of various geometries within a granular flow

    Science.gov (United States)

    Acevedo-Escalante, M. F.; Caballero-Robledo, G. A.

    2017-06-01

    Obstacles within fluids have been widely used in engineering and in physics to study hydrodynamic interactions. In granular matter, objects within a granular flow have helped to understand fundamental features of drag and lift forces. In our group, we have studied numerically the flow mediated interaction between two static disks within a vertical granular flow in a two-dimensional container where the flow velocity and the distance between obstacles were varied. Attractive and repulsive forces were found depending on flow velocity and separation between intruders. The simulations evidenced a relationship between the average flow velocity in a specific section ahead of the obstacles and the attractive-repulsive lift. On the other hand, it was showed that the lift force on an object dragged within a granular medium depends on the shape of the intruder. Here we present experimental results of the interaction between two side-by-side intruders of different shapes within a vertical granular flow. We built a quasi-two-dimensional container in which we placed the intruders and using load cells we measured lift and drag forces during the discharge process for different flow velocities.

  4. A direct method for calculating instrument noise levels in side-by-side seismometer evaluations

    Science.gov (United States)

    Holcomb, L. Gary

    1989-01-01

    The subject of determining the inherent system noise levels present in modem broadband closed loop seismic sensors has been an evolving topic ever since closed loop systems became available. Closed loop systems are unique in that the system noise can not be determined via a blocked mass test as in older conventional open loop seismic sensors. Instead, most investigators have resorted to performing measurements on two or more systems operating in close proximity to one another and to analyzing the outputs of these systems with respect to one another to ascertain their relative noise levels.The analysis of side-by-side relative performance is inherently dependent on the accuracy of the mathematical modeling of the test configuration. This report presents a direct approach to extracting the system noise levels of two linear systems with a common coherent input signal. The mathematical solution to the problem is incredibly simple; however the practical application of the method encounters some difficulties. Examples of expected accuracies are presented as derived by simulating real systems performance using computer generated random noise. In addition, examples of the performance of the method when applied to real experimental test data are shown.

  5. Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States). Building America Partnership for Improved Residential Construction (BA-PIRC)

    2017-07-01

    The Florida Solar Energy Center (FSEC) completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). The evaluation studied the performance of five hot water systems (HWS) plus a reference baseline system for each fuel, (i.e., electric and natural gas). Electric HWS consisted of two residential electric heat pump water heaters (HPWHs, 60 and 80 gallons), a solar thermal system using a polymer absorber (glazed) collector with 80-gallon storage and a duplicate 50-gallon standard electric water heater with added cap and wrap insulation. Baseline performance data were collected from a standard 50-gallon electric water heater of minimum code efficiency to compare energy savings. Similarly, a standard 40-gallon upright vented natural gas water heater served as baseline for the natural gas fuel category. The latter, having a larger jacket diameter [18 in., with an energy factor (EF) of 0.62] with increased insulation, replaced a former baseline (17 in. diameter, EF = 0.59) that served during three previous testing rotations (2009–2013). A high-efficiency, condensing natural gas hybrid water heater with 27-gallon buffered tank was also tested and compared against the gas baseline. All systems underwent testing simultaneously side-by-side under the criteria specified elsewhere in this report.

  6. Flapping modes of three filaments placed side by side in a free stream

    Science.gov (United States)

    Tian, Fang-Bao; Luo, Haoxiang; Zhu, Luoding; Lu, Xi-Yun

    2010-11-01

    Flexible filaments flapping in a surrounding flow are useful models for understanding the flow-induced vibration and mimicking the schooling behavior of fish. In the present work, the coupled modes of three identical filaments in a side-by- side arrangement are studied using the linear stability analysis and also an immersed boundary--lattice Boltzmann method for low Reynolds numbers (Re on order of 100). The numerical simulations show that the system dynamics exhibits several patterns that depend on the spacing between the filaments. Among these patterns, three can be predicted by the linear analysis and have been reported before. These modes are: (1) the three filaments all flap in phase; (2) the two outer filaments are out of phase while the middle one is stable; (3) the two outer filaments are in phase while the middle one is out of phase. The simulations also identified two additional modes: (1) the outer two filaments are out of phase while the middle one flaps at a frequency reduced by half; (2) the outer two filaments are out of phase while the middle one flaps at a slightly different frequency. In addition to the vibratory modes, the drag force and the flapping amplitude are also computed, and the implication of the result will be discussed.

  7. Side-by-side comparison of Raman spectra of anchored and suspended carbon nanomaterials

    International Nuclear Information System (INIS)

    Sidorov, Anton N; Pabba, Santosh; Cohn, Robert W; Sumanasekera, G U; Hewaparakrama, Kapila P

    2008-01-01

    Raman spectra of ordered carbon nanomaterials are quite sensitive to surface perturbations, including trace residues, structural defects and residual stress. This is demonstrated by a series of experiments with carbon nanotubes and graphene. Their spectra change due to subtle changes in preparation and attachment to the substrate and to each other. Differences are most clearly seen by forming a material into an air bridge and probing it in the air gap and at the anchor points. A monolayer graphene sheet, shows a larger disorder band at the anchor points than in the air gap. However, a bundle or rope of parallel-aligned single-wall nanotubes shows a larger disorder band in the gap than at the anchor points. For the graphene sheet the substrate surface deforms the graphene, leading to increases in the disorder band. For the rope, the close proximity of the nanotubes to each other appears to produce a larger stress than the rope resting on the substrate

  8. Side-by-side comparison of gene-based smallpox vaccine with MVA in nonhuman primates.

    Science.gov (United States)

    Golden, Joseph W; Josleyn, Matthew; Mucker, Eric M; Hung, Chien-Fu; Loudon, Peter T; Wu, T C; Hooper, Jay W

    2012-01-01

    Orthopoxviruses remain a threat as biological weapons and zoonoses. The licensed live-virus vaccine is associated with serious health risks, making its general usage unacceptable. Attenuated vaccines are being developed as alternatives, the most advanced of which is modified-vaccinia virus Ankara (MVA). We previously developed a gene-based vaccine, termed 4pox, which targets four orthopoxvirus antigens, A33, B5, A27 and L1. This vaccine protects mice and non-human primates from lethal orthopoxvirus disease. Here, we investigated the capacity of the molecular adjuvants GM-CSF and Escherichia coli heat-labile enterotoxin (LT) to enhance the efficacy of the 4pox gene-based vaccine. Both adjuvants significantly increased protective antibody responses in mice. We directly compared the 4pox plus LT vaccine against MVA in a monkeypox virus (MPXV) nonhuman primate (NHP) challenge model. NHPs were vaccinated twice with MVA by intramuscular injection or the 4pox/LT vaccine delivered using a disposable gene gun device. As a positive control, one NHP was vaccinated with ACAM2000. NHPs vaccinated with each vaccine developed anti-orthopoxvirus antibody responses, including those against the 4pox antigens. After MPXV intravenous challenge, all control NHPs developed severe disease, while the ACAM2000 vaccinated animal was well protected. All NHPs vaccinated with MVA were protected from lethality, but three of five developed severe disease and all animals shed virus. All five NHPs vaccinated with 4pox/LT survived and only one developed severe disease. None of the 4pox/LT-vaccinated animals shed virus. Our findings show, for the first time, that a subunit orthopoxvirus vaccine delivered by the same schedule can provide a degree of protection at least as high as that of MVA.

  9. Side-by-side comparison of gene-based smallpox vaccine with MVA in nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Joseph W Golden

    Full Text Available Orthopoxviruses remain a threat as biological weapons and zoonoses. The licensed live-virus vaccine is associated with serious health risks, making its general usage unacceptable. Attenuated vaccines are being developed as alternatives, the most advanced of which is modified-vaccinia virus Ankara (MVA. We previously developed a gene-based vaccine, termed 4pox, which targets four orthopoxvirus antigens, A33, B5, A27 and L1. This vaccine protects mice and non-human primates from lethal orthopoxvirus disease. Here, we investigated the capacity of the molecular adjuvants GM-CSF and Escherichia coli heat-labile enterotoxin (LT to enhance the efficacy of the 4pox gene-based vaccine. Both adjuvants significantly increased protective antibody responses in mice. We directly compared the 4pox plus LT vaccine against MVA in a monkeypox virus (MPXV nonhuman primate (NHP challenge model. NHPs were vaccinated twice with MVA by intramuscular injection or the 4pox/LT vaccine delivered using a disposable gene gun device. As a positive control, one NHP was vaccinated with ACAM2000. NHPs vaccinated with each vaccine developed anti-orthopoxvirus antibody responses, including those against the 4pox antigens. After MPXV intravenous challenge, all control NHPs developed severe disease, while the ACAM2000 vaccinated animal was well protected. All NHPs vaccinated with MVA were protected from lethality, but three of five developed severe disease and all animals shed virus. All five NHPs vaccinated with 4pox/LT survived and only one developed severe disease. None of the 4pox/LT-vaccinated animals shed virus. Our findings show, for the first time, that a subunit orthopoxvirus vaccine delivered by the same schedule can provide a degree of protection at least as high as that of MVA.

  10. Side-by-Side Comparison of Hydroperoxide and Corresponding Alcohol as Hydrogen-Bond Donors

    DEFF Research Database (Denmark)

    Møller, Kristian Holten; Tram, Camilla Mia; Kjærgaard, Henrik Grum

    2017-01-01

    tert-butanol (t-BuOH), with dimethyl ether (DME) as the hydrogen-bond acceptor. Using a combination of Fourier-transform infrared spectroscopy and quantum chemical calculations, we compare the strength of the OH-O hydrogen bond and the total strength of complexation. We find that, both in terms...... results, we find that the hydroperoxide complex is stabilized by ∼4 kJ/mol (Gibbs free energy) more than the alcohol complex. Measured red shifts show the same trend in hydrogen-bond strength with trimethylamine (N acceptor atom) and dimethyl sulfide (S acceptor atom) as the hydrogen-bond acceptors....

  11. Simultaneous Versus Sequential Side-by-Side Bilateral Metal Stent Placement for Malignant Hilar Biliary Obstructions.

    Science.gov (United States)

    Inoue, Tadahisa; Ishii, Norimitsu; Kobayashi, Yuji; Kitano, Rena; Sakamoto, Kazumasa; Ohashi, Tomohiko; Nakade, Yukiomi; Sumida, Yoshio; Ito, Kiyoaki; Nakao, Haruhisa; Yoneda, Masashi

    2017-09-01

    Endoscopic bilateral self-expandable metallic stent (SEMS) placement for malignant hilar biliary obstructions (MHBOs) is technically demanding, and a second SEMS insertion is particularly challenging. A simultaneous side-by-side (SBS) placement technique using a thinner delivery system may mitigate these issues. We aimed to examine the feasibility and efficacy of simultaneous SBS SEMS placement for treating MHBOs using a novel SEMS that has a 5.7-Fr ultra-thin delivery system. Thirty-four patients with MHBOs underwent SBS SEMS placement between 2010 and 2016. We divided the patient cohort into those who underwent sequential (conventional) SBS placement between 2010 and 2014 (sequential group) and those who underwent simultaneous SBS placement between 2015 and 2016 (simultaneous group), and compared the groups with respect to the clinical outcomes. The technical success rates were 71% (12/17) and 100% (17/17) in the sequential and simultaneous groups, respectively, a difference that was significant (P = .045). The median procedure time was significantly shorter in the simultaneous group (22 min) than in the sequential group (52 min) (P = .017). There were no significant group differences in the time to recurrent biliary obstruction (sequential group: 113 days; simultaneous group: 140 days) or other adverse event rates (sequential group: 12%; simultaneous group: 12%). Simultaneous SBS placement using the novel 5.7-Fr SEMS delivery system may be more straightforward and have a higher success rate compared to that with sequential SBS placement. This new method may be useful for bilateral stenting to treat MHBOs.

  12. Advection within side-by-side liquid micro-cylinders in a cross-flow

    Science.gov (United States)

    Dong, Qingming; Sau, Amalendu

    2017-11-01

    The gaseous SO2 entrainment from outer air stream and dispersion in binary and ternary liquid micro-cylinders appearing side-by-side are examined hereby. The separation/attachment regulated non-uniform interfacial momentum exchange creates main stream driven "primary" and shear reversed "secondary" vortices in the liquid cylinders. At separation points, the sense of rotation of the generated "primary-secondary" vortex pair remains inward directed. We define such a vortex pair as the "inflow" type. However, at stagnation or attachment points, the sense of rotation of a "primary-primary" or "secondary-secondary" vortex pair remains outward directed, and such a vortex pair is defined as the "outflow" type. For the coupled water cylinders facing an oncoming stream contaminated by gaseous SO2, its absorption and internal transport are effectively controlled by dominant "inflow" and "outflow" natured dynamics of the said vortex pairs, besides by diffusion. The evolving "inflow" natured "primary-secondary" vortex pairs at separation points actively entrain the outer SO2, whereas the "outflow" natured vortex-pairs oppose SO2 entry through the stagnation regions. Moreover, the blockage induced steady-symmetric, steady-deflected, and flip-flopping air-jets through gaps, for varied gap-ratio (1 ≤ G/R ≤ 4) and Reynolds number (30 ≤ Re ≤ 160), create distinctive impact both on quantitative SO2 absorption (mso2 ') and convective nature of the SO2 transport in upper, lower, and middle cylinders, by virtue of modified strength and size of the inflow and outflow paired vortices. The present study shows that the tiny "secondary vortices" play important roles in SO2 entrainment and in effectively controlling the local absorption rate Rs o2. The sudden acceleration and upward/downward deflection of gap-flows enhanced near-neck advective SO2 entrainment by suitably strengthening the "inflow" natured local vortex dynamics. Conversely, for the reduced size of secondary vortices

  13. Thickness control and interface quality as functions of slurry formulation and casting speed in side-by-side tape casting

    DEFF Research Database (Denmark)

    Bulatova, Regina; Jabbari, Mirmasoud; Kaiser, Andreas

    2014-01-01

    A novel method of co-casting called side-by-side tape casting was developed aiming to form thin functionally graded films with varying properties within a single plane. The standard organic-based recipe was optimized to co-cast slurries into thick graded tapes. Performed numerical simulations...... identified the stable flow beneath the blade with a shear rate profile independent of slurry viscosity as long as the slurry load in the casting tank was low. Thickness and interface shape could be well predicted if the rheological behaviour of slurries is known and the processing parameters are well...

  14. Influence of the side-by-side arrangement on the performance of a small Savonius wind turbine

    Directory of Open Access Journals (Sweden)

    Jang Choon-Man

    2016-01-01

    Full Text Available Scaled-down Savonius turbine rotors arrayed side-by-side are introduced to analyze the effects of design parameters on the performance between turbine rotors. Unsteady flow simulation and experimental measurement have been performed to compare turbine performance and validate the numerical simulation of the turbine rotor. Commercial code, SC/Tetra, which uses an unstructured grid system, has been used to solve the three-dimensional unsteady Reynolds-averaged Navier–Stokes equations. Single turbine rotors and two turbine rotors arrayed side-by-side were numerically analyzed. The distance between rotor tips is 0.5 times the rotor diameter. Throughout the numerical simulation, the power coefficient obtained by the time-averaged result of unsteady flow simulation was found to be in good agreement with the experimental result. A discussion on the design parameters using both a single and arrayed turbine rotors is presented based on the results of the unsteady flow simulation, including the flow field, power coefficient, velocity and vorticity contours.

  15. Side by Side

    Science.gov (United States)

    Olson, Cathy Applefeld

    2011-01-01

    Every city, town, and village in America has been affected by the Great Recession, but of course some have felt a bigger impact than others. In Port Angeles, Washington, on the northern edge of the Olympic Peninsula, the latest downturn is just one more twist of the economic vise that's been tightening steadily since at least the mid-'90s. During…

  16. A randomized side-by-side study comparing alexandrite laser at different pulse durations for port wine stains

    DEFF Research Database (Denmark)

    Carlsen, Berit C; Wenande, Emily; Erlendsson, Andres M

    2017-01-01

    hypertrophic (n = 7) PWS were included. Four side-by-side test areas were marked within each lesion. Three test areas were randomized to Alex laser at pulse durations of 3, 5, or 10 ms (8 mm spot, DCD 60/40), while the fourth was untreated. The lowest effective fluence to create purpura within the entire test...... spot was titrated and applied to intervention areas. Standardized clinical photographs were taken prior to, immediately after laser exposure and at 6-8 weeks follow up. Clinical PWS clearance and laser-related side effects were assessed using clinical photos. RESULTS: Alex laser at 3, 5, and 10 ms......BACKGROUND AND OBJECTIVES: Pulsed dye laser (PDL) represents the gold-standard treatment for port wine stains (PWS). However, approximately 20% of patients are poor responders and yield unsatisfactory end-results. The Alexandrite (Alex) laser may be a therapeutic alternative for selected PWS...

  17. Human-Human Interaction Forces and Interlimb Coordination During Side-by-Side Walking With Hand Contact.

    Science.gov (United States)

    Sylos-Labini, Francesca; d'Avella, Andrea; Lacquaniti, Francesco; Ivanenko, Yury

    2018-01-01

    Handholding can naturally occur between two walkers. When people walk side-by-side, either with or without hand contact, they often synchronize their steps. However, despite the importance of haptic interaction in general and the natural use of hand contact between humans during walking, few studies have investigated forces arising from physical interactions. Eight pairs of adult subjects participated in this study. They walked on side-by-side treadmills at 4 km/h independently and with hand contact. Only hand contact-related sensory information was available for unintentional synchronization, while visual and auditory communication was obstructed. Subjects walked at their natural cadences or following a metronome. Limb kinematics, hand contact 3D interaction forces and EMG activity of 12 upper limb muscles were recorded. Overall, unintentional step frequency locking was observed during about 40% of time in 88% of pairs walking with hand contact. On average, the amplitude of contact arm oscillations decreased while the contralateral (free) arm oscillated in the same way as during normal walking. Interestingly, EMG activity of the shoulder muscles of the contact arm did not decrease, and their synergistic pattern remained similar. The amplitude of interaction forces and of trunk oscillations was similar for synchronized and non-synchronized steps, though the synchronized steps were characterized by significantly more regular orientations of interaction forces. Our results further support the notion that gait synchronization during natural walking is common, and that it may occur through interaction forces. Conservation of the proximal muscle activity of the contact (not oscillating) arm is consistent with neural coupling between cervical and lumbosacral pattern generation circuitries ("quadrupedal" arm-leg coordination) during human gait. Overall, the findings suggest that individuals might integrate force interaction cues to communicate and coordinate steps during

  18. Human-Human Interaction Forces and Interlimb Coordination During Side-by-Side Walking With Hand Contact

    Directory of Open Access Journals (Sweden)

    Francesca Sylos-Labini

    2018-03-01

    Full Text Available Handholding can naturally occur between two walkers. When people walk side-by-side, either with or without hand contact, they often synchronize their steps. However, despite the importance of haptic interaction in general and the natural use of hand contact between humans during walking, few studies have investigated forces arising from physical interactions. Eight pairs of adult subjects participated in this study. They walked on side-by-side treadmills at 4 km/h independently and with hand contact. Only hand contact-related sensory information was available for unintentional synchronization, while visual and auditory communication was obstructed. Subjects walked at their natural cadences or following a metronome. Limb kinematics, hand contact 3D interaction forces and EMG activity of 12 upper limb muscles were recorded. Overall, unintentional step frequency locking was observed during about 40% of time in 88% of pairs walking with hand contact. On average, the amplitude of contact arm oscillations decreased while the contralateral (free arm oscillated in the same way as during normal walking. Interestingly, EMG activity of the shoulder muscles of the contact arm did not decrease, and their synergistic pattern remained similar. The amplitude of interaction forces and of trunk oscillations was similar for synchronized and non-synchronized steps, though the synchronized steps were characterized by significantly more regular orientations of interaction forces. Our results further support the notion that gait synchronization during natural walking is common, and that it may occur through interaction forces. Conservation of the proximal muscle activity of the contact (not oscillating arm is consistent with neural coupling between cervical and lumbosacral pattern generation circuitries (“quadrupedal” arm-leg coordination during human gait. Overall, the findings suggest that individuals might integrate force interaction cues to communicate and

  19. Effect of Rotational Speed on the Stability of Two Rotating Side-by-side Circular Cylinders at Low Reynolds Number

    Science.gov (United States)

    Dou, Huashu; Zhang, Shuo; Yang, Hui; Setoguchi, Toshiaki; Kinoue, Yoichi

    2018-04-01

    Flow around two rotating side-by-side circular cylinders of equal diameter D is numerically studied at the Reynolds number 40≤ Re ≤200 and various rotation rate θ i . The incoming flow is assumed to be two-dimensional laminar flow. The governing equations are the incompressible Navier-Stokes equations and solved by the finite volume method (FVM). The ratio of the center-to-center spacing to the cylinder diameter is T/D=2. The objective of the present work is to investigate the effect of rotational speed and Reynolds number on the stability of the flow. The simulation results are compared with the experimental data and a good agreement is achieved. The stability of the flow is analyzed by using the energy gradient theory, which produces the energy gradient function K to identify the region where the flow is the most prone to be destabilized and the degree of the destabilization. Numerical results reveal that K is the most significant at the separated shear layers of the cylinder pair. With Re increases, the length of the wake is shorter and the vortex shedding generally exhibits a symmetrical distribution for θ i < θ crit . It is also shown that the unsteady vortex shedding can be suppressed by rotating the cylinders in the counter-rotating mode.

  20. Bilateral metal stents for hilar biliary obstruction using a 6Fr delivery system: outcomes following bilateral and side-by-side stent deployment.

    Science.gov (United States)

    Law, Ryan; Baron, Todd H

    2013-09-01

    Controversy exists on optimal endoscopic management for palliation of malignant hilar obstruction, with advocates for metal "side-by-side" (SBS) and "stent-in-stent" (SIS) techniques. We sought to evaluate the technical feasibility, efficacy, and outcomes of bilateral biliary self-expanding metal stents (SEMS) for treatment of malignant hilar obstruction using a stent with a 6Fr delivery system. This was a single-center, retrospective review of all patients who underwent bilateral placement of Zilver® biliary SEMS for malignant hilar obstruction from January 2010 to August 2012. Patients underwent endoscopic retrograde cholangiopancreatography with placement of stents using either the SIS or SBS stent techniques. Twenty-four patients (19 men, mean age 63 years) underwent bilateral stenting for malignant hilar obstruction during the study period. Seventeen and seven patients underwent the SBS and SIS technique, respectively. Cholangiocarcinoma (n=14) was the most common cause of hilar obstruction. Initial technical success was achieved in 24/24 (100%) of patients; however, 12 (50%) patients required re-intervention during the study period (median 98 days). Comparison of the SBS and SIS groups revealed no statistical difference with respect to need for re-intervention (P=0.31), successful re-intervention (P=0.60), or procedural length (P=0.89). Use of bilateral Zilver® SEMS in either the SBS or SIS configuration is safe, technically feasible, and effective for drainage of malignant hilar obstruction; however, duration of stent patency and procedure-free survival remain variable.

  1. Side-by-side comparison of analytical techniques; organic acids, total organic carbon, and anions in PWR secondary cycles

    International Nuclear Information System (INIS)

    Hobart, S.A.; Byers, W.A.; Miller, M.R.; Richards, J.; Silva, H.; Palino, G.F.; Wall, P.S.

    1986-01-01

    Total Organic Carbon TOC samples should be analyzed no later than one week after they are taken and they should be stored in a refrigerated condition, if at all possible. It can be inferred that for TOC levels in the range of 50 to 120 ppb, state-of-the-art sampling and analysis techniques can produce results varying by 20 to 50 ppb. Any proposed limits for TOC should be reviewed in that light. Agreement between anion results appeared to improve over the course of the project. Both contractors agree that increased attention and care with sampling and analytical techniques probably accounted for this improvement. Utility personnel can therefore conclude that proper employee training, supervision, and motivation for proper sampling and analysis are critical if accurate anion results are to be obtained. Resonable agreement between calculated and measured values of cation conductivity suggest that both contractors had accurately determined all major anionic species

  2. Side by Side Comparison of Chemical Compounds Generated by Aqueous Pretreatments of Maize Stover, Miscanthus and Sugarcane Bagasse

    NARCIS (Netherlands)

    Gomez, L.D.; Vanholme, R.; Bird, S.; Goeminne, G.; Trindade, L.M.; Polikarpov, I.; Simister, R.; Morreel, K.; Boerjan, W.; McQueen-Mason, S.J.

    2014-01-01

    In order to examine the potential for coproduct generation, we have characterised chemical compounds released by a range of alkaline and acidic aqueous pretreatments as well as the effect of these pretreatments on the saccharification ability of the lignocellulosic material. Comparative experiments

  3. Side-by-Side Comparison of Commonly Used Biomolecules That Differ in Size and Affinity on Tumor Uptake and Internalization

    Science.gov (United States)

    Leelawattanachai, Jeerapond; Kwon, Keon-Woo; Michael, Praveesuda; Ting, Richard; Kim, Ju-Young; Jin, Moonsoo M.

    2015-01-01

    The ability to use a systemically injected agent to image tumor is influenced by tumor characteristics such as permeability and vascularity, and the size, shape, and affinity of the imaging agent. In this study, six different imaging biomolecules, with or without specificity to tumor, were examined for tumor uptake and internalization at the whole body, ex-vivo tissue, and cellular levels: antibodies, antibody fragments (Fab), serum albumin, and streptavidin. The time of peak tumor uptake was dependent solely on the size of molecules, suggesting that molecular size is the major factor that influences tumor uptake by its effect on systemic clearance and diffusion into tumor. Affinity to tumor antigen failed to augment tumor uptake of Fab above non-specific accumulation, which suggests that Fab fragments of typical monoclonal antibodies may fall below an affinity threshold for use as molecular imaging agents. Despite abundant localization into the tumor, albumin and streptavidin were not found on cell surface or inside cells. By comparing biomolecules differing in size and affinity, our study highlights that while pharmacokinetics are a dominant factor in tumor uptake for biomolecules, affinity to tumor antigen is required for tumor binding and internalization. PMID:25901755

  4. Lock-on characteristics behind two side-by-side cylinders of diameter ratio two at small gap ratio

    Science.gov (United States)

    Lee, Petry Y. R.; Lu, Wei-Ting; Chou, Shy-Tsin; Kuo, Cheng-Hsiung

    2012-10-01

    The lock-on characteristics, the detailed interactions and downstream evolutions of the wakes behind side-by-side cylinders of unequal diameter ( D/ d = 2), spaced by a gap ratio 0.75 ( G/ D = 0.75), are investigated at Reynolds number 600 by the dye flow visualization, laser Doppler anemometry (LDA) and particle image velocimeter (PIV) velocity measurements. The lock-on frequency bands are studied by LDA and PIV at Reynolds number 2,000. The D, d and G are the diameters of the large, the small cylinders and the net gap between two cylinders, respectively. Periodic excitations, in form of rotary oscillation about the cylinder center, are applied to the large cylinder with the same amplitude. It is found that while the large cylinder is excited, two lock-on frequency bands of the wake behind the large cylinder are detected. These two lock-on frequency bands correspond to the primary and the one-third sub-harmonic lock-on of the wake behind large cylinder, respectively. These two lock-on frequency bands distribute symmetrically about the fundamental and the third superharmonic of the natural shedding frequency behind a single cylinder at the same Reynolds number. The left-shifted frequency band (1.8 ≤ f e / f os ≤ 2.0) is not considered as a locked-on frequency band because the phase difference between two excitation frequencies across f e / f os = 2.0 vary significantly. While the wake behind the large cylinder is locked-on at f e /3 (or f os ), the gap flow becomes unbiased and the frequency of the wake behind small cylinder remains around the natural shedding frequency. Thus, the frequency band of 3.0 ≤ f e / f os ≤ 3.22 is also not locked-on because the phase difference in the narrow wake excited at f e / f os = 2.93 and 3.07 changes significantly. Note f e and f os denote the excitation frequency and the natural shedding frequency behind a single large cylinder, respectively.

  5. Lock-on characteristics behind two side-by-side cylinders of diameter ratio two at small gap ratio

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Petry Y.R.; Lu, Wei-Ting; Chou, Shy-Tsin; Kuo, Cheng-Hsiung [National Chung Hsing University, Department of Mechanical Engineering, Taichung (China)

    2012-10-15

    The lock-on characteristics, the detailed interactions and downstream evolutions of the wakes behind side-by-side cylinders of unequal diameter (D/d = 2), spaced by a gap ratio 0.75 (G/D = 0.75), are investigated at Reynolds number 600 by the dye flow visualization, laser Doppler anemometry (LDA) and particle image velocimeter (PIV) velocity measurements. The lock-on frequency bands are studied by LDA and PIV at Reynolds number 2,000. The D, d and G are the diameters of the large, the small cylinders and the net gap between two cylinders, respectively. Periodic excitations, in form of rotary oscillation about the cylinder center, are applied to the large cylinder with the same amplitude. It is found that while the large cylinder is excited, two lock-on frequency bands of the wake behind the large cylinder are detected. These two lock-on frequency bands correspond to the primary and the one-third sub-harmonic lock-on of the wake behind large cylinder, respectively. These two lock-on frequency bands distribute symmetrically about the fundamental and the third superharmonic of the natural shedding frequency behind a single cylinder at the same Reynolds number. The left-shifted frequency band (1.8 {<=} f{sub e} /f{sub os} {<=} 2.0) is not considered as a locked-on frequency band because the phase difference between two excitation frequencies across f{sub e} /f{sub os} = 2.0 vary significantly. While the wake behind the large cylinder is locked-on at f{sub e} /3 (or f{sub os}), the gap flow becomes unbiased and the frequency of the wake behind small cylinder remains around the natural shedding frequency. Thus, the frequency band of 3.0 {<=} f{sub e} /f{sub os} {<=} 3.22 is also not locked-on because the phase difference in the narrow wake excited at f{sub e} /f{sub os} = 2.93 and 3.07 changes significantly. Note f{sub e} and f{sub os} denote the excitation frequency and the natural shedding frequency behind a single large cylinder, respectively. (orig.)

  6. Stability and variability of acoustically specified coordination patterns while walking side-by-side on a treadmill: Does the seagull effect hold?

    NARCIS (Netherlands)

    van Ulzen, N.R.; Lamoth, C.J.C.; Daffertshofer, A.; Semin, G.R.; Beek, P.J.

    2010-01-01

    To examine whether the Haken-Kelso-Bunz model for rhythmic interlimb coordination applies to walking side-by-side on a treadmill, we invited six pairs of participants to coordinate their stepping movements at seven prescribed relative phases (between 0° and 180°) to scan the attractor layout

  7. Application of Piezocomposite Twin, Side by Side, Phased Array UT Probes for the Inspection of Stainless Steel

    International Nuclear Information System (INIS)

    Delaide, M.; Dumas, Ph

    2005-01-01

    UT probes to be used for the examination of coarse-grain structure must allow to detect and size cracks, with a high reliability level. The combination of TRL probes, with phased array and piezocomposite technologies allows to improve probes performances and inspection speed. Single element crystals are replaced by matrix arrays, allowing to deflect and skew the beams, to change the inspection depth. This paper describes the designing, the manufacturing and the characterisation of several probes

  8. Molecules and elements for quantitative bioanalysis: The allure of using electrospray, MALDI, and ICP mass spectrometry side-by-side.

    Science.gov (United States)

    Linscheid, Michael W

    2018-03-30

    To understand biological processes, not only reliable identification, but quantification of constituents in biological processes play a pivotal role. This is especially true for the proteome: protein quantification must follow protein identification, since sometimes minute changes in abundance tell the real tale. To obtain quantitative data, many sophisticated strategies using electrospray and MALDI mass spectrometry (MS) have been developed in recent years. All of them have advantages and limitations. Several years ago, we started to work on strategies, which are principally capable to overcome some of these limits. The fundamental idea is to use elemental signals as a measure for quantities. We began by replacing the radioactive 32 P with the "cold" natural 31 P to quantify modified nucleotides and phosphorylated peptides and proteins and later used tagging strategies for quantification of proteins more generally. To do this, we introduced Inductively Coupled Plasma Mass Spectrometry (ICP-MS) into the bioanalytical workflows, allowing not only reliable and sensitive detection but also quantification based on isotope dilution absolute measurements using poly-isotopic elements. The detection capability of ICP-MS becomes particularly attractive with heavy metals. The covalently bound proteins tags developed in our group are based on the well-known DOTA chelate complex (1,4,7,10-tetraazacyclododecane-N,N',N″,N‴-tetraacetic acid) carrying ions of lanthanoides as metal core. In this review, I will outline the development of this mutual assistance between molecular and elemental mass spectrometry and discuss the scope and limitations particularly of peptide and protein quantification. The lanthanoide tags provide low detection limits, but offer multiplexing capabilities due to the number of very similar lanthanoides and their isotopes. With isotope dilution comes previously unknown accuracy. Separation techniques such as electrophoresis and HPLC were used and just

  9. Side-by-side reading of PET and CT scans in oncology: Which patients might profit from integrated PET/CT?

    International Nuclear Information System (INIS)

    Reinartz, Patrick; Wieres, Franz-Josef; Schneider, Wolfram; Schur, Alexander; Buell, Ulrich

    2004-01-01

    Most early publications on integrated positron emission tomography/computed tomography (PET/CT) devices have reported the new scanner generation to be superior to conventional PET. However, few of these studies have analysed the situation where, in addition to PET, a current CT scan is available for side-by-side viewing. This fact is important, because combined PET/CT or a software-based fusion of the two modalities may improve diagnosis only in cases where side-by-side reading of PET and CT data does not lead to a definitive diagnosis. The aim of this study was to analyse which patients will profit from integrated PET/CT in terms of lesion characterization. A total of 328 consecutively admitted patients referred for PET in whom a current CT scan was available were included in the study. The localization of all pathological PET lesions, as well as possible infiltration of adjacent anatomical structures, was assessed. Of 467 pathological lesions, 94.0% were correctly assessed with respect to localization and infiltration by either conventional PET alone (51.6%) or combined reading of PET and the already existing CT scans (42.4%). Hence, in only 6.0% of all lesions, affecting 6.7% of all patients, could evaluation have profited from integrated PET/CT. We conclude that side-by-side viewing of PET and CT scans is essential, as in 42.4% of all cases, combined viewing was important for a correct diagnosis in our series. In up to 6.7% of patients, integrated PET/CT might have given additional information, so that in nearly 50% of patients some form of combined viewing of PET and CT data is needed for accurate lesion characterization. (orig.)

  10. 18FDG-PET in 733 consecutive patients with or without side-by-side CT evaluation. Analysis of 921 lesions

    International Nuclear Information System (INIS)

    Buell, U.; Wieres, F.J.; Schneider, W.; Reinartz, P.

    2004-01-01

    Side-by-side analysis of CT and conventional 18 FDG-PET in oncological imaging is well established. Aim of this study was to find out which patients or diagnostic groups may benefit the most from the newly introduced integrated PET/CT scanners. Patients, methods: 407 consecutively admitted oncological patients with accompanying CT (groups A-D) and 326 patients without CT (groups E-G) were examined by conventional ring PET. Two nuclear medicine physicians and two radiologists assessed each patient's PET and CT scans for pathological lesions with regard to localisation and infiltration of adjacent anatomical structures. Patients without pathological PET findings were assigned to groups A (with CT) or E (without CT). If the localisation and/or extent of a pathological PET focus could only be assessed by taking into account the CT scan, the patient was assigned to group C (with CT) or G (without CT). If PET alone was sufficient for both questions the patient was assigned to groups B (with CT) or F (without CT). If neither method allowed for a precise lesion characterisation, the patient was assigned to group D. Results: 38.6% (A, E) of all patients were PET-negative. PET alone sufficed in 20.6% (B, F). Side-by-side reading of PET and CT was needed for 43.5% (C) of patients referred to PET with a current CT. Side-by-side reading of CT and PET did not suffice for 7.3% (D) of patients in that cohort. A total of 28.2% (G) of the cases without CT would have profited from it. The most frequent oncological diagnoses in group D (PET and conventional CT not sufficient) were bronchial carcinoma with abdominal lesions, while in group G (without CT but CT required) head/neck cancer with thoracic lesions was predominant. Conclusions: Side-by-side reading of PET and already existing conventional CT failed to yield conclusive data with regard to lesion characterisation in only 7.4% of patients so that PET/CT might have been helpful in these cases. 28.2% of the patients without

  11. Pulsed dye laser vs. intense pulsed light for port-wine stains: a randomized side-by-side trial with blinded response evaluation

    DEFF Research Database (Denmark)

    Faurschou, A; Togsverd-Bo, K; Zachariae, C

    2009-01-01

    Corporation, Wayland, MA, U.S.A.) and IPL (StarLux, Lux G prototype handpiece, 500-670 and 870-1400 nm, 5-10 ms; Palomar Medical Technologies, Burlington, MA, U.S.A.). Settings depended on the preoperative lesional colour. Treatment outcome was evaluated by blinded, clinical evaluations and by skin......: To compare efficacy and adverse events of PDL and IPL in an intraindividual randomized clinical trial. METHODS: Twenty patients with PWS (face, trunk, extremities; pink, red and purple colours; skin types I-III) received one side-by-side treatment with PDL (V-beam Perfecta, 595 nm, 0.45-1.5 ms; Candela Laser...

  12. Interprofessional immersion: Use of interprofessional education collaborative competencies in side-by-side training of family medicine, pharmacy, nursing, and counselling psychology trainees.

    Science.gov (United States)

    Boland, Daubney Harper; Scott, Mary Alice; Kim, Helen; White, Traci; Adams, Eve

    2016-11-01

    While supported by the Affordable Care Act, in the United States, interprofessional training often takes place after healthcare providers graduate and are practicing in the field. This article describes the implementation and evaluation of an interprofessional training for graduate-level healthcare trainees. A group of interprofessional healthcare faculty provided a weeklong interprofessional immersion for doctoral-level healthcare trainees (n = 24) in Pharmacy, Counselling Psychology, Nursing, and Family Medicine residents. Healthcare faculty and staff from each profession worked side-by-side to provide integrated training utilising the Interprofessional Education Collaborative core competency domains. Trainees were placed into small teams with representatives from each profession; each team observed, learned, and practiced working within teams to provide quality patient care. Qualitative and quantitative data were collected to identify the effect of the training on trainees' self-reported team skills, as well as the extent to which the trainees learned and utilised the competencies. The results suggest that after completing the training, trainees felt more confident in their ability to work within an interprofessional team and more likely to utilise a team-based approach in the future.

  13. EMLA cream does not influence efficacy and pain reduction during pulsed-dye laser treatment of port-wine stain: a prospective side-by-side comparison.

    Science.gov (United States)

    Yu, Wenxin; Wang, Tianyou; Zhu, Jiafang; Qiu, Yajing; Chen, Hui; Jin, Yunbo; Yang, Xi; Hu, Xiaojie; Chang, Lei; Chen, Yijie; Ma, Gang; Lin, Xiaoxi

    2018-04-01

    EMLA cream was developed to reduce pain during pulsed-dye laser (PDL) treatment; however, no standard assessment for the therapeutic outcomes of PDL with EMLA creams thus far available. This comparative, prospective clinical trial evaluates laser efficacy and pain reduction during PDL treatment with EMLA cream for local topical anesthesia. Nineteen patients with untreated port-wine stain (PWS) were treated using PDL and examined in this study. Treatment specifications included Vbeam® PDL (Candela Corp.), 595-nm wavelength, 9 J/cm 2 radiant exposure, 0.45 ms pulse duration, 10 mm spot size, and cryogen spray cooling (40 ms cooling plus a 20 ms delay). A topical anesthetic (EMLA cream: 2.5% lidocaine and 2.5% prilocaine) and a placebo were applied to two respective testing areas on all patients prior to treatment. The visual analog scale (VAS) was used for pain assessment. Clinical therapeutic outcomes were evaluated by visual evaluation and with the use of a chromameter 2 months after 3PDL treatments. The average VAS scores were 3.15 ± 0.95 and 8 ± 0.57 for the EMLA cream site and the placebo site, respectively, at a significance level p < 0.001. The EMLA cream site and the placebo site had clearance or fading rates of 45.08 and 44.12%, respectively (p < 0.05). No serious side effects were reported. Patients reported a consistent decrease in pain during PDL treatment when the topical anesthetic EMLA cream was administered. Treatment of PWS by PDL with EMLA cream does not lead to a decrease in efficacy or an increase in side effects; instead, it significantly reduces pain during treatment. EMLA cream is a safe and effective local topical anesthetic for PWS treatment by PDL.

  14. Comparison and correction of the light sensor output from 48 wearable light exposure devices by using a side-by-side field calibration method

    DEFF Research Database (Denmark)

    Markvart, Jakob; Hansen, Åse Marie; Christoffersen, Jens

    2015-01-01

    Measurement of personal light exposures and activity has gained popularity in studies of the circadian rhythm and its effects on human health. Calibration of a batch of measuring devices may be needed, especially before initiating interventional studies, but manufactory calibration of devices...... illuminance only to a minor degree and light source-specific calibration may therefore be needed in some cases. Moreover, light responses were found to vary between devices by up to 60%. Implications are that the results of light effects on health issues in studies using Actiwatches are blurred...

  15. Java/JNI/C/Fortran makefile project for a Java plug-in and related Android app in Eclipse ADT bundle : A side-by-side comparison

    NARCIS (Netherlands)

    De Beer, R.; Van Ormondt, D.

    2015-01-01

    We have developed a Java/Fortran based application, called MonteCarlo, that enables the users can carry out Monte Carlo studies in the field of in vivo MRS. The application is supposed to be used as a tool for the jMRUI platform, being the in vivo MRS software system of the TRANSACT European Union

  16. WIA Reauthorization Recommendations [and] Side-by-Side Comparison of Title I Provisions in Recent WIA Reauthorization Proposals (June 25, 2003 Update).

    Science.gov (United States)

    Patel, Nisha; Strawn, Julie; Greenberg, Mark

    This publication on reauthorization recommendations for the Workforce Investment Act of 1998 (WIA) comprises three documents. The first is a short summary of reauthorization recommendations for Title I and II. Title I recommendations are to eliminate sequential eligibility; promote greater access to training; improve adjustment of performance…

  17. A side-by-side comparison of two systems of sequencing coupled reactors for anaerobic digestion of the organic fraction of municipal solid waste.

    Science.gov (United States)

    Poggi-Varaldo, Héctor M; Alzate-Gaviria, Liliana M; Pérez-Hernández, Antonino; Nevarez-Morillón, Virginia G; Rinderknecht-Seijas, Noemí

    2005-06-01

    The objective of this work was to compare the performance of two laboratory-scale, mesophilic systems aiming at the anaerobic digestion of the organic fraction of municipal solid wastes (OFMSW). The first system consisted of two coupled reactors packed with OFMSW (PBR1.1-PBR1.2) and the second system consisted of an upflow anaerobic sludge bed reactor (UASB) coupled to a packed reactor (UASB2.1-PBR2.2). For the start-up phase, both reactors PBR 1.1 and the UASB 2.1 (also called leading reactors) were inoculated with a mixture of non-anaerobic inocula and worked with leachate and effluent full recirculation, respectively. Once a full methanogenic regime was achieved in the leading reactors, their effluents were fed to the fresh-packed reactors PBR1.2 and PBR2.2, respectively. The leading PBR 1.1 reached its full methanogenic regime after 118 days (Tm, time to achieve methanogenesis) whereas the other leading UASB 2.1 reactor reached its full methanogenesis regime after only 34 days. After coupling the leading reactors to the corresponding packed reactors, it was found that both coupled anaerobic systems showed similar performances regarding the degradation of the OFMSW. Removal efficiencies of volatile solids and cellulose and the methane pseudo-yield were 85.95%, 80.88% and 0.109 NL CH4 g(-1) VS(fed) in the PBR-PBR system; and 88.75%, 82.61% and 0.115 NL CH4 g(-1) VS(fed0 in the UASB-PBR system [NL, normalized litre (273 degrees K, 1 ata basis)]. Yet, the second system UASB-PBR system showed a faster overall start-up.

  18. Single-step simultaneous side-by-side placement of a self-expandable metallic stent with a 6-Fr delivery system for unresectable malignant hilar biliary obstruction: a feasibility study.

    Science.gov (United States)

    Kawakubo, Kazumichi; Kawakami, Hiroshi; Kuwatani, Masaki; Kudo, Taiki; Abe, Yoko; Kawahata, Shuhei; Kubo, Kimitoshi; Kubota, Yoshimasa; Sakamoto, Naoya

    2015-02-01

    Bilateral self-expandable metallic stent (SEMS) placement for the management of unresectable malignant hilar biliary obstruction (UMHBO) is technically challenging to perform using the existing metallic stents with thick delivery systems. The recently developed 6-Fr delivery systems could facilitate a single-step simultaneous side-by-side placement through the accessory channel of the duodenoscope. The aim of this study was to evaluate the feasibility of this procedure. Between May and September 2013, 13 consecutive patients with UMHBO underwent a single-step simultaneous side-by-side placement of SEMS with the 6-Fr delivery system. The technical success rate, stent patency, and rate of complications were evaluated from the prospectively collected database. Technical success was achieved in 11 (84.6%, 95% confidence interval [CI]: 57.8-95.8) patients. The median procedure time was 25 min. Early and late complications were observed in 23% (one segmental cholangitis and two liver abscesses) and 15% (one segmental cholangitis and one cholecystitis) patients, respectively. Median dysfunction free patency was 263 days (95% CI: 37-263). Five patients (38%) experienced stent occlusion that was successfully managed by endoscopic stent placement. A single-step simultaneous side-by-side placement of SEMS with a 6-Fr delivery system was feasible for the management of UMHBO. © 2014 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  19. Value of image fusion using single photon emission computed tomography with integrated low dose computed tomography in comparison with a retrospective voxel-based method in neuroendocrine tumours

    International Nuclear Information System (INIS)

    Amthauer, H.; Denecke, T.; Ruf, J.; Gutberlet, M.; Felix, R.; Lemke, A.J.; Rohlfing, T.; Boehmig, M.; Ploeckinger, U.

    2005-01-01

    The objective was the evaluation of single photon emission computed tomography (SPECT) with integrated low dose computed tomography (CT) in comparison with a retrospective fusion of SPECT and high-resolution CT and a side-by-side analysis for lesion localisation in patients with neuroendocrine tumours. Twenty-seven patients were examined by multidetector CT. Additionally, as part of somatostatin receptor scintigraphy (SRS), an integrated SPECT-CT was performed. SPECT and CT data were fused using software with a registration algorithm based on normalised mutual information. The reliability of the topographic assignment of lesions in SPECT-CT, retrospective fusion and side-by-side analysis was evaluated by two blinded readers. Two patients were not enrolled in the final analysis because of misregistrations in the retrospective fusion. Eighty-seven foci were included in the analysis. For the anatomical assignment of foci, SPECT-CT and retrospective fusion revealed overall accuracies of 91 and 94% (side-by-side analysis 86%). The correct identification of foci as lymph node manifestations (n=25) was more accurate by retrospective fusion (88%) than from SPECT-CT images (76%) or by side-by-side analysis (60%). Both modalities of image fusion appear to be well suited for the localisation of SRS foci and are superior to side-by-side analysis of non-fused images especially concerning lymph node manifestations. (orig.)

  20. Diagnosis and Treatment of Osteoporosis Before and After Fracture: A Side-by-Side Analysis of Commercially Insured and Medicare Advantage Osteoporosis Patients.

    Science.gov (United States)

    Weaver, Jessica; Sajjan, Shiva; Lewiecki, E Michael; Harris, Steven T

    2017-07-01

    Although treatment for osteoporosis is recommended by U.S. clinical guidelines, a lack of diagnosis and treatment is common among patients with osteoporotic fractures. To determine the rates of osteoporosis diagnosis and treatment before and after various types of fractures. This was a retrospective claims analysis using data from the Humana Medicare Advantage claims (Medicare group) and Optum Insight Clinformatics Data Mart commercial claims (Commercial group). Patients included in the study had a claim for a qualifying fracture occurring between January 2008 and December 2013 (the index fracture), were continuously enrolled in the health plan for ≥ 1 year before and after the index fracture, and were aged ≥ 65 years in the Medicare group or ≥ 50 years in the Commercial group at the time of the index fracture. Fragility fractures and osteoporosis diagnoses were identified from ICD-9-CM codes. Treatment for osteoporosis included oral and injectable therapies identified by National Drug Code numbers and Healthcare Common Procedure Coding System codes. Diagnosis and treatment rates were assessed during the 1-year periods before and after the index fracture. All analyses were conducted by fracture type (vertebral, hip, nonhip/nonvertebral [NHNV], and multiple), with stratification by age and sex. No comparisons were made between the Medicare and Commercial groups; rather, McNemar tests were used to compare prefracture versus postfracture diagnosis and treatment rates within each group. For inclusion in the Medicare group, 45,603 patients were identified, and 54,145 patients were identified for the Commercial group. In the prefracture period, the osteoporosis diagnosis rates ranged from 12.0% (NHNV) to 21.5% (vertebral) in the Medicare group and from 5.3% (NHNV) to 12.1% (vertebral) in the Commercial group. In the postfracture period, diagnosis rates significantly increased (P types but did not exceed 42.1% (vertebral) in the Medicare group and 27.7% (vertebral

  1. Exploration of reliability databases and comparison of former IFMIF's results

    International Nuclear Information System (INIS)

    Tapia, Carlos; Dies, Javier; Abal, Javier; Ibarra, Angel; Arroyo, Jose M.

    2011-01-01

    There is an uncertainty issue about the applicability of industrial databases to new designs, such as the International Fusion Materials Irradiation Facility (IFMIF), as they usually contain elements for which no historical statistics exist. The exploration of common components reliability data in Accelerator Driven Systems (ADS) and Liquid Metal Technologies (LMT) frameworks is the milestone to analyze the data used in IFMIF reliability's reports and for future studies. The comparison between the reliability accelerator results given in the former IFMIF's reports and the databases explored has been made by means of a new accelerator Reliability, Availability, Maintainability (RAM) analysis. The reliability database used in this analysis is traceable.

  2. In Vivo Investigation of the Safety and Efficacy of Pulsed Dye Laser with Two Spot Sizes in Port-Wine Stain Treatment: A Prospective Side-by-Side Comparison.

    Science.gov (United States)

    Yu, Wenxin; Ying, Hanru; Chen, Yijie; Qiu, Yajing; Chen, Hui; Jin, Yunbo; Yang, Xi; Wang, Tianyou; Ma, Gang; Lin, Xiaoxi

    2017-09-01

    Pulsed dye laser (PDL) with 7 and 10 mm spot sizes is widely used on a regular basis for the treatment of port-wine stain (PWS). No studies have reported on the differences in efficacy outcomes resulting from the use of different laser spot sizes in the treatment of PWS by PDL. Thus, an in vivo investigation into the differences in safety and efficacy of treatment between two spot sizes (7 vs. 10 mm) of PWS by PDL was conducted. A total of 35 PWS patients underwent three treatment sessions by using a 595 nm wavelength PDL (Vbeam ® , Candela Corp) with two laser settings: (1) 7 mm spot size, radiant exposure of 12 J/cm 2 and (2) 10 mm spot size, radiant exposure of 10 J/cm 2 . Cryogen spray cooling and 1.5 msec pulse duration were applied. Therapeutic outcomes were evaluated by visual and chromametric evaluation 3 months after the final treatment. Average blanching rates were 34.03% and 36.51% at sites treated by PDL with 7 and 10 mm laser spot sizes, respectively (p spot sizes were similar. PDL with a 10 mm laser spot size is more efficacious with lower radiant exposure than PDL with a 7 mm spot size; it can also reduce the treatment time.

  3. On the Reliability of Unit Value Ratios in International Comparisons

    NARCIS (Netherlands)

    Timmer, Marcel P.

    1996-01-01

    In this paper reliability indicators are developed for the Laspeyres and Paasche index type currency conversion factors used in the industry of origin approach to international comparisons of output. Given the fact that these conversion factors are calculated on basis of a sampling technique,

  4. Reliability

    OpenAIRE

    Condon, David; Revelle, William

    2017-01-01

    Separating the signal in a test from the irrelevant noise is a challenge for all measurement. Low test reliability limits test validity, attenuates important relationships, and can lead to regression artifacts. Multiple approaches to the assessment and improvement of reliability are discussed. The advantages and disadvantages of several different approaches to reliability are considered. Practical advice on how to assess reliability using open source software is provided.

  5. Comparison of reliability of lateral cephalogram and computed ...

    African Journals Online (AJOL)

    2014-05-07

    May 7, 2014 ... measurements acquired from both the modalities are reliable and reproducible, but .... paint on all the slice of the image stack in the axial plane of ..... between body mass index, age and upper airway measurements in snorers.

  6. Comparison of reliability of lateral cephalogram and computed ...

    African Journals Online (AJOL)

    of malocclusion and airway space using lateral cephalogram and computed tomography (CT) and to compare its reliability. To obtain important information on the morphology of the soft palate on lateral cephalogram and to determine its etiopathogenesis in obstructive sleep apnea (OSA). Materials and Methods: Lateral ...

  7. Comparison of Methods for Dependency Determination between Human Failure Events within Human Reliability Analysis

    International Nuclear Information System (INIS)

    Cepin, M.

    2008-01-01

    The human reliability analysis (HRA) is a highly subjective evaluation of human performance, which is an input for probabilistic safety assessment, which deals with many parameters of high uncertainty. The objective of this paper is to show that subjectivism can have a large impact on human reliability results and consequently on probabilistic safety assessment results and applications. The objective is to identify the key features, which may decrease subjectivity of human reliability analysis. Human reliability methods are compared with focus on dependency comparison between Institute Jozef Stefan human reliability analysis (IJS-HRA) and standardized plant analysis risk human reliability analysis (SPAR-H). Results show large differences in the calculated human error probabilities for the same events within the same probabilistic safety assessment, which are the consequence of subjectivity. The subjectivity can be reduced by development of more detailed guidelines for human reliability analysis with many practical examples for all steps of the process of evaluation of human performance

  8. Comparison of methods for dependency determination between human failure events within human reliability analysis

    International Nuclear Information System (INIS)

    Cepis, M.

    2007-01-01

    The Human Reliability Analysis (HRA) is a highly subjective evaluation of human performance, which is an input for probabilistic safety assessment, which deals with many parameters of high uncertainty. The objective of this paper is to show that subjectivism can have a large impact on human reliability results and consequently on probabilistic safety assessment results and applications. The objective is to identify the key features, which may decrease of subjectivity of human reliability analysis. Human reliability methods are compared with focus on dependency comparison between Institute Jozef Stefan - Human Reliability Analysis (IJS-HRA) and Standardized Plant Analysis Risk Human Reliability Analysis (SPAR-H). Results show large differences in the calculated human error probabilities for the same events within the same probabilistic safety assessment, which are the consequence of subjectivity. The subjectivity can be reduced by development of more detailed guidelines for human reliability analysis with many practical examples for all steps of the process of evaluation of human performance. (author)

  9. Advances in ranking and selection, multiple comparisons, and reliability methodology and applications

    CERN Document Server

    Balakrishnan, N; Nagaraja, HN

    2007-01-01

    S. Panchapakesan has made significant contributions to ranking and selection and has published in many other areas of statistics, including order statistics, reliability theory, stochastic inequalities, and inference. Written in his honor, the twenty invited articles in this volume reflect recent advances in these areas and form a tribute to Panchapakesan's influence and impact on these areas. Thematically organized, the chapters cover a broad range of topics from: Inference; Ranking and Selection; Multiple Comparisons and Tests; Agreement Assessment; Reliability; and Biostatistics. Featuring

  10. Examiner Reliability of Fluorosis Scoring: A Comparison of Photographic and Clinical Examination Findings

    Science.gov (United States)

    Cruz-Orcutt, Noemi; Warren, John J.; Broffitt, Barbara; Levy, Steven M.; Weber-Gasparoni, Karin

    2012-01-01

    Objective To assess and compare examiner reliability of clinical and photographic fluorosis examinations using the Fluorosis Risk Index (FRI) among children in the Iowa Fluoride Study (IFS). Methods The IFS examined 538 children for fluorosis and dental caries at age 13 and obtained intra-oral photographs from nearly all of them. To assess examiner reliability, duplicate clinical examinations were conducted for 40 of the subjects. In addition, 200 of the photographs were scored independently for fluorosis by two examiners in a standardized manner. Fluorosis data were compared between examiners for the clinical exams and separately for the photographic exams, and a comparison was made between clinical and photographic exams. For all 3 comparisons, examiner reliability was assessed using kappa statistics at the tooth level. Results Inter-examiner reliability for the duplicate clinical exams on the sample of 40 subjects as measured by kappa was 0.59, while the repeat exams of the 200 photographs yielded a kappa of 0.64. For the comparison of photographic and clinical exams, inter-examiner reliability, as measured by weighted kappa, was 0.46. FRI scores obtained using the photographs were higher on average than those obtained from the clinical exams. Fluorosis prevalence was higher for photographs (33%) than found for clinical exam (18%). Conclusion Results suggest inter-examiner reliability is greater and fluorosis scores higher when using photographic compared to clinical examinations. PMID:22316120

  11. Inter comparison of REPAS and APSRA methodologies for passive system reliability analysis

    International Nuclear Information System (INIS)

    Solanki, R.B.; Krishnamurthy, P.R.; Singh, Suneet; Varde, P.V.; Verma, A.K.

    2014-01-01

    The increasing use of passive systems in the innovative nuclear reactors puts demand on the estimation of the reliability assessment of these passive systems. The passive systems operate on the driving forces such as natural circulation, gravity, internal stored energy etc. which are moderately weaker than that of active components. Hence, phenomenological failures (virtual components) are equally important as that of equipment failures (real components) in the evaluation of passive systems reliability. The contribution of the mechanical components to the passive system reliability can be evaluated in a classical way using the available component reliability database and well known methods. On the other hand, different methods are required to evaluate the reliability of processes like thermohydraulics due to lack of adequate failure data. The research is ongoing worldwide on the reliability assessment of the passive systems and their integration into PSA, however consensus is not reached. Two of the most widely used methods are Reliability Evaluation of Passive Systems (REPAS) and Assessment of Passive System Reliability (APSRA). Both these methods characterize the uncertainties involved in the design and process parameters governing the function of the passive system. However, these methods differ in the quantification of passive system reliability. Inter comparison among different available methods provides useful insights into the strength and weakness of different methods. This paper highlights the results of the thermal hydraulic analysis of a typical passive isolation condenser system carried out using RELAP mode 3.2 computer code applying REPAS and APSRA methodologies. The failure surface is established for the passive system under consideration and system reliability has also been evaluated using these methods. Challenges involved in passive system reliabilities are identified, which require further attention in order to overcome the shortcomings of these

  12. Evaluating the reliability of uranium concentration and isotope ratio measurements via an interlaboratory comparison program

    International Nuclear Information System (INIS)

    Oliveira Junior, Olivio Pereira de; Oliveira, Inez Cristina de; Pereira, Marcia Regina; Tanabe, Eduardo

    2009-01-01

    The nuclear fuel cycle is a strategic area for the Brazilian development because it is associated with the generation of electricity needed to boost the country economy. Uranium is one the chemical elements in this cycle and its concentration and isotope composition must be accurately known. In this present work, the reliability of the uranium concentration and isotope ratio measurements carried out at the CTMSP analytical laboratories is evaluated by the results obtained in an international interlaboratory comparison program. (author)

  13. A methodological comparison of customer service analysis techniques

    Science.gov (United States)

    James Absher; Alan Graefe; Robert Burns

    2003-01-01

    Techniques used to analyze customer service data need to be studied. Two primary analysis protocols, importance-performance analysis (IP) and gap score analysis (GA), are compared in a side-by-side comparison using data from two major customer service research projects. A central concern is what, if any, conclusion might be different due solely to the analysis...

  14. A Comparison of Three Methods for the Analysis of Skin Flap Viability: Reliability and Validity.

    Science.gov (United States)

    Tim, Carla Roberta; Martignago, Cintia Cristina Santi; da Silva, Viviane Ribeiro; Dos Santos, Estefany Camila Bonfim; Vieira, Fabiana Nascimento; Parizotto, Nivaldo Antonio; Liebano, Richard Eloin

    2018-05-01

    Objective: Technological advances have provided new alternatives to the analysis of skin flap viability in animal models; however, the interrater validity and reliability of these techniques have yet to be analyzed. The present study aimed to evaluate the interrater validity and reliability of three different methods: weight of paper template (WPT), paper template area (PTA), and photographic analysis. Approach: Sixteen male Wistar rats had their cranially based dorsal skin flap elevated. On the seventh postoperative day, the viable tissue area and the necrotic area of the skin flap were recorded using the paper template method and photo image. The evaluation of the percentage of viable tissue was performed using three methods, simultaneously and independently by two raters. The analysis of interrater reliability and viability was performed using the intraclass correlation coefficient and Bland Altman Plot Analysis was used to visualize the presence or absence of systematic bias in the evaluations of data validity. Results: The results showed that interrater reliability for WPT, measurement of PTA, and photographic analysis were 0.995, 0.990, and 0.982, respectively. For data validity, a correlation >0.90 was observed for all comparisons made between the three methods. In addition, Bland Altman Plot Analysis showed agreement between the comparisons of the methods and the presence of systematic bias was not observed. Innovation: Digital methods are an excellent choice for assessing skin flap viability; moreover, they make data use and storage easier. Conclusion: Independently from the method used, the interrater reliability and validity proved to be excellent for the analysis of skin flaps' viability.

  15. Comparison of sample preparation methods for reliable plutonium and neptunium urinalysis using automatic extraction chromatography

    DEFF Research Database (Denmark)

    Qiao, Jixin; Xu, Yihong; Hou, Xiaolin

    2014-01-01

    This paper describes improvement and comparison of analytical methods for simultaneous determination of trace-level plutonium and neptunium in urine samples by inductively coupled plasma mass spectrometry (ICP-MS). Four sample pre-concentration techniques, including calcium phosphate, iron......), it endows urinalysis methods with better reliability and repeatability compared with co-precipitation techniques. In view of the applicability of different pre-concentration techniques proposed previously in the literature, the main challenge behind relevant method development is pointed to be the release...

  16. Analyzing the reliability of volcanic and archeomagnetic data by comparison with historical records

    Science.gov (United States)

    Arneitz, Patrick; Egli, Ramon; Leonhardt, Roman

    2017-04-01

    Records of the past geomagnetic field are obtained from historical observations (direct records) on the one hand, and by the magnetization acquired by archeological artifacts, rocks and sediments (indirect records) on the other hand. Indirect records are generally less reliable than direct ones due to recording mechanisms that cannot be fully reproduced in the laboratory, age uncertainties and alteration problems. Therefore, geomagnetic field modeling approaches must deal with random and systematic errors of field values and age estimates that are hard to assess. Here, we present a new approach to investigate the reliability of volcanic and archeomagnetic data, which is based on comparisons with historical records. Temporal and spatial mismatches between data are handled by the implementation of weighting functions and error estimates derived from a stochastic model of secular variation. Furthermore, a new strategy is introduced for the statistical analysis of inhomogeneous and internally correlated data sets. Application of these new analysis tools to an extended database including direct and indirect records shows an overall good agreement between different record categories. Nevertheless, some biases exist between selected material categories, laboratory procedures, and quality checks/corrections (e.g., inclination shallowing of volcanic records). These findings can be used to obtain a better understanding of error sources affecting indirect records, thereby facilitating more reliable reconstructions of the geomagnetic past.

  17. A comparison between fault tree analysis and reliability graph with general gates

    International Nuclear Information System (INIS)

    Kim, Man Cheol; Seong, Poong Hyun; Jung, Woo Sik

    2004-01-01

    Currently, level-1 probabilistic safety assessment (PSA) is performed on the basis of event tree analysis and fault tree analysis. Kim and Seong developed a new method for system reliability analysis named reliability graph with general gates (RGGG). The RGGG is an extension of conventional reliability graph, and it utilizes the transformation of system structures to equivalent Bayesian networks for quantitative calculation. The RGGG is considered to be intuitive and easy-to-use while as powerful as fault tree analysis. As an example, Kim and Seong already showed that the Bayesian network model for digital plant protection system (DPPS), which is transformed from the RGGG model for DPPS, can be shown in 1 page, while the fault tree model for DPPS consists of 64 pages of fault trees. Kim and Seong also insisted that Bayesian network model for DPPS is more intuitive because the one-to-one matching between each node in the Bayesian network model and an actual component of DPPS is possible. In this paper, we are going to give a comparison between fault tree analysis and the RGGG method with two example systems. The two example systems are the recirculation of in Korean standard nuclear power plants (KSNP) and the fault tree model developed by Rauzy

  18. reliability reliability

    African Journals Online (AJOL)

    eobe

    Corresponding author, Tel: +234-703. RELIABILITY .... V , , given by the code of practice. However, checks must .... an optimization procedure over the failure domain F corresponding .... of Concrete Members based on Utility Theory,. Technical ...

  19. Reliability and comparison of acromion assessment techniques on x-ray and magnetic resonance imaging (reliability of acromion assessment techniques)

    International Nuclear Information System (INIS)

    Viskontas, D.G.; MacDermid, J.C.; Drosdowech, D.S.; Garvin, G.J.; Romano, W.M.; Faber, K.J.

    2005-01-01

    To determine the reliability and correlation of plain radiography and magnetic resonance imaging (MRI) in the assessment of acromion morphology. Materials and Methods: Acromion morphology was assessed using the lateral acromion angle (LAA) and the acromion-humeral interval (AHI). Thirty patients who had x-rays and MRI for impingement syndrome were included. Six blinded observers assessed the acromion morphology subjectively and objectively. Results: Neither acromion assessment technique demonstrated a positive correlation (kappa and intraclass coefficient 0.55) when measured objectively by experienced observers. Conclusion: The LAA and the AHI are both reliable acromion assessment techniques on X-ray and MRI when measured objectively and by experienced observers. (author)

  20. Comparison of cellulosic ethanol yields from midwestern maize and reconstructed tallgrass prairie systems managed for bioenergy

    Science.gov (United States)

    Maize- and prairie-based systems were investigated as cellulosic feedstocks by conducting a 9 ha side-by-side comparison on fertile soils in the Midwestern United States. Maize was grown continuously with adequate fertilization over years both with and without a winter rye cover crop, and the 31-spe...

  1. Inspection reliability comparison of digital radiography, film radiography and radioscopy for inspection of Inconel welds

    International Nuclear Information System (INIS)

    Meade, W.; Kidwell, C.; Warren, G.

    2004-01-01

    Digital Radiography offers the promise of economic and environmental advantages over traditional film based inspection. Boeing Commercial Aircraft Group has an on-going effort to evaluate this emerging radiographic method for production of aerospace hardware. Included in this effort was a program to evaluate the potential for utilizing amorphous silicon based digital radiography for the inspection of inconel weldments in engine ducting. For this particular program, probability of detection (POD) studies were conducted to compare the reliability of digital radiography with the existing production processes that utilize film radiography and image-intensifier based radioscopy. Cycle time studies were also conducted to determine the potential economic benefit for switching to the new process. The methodology and findings of this comparison are presented. (author)

  2. Inspection reliability comparison of digital radiography, film radiography and radioscopy for inspection of Inconel welds

    Energy Technology Data Exchange (ETDEWEB)

    Meade, W.; Kidwell, C.; Warren, G. [Boeing Commercial Aircraft Group, Renton, Washington (United States)

    2004-07-01

    Digital Radiography offers the promise of economic and environmental advantages over traditional film based inspection. Boeing Commercial Aircraft Group has an on-going effort to evaluate this emerging radiographic method for production of aerospace hardware. Included in this effort was a program to evaluate the potential for utilizing amorphous silicon based digital radiography for the inspection of inconel weldments in engine ducting. For this particular program, probability of detection (POD) studies were conducted to compare the reliability of digital radiography with the existing production processes that utilize film radiography and image-intensifier based radioscopy. Cycle time studies were also conducted to determine the potential economic benefit for switching to the new process. The methodology and findings of this comparison are presented. (author)

  3. Reliable classification of facial phenotypic variation in craniofacial microsomia: a comparison of physical exam and photographs.

    Science.gov (United States)

    Birgfeld, Craig B; Heike, Carrie L; Saltzman, Babette S; Leroux, Brian G; Evans, Kelly N; Luquetti, Daniela V

    2016-03-31

    Craniofacial microsomia is a common congenital condition for which children receive longitudinal, multidisciplinary team care. However, little is known about the etiology of craniofacial microsomia and few outcome studies have been published. In order to facilitate large, multicenter studies in craniofacial microsomia, we assessed the reliability of phenotypic classification based on photographs by comparison with direct physical examination. Thirty-nine children with craniofacial microsomia underwent a physical examination and photographs according to a standardized protocol. Three clinicians completed ratings during the physical examination and, at least a month later, using respective photographs for each participant. We used descriptive statistics for participant characteristics and intraclass correlation coefficients (ICCs) to assess reliability. The agreement between ratings on photographs and physical exam was greater than 80 % for all 15 categories included in the analysis. The ICC estimates were higher than 0.6 for most features. Features with the highest ICC included: presence of epibulbar dermoids, ear abnormalities, and colobomas (ICC 0.85, 0.81, and 0.80, respectively). Orbital size, presence of pits, tongue abnormalities, and strabismus had the lowest ICC, values (0.17 or less). There was not a strong tendency for either type of rating, physical exam or photograph, to be more likely to designate a feature as abnormal. The agreement between photographs and physical exam regarding the presence of a prior surgery was greater than 90 % for most features. Our results suggest that categorization of facial phenotype in children with CFM based on photographs is reliable relative to physical examination for most facial features.

  4. Coaching Side by Side: One-on-One Collaboration Creates Caring, Connected Teachers

    Science.gov (United States)

    Akhavan, Nancy

    2015-01-01

    This article describes a school district administrator's research on optimal coaching experiences for classroom teachers. This research was done with the intent of gaining a better understanding of how coaching affects student learning. The author defines coaching as the assistance given to a teacher to improve on teaching practices in order to…

  5. Moon Zoo: Educating side-by-side with Doing Science (Invited)

    Science.gov (United States)

    Gay, P. L.; Moon Zoo Team

    2010-12-01

    The Moon Zoo citizen science project (http://www.moonzoo.org) engages individuals - primarily members of the public - in identifying geological (and sometimes technological) features on the lunar surface. Using a flash-based interface that runs in a web browser, users can mark craters, linear features, and even left-behind lunar landers on Lunar Reconnaissance Orbiter images. These science tools are embedded in an environment designed to encourage learning and collaboration. On the main Moon Zoo site users can explore educational content, including video tutorials, articles, glossary terms, and flash interactive activities. Additionally, there is a blog and a forum to encourage collaboration and social learning, and a twitter feed for general communications. Through this suite of software Moon Zoo users can contribute to science while learning about the Moon and geology. The Moon Zoo educational content is designed with one purpose in mind: To make sure that a curious user can find information quickly, easily, and on (or within 1-click of) the Moon Zoo site. The Internet is filled with many excellent lunar educational products, and many high-quality digital products exist in offline archives. Finding desired resources, however, can sometimes be a challenge even for professional educators. In order to make finding content easier, we developed a glossary list and a basic concept map for our website that addresses geology, lunar exploration, observing, and the moon in history and culture, and then we populated these terms and concepts with already available materials. We also do things in a way that encourages both doing science tasks and learning at the same time! Specifically, we use pop-out audio and video players that allow users to listen, learn, and classify the lunar surface all at once. To try and understand our users better we are conducting both learning and motivations studies while also monitoring site usage. Our learning assessments use an assessment tool designed by Sebastien Cormier and Ed Prather. At the time of this writing, data collection is still in progress. We are asking users with a variety of different experience levels within Moon Zoo to answer concept questions to assess if we can measure a higher conceptual knowledge in people who have spent more time in Moon Zoo and see change over time in individual users. We are also doing interview-based grounded theory investigations into what motivates people to come to Moon Zoo and to continue using the site. Preliminary results of the investigations will be presented, along with user behaviors, and other website statistics-based research. This work is funded through NASA ROSES grant NNX09AD34G and NSF grant DRL-0917608.

  6. Side-by-Side Testing of Water Heating Systems: Results from the 2013-2014 Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Colon, Carlos [Florida Solar Energy Center, Cocoa, FL (United States). Bulding America Partnership for Improved Residential Construction

    2017-07-12

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  7. Side by Side: What a Comparative Usability Study Told Us about a Web Site Redesign

    Science.gov (United States)

    Dougan, Kirstin; Fulton, Camilla

    2009-01-01

    Library Web sites must compete against easy-to-use sites, such as Google Scholar, Google Books, and Wikipedia, for students' time and attention. Library Web sites must therefore be designed with aesthetics and user perceptions at the forefront. The Music and Performing Arts Library at Urbana-Champaign's Web site was overcrowded and in much need of…

  8. Comparison of the THERP quantitative tables with the human reliability analysis techniques of second generation

    International Nuclear Information System (INIS)

    Alvarenga, Marco Antonio Bayout; Fonseca, Renato Alves

    2009-01-01

    The methodology THERP is classified as a Human Reliability Analysis (HRA) technique of first generation and its emergence was an important initial step for the development of HRA techniques in the industry. Due to the fact of being a first generation technique, THERP quantification tables of human errors are based on a taxonomy that does not take into account the human errors mechanisms. Concerning the three cognitive levels in the Rasmussen framework for the cognitive information processing in human beings, THERP deals in most cases with errors that happen in the perceptual-motor level (stimulus-response). In the rules level, this technique can work better using the time dependent probabilities curves of diagnosis errors, obtained in nuclear power plants simulators. Nevertheless, this is done without processing any error mechanisms. Another deficiency is the fact that the performance shaping factors are in limited number. Furthermore, the influences (predictable or not) of operational context, arising from operational deviations of the most probable (in terms of occurrence probabilities) standard scenarios beside the consequent operational tendencies (operator actions) are not estimated. This work makes a critical analysis of these deficiencies and it points out possible solutions in order to modify the THERP tables, seeking a realistic quantification, that does not underestimate or overestimate the human errors probabilities when applying the HRA techniques to nuclear power plants. The critical analysis is accomplished through a qualitative comparison between THERP, a HRA technique of first generation, with CREAM, as well as ATHEANA, which are HRA techniques of second generation. (author)

  9. Comparison of the THERP quantitative tables with the human reliability analysis techniques of second generation

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga, Marco Antonio Bayout; Fonseca, Renato Alves [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)], e-mail: bayout@cnen.gov.br, e-mail: rfonseca@cnen.gov.br

    2009-07-01

    The methodology THERP is classified as a Human Reliability Analysis (HRA) technique of first generation and its emergence was an important initial step for the development of HRA techniques in the industry. Due to the fact of being a first generation technique, THERP quantification tables of human errors are based on a taxonomy that does not take into account the human errors mechanisms. Concerning the three cognitive levels in the Rasmussen framework for the cognitive information processing in human beings, THERP deals in most cases with errors that happen in the perceptual-motor level (stimulus-response). In the rules level, this technique can work better using the time dependent probabilities curves of diagnosis errors, obtained in nuclear power plants simulators. Nevertheless, this is done without processing any error mechanisms. Another deficiency is the fact that the performance shaping factors are in limited number. Furthermore, the influences (predictable or not) of operational context, arising from operational deviations of the most probable (in terms of occurrence probabilities) standard scenarios beside the consequent operational tendencies (operator actions) are not estimated. This work makes a critical analysis of these deficiencies and it points out possible solutions in order to modify the THERP tables, seeking a realistic quantification, that does not underestimate or overestimate the human errors probabilities when applying the HRA techniques to nuclear power plants. The critical analysis is accomplished through a qualitative comparison between THERP, a HRA technique of first generation, with CREAM, as well as ATHEANA, which are HRA techniques of second generation. (author)

  10. Application of reliability analysis methods to the comparison of two safety circuits

    International Nuclear Information System (INIS)

    Signoret, J.-P.

    1975-01-01

    Two circuits of different design, intended for assuming the ''Low Pressure Safety Injection'' function in PWR reactors are analyzed using reliability methods. The reliability analysis of these circuits allows the failure trees to be established and the failure probability derived. The dependence of these results on test use and maintenance is emphasized as well as critical paths. The great number of results obtained may allow a well-informed choice taking account of the reliability wanted for the type of circuits [fr

  11. Comparison of reading performance tests concerning difficulty of sentences and paragraphs and their reliability

    NARCIS (Netherlands)

    Brussee, T.; van Nispen, R.M.A.; Klerkx, E.M.F.J.; Knol, D.L.; van Rens, G.H.M.B.

    2015-01-01

    In research and practice, sentences or paragraphs of reading tests may be randomly chosen to assess reading performance. This means that in addition to test reliability, all sentences or paragraphs should be reliable and equally difficult to read. The sentences and paragraphs of five (un-)

  12. Comparison of Model Reliabilities from Single-Step and Bivariate Blending Methods

    DEFF Research Database (Denmark)

    Taskinen, Matti; Mäntysaari, Esa; Lidauer, Martin

    2013-01-01

    Model based reliabilities in genetic evaluation are compared between three methods: animal model BLUP, single-step BLUP, and bivariate blending after genomic BLUP. The original bivariate blending is revised in this work to better account animal models. The study data is extracted from...... be calculated. Model reliabilities by the single-step and the bivariate blending methods were higher than by animal model due to genomic information. Compared to the single-step method, the bivariate blending method reliability estimates were, in general, lower. Computationally bivariate blending method was......, on the other hand, lighter than the single-step method....

  13. "A Comparison of Consensus, Consistency, and Measurement Approaches to Estimating Interrater Reliability"

    OpenAIRE

    Steven E. Stemler

    2004-01-01

    This article argues that the general practice of describing interrater reliability as a single, unified concept is..at best imprecise, and at worst potentially misleading. Rather than representing a single concept, different..statistical methods for computing interrater reliability can be more accurately classified into one of three..categories based upon the underlying goals of analysis. The three general categories introduced and..described in this paper are: 1) consensus estimates, 2) cons...

  14. An enquiry into the method of paired comparison: reliability, scaling, and Thurstone's Law of Comparative Judgment

    Science.gov (United States)

    Thomas C. Brown; George L. Peterson

    2009-01-01

    The method of paired comparisons is used to measure individuals' preference orderings of items presented to them as discrete binary choices. This paper reviews the theory and application of the paired comparison method, describes a new computer program available for eliciting the choices, and presents an analysis of methods for scaling paired choice data to...

  15. Comparison of reliability and responsiveness of patient-reported clinical outcome measures in knee osteoarthritis rehabilitation.

    Science.gov (United States)

    Williams, Valerie J; Piva, Sara R; Irrgang, James J; Crossley, Chad; Fitzgerald, G Kelley

    2012-08-01

    Secondary analysis, pretreatment-posttreatment observational study. To compare the reliability and responsiveness of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Knee Outcome Survey activities of daily living subscale (KOS-ADL), and the Lower Extremity Functional Scale (LEFS) in individuals with knee osteoarthritis (OA). The WOMAC is the current standard in patient-reported measures of function in patients with knee OA. The KOS-ADL and LEFS were designed for potential use in patients with knee OA. If the KOS-ADL and LEFS are to be considered viable alternatives to the WOMAC for measuring patient-reported function in individuals with knee OA, they should have measurement properties comparable to the WOMAC. It would also be important to determine whether either of these instruments may be superior to the WOMAC in terms of reliability or responsiveness in this population. Data from 168 subjects with knee OA, who participated in a rehabilitation program, were used in the analyses. Reliability and responsiveness of each outcome measure were estimated at follow-ups of 2, 6, and 12 months. Reliability was estimated by calculating the intraclass correlation coefficient (ICC2,1) for subjects who were unchanged in status from baseline at each follow-up time, based on a global rating of change score. To examine responsiveness, the standard error of the measurement, minimal detectable change, minimal clinically important difference, and the Guyatt responsiveness index were calculated for each outcome measure at each follow-up time. All 3 outcome measures demonstrated reasonable reliability and responsiveness to change. Reliability and responsiveness tended to decrease somewhat with increasing follow-up time. There were no substantial differences between outcome measures for reliability or any of the 3 measures of responsiveness at any follow-up time. The results do not indicate that one outcome measure is more reliable or responsive than

  16. Comparison of validity and reliability of the Migraine disability assessment (MIDAS) versus headache impact test (HIT) in an Iranian population.

    Science.gov (United States)

    Ghorbani, Abbas; Chitsaz, Ahmad

    2011-01-01

    Migraine is one of the most common headaches that affect 11% or more adult population. Recently, researchers have designed two questionnaires, namely Headache Impact Test (HIT) and Migraine Disability Assessment (MIDAS), with the aim of improving migraine care. These two tests provide a standard measurement about migraine's effects on people's life style that divide patients into 4 groups (grades) based on headaches intensity. The aim of this study was to compare the validity and reliability of these two tests. This study was designed as a multicenter, descriptive study to compare validity and reliability of Persian version of MIDAS and HIT questionnaires in 240 males and females with a migraine diagnosis according to criteria for headache and facial pain of the International Headache Society (IHS). The patients were enrolled in the study from 3 neurology clinics in Isfahan, Iran, between July 2004 and January 2005 and were evaluated at baseline (visit 1) and 4 weeks later (visit 2). According to our study, there was a high correlation between two tests (r = 0.94). This decreased their MIDAS grade in comparison to their grade HIT questionnaire. These findings demonstrated that Persian version of HIT have the same validity and reliability as MIDAS. Replying to HIT questionnaire was easier than MIDAS for Iranian patients. Physicians can reliably use the Persian translation of both MIDAS and HIT questionnaires to define the severity of illness and its treatment strategy as a self-administered report by migraine patients. However, we recommend HIT for its simplicity in headache clinics.

  17. Accuracy and reliability of continuous glucose monitoring systems: a head-to-head comparison

    NARCIS (Netherlands)

    Luijf, Yoeri M.; Mader, Julia K.; Doll, Werner; Pieber, Thomas; Farret, Anne; Place, Jerome; Renard, Eric; Bruttomesso, Daniela; Filippi, Alessio; Avogaro, Angelo; Arnolds, Sabine; Benesch, Carsten; Heinemann, Lutz; DeVries, J. Hans

    2013-01-01

    This study assessed the accuracy and reliability of three continuous glucose monitoring (CGM) systems. We studied the Animas® (West Chester, PA) Vibe™ with Dexcom® (San Diego, CA) G4™ version A sensor (G4A), the Abbott Diabetes Care (Alameda, CA) Freestyle® Navigator I (NAV), and the Medtronic

  18. Test-retest reliability of jump execution variables using mechanography: a comparison of jump protocols.

    Science.gov (United States)

    Fitzgerald, John S; Johnson, LuAnn; Tomkinson, Grant; Stein, Jesse; Roemmich, James N

    2018-05-01

    Mechanography during the vertical jump may enhance screening and determining mechanistic causes underlying physical performance changes. Utility of jump mechanography for evaluation is limited by scant test-retest reliability data on force-time variables. This study examined the test-retest reliability of eight jump execution variables assessed from mechanography. Thirty-two women (mean±SD: age 20.8 ± 1.3 yr) and 16 men (age 22.1 ± 1.9 yr) attended a familiarization session and two testing sessions, all one week apart. Participants performed two variations of the squat jump with squat depth self-selected and controlled using a goniometer to 80º knee flexion. Test-retest reliability was quantified as the systematic error (using effect size between jumps), random error (using coefficients of variation), and test-retest correlations (using intra-class correlation coefficients). Overall, jump execution variables demonstrated acceptable reliability, evidenced by small systematic errors (mean±95%CI: 0.2 ± 0.07), moderate random errors (mean±95%CI: 17.8 ± 3.7%), and very strong test-retest correlations (range: 0.73-0.97). Differences in random errors between controlled and self-selected protocols were negligible (mean±95%CI: 1.3 ± 2.3%). Jump execution variables demonstrated acceptable reliability, with no meaningful differences between the controlled and self-selected jump protocols. To simplify testing, a self-selected jump protocol can be used to assess force-time variables with negligible impact on measurement error.

  19. Testing comparison models of DASS-12 and its reliability among adolescents in Malaysia.

    Science.gov (United States)

    Osman, Zubaidah Jamil; Mukhtar, Firdaus; Hashim, Hairul Anuar; Abdul Latiff, Latiffah; Mohd Sidik, Sherina; Awang, Hamidin; Ibrahim, Normala; Abdul Rahman, Hejar; Ismail, Siti Irma Fadhilah; Ibrahim, Faisal; Tajik, Esra; Othman, Norlijah

    2014-10-01

    The 21-item Depression, Anxiety and Stress Scale (DASS-21) is frequently used in non-clinical research to measure mental health factors among adults. However, previous studies have concluded that the 21 items are not stable for utilization among the adolescent population. Thus, the aims of this study are to examine the structure of the factors and to report on the reliability of the refined version of the DASS that consists of 12 items. A total of 2850 students (aged 13 to 17 years old) from three major ethnic in Malaysia completed the DASS-21. The study was conducted at 10 randomly selected secondary schools in the northern state of Peninsular Malaysia. The study population comprised secondary school students (Forms 1, 2 and 4) from the selected schools. Based on the results of the EFA stage, 12 items were included in a final CFA to test the fit of the model. Using maximum likelihood procedures to estimate the model, the selected fit indices indicated a close model fit (χ(2)=132.94, df=57, p=.000; CFI=.96; RMR=.02; RMSEA=.04). Moreover, significant loadings of all the unstandardized regression weights implied an acceptable convergent validity. Besides the convergent validity of the item, a discriminant validity of the subscales was also evident from the moderate latent factor inter-correlations, which ranged from .62 to .75. The subscale reliability was further estimated using Cronbach's alpha and the adequate reliability of the subscales was obtained (Total=76; Depression=.68; Anxiety=.53; Stress=.52). The new version of the 12-item DASS for adolescents in Malaysia (DASS-12) is reliable and has a stable factor structure, and thus it is a useful instrument for distinguishing between depression, anxiety and stress. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Linear and evolutionary polynomial regression models to forecast coastal dynamics: Comparison and reliability assessment

    Science.gov (United States)

    Bruno, Delia Evelina; Barca, Emanuele; Goncalves, Rodrigo Mikosz; de Araujo Queiroz, Heithor Alexandre; Berardi, Luigi; Passarella, Giuseppe

    2018-01-01

    In this paper, the Evolutionary Polynomial Regression data modelling strategy has been applied to study small scale, short-term coastal morphodynamics, given its capability for treating a wide database of known information, non-linearly. Simple linear and multilinear regression models were also applied to achieve a balance between the computational load and reliability of estimations of the three models. In fact, even though it is easy to imagine that the more complex the model, the more the prediction improves, sometimes a "slight" worsening of estimations can be accepted in exchange for the time saved in data organization and computational load. The models' outcomes were validated through a detailed statistical, error analysis, which revealed a slightly better estimation of the polynomial model with respect to the multilinear model, as expected. On the other hand, even though the data organization was identical for the two models, the multilinear one required a simpler simulation setting and a faster run time. Finally, the most reliable evolutionary polynomial regression model was used in order to make some conjecture about the uncertainty increase with the extension of extrapolation time of the estimation. The overlapping rate between the confidence band of the mean of the known coast position and the prediction band of the estimated position can be a good index of the weakness in producing reliable estimations when the extrapolation time increases too much. The proposed models and tests have been applied to a coastal sector located nearby Torre Colimena in the Apulia region, south Italy.

  1. Multivariate normative comparison, a novel method for more reliably detecting cognitive impairment in HIV infection

    NARCIS (Netherlands)

    Su, Tanja; Schouten, Judith; Geurtsen, Gert J.; Wit, Ferdinand W.; Stolte, Ineke G.; Prins, Maria; Portegies, Peter; Caan, Matthan W. A.; Reiss, Peter; Majoie, Charles B.; Schmand, Ben A.

    2015-01-01

    The objective of this study is to assess whether multivariate normative comparison (MNC) improves detection of HIV-1-associated neurocognitive disorder (HAND) as compared with Frascati and Gisslén criteria. One-hundred and three HIV-1-infected men with suppressed viremia on combination

  2. On stochastic inequalities and comparisons of reliability measures for weighted distributions

    Directory of Open Access Journals (Sweden)

    Oluyede Broderick O.

    2002-01-01

    Full Text Available Inequalities, relations and stochastic orderings, as well as useful ageing notions for weighted distributions are established. Also presented are preservation and stability results and comparisons for weighted and length-biased distributions. Relations for length-biased and equilibrium distributions as examples of weighted distributions are also presented.

  3. The reliability and validity of subjective notational analysis in comparison to global positioning system tracking to assess athlete movement patterns.

    Science.gov (United States)

    Doğramac, Sera N; Watsford, Mark L; Murphy, Aron J

    2011-03-01

    Subjective notational analysis can be used to track players and analyse movement patterns during match-play of team sports such as futsal. The purpose of this study was to establish the validity and reliability of the Event Recorder for subjective notational analysis. A course was designed, replicating ten minutes of futsal match-play movement patterns, where ten participants undertook the course. The course allowed a comparison of data derived from subjective notational analysis, to the known distances of the course, and to GPS data. The study analysed six locomotor activity categories, focusing on total distance covered, total duration of activities and total frequency of activities. The values between the known measurements and the Event Recorder were similar, whereas the majority of significant differences were found between the Event Recorder and GPS values. The reliability of subjective notational analysis was established with all ten participants being analysed on two occasions, as well as analysing five random futsal players twice during match-play. Subjective notational analysis is a valid and reliable method of tracking player movements, and may be a preferred and more effective method than GPS, particularly for indoor sports such as futsal, and field sports where short distances and changes in direction are observed.

  4. Comparison of different reliability improving investment strategies of Finnish medium-voltage distribution systems

    Energy Technology Data Exchange (ETDEWEB)

    Laagland, H.

    2012-07-01

    The electricity distribution sector in Finland is highly regulated and the return on investments in distribution networks is low. Low profits don't make the electricity distribution sector attractive to outside investors. During the second regulatory period of 2008-2011 incentives are included into the Finnish regulation model which allows higher profits for the network owners for right allocated network investments leading to lower operation and interruption costs. The goal of the thesis is to find cost-effective medium-voltage distribution system investment strategies for the Finnish power distribution companies with respect to the incentives of the second regulatory period. In this work the sectionalisation concept is further developed by deriving equations for a homogeneous electricity distribution system for the economical and reliability indices as a function of the number of sectionalisation zones. The cost-effective medium-voltage distribution system investment strategies are found by studying the technical and economic interaction of feeder automation on different network structures. Ten feeder automation schemes have been applied to six urban/rural area generic feeders and two real rural area feeders of a distribution company in western Finland. The analytical approach includes modelling of the feeders and feeder functions and calculation of the economical and reliability indices. The following investment areas are included: different electricity distribution systems, new substation, new switching station, central earth-fault current compensation, cabling and feeder automation. The value of the results of this work is that they reveal the influence that feeder automation has on the reliability and economy of different distribution structures. This created transparency enables a national and/or distribution company network investment strategy to optimise the economic benefits of investments. (orig.)

  5. A comparison between Markovian models and Bayesian networks for treating some dependent events in reliability evaluations

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Juliana P.; Leite, Victor C.; Melo, P.F. Frutuoso e, E-mail: julianapduarte@poli.ufrj.br, E-mail: victor.coppo.leite@poli.ufrj.br, E-mail: frutuoso@nuclear.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    Bayesian networks have become a very handy tool for solving problems in various application areas. This paper discusses the use of Bayesian networks to treat dependent events in reliability engineering typically modeled by Markovian models. Dependent events play an important role as, for example, when treating load-sharing systems, bridge systems, common-cause failures, and switching systems (those for which a standby component is activated after the main one fails by means of a switching mechanism). Repair plays an important role in all these cases (as, for example, the number of repairmen). All Bayesian network calculations are performed by means of the Netica™ software, of Norsys Software Corporation, and Fortran 90 to evaluate them over time. The discussion considers the development of time-dependent reliability figures of merit, which are easily obtained, through Markovian models, but not through Bayesian networks, because these latter need probability figures as input and not failure and repair rates. Bayesian networks produced results in very good agreement with those of Markov models and pivotal decomposition. Static and discrete time (DTBN) Bayesian networks were used in order to check their capabilities of modeling specific situations, like switching failures in cold-standby systems. The DTBN was more flexible to modeling systems where the time of occurrence of an event is important, for example, standby failure and repair. However, the static network model showed as good results as DTBN by a much more simplified approach. (author)

  6. A comparison between Markovian models and Bayesian networks for treating some dependent events in reliability evaluations

    International Nuclear Information System (INIS)

    Duarte, Juliana P.; Leite, Victor C.; Melo, P.F. Frutuoso e

    2013-01-01

    Bayesian networks have become a very handy tool for solving problems in various application areas. This paper discusses the use of Bayesian networks to treat dependent events in reliability engineering typically modeled by Markovian models. Dependent events play an important role as, for example, when treating load-sharing systems, bridge systems, common-cause failures, and switching systems (those for which a standby component is activated after the main one fails by means of a switching mechanism). Repair plays an important role in all these cases (as, for example, the number of repairmen). All Bayesian network calculations are performed by means of the Netica™ software, of Norsys Software Corporation, and Fortran 90 to evaluate them over time. The discussion considers the development of time-dependent reliability figures of merit, which are easily obtained, through Markovian models, but not through Bayesian networks, because these latter need probability figures as input and not failure and repair rates. Bayesian networks produced results in very good agreement with those of Markov models and pivotal decomposition. Static and discrete time (DTBN) Bayesian networks were used in order to check their capabilities of modeling specific situations, like switching failures in cold-standby systems. The DTBN was more flexible to modeling systems where the time of occurrence of an event is important, for example, standby failure and repair. However, the static network model showed as good results as DTBN by a much more simplified approach. (author)

  7. Comparison of Endotoxin Exposure Assessment by Bioaerosol Impinger and Filter-Sampling Methods

    OpenAIRE

    Duchaine, Caroline; Thorne, Peter S.; Mériaux, Anne; Grimard, Yan; Whitten, Paul; Cormier, Yvon

    2001-01-01

    Environmental assessment data collected in two prior occupational hygiene studies of swine barns and sawmills allowed the comparison of concurrent, triplicate, side-by-side endotoxin measurements using air sampling filters and bioaerosol impingers. Endotoxin concentrations in impinger solutions and filter eluates were assayed using the Limulus amebocyte lysate assay. In sawmills, impinger sampling yielded significantly higher endotoxin concentration measurements and lower variances than filte...

  8. Accuracy and reliability of 3D stereophotogrammetry: A comparison to direct anthropometry and 2D photogrammetry.

    Science.gov (United States)

    Dindaroğlu, Furkan; Kutlu, Pınar; Duran, Gökhan Serhat; Görgülü, Serkan; Aslan, Erhan

    2016-05-01

    To evaluate the accuracy of three-dimensional (3D) stereophotogrammetry by comparing it with the direct anthropometry and digital photogrammetry methods. The reliability of 3D stereophotogrammetry was also examined. Six profile and four frontal parameters were directly measured on the faces of 80 participants. The same measurements were repeated using two-dimensional (2D) photogrammetry and 3D stereophotogrammetry (3dMDflex System, 3dMD, Atlanta, Ga) to obtain images of the subjects. Another observer made the same measurements for images obtained with 3D stereophotogrammetry, and interobserver reproducibility was evaluated for 3D images. Both observers remeasured the 3D images 1 month later, and intraobserver reproducibility was evaluated. Statistical analysis was conducted using the paired samples t-test, intraclass correlation coefficient, and Bland-Altman limits of agreement. The highest mean difference was 0.30 mm between direct measurement and photogrammetry, 0.21 mm between direct measurement and 3D stereophotogrammetry, and 0.5 mm between photogrammetry and 3D stereophotogrammetry. The lowest agreement value was 0.965 in the Sn-Pro parameter between the photogrammetry and 3D stereophotogrammetry methods. Agreement between the two observers varied from 0.90 (Ch-Ch) to 0.99 (Sn-Me) in linear measurements. For intraobserver agreement, the highest difference between means was 0.33 for observer 1 and 1.42 mm for observer 2. Measurements obtained using 3D stereophotogrammetry indicate that it may be an accurate and reliable imaging method for use in orthodontics.

  9. Comparison of macro and micro Raman measurement for reliable quantitative analysis of pharmaceutical polymorphs.

    Science.gov (United States)

    Paiva, Eduardo M; da Silva, Vitor H; Poppi, Ronei J; Pereira, Claudete F; Rohwedder, Jarbas J R

    2018-05-12

    This work reports on the use of micro- and macro-Raman measurements for quantification of mebendazole (MBZ) polymorphs A, B, and C in mixtures. Three Raman spectrophotometers were studied with a laser spot size of 3, 80 and 100 μm and spectral resolutions of 3.9, 9 and 4 cm -1 , respectively. The samples studied were ternary mixtures varying the MBZ polymorphs A and C from 0 to 100% and polymorph B from 0 to 30%. Partial Least Squares (PLS) regression models were developed using the pre-processing spectra (2nd derivative) of the ternary mixtures. The best performance was obtained when the macro-Raman configuration was applied, obtaining RMSEP values of 1.68%, 1.24% and 2.03% w/w for polymorphs A, B, and C, respectively. In general, micro-Raman presented worst results for MBZ polymorphs prediction because the spectra obtained with this configuration does not represent the bulk proportion of mixtures, which have different particle morphologies and sizes. In addition, the influence of these particle features on micro-Raman measurements was also studied. Finally, the results demonstrated that reliable analytical quantifying of MBZ polymorphs can be reached using a laser with wider area illuminated, thus enabling acquisition of more reproductive and representative spectra of the mixtures. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Wrist and Hand Ultrasound: Reliability of Side-to-Side Comparisons of Very Small (Structures.

    Science.gov (United States)

    Rossi, Federica; Romano, Nicola; Muda, Alessandro; Martinoli, Carlo; Tagliafico, Alberto

    2018-04-24

    In ultrasound (US) examinations of clinically relevant very small structures of the wrist and hand, the healthy contralateral side can be used as a reference to identify subtle abnormalities. Intraindividual side-to-side variability must be minimal. The aim of this study was to assess the reliability of side-to-side US evaluations of very small structures of the wrist and hand. Forty-one healthy volunteers were prospectively studied. Small structures of the wrist and hand were evaluated bilaterally by 2 musculoskeletal radiologists in separate sessions. The first annular pulleys of the second finger and the thumb, sagittal band of the third finger, extensor and flexor retinacula, ulnar collateral ligament of the thumb, radial collateral ligament of the second finger, and palmar cutaneous branches of the median and ulnar nerves were considered. To assess intra- and inter-reader agreement, 10 of 41 (24%) examinations were repeated. Nonparametric statistics were used. Data were not normally distributed (P > .001). Intra-reader agreement was κ = 0.674 (95% confidence interval [CI], 0.57-0.78), and inter-reader agreement was κ = 0.935 (95% CI, 0.92-0.95). The mean value ± SD for all of the structures was 0.78 ± 0.44 mm. The overall coefficient of variation was 9.8% ± 0.07%. The intraclass correlation coefficient was 0.97 (95% CI, 0.96-0.98). In clinical practice, the healthy contralateral side can be used as a reference during a real-time musculoskeletal US evaluation of small (structures. © 2018 by the American Institute of Ultrasound in Medicine.

  11. Distinguishing between forensic science and forensic pseudoscience: testing of validity and reliability, and approaches to forensic voice comparison.

    Science.gov (United States)

    Morrison, Geoffrey Stewart

    2014-05-01

    In this paper it is argued that one should not attempt to directly assess whether a forensic analysis technique is scientifically acceptable. Rather one should first specify what one considers to be appropriate principles governing acceptable practice, then consider any particular approach in light of those principles. This paper focuses on one principle: the validity and reliability of an approach should be empirically tested under conditions reflecting those of the case under investigation using test data drawn from the relevant population. Versions of this principle have been key elements in several reports on forensic science, including forensic voice comparison, published over the last four-and-a-half decades. The aural-spectrographic approach to forensic voice comparison (also known as "voiceprint" or "voicegram" examination) and the currently widely practiced auditory-acoustic-phonetic approach are considered in light of this principle (these two approaches do not appear to be mutually exclusive). Approaches based on data, quantitative measurements, and statistical models are also considered in light of this principle. © 2013.

  12. Comparison of Quantity Versus Quality Using Performance, Reliability, and Life Cycle Cost Data. A Case Study of the F-15, F-16, and A-10 Aircraft.

    Science.gov (United States)

    1985-09-01

    CoC S~04 COMPARISON OF QUANTITY VERSUS QUALITY USING PERFORMANCE, RELIABILITY, AND LIFE CYCLE COST DATA. A CASE STUDY OF THE F-15, F-16, AND A-10...CYCLE COSTIATU.AT CAE AIR ORE HEO OG .- jAITR UIVERSITY W right.,Patterson Air Force Base, Ohio .! 5ൔ ,6 198 C.IT. U AF’IT/GSL,4/L3Q/65:S Ŗ J...COMPARISON OF QUANTITY VERSUS QUALITY USING PERFORMANCE, RELIABILITY, AND LIFE CYCLE COST DATA. A CASE STUDY OF THE F-15, F-16, AND A-10 AIRCRAFT THESIS David

  13. ATHENA model for 4 x 350 MW(t) HTGR plant side-by-side steel vessel prismatic core concept

    International Nuclear Information System (INIS)

    Ambrosek, R.G.

    1986-01-01

    ATHENA is a computer code being developed at the Idaho National Engineering Laboratory under US Department of Energy support. The code will provide advanced best-estimate predictive capability for a wide spectrum of applications. The code has capability for modeling independent hydrodynamic systems which can currently include water, helium, Freon-II, idealgas, lithium, or lithium-lead as fluids. ATHENA was modified to allow point reactor kinetics evaluations for two nuclear reactor cores. Capability for specifying gas circulators was added and representative homologous curves were added for a helium circulator. A full system model was developed for a High Temperature Gas Reactor modular concept with a full secondary system model. The code capability to model the complete system was demonstrated and a representative transient for a circulator coastdown without reactor scram was modeled and evaluated to the point of flow stagnation

  14. 'Co-operation and Communism cannot work side by side': Organized Consumers and the Early Cold War in Britain.

    Science.gov (United States)

    Gurney, Peter

    2018-04-02

    This article contributes to a better understanding of labour anti-communism in Britain through an exploration of the evolution of ideas and attitudes within the co-operative movement during the early Cold War. It demonstrates that the period witnessed an increasingly rigid separation of co-operation from communism and argues that this separation made it harder for activists within the co-operative movement to imagine a total or utopian alternative to capitalism. Drawing particularly on a close reading of the co-operative press as well as other sources, the study is divided into three main parts. The first section discusses sympathy among co-operators for the achievements of the Soviet Union, which increased during the war against fascism. The article then moves on to consider the continuing dialogue between British co-operators and their counterparts in European communist states and how international tensions shaped co-operators' views. The final major section explores the hardening of attitude towards communism after Marshall Aid was declared in June 1947, and underlines the role played by figures such as A. V. Alexander and Jack Bailey who worked with the Information Research Department at the Foreign Office to spread anti-communism within the movement. The conclusion reflects, more speculatively, on what implications this shift may have had for the medium and long-term decline of co-operation and the hegemony of capitalist consumerism post-war.

  15. Side-by-Side In(OH3 and In2O3 Nanotubes: Synthesis and Optical Properties

    Directory of Open Access Journals (Sweden)

    Tao Xiaojun

    2009-01-01

    Full Text Available Abstract A simple and mild wet-chemical approach was developed for the synthesis of one-dimensional (1D In(OH3 nanostructures. By calcining the 1D In(OH3 nanocrystals in air at 250 °C, 1D In2O3 nanocrystals with the same morphology were obtained. TEM results show that both 1D In(OH3 and 1D In2O3 are composed of uniform nanotube bundles. SAED and XRD patterns indicate that 1D In(OH3 and 1D In2O3 nanostructures are single crystalline and possess the same bcc crystalline structure as the bulk In(OH3 and In2O3, respectively. TGA/DTA analyses of the precursor In(OH3 and the final product In2O3 confirm the existence of CTAB molecules, and its content is about 6%. The optical absorption band edge of 1D In2O3 exhibits an evident blueshift with respect to that of the commercial In2O3 powders, which is caused by the increasing energy gap resulted from decreasing the grain size. A relatively strong and broad purple-blue emission band centered at 440 nm was observed in the room temperature PL spectrum of 1D In2O3 nanotube bundles, which was mainly attributed to the existence of the oxygen vacancies.

  16. Host generalists and specialists emerging side by side: an analysis of evolutionary patterns in the cosmopolitan chewing louse genus Menacanthus

    Czech Academy of Sciences Publication Activity Database

    Martinů, Jana; Sychra, O.; Literák, I.; Čapek, Miroslav; Gustafsson, D. L.; Štefka, Jan

    2015-01-01

    Roč. 45, č. 1 (2015), s. 63-73 ISSN 0020-7519 R&D Projects: GA AV ČR IAA601690901 Institutional support: RVO:60077344 ; RVO:68081766 Keywords : Host specificity * Specialist * Generalist * Population structure * Geographic distribution * Menacanthus Subject RIV: EG - Zoology; EG - Zoology (UBO-W) Impact factor: 4.242, year: 2015

  17. The effects of dual tasking on gait synchronization during over-ground side-by-side walking.

    Science.gov (United States)

    Zivotofsky, Ari Z; Bernad-Elazari, Hagar; Grossman, Pnina; Hausdorff, Jeffrey M

    2018-03-23

    Recent studies have shown that gait synchronization during natural walking is not merely anecdotal, but it is a repeatable phenomenon that is quantifiable and is apparently related to available sensory feedback modalities. However, the mechanisms underlying this phase-locking of gait have only recently begun to be investigated. For example, it is not known what role, if any, attention plays. We employed a dual tasking paradigm in order to investigate the role attention plays in gait synchronization. Sixteen pairs of subjects walked under six conditions that manipulated the available sensory feedback and the degree of difficulty of the dual task, i.e., the attention. Movement was quantified using a trunk-mounted tri-axial accelerometer. A gait synchronization index (GSI) was calculated in order to quantify the degree of synchronization of the gait pattern. A simple dual task resulted in an increased level of synchronization, whereas a more complex dual task lead to a reduction in synchronization. Handholding increased synchronization, compared to the same attention condition without handholding. These results indicate that in order for two walkers to synchronize, some level of attention is apparently required, such that a relatively complex dual task utilizes enough attentional resources to reduce the occurrence of synchronization. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Addressing the fundamental issues in reliability evaluation of passive safety of AP1000 for a comparison with active safety of PWR

    International Nuclear Information System (INIS)

    Hashim Muhammad; Yoshikawa, Hidekazu; Yang Ming

    2013-01-01

    Passive safety systems adopted in advanced Pressurized Water Reactor (PWR), such as AP1000 and EPR, should attain higher reliability than the existing active safety systems of the conventional PWR. The objective of this study is to discuss the fundamental issues relating to the reliability evaluation of AP1000 passive safety systems for a comparison with the active safety systems of conventional PWR, based on several aspects. First, comparisons between conventional PWR and AP1000 are made from the both aspects of safety design and cost reduction. The main differences between these PWR plants exist in the configurations of safety systems: AP1000 employs the passive safety system while reducing the number of active systems. Second, the safety of AP1000 is discussed from the aspect of severe accident prevention in the event of large break loss of coolant accidents (LOCA). Third, detailed fundamental issues on reliability evaluation of AP1000 passive safety systems are discussed qualitatively by using single loop models of safety systems of both PWRs plants. Lastly, methodology to conduct quantitative estimation of dynamic reliability for AP1000 passive safety systems in LOCA condition is discussed, in order to evaluate the reliability of AP1000 in future by a success-path-based reliability analysis method (i.e., GO-FLOW). (author)

  19. Reliability engineering

    International Nuclear Information System (INIS)

    Lee, Chi Woo; Kim, Sun Jin; Lee, Seung Woo; Jeong, Sang Yeong

    1993-08-01

    This book start what is reliability? such as origin of reliability problems, definition of reliability and reliability and use of reliability. It also deals with probability and calculation of reliability, reliability function and failure rate, probability distribution of reliability, assumption of MTBF, process of probability distribution, down time, maintainability and availability, break down maintenance and preventive maintenance design of reliability, design of reliability for prediction and statistics, reliability test, reliability data and design and management of reliability.

  20. Reliability in engineering '87

    International Nuclear Information System (INIS)

    Tuma, M.

    1987-01-01

    The participants heard 51 papers dealing with the reliability of engineering products. Two of the papers were incorporated in INIS, namely ''Reliability comparison of two designs of low pressure regeneration of the 1000 MW unit at the Temelin nuclear power plant'' and ''Use of probability analysis of reliability in designing nuclear power facilities.''(J.B.)

  1. A comparison of manual anthropometric measurements with Kinect-based scanned measurements in terms of precision and reliability.

    Science.gov (United States)

    Bragança, Sara; Arezes, Pedro; Carvalho, Miguel; Ashdown, Susan P; Castellucci, Ignacio; Leão, Celina

    2018-01-01

    Collecting anthropometric data for real-life applications demands a high degree of precision and reliability. It is important to test new equipment that will be used for data collectionOBJECTIVE:Compare two anthropometric data gathering techniques - manual methods and a Kinect-based 3D body scanner - to understand which of them gives more precise and reliable results. The data was collected using a measuring tape and a Kinect-based 3D body scanner. It was evaluated in terms of precision by considering the regular and relative Technical Error of Measurement and in terms of reliability by using the Intraclass Correlation Coefficient, Reliability Coefficient, Standard Error of Measurement and Coefficient of Variation. The results obtained showed that both methods presented better results for reliability than for precision. Both methods showed relatively good results for these two variables, however, manual methods had better results for some body measurements. Despite being considered sufficiently precise and reliable for certain applications (e.g. apparel industry), the 3D scanner tested showed, for almost every anthropometric measurement, a different result than the manual technique. Many companies design their products based on data obtained from 3D scanners, hence, understanding the precision and reliability of the equipment used is essential to obtain feasible results.

  2. The Physical Activity Scale for Individuals with Physical Disabilities: test-retest reliability and comparison with an accelerometer.

    Science.gov (United States)

    van der Ploeg, Hidde P; Streppel, Kitty R M; van der Beek, Allard J; van der Woude, Luc H V; Vollenbroek-Hutten, Miriam; van Mechelen, Willem

    2007-01-01

    The objective was to determine the test-retest reliability and criterion validity of the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD). Forty-five non-wheelchair dependent subjects were recruited from three Dutch rehabilitation centers. Subjects' diagnoses were: stroke, spinal cord injury, whiplash, and neurological-, orthopedic- or back disorders. The PASIPD is a 7-d recall physical activity questionnaire that was completed twice, 1 wk apart. During this week, physical activity was also measured with an Actigraph accelerometer. The test-retest reliability Spearman correlation of the PASIPD was 0.77. The criterion validity Spearman correlation was 0.30 when compared to the accelerometer. The PASIPD had test-retest reliability and criterion validity that is comparable to well established self-report physical activity questionnaires from the general population.

  3. The Physical Activity Scale for Individuals with Physical Disabilities : test-retest reliability and comparison with an accelerometer

    NARCIS (Netherlands)

    van der Ploeg, Hidde P; Streppel, Kitty R M; van der Beek, Allard J; van der Woude, Luc H V; Vollenbroek-Hutten, Miriam; van Mechelen, Willem; van der Woude, Lucas

    BACKGROUND: The objective was to determine the test-retest reliability and criterion validity of the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD). METHODS: Forty-five non-wheelchair dependent subjects were recruited from three Dutch rehabilitation centers. Subjects'

  4. Comparison of the reliability of parental reporting and the direct test of the Thai Speech and Language Test.

    Science.gov (United States)

    Prathanee, Benjamas; Angsupakorn, Nipa; Pumnum, Tawitree; Seepuaham, Cholada; Jaiyong, Pechcharat

    2012-11-01

    To find reliability of parental or caregiver's report and testing of the Thai Speech and Language Test for Children Aged 0-4 Years Old. Five investigators assessed speech and language abilities from video both contexts: parental or caregivers' report and test forms of Thai Speech and Language Test for Children Aged 0-4 Years Old. Twenty-five normal and 30 children with delayed development or risk for delayed speech and language skills were assessed at age intervals of 3, 6, 9, 12, 15, 18, 24, 30, 36 and 48 months. Reliability of parental or caregivers' testing and reporting was at a moderate level (0.41-0.60). Inter-rater reliability among investigators was excellent (0.86-1.00). The parental or caregivers' report form of the Thai Speech and Language test for Children aged 0-4 years old was an indicator for success at a moderate level. Trained professionals could use both forms of this test as reliable tools at an excellent level.

  5. Interoperability and Reliability of Multiplatform MPLS VPN: Comparison of Traffic Engineering with RSVP-TE Protocol and LDP Protocol

    Directory of Open Access Journals (Sweden)

    Nanang Ismail

    2017-10-01

    48% of packet loss per 100 sent packets while on RSVP packet loss percentage is 35.5% per 100 sent packets. Both protocols have interoperability on the third layer of multiplatform MPLS VPN, but on heavy loaded traffic condition, RSVP protocol has better reliability than the LDP protocol.

  6. Reliability Engineering

    International Nuclear Information System (INIS)

    Lee, Sang Yong

    1992-07-01

    This book is about reliability engineering, which describes definition and importance of reliability, development of reliability engineering, failure rate and failure probability density function about types of it, CFR and index distribution, IFR and normal distribution and Weibull distribution, maintainability and movability, reliability test and reliability assumption in index distribution type, normal distribution type and Weibull distribution type, reliability sampling test, reliability of system, design of reliability and functionality failure analysis by FTA.

  7. A comparison of reliability and construct validity between the original and revised versions of the Rosenberg Self-Esteem Scale.

    Science.gov (United States)

    Wongpakaran, Tinakon; Tinakon, Wongpakaran; Wongpakaran, Nahathai; Nahathai, Wongpakaran

    2012-03-01

    The Rosenberg Self-Esteem Scale (RSES) is a widely used instrument that has been tested for reliability and validity in many settings; however, some negative-worded items appear to have caused it to reveal low reliability in a number of studies. In this study, we revised one negative item that had previously (from the previous studies) produced the worst outcome in terms of the structure of the scale, then re-analyzed the new version for its reliability and construct validity, comparing it to the original version with respect to fit indices. In total, 851 students from Chiang Mai University (mean age: 19.51±1.7, 57% of whom were female), participated in this study. Of these, 664 students completed the Thai version of the original RSES - containing five positively worded and five negatively worded items, while 187 students used the revised version containing six positively worded and four negatively worded items. Confirmatory factor analysis was applied, using a uni-dimensional model with method effects and a correlated uniqueness approach. The revised version showed the same level of reliability (good) as the original, but yielded a better model fit. The revised RSES demonstrated excellent fit statistics, with χ²=29.19 (df=19, n=187, p=0.063), GFI=0.970, TFI=0.969, NFI=0.964, CFI=0.987, SRMR=0.040 and RMSEA=0.054. The revised version of the Thai RSES demonstrated an equivalent level of reliability but a better construct validity when compared to the original.

  8. Use of a tibial accelerometer to measure ground reaction force in running: A reliability and validity comparison with force plates.

    Science.gov (United States)

    Raper, Damian P; Witchalls, Jeremy; Philips, Elissa J; Knight, Emma; Drew, Michael K; Waddington, Gordon

    2018-01-01

    The use of microsensor technologies to conduct research and implement interventions in sports and exercise medicine has increased recently. The objective of this paper was to determine the validity and reliability of the ViPerform as a measure of load compared to vertical ground reaction force (GRF) as measured by force plates. Absolute reliability assessment, with concurrent validity. 10 professional triathletes ran 10 trials over force plates with the ViPerform mounted on the mid portion of the medial tibia. Calculated vertical ground reaction force data from the ViPerform was matched to the same stride on the force plate. Bland-Altman (BA) plot of comparative measure of agreement was used to assess the relationship between the calculated load from the accelerometer and the force plates. Reliability was calculated by intra-class correlation coefficients (ICC) with 95% confidence intervals. BA plot indicates minimal agreement between the measures derived from the force plate and ViPerform, with variation at an individual participant plot level. Reliability was excellent (ICC=0.877; 95% CI=0.825-0.917) in calculating the same vertical GRF in a repeated trial. Standard error of measure (SEM) equalled 99.83 units (95% CI=82.10-119.09), which, in turn, gave a minimum detectable change (MDC) value of 276.72 units (95% CI=227.32-330.07). The ViPerform does not calculate absolute values of vertical GRF similar to those measured by a force plate. It does provide a valid and reliable calculation of an athlete's lower limb load at constant velocity. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  9. Reliability and validity of MicroScribe-3DXL system in comparison with radiographic cephalometric system: Angular measurements.

    Science.gov (United States)

    Barmou, Maher M; Hussain, Saba F; Abu Hassan, Mohamed I

    2018-06-01

    The aim of the study was to assess the reliability and validity of cephalometric variables from MicroScribe-3DXL. Seven cephalometric variables (facial angle, ANB, maxillary depth, U1/FH, FMA, IMPA, FMIA) were measured by a dentist in 60 Malay subjects (30 males and 30 females) with class I occlusion and balanced face. Two standard images were taken for each subject with conventional cephalometric radiography and MicroScribe-3DXL. All the images were traced and analysed. SPSS version 2.0 was used for statistical analysis with P-value was set at P<0.05. The results revealed a significant statistic difference in four measurements (U1/FH, FMA, IMPA, FMIA) with P-value range (0.00 to 0.03). The difference in the measurements was considered clinically acceptable. The overall reliability of MicroScribe-3DXL was 92.7% and its validity was 91.8%. The MicroScribe-3DXL is reliable and valid to most of the cephalometric variables with the advantages of saving time and cost. This is a promising device to assist in diverse areas in dental practice and research. Copyright © 2018. Published by Elsevier Masson SAS.

  10. Personal noise dosimeters: Accuracy and reliability in varied settings

    Directory of Open Access Journals (Sweden)

    Sheri Lynn Cook-Cunningham

    2014-01-01

    Full Text Available This study investigated the accuracy, reliability, and characteristics of three brands of personal noise dosimeters (N = 7 units in both pink noise (PN environments and natural environments (NEs through the acquisition of decibel readings, Leq readings and noise doses. Acquisition periods included repeated PN conditions, choir room rehearsals and participant (N = 3 Leq and noise dosages procured during a day in the life of a music student. Among primary results: (a All dosimeters exhibited very strong positive correlations for PN measurements across all instruments; (b all dosimeters were within the recommended American National Standard Institute (ANSI SI.25-1991 standard of ±2 dB (A of a reference measurement; and (c all dosimeters were within the recommended ANSI SI.25-1991 standard of ±2 dB (A when compared with each other. Results were discussed in terms of using personal noise dosimeters within hearing conservation and research contexts and recommendations for future research. Personal noise dosimeters were studied within the contexts of PN environments and NEs (choral classroom and the day in the life of collegiate music students. This quantitative study was a non-experimental correlation design. Three brands of personal noise dosimeters (Cirrus doseBadge, Quest Edge Eg5 and Etymotic ER200D were tested in two environments, a PN setting and a natural setting. There were two conditions within each environment. In the PN environment condition one, each dosimeter was tested individually in comparison with two reference measuring devices (Ivie and Easera while PN was generated by a Whites Instrument PN Tube. In condition two, the PN procedures were replicated for longer periods while all dosimeters measured the sound levels simultaneously. In the NE condition one, all dosimeters were placed side by side on a music stand and recorded sound levels of choir rehearsals over a 7-h rehearsal period. In NE, condition two noise levels were measured

  11. Past-behavioural versus situational questions in a postgraduate admissions multiple mini-interview: a reliability and acceptability comparison.

    Science.gov (United States)

    Yoshimura, Hiroshi; Kitazono, Hidetaka; Fujitani, Shigeki; Machi, Junji; Saiki, Takuya; Suzuki, Yasuyuki; Ponnamperuma, Gominda

    2015-04-14

    The Multiple Mini-Interview (MMI) mostly uses 'Situational' Questions (SQs) as an interview format within a station, rather than 'Past-Behavioural' Questions (PBQs), which are most frequently adopted in traditional single-station personal interviews (SSPIs) for non-medical and medical selection. This study investigated reliability and acceptability of the postgraduate admissions MMI with PBQ and SQ interview formats within MMI stations. Twenty-six Japanese medical graduates, first completed the two-year national obligatory initial postgraduate clinical training programme and then applied to three specialty training programmes - internal medicine, general surgery, and emergency medicine - in a Japanese teaching hospital, where they underwent the Accreditation Council for Graduate Medical Education (ACGME)-competency-based MMI. This MMI contained five stations, with two examiners per station. In each station, a PBQ, and then an SQ were asked consecutively. PBQ and SQ interview formats were not separated into two different stations, or the order of questioning of PBQs and SQs in individual stations was not changed due to lack of space and experienced examiners. Reliability was analysed for the scores of these two MMI question types. Candidates and examiners were surveyed on this experience. The PBQ and SQ formats had generalisability coefficients of 0.822 and 0.821, respectively. With one examiner per station, seven stations could produce a reliability of more than 0.80 in both PBQ and SQ formats. More than 60% of both candidates and examiners felt positive about the overall candidates' ability. All participants liked the fairness of this MMI when compared with the previously experienced SSPI. SQs were perceived more favourable by candidates; in contrast, PBQs were perceived more relevant by examiners. Both PBQs and SQs are equally reliable and acceptable as station interview formats in the postgraduate admissions MMI. However, the use of the two formats within the

  12. An interobserver reliability comparison between the Orthopaedic Trauma Association's open fracture classification and the Gustilo and Anderson classification.

    Science.gov (United States)

    Ghoshal, A; Enninghorst, N; Sisak, K; Balogh, Z J

    2018-02-01

    To evaluate interobserver reliability of the Orthopaedic Trauma Association's open fracture classification system (OTA-OFC). Patients of any age with a first presentation of an open long bone fracture were included. Standard radiographs, wound photographs, and a short clinical description were given to eight orthopaedic surgeons, who independently evaluated the injury using both the Gustilo and Anderson (GA) and OTA-OFC classifications. The responses were compared for variability using Cohen's kappa. The overall interobserver agreement was ĸ = 0.44 for the GA classification and ĸ = 0.49 for OTA-OFC, which reflects moderate agreement (0.41 to 0.60) for both classifications. The agreement in the five categories of OTA-OFC was: for skin, ĸ = 0.55 (moderate); for muscle, ĸ = 0.44 (moderate); for arterial injury, ĸ = 0.74 (substantial); for contamination, ĸ = 0.35 (fair); and for bone loss, ĸ = 0.41 (moderate). Although the OTA-OFC, with similar interobserver agreement to GA, offers a more detailed description of open fractures, further development may be needed to make it a reliable and robust tool. Cite this article: Bone Joint J 2018;100-B:242-6. ©2018 The British Editorial Society of Bone & Joint Surgery.

  13. Comparison of positron emission tomography/CT and bremsstrahlung imaging following Y-90 radiation synovectomy

    International Nuclear Information System (INIS)

    Barber, Thomas W.; Yap, Kenneth S.K.; Cherk, Martin H.; Kalff, Victor; Powell, Anne

    2013-01-01

    The aim of this study is to compare the results of positron emission tomography (PET)/CT with bremsstrahlung imaging following Y-90 radiation synovectomy. All patients referred to our institution for Y-90 radiation synovectomy between July 2011 and February 2012 underwent both PET/CT and bremsstrahlung planar (±single photon emission computed tomography (SPECT) or SPECT/CT) imaging at 4 or 24 h following administration of Y-90 silicate colloid. PET image acquisition was performed for between 15 and 20min. In patients who underwent SPECT, side-by-side comparison with PET was performed and image quality/resolution scored using a five-point scale. The distribution pattern of Y-90 on PET and bremsstrahlung imaging was compared with the intra- or extra-articular location of Y-90 activity on fused PET/CT. Thirteen joints (11 knees and two ankles) were imaged with both PET/CT and planar bremsstrahlung imaging with 12 joints also imaged with bremsstrahlung SPECT. Of the 12 joints imaged with SPECT, PET image quality/resolution was superior in 11 and inferior in one. PET demonstrated a concordant distribution pattern compared with bremsstrahlung imaging in all scans, with the pattern classified as diffuse in 12 and predominantly focal in one. In all 12 diffuse scans, PET/CT confirmed the Y-90 activity to be located intra-articularly. In the one predominantly focal scan, the fused PET/CT images localised the Y-90 activity to mostly lie in the extra-articular space of the knee. PET/CT can provide superior image quality compared with bremsstrahlung imaging and may enable reliable detection of extra-articular Y-90 activity when there are focal patterns on planar bremsstrahlung imaging.

  14. Intraoperative use of indocyanine green angiography for selecting the more reliable perforator of the anterolateral thigh flap: A comparison study.

    Science.gov (United States)

    La Padula, Simone; Hersant, Barbara; Meningaud, Jean Paul

    2018-03-30

    Anatomical variability of anterolateral thigh flap (ALT) perforators has been reported. The aim of this study is to assess if the use of intraoperative indocyanine green angiography (iICGA) can help surgeons to choose the ALT flap best perforator to be preserved. A retrospective study was conducted in 28 patients with open tibial fracture, following a road traffic crash, who had undergone ALT flap. Patients were classified into two groups: ICGA group (iICGA was used to select the more reliable perforator) and control group. The mean tissue loss size of the ICGA group (n = 13, 11 men and 2 women, mean age: 52 ± 6 years) was of 16.6 cm × 12.2 cm. The mean defect size of the control group (n = 15, 14 men and 1 women, mean age: 50 ± 5.52 years) was of 15.3 cm × 11.1 cm. Statistical analysis was performed to analyze and compare the results. ICGA allowed preserving only the most functional perforator, that provided the best ALT flap perfusion in 10 out of the 13 cases (77%). ICGA allowed a significant operative time reduction (160 ± 23 vs. 202 ± 48 minutes; P < .001). One case of distal necrosis was observed in the ICGA group (mean follow-up 12.3 months), while partial skin necrosis occurred in three cases of the control group (mean follow-up 13.1 months); P = .35. No additional coverage was required and a successful bone healing was observed in both groups. These findings suggest that iICGA is an effective method that allows to select the most reliable ALT flap perforators and to reduce operative time. © 2018 Wiley Periodicals, Inc.

  15. Reliable and accurate point-based prediction of cumulative infiltration using soil readily available characteristics: A comparison between GMDH, ANN, and MLR

    Science.gov (United States)

    Rahmati, Mehdi

    2017-08-01

    Developing accurate and reliable pedo-transfer functions (PTFs) to predict soil non-readily available characteristics is one of the most concerned topic in soil science and selecting more appropriate predictors is a crucial factor in PTFs' development. Group method of data handling (GMDH), which finds an approximate relationship between a set of input and output variables, not only provide an explicit procedure to select the most essential PTF input variables, but also results in more accurate and reliable estimates than other mostly applied methodologies. Therefore, the current research was aimed to apply GMDH in comparison with multivariate linear regression (MLR) and artificial neural network (ANN) to develop several PTFs to predict soil cumulative infiltration point-basely at specific time intervals (0.5-45 min) using soil readily available characteristics (RACs). In this regard, soil infiltration curves as well as several soil RACs including soil primary particles (clay (CC), silt (Si), and sand (Sa)), saturated hydraulic conductivity (Ks), bulk (Db) and particle (Dp) densities, organic carbon (OC), wet-aggregate stability (WAS), electrical conductivity (EC), and soil antecedent (θi) and field saturated (θfs) water contents were measured at 134 different points in Lighvan watershed, northwest of Iran. Then, applying GMDH, MLR, and ANN methodologies, several PTFs have been developed to predict cumulative infiltrations using two sets of selected soil RACs including and excluding Ks. According to the test data, results showed that developed PTFs by GMDH and MLR procedures using all soil RACs including Ks resulted in more accurate (with E values of 0.673-0.963) and reliable (with CV values lower than 11 percent) predictions of cumulative infiltrations at different specific time steps. In contrast, ANN procedure had lower accuracy (with E values of 0.356-0.890) and reliability (with CV values up to 50 percent) compared to GMDH and MLR. The results also revealed

  16. Comparison of two non-radiographic techniques of mixed dentition space analysis and evaluation of their reliability for Bengali population.

    Science.gov (United States)

    Dasgupta, Barun; Zahir, Shabnam

    2012-09-01

    Mixed dentition arch analysis system is an important criterion in determining the type of orthodontic treatment plan. Different mixed dentition arch analysis system are available and among them both Moyer's and Tanaka-Jhonson method of space analysis was developed for North American children. Anthropological study reveals that tooth size varies among different ethnicities The present study was performed to determine the reliability of Moyer's and Tanaka-Jhonson's method of mixed dentition arch analysis system among Bengali population. To perform the comparative evaluation of the two mixed dentition space analysis system among Bengali population. Dental casts of maxillary and mandibular arches of 70 Bengali children with permanent dentitions were fabricated. The mesiodistal crown dimensions of all erupted permanent incisors, canines, and premolars were measured with digital callipers. For particular sum of mandibular incisors, Moyer's and Tanaka-Jhonson's mixed dentition arch analysis were calculated and further statistical analysis was carried on. Descriptive statistics including the mean, standard deviation, and minimum and maximum values, unpaired't' tests, correlation coefficient "r" were calculated and tabulated. Tanaka and Johnston regression equations under-estimated the mesiodistal widths of permanent canines and premolars. On the other hand, there were no statistically significant differences between actual mesiodistal widths of canines and premolars and the predicted widths from Moyers charts at the 50% level for the lower and upper arches, among Bengali population. The study suggested that both Moyer's and Tanaka-Jhonson's mixed dentition arch analysis are applicable in Bengali population but with little modification in their regression equation.

  17. Reliability of an HTR-module primary circuit pressure boundary. Influences, sensitivity, and comparison with a PWR

    International Nuclear Information System (INIS)

    Staat, M.

    1995-01-01

    The reliability of the HTR-module for electricity and steam generation was analysed for normal operation, as well as accident conditions. The probabilistic fracture mechanics assessment was performed with a modification of the ZERBERUS code on the basis of widely used data. The calculated failure probabilities may thus be compared with similar investigations. The HTR-module primary circuit pressure boundary as a unit showed leak-before-break behaviour in a probabilistic sense, although a break was more probable than a leak for some of its parts.However, the findings may depend greatly on the stochastic data. Therefore a stochastic reference problem is defined and the results are compared with the Japanese round robin on a PWR section. Possible changes of failure probabilities and of the leak-before-break behaviour are discussed for different criteria for the events leading to a leak, and for modifications of the stochastic reference problem such as the inclusion of NDE. The results may be used to identify those stochastic variables which have the greatest influence on the computed failure probabilities, and to perhaps justify further work which would provide more detailed information on these probabilities. Furthermore, there is an obvious need for reduction of the non-statistical reasons for great variations of failure probabilities. (orig.)

  18. Comparison of two non-radiographic techniques of mixed dentition space analysis and evaluation of their reliability for Bengali population

    Directory of Open Access Journals (Sweden)

    Barun Dasgupta

    2012-01-01

    Full Text Available Context: Mixed dentition arch analysis system is an important criterion in determining the type of orthodontic treatment plan. Different mixed dentition arch analysis system are available and among them both Moyer′s and Tanaka-Jhonson method of space analysis was developed for North American children. Anthropological study reveals that tooth size varies among different ethnicities The present study was performed to determine the reliability of Moyer′s and Tanaka-Jhonson′s method of mixed dentition arch analysis system among Bengali population. Aims: To perform the comparative evaluation of the two mixed dentition space analysis system among Bengali population. Materials and Methods: Dental casts of maxillary and mandibular arches of 70 Bengali children with permanent dentitions were fabricated. The mesiodistal crown dimensions of all erupted permanent incisors, canines, and premolars were measured with digital callipers. For particular sum of mandibular incisors, Moyer′s and Tanaka-Jhonson′s mixed dentition arch analysis were calculated and further statistical analysis was carried on. Statistical analysis used: Descriptive statistics including the mean, standard deviation, and minimum and maximum values, unpaired′t′ tests, correlation coefficient "r" were calculated and tabulated. Results: Tanaka and Johnston regression equations under-estimated the mesiodistal widths of permanent canines and premolars. On the other hand, there were no statistically significant differences between actual mesiodistal widths of canines and premolars and the predicted widths from Moyers charts at the 50% level for the lower and upper arches, among Bengali population. Conclusions: The study suggested that both Moyer′s and Tanaka-Jhonson′s mixed dentition arch analysis are applicable in Bengali population but with little modification in their regression equation.

  19. Reliability of plant root comet assay in comparison with human leukocyte comet assay for assessment environmental genotoxic agents.

    Science.gov (United States)

    Reis, Gabriela Barreto Dos; Andrade-Vieira, Larissa Fonseca; Moraes, Isabella de Campos; César, Pedro Henrique Souza; Marcussi, Silvana; Davide, Lisete Chamma

    2017-08-01

    Comet assay is an efficient test to detect genotoxic compounds based on observation of DNA damage. The aim of this work was to compare the results obtained from the comet assay in two different type of cells extracted from the root tips from Lactuca sativa L. and human blood. For this, Spent Pot Liner (SPL), and its components (aluminum and fluoride) were applied as toxic agents. SPL is a solid waste generated in industry from the aluminum mining and processing with known toxicity. Three concentrations of all tested solutions were applied and the damages observed were compared to negative and positive controls. It was observed an increase in the frequency of DNA damage for human leukocytes and plant cells, in all treatments. On human leukocytes, SPL induced the highest percentage of damage, with an average of 87.68%. For root tips cells of L. sativa the highest percentage of damage was detected for aluminum (93.89%). Considering the arbitrary units (AU), the average of nuclei with high levels of DNA fragmentation was significant for both cells type evaluated. The tested cells demonstrated equal effectiveness for detection of the genotoxicity induced by the SPL and its chemical components, aluminum and fluoride. Further, using a unique method, the comet assay, we proved that cells from root tips of Lactuca sativa represent a reliable model to detect DNA damage induced by genotoxic pollutants is in agreement of those observed in human leukocytes as model. So far, plant cells may be suggested as important system to assess the toxicological risk of environmental agents. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Mental Help Seeking Attitudes Scale (MHSAS): Development, reliability, validity, and comparison with the ATSPPH-SF and IASMHS-PO.

    Science.gov (United States)

    Hammer, Joseph H; Parent, Mike C; Spiker, Douglas A

    2018-01-01

    Attitudes is a key help-seeking construct that influences treatment seeking behavior via intention to seek help, per the theory of planned behavior (TPB). This article presents the development and psychometric evaluation of the Mental Help Seeking Attitudes Scale (MHSAS), designed to measure respondents' overall evaluation (unfavorable vs. favorable) of their seeking help from a mental health professional. In Study 1 (N = 857 United States adults), exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and item response theory (IRT) analysis were used to identify an optimal set of 9 items that demonstrated initial evidence of internal consistency, unidimensionality, and strong measurement equivalence/invariance (ME/I) across gender, past help-seeking experience, and psychological distress. Initial convergent evidence of validity was demonstrated via theoretically anticipated relationships between the MHSAS and key variables in the help-seeking nomological network (e.g., subjective norms, perceived behavioral control, intention, public stigma, self-stigma, anticipated risks and benefits, gender, previous help seeking). Initial incremental evidence of validity was demonstrated when the MHSAS demonstrated the ability to account for unique variance in help-seeking intention, beyond that accounted for by the Attitudes Toward Seeking Professional Psychological Help-Short Form scale (ATSPPH-SF) and the Psychological Openness subscale of the Inventory of Attitudes Toward Seeking Mental Health Services (IASMHS-PO). Study 2 (N = 207 United States adults at Times 1 and 2) provided initial evidence of test-retest reliability over a 3-week period. The MHSAS offers mental health professionals a new tool for measuring attitudes that may avoid limitations of current help seeking-attitudes measures (e.g., construct-irrelevant variance). (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  1. Computed tomographic angiography criteria in the diagnosis of brain death - comparison of sensitivity and interobserver reliability of different evaluation scales

    International Nuclear Information System (INIS)

    Sawicki, Marcin; Walecka, A.; Bohatyrewicz, R.; Solek-Pastuszka, J.; Safranow, K.; Walecki, J.; Rowinski, O.; Czajkowski, Z.; Guzinski, M.; Burzynska, M.; Wojczal, J.

    2014-01-01

    The standardized diagnostic criteria for computed tomographic angiography (CTA) in diagnosis of brain death (BD) are not yet established. The aim of the study was to compare the sensitivity and interobserver agreement of the three previously used scales of CTA for the diagnosis of BD. Eighty-two clinically brain-dead patients underwent CTA with a delay of 40 s after contrast injection. Catheter angiography was used as the reference standard. CTA results were assessed by two radiologists, and the diagnosis of BD was established according to 10-, 7-, and 4-point scales. Catheter angiography confirmed the diagnosis of BD in all cases. Opacification of certain cerebral vessels as indicator of BD was highly sensitive: cortical segments of the middle cerebral artery (96.3 %), the internal cerebral vein (98.8 %), and the great cerebral vein (98.8 %). Other vessels were less sensitive: the pericallosal artery (74.4 %), cortical segments of the posterior cerebral artery (79.3 %), and the basilar artery (82.9 %). The sensitivities of the 10-, 7-, and 4-point scales were 67.1, 74.4, and 96.3 %, respectively (p < 0.001). Percentage interobserver agreement in diagnosis of BD reached 93 % for the 10-point scale, 89 % for the 7-point scale, and 95 % for the 4-point scale (p = 0.37). In the application of CTA to the diagnosis of BD, reducing the assessment of vascular opacification scale from a 10- to a 4-point scale significantly increases the sensitivity and maintains high interobserver reliability. (orig.)

  2. Computed tomographic angiography criteria in the diagnosis of brain death - comparison of sensitivity and interobserver reliability of different evaluation scales

    Energy Technology Data Exchange (ETDEWEB)

    Sawicki, Marcin; Walecka, A. [Pomeranian Medical University, Department of Diagnostic Imaging and Interventional Radiology, Szczecin (Poland); Bohatyrewicz, R.; Solek-Pastuszka, J. [Pomeranian Medical University, Clinic of Anesthesiology and Intensive Care, Szczecin (Poland); Safranow, K. [Pomeranian Medical University, Department of Biochemistry and Medical Chemistry, Szczecin (Poland); Walecki, J. [The Centre of Postgraduate Medical Education, Warsaw (Poland); Rowinski, O. [Medical University of Warsaw, 2nd Department of Clinical Radiology, Warsaw (Poland); Czajkowski, Z. [Regional Joint Hospital, Szczecin (Poland); Guzinski, M. [Wroclaw Medical University, Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw (Poland); Burzynska, M. [Wroclaw Medical University, Department of Anesthesiology and Intensive Therapy, Wroclaw (Poland); Wojczal, J. [Medical University of Lublin, Department of Neurology, Lublin (Poland)

    2014-08-15

    The standardized diagnostic criteria for computed tomographic angiography (CTA) in diagnosis of brain death (BD) are not yet established. The aim of the study was to compare the sensitivity and interobserver agreement of the three previously used scales of CTA for the diagnosis of BD. Eighty-two clinically brain-dead patients underwent CTA with a delay of 40 s after contrast injection. Catheter angiography was used as the reference standard. CTA results were assessed by two radiologists, and the diagnosis of BD was established according to 10-, 7-, and 4-point scales. Catheter angiography confirmed the diagnosis of BD in all cases. Opacification of certain cerebral vessels as indicator of BD was highly sensitive: cortical segments of the middle cerebral artery (96.3 %), the internal cerebral vein (98.8 %), and the great cerebral vein (98.8 %). Other vessels were less sensitive: the pericallosal artery (74.4 %), cortical segments of the posterior cerebral artery (79.3 %), and the basilar artery (82.9 %). The sensitivities of the 10-, 7-, and 4-point scales were 67.1, 74.4, and 96.3 %, respectively (p < 0.001). Percentage interobserver agreement in diagnosis of BD reached 93 % for the 10-point scale, 89 % for the 7-point scale, and 95 % for the 4-point scale (p = 0.37). In the application of CTA to the diagnosis of BD, reducing the assessment of vascular opacification scale from a 10- to a 4-point scale significantly increases the sensitivity and maintains high interobserver reliability. (orig.)

  3. Deterministic and stochastic approach for safety and reliability optimization of captive power plant maintenance scheduling using GA/SA-based hybrid techniques: A comparison of results

    International Nuclear Information System (INIS)

    Mohanta, Dusmanta Kumar; Sadhu, Pradip Kumar; Chakrabarti, R.

    2007-01-01

    This paper presents a comparison of results for optimization of captive power plant maintenance scheduling using genetic algorithm (GA) as well as hybrid GA/simulated annealing (SA) techniques. As utilities catered by captive power plants are very sensitive to power failure, therefore both deterministic and stochastic reliability objective functions have been considered to incorporate statutory safety regulations for maintenance of boilers, turbines and generators. The significant contribution of this paper is to incorporate stochastic feature of generating units and that of load using levelized risk method. Another significant contribution of this paper is to evaluate confidence interval for loss of load probability (LOLP) because some variations from optimum schedule are anticipated while executing maintenance schedules due to different real-life unforeseen exigencies. Such exigencies are incorporated in terms of near-optimum schedules obtained from hybrid GA/SA technique during the final stages of convergence. Case studies corroborate that same optimum schedules are obtained using GA and hybrid GA/SA for respective deterministic and stochastic formulations. The comparison of results in terms of interval of confidence for LOLP indicates that levelized risk method adequately incorporates the stochastic nature of power system as compared with levelized reserve method. Also the interval of confidence for LOLP denotes the possible risk in a quantified manner and it is of immense use from perspective of captive power plants intended for quality power

  4. A Comparison of Result Reliability for Investigation of Milk Composition by Alternative Analytical Methods in Czech Republic

    Directory of Open Access Journals (Sweden)

    Oto Hanuš

    2014-01-01

    Full Text Available The milk analyse result reliability is important for assurance of foodstuff chain quality. There are more direct and indirect methods for milk composition measurement (fat (F, protein (P, lactose (L and solids non fat (SNF content. The goal was to evaluate some reference and routine milk analytical procedures on result basis. The direct reference analyses were: F, fat content (Röse–Gottlieb method; P, crude protein content (Kjeldahl method; L, lactose (monohydrate, polarimetric method; SNF, solids non fat (gravimetric method. F, P, L and SNF were determined also by various indirect methods: – MIR (infrared (IR technology with optical filters, 7 instruments in 4 labs; – MIR–FT (IR spectroscopy with Fourier’s transformations, 10 in 6; – ultrasonic method (UM, 3 in 1; – analysis by the blue and red box (BRB, 1 v 1. There were used 10 reference milk samples. Coefficient of determination (R2, correlation coefficient (r and standard deviation of the mean of individual differences (MDsd, for n were evaluated. All correlations (r; for all indirect and alternative methods and all milk components were significant (P ≤ 0.001. MIR and MIR–FT (conventional methods explained considerably higher proportion of the variability in reference results than the UM and BRB methods (alternative. All r average values (x minus 1.64 × sd for 95% confidence interval can be used as standards for calibration quality evaluation (MIR, MIR–FT, UM and BRB: – for F 0.997, 0.997, 0.99 and 0.995; – for P 0.986, 0.981, 0.828 and 0.864; – for L 0.968, 0.871, 0.705 and 0.761; – for SNF 0.992, 0.993, 0.911 and 0.872. Similarly ​MDsd (x plus 1.64 × sd: – for F 0.071, 0.068, 0.132 and 0.101%; – for P 0.051, 0.054, 0.202 and 0.14%; – for L 0.037, 0.074, 0.113 and 0.11%; – for SNF 0.052, 0.068, 0.141 and 0.204.

  5. A comparison of patency and interventions in thigh versus Hemodialysis Reliable Outflow grafts for chronic hemodialysis vascular access.

    Science.gov (United States)

    Brownie, Evan R; Kensinger, Clark D; Feurer, Irene D; Moore, Derek E; Shaffer, David

    2016-11-01

    With improvements in medical management and survival of patients with end-stage renal disease, maintaining durable vascular access is increasingly challenging. This study compared primary, assisted primary, and secondary patency, and procedure-specific complications, and evaluated whether the number of interventions to maintain or restore patency differed between prosthetic femoral-femoral looped inguinal access (thigh) grafts and Hemodialysis Reliable Outflow (HeRO; Hemosphere Inc, Minneapolis, Minn) grafts. A single-center, retrospective, intention-to-treat analysis was conducted of consecutive thigh and HeRO grafts placed between May 2004 and June 2015. Medical history, interventions to maintain or restore patency, and complications were abstracted from the electronic medical record. Data were analyzed using parametric and nonparametric statistical tests, Kaplan-Meier survival methods, and multivariable proportional hazards regression and logistic regression. Seventy-six (43 thigh, 33 HeRO) grafts were placed in 61 patients (54% male; age 53 [standard deviation, 13] years). Median follow-up time in the intention-to-treat analysis was 21.2 months (min, 0.0; max, 85.3 months) for thigh grafts and 6.7 months (min, 0.0; max, 56.3 months) for HeRO grafts (P = .02). The groups were comparable for sex, age, coronary artery disease, diabetes mellitus, peripheral vascular disease, and smoking history (all P ≥ .12). One thigh graft (2%) and five HeRO (15%) grafts failed primarily. In the intention-to-treat analysis, patency durations were significantly longer in the thigh grafts (all log-rank P ≤ .01). Point estimates of primary patency at 6 months, 1 year, and 3 years were 61%, 46%, and 4% for the thigh grafts and 25%, 15%, and 6% for the HeRO grafts. Point estimates of assisted primary patency at 6 months, 1 year, and 3 years were 75%, 66%, and 54% for the thigh grafts and 41%, 30%, and 10% for the HeRO grafts. Point estimates of secondary patency at 6

  6. Software reliability

    CERN Document Server

    Bendell, A

    1986-01-01

    Software Reliability reviews some fundamental issues of software reliability as well as the techniques, models, and metrics used to predict the reliability of software. Topics covered include fault avoidance, fault removal, and fault tolerance, along with statistical methods for the objective assessment of predictive accuracy. Development cost models and life-cycle cost models are also discussed. This book is divided into eight sections and begins with a chapter on adaptive modeling used to predict software reliability, followed by a discussion on failure rate in software reliability growth mo

  7. A Comparison and Calibration of a Wrist-Worn Blood Pressure Monitor for Patient Management: Assessing the Reliability of Innovative Blood Pressure Devices

    Science.gov (United States)

    Melville, Sarah; Teskey, Robert; Philip, Shona; Simpson, Jeremy A; Lutchmedial, Sohrab

    2018-01-01

    Background Clinical guidelines recommend monitoring of blood pressure at home using an automatic blood pressure device for the management of hypertension. Devices are not often calibrated against direct blood pressure measures, leaving health care providers and patients with less reliable information than is possible with current technology. Rigorous assessments of medical devices are necessary for establishing clinical utility. Objective The purpose of our study was 2-fold: (1) to assess the validity and perform iterative calibration of indirect blood pressure measurements by a noninvasive wrist cuff blood pressure device in direct comparison with simultaneously recorded peripheral and central intra-arterial blood pressure measurements and (2) to assess the validity of the measurements thereafter of the noninvasive wrist cuff blood pressure device in comparison with measurements by a noninvasive upper arm blood pressure device to the Canadian hypertension guidelines. Methods The cloud-based blood pressure algorithms for an oscillometric wrist cuff device were iteratively calibrated to direct pressure measures in 20 consented patient participants. We then assessed measurement validity of the device, using Bland-Altman analysis during routine cardiovascular catheterization. Results The precalibrated absolute mean difference between direct intra-arterial to wrist cuff pressure measurements were 10.8 (SD 9.7) for systolic and 16.1 (SD 6.3) for diastolic. The postcalibrated absolute mean difference was 7.2 (SD 5.1) for systolic and 4.3 (SD 3.3) for diastolic pressures. This is an improvement in accuracy of 33% systolic and 73% diastolic with a 48% reduction in the variability for both measures. Furthermore, the wrist cuff device demonstrated similar sensitivity in measuring high blood pressure compared with the direct intra-arterial method. The device, when calibrated to direct aortic pressures, demonstrated the potential to reduce a treatment gap in high blood

  8. RTE - 2013 Reliability Report

    International Nuclear Information System (INIS)

    Denis, Anne-Marie

    2014-01-01

    RTE publishes a yearly reliability report based on a standard model to facilitate comparisons and highlight long-term trends. The 2013 report is not only stating the facts of the Significant System Events (ESS), but it moreover underlines the main elements dealing with the reliability of the electrical power system. It highlights the various elements which contribute to present and future reliability and provides an overview of the interaction between the various stakeholders of the Electrical Power System on the scale of the European Interconnected Network. (author)

  9. Human reliability

    International Nuclear Information System (INIS)

    Embrey, D.E.

    1987-01-01

    Concepts and techniques of human reliability have been developed and are used mostly in probabilistic risk assessment. For this, the major application of human reliability assessment has been to identify the human errors which have a significant effect on the overall safety of the system and to quantify the probability of their occurrence. Some of the major issues within human reliability studies are reviewed and it is shown how these are applied to the assessment of human failures in systems. This is done under the following headings; models of human performance used in human reliability assessment, the nature of human error, classification of errors in man-machine systems, practical aspects, human reliability modelling in complex situations, quantification and examination of human reliability, judgement based approaches, holistic techniques and decision analytic approaches. (UK)

  10. Reliability Calculations

    DEFF Research Database (Denmark)

    Petersen, Kurt Erling

    1986-01-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety...... and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic...... approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very...

  11. Accuracy and reliability in sex determination from skulls: a comparison of Fordisc® 3.0 and the discriminant function analysis.

    Science.gov (United States)

    Guyomarc'h, Pierre; Bruzek, Jaroslav

    2011-05-20

    Identification in forensic anthropology and the definition of a biological profile in bioarchaeology are essential to each of those fields and use the same methodologies. Sex, age, stature and ancestry can be conclusive or dispensable, depending on the field. The Fordisc(®) 3.0 computer program was developed to aid in the identification of the sex, stature and ancestry of skeletal remains by exploiting the Forensic Data Bank (FDB) and computing discriminant function analyses (DFAs). Although widely used, this tool has been recently criticised, principally when used to determine ancestry. Two sub-samples of individuals of known sex were drawn from French (n=50) and Thai (n=91) osteological collections and used to assess the reliability of sex determination using Fordisc(®) 3.0 with 12 cranial measurements. Comparisons were made using the whole FDB as well as using select groups, taking into account the posterior and typicality probabilities. The results of Fordisc(®) 3.0 vary between 52.2% and 77.8% depending on the options and groups selected. Tests of published discriminant functions and the computation of specific DFA were performed in order to discuss the applicability of this software and, overall, to question the pertinence of the use of DFA and linear distances in sex determination, in light of the huge cranial morphological variability. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Split-bolus single-phase cardiac multidetector computed tomography for reliable detection of left atrial thrombus. Comparison to transesophageal echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Staab, W.; Zwaka, P.A.; Sohns, J.M.; Schwarz, A.; Lotz, J. [University Medical Center Goettingen Univ. (Germany). Inst. for Diagnostic and Interventional Radiology; Sohns, C.; Vollmann, D.; Zabel, M.; Hasenfuss, G. [Goettingen Univ. (Germany). Dept. of Cardiology and Pneumology; Schneider, S. [Goettingen Univ. (Germany). Dept. of Medical Statistics

    2014-11-15

    Evaluation of a new cardiac MDCT protocol using a split-bolus contrast injection protocol and single MDCT scan for reliable diagnosis of LA/LAA thrombi in comparison to TEE, optimizing radiation exposure and use of contrast agent. A total of 182 consecutive patients with drug refractory AF scheduled for PVI (62.6% male, mean age: 64.1 ± 10.2 years) underwent routine diagnostic work including TEE and cardiac MDCT for the evaluation of LA/LAA anatomy and thrombus formation between November 2010 and March 2012. Contrast media injection was split into a pre-bolus of 30 ml and main bolus of 70 ml iodinated contrast agent separated by a short time delay. In this study, split-bolus cardiac MDCT identified 14 of 182 patients with filling defects of the LA/LAA. In all of these 14 patients, abnormalities were found in TEE. All 5 of the 14 patients with thrombus formation in cardiac MDCT were confirmed by TEE. MDCT was 100% accurate for thrombus, with strong but not perfect overall results for SEC equivalent on MDCT.

  13. Accuracy and reliability of different cone beam computed tomography (CBCT) devices for structural analysis of alveolar bone in comparison with multislice CT and micro-CT.

    Science.gov (United States)

    Van Dessel, Jeroen; Nicolielo, Laura Ferreira Pinheiro; Huang, Yan; Coudyzer, Walter; Salmon, Benjamin; Lambrichts, Ivo; Jacobs, Reinhilde

    The aim of this study was to assess whether cone beam computed tomography (CBCT) may be used for clinically reliable alveolar bone quality assessment in comparison to its clinical alternatives, multislice computed tomography and the gold standard (micro-CT). Six dentate mandibular bone samples were scanned with seven CBCT devices (ProMax 3D Max, NewTom GiANO, Cranex 3D, 3D Accuitomo 170, Carestream 9300, Scanora 3D, I-CAT Next generation), one micro-CT scanner (SkyScan 1174) and one MSCT machine (Somatom Definition Flash) using two protocols (standard and high-resolution). MSCT and CBCT images were automatically spatially aligned on the micro-CT scan of the corresponding sample. A volume of interest was manually delineated on the micro-CT image and overlaid on the other scanning devices. Alveolar bone structures were automatically extracted using the adaptive thresholding algorithm. Based on the resulting binary images, an automatic 3D morphometric quantification was performed in a CT-Analyser (Bruker, Kontich, Belgium). The reliability and measurement errors were calculated for each modality compared to the gold standard micro-CT. Both MSCT and CBCT were associated with a clinically and statistically (P max, bone surface density -0.47 mm-1 min to 0.16 mm-1 max and trabecular thickness 0.15 mm min to 0.31 mm max) were significantly (P max and fractal dimension 0.08 min to 0.17 max) in all scanners compared to micro-CT. However, the structural pattern of the alveolar bone remained similar compared to that of the micro-CT for the ProMax 3D Max, NewTom GiANO, Cranex 3D, 3D Accuitomo 170 and Carestream 9300. On the other hand, the Scanora 3D, i-CAT Next Generation, standard and high-resolution MSCT displayed an overrated bone quantity and aberrant structural pattern compared to other scanning devices. The calculation of morphometric indices had an overall high reliability (intraclass correlation coefficient [ICC] 0.62 min to 0.99 max), except

  14. Hawaii Electric System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Loose, Verne William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Silva Monroy, Cesar Augusto [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2012-08-01

    This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers’ views of reliability “worth” and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and for application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers’ views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.

  15. Hawaii electric system reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Silva Monroy, Cesar Augusto; Loose, Verne William

    2012-09-01

    This report addresses Hawaii electric system reliability issues; greater emphasis is placed on short-term reliability but resource adequacy is reviewed in reference to electric consumers' views of reliability %E2%80%9Cworth%E2%80%9D and the reserve capacity required to deliver that value. The report begins with a description of the Hawaii electric system to the extent permitted by publicly available data. Electrical engineering literature in the area of electric reliability is researched and briefly reviewed. North American Electric Reliability Corporation standards and measures for generation and transmission are reviewed and identified as to their appropriateness for various portions of the electric grid and for application in Hawaii. Analysis of frequency data supplied by the State of Hawaii Public Utilities Commission is presented together with comparison and contrast of performance of each of the systems for two years, 2010 and 2011. Literature tracing the development of reliability economics is reviewed and referenced. A method is explained for integrating system cost with outage cost to determine the optimal resource adequacy given customers' views of the value contributed by reliable electric supply. The report concludes with findings and recommendations for reliability in the State of Hawaii.

  16. A Comparison of the Approaches of Generalizability Theory and Item Response Theory in Estimating the Reliability of Test Scores for Testlet-Composed Tests

    Science.gov (United States)

    Lee, Guemin; Park, In-Yong

    2012-01-01

    Previous assessments of the reliability of test scores for testlet-composed tests have indicated that item-based estimation methods overestimate reliability. This study was designed to address issues related to the extent to which item-based estimation methods overestimate the reliability of test scores composed of testlets and to compare several…

  17. Building America Case Study: Side-by-Side Testing of Water Heating Systems: Results from 2013-2014 Evaluation Final Report, Cocoa, FL

    Energy Technology Data Exchange (ETDEWEB)

    Rothgeb, Stacey K [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Colon, C. [BA-PIRC; Martin, E. [BA-PIRC

    2017-08-24

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  18. Building America Case Study: Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation Final Report

    Energy Technology Data Exchange (ETDEWEB)

    C. Colon and E. Martin

    2017-08-24

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  19. Reliability Engineering

    CERN Document Server

    Lazzaroni, Massimo

    2012-01-01

    This book gives a practical guide for designers and users in Information and Communication Technology context. In particular, in the first Section, the definition of the fundamental terms according to the international standards are given. Then, some theoretical concepts and reliability models are presented in Chapters 2 and 3: the aim is to evaluate performance for components and systems and reliability growth. Chapter 4, by introducing the laboratory tests, puts in evidence the reliability concept from the experimental point of view. In ICT context, the failure rate for a given system can be

  20. Reliability training

    Science.gov (United States)

    Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Dillard, Richard B.; Wong, Kam L.; Barber, Frank J.; Barina, Frank J.

    1992-01-01

    Discussed here is failure physics, the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low cost reliable products. A review of reliability for the years 1940 to 2000 is given. Next, a review of mathematics is given as well as a description of what elements contribute to product failures. Basic reliability theory and the disciplines that allow us to control and eliminate failures are elucidated.

  1. Reliability calculations

    International Nuclear Information System (INIS)

    Petersen, K.E.

    1986-03-01

    Risk and reliability analysis is increasingly being used in evaluations of plant safety and plant reliability. The analysis can be performed either during the design process or during the operation time, with the purpose to improve the safety or the reliability. Due to plant complexity and safety and availability requirements, sophisticated tools, which are flexible and efficient, are needed. Such tools have been developed in the last 20 years and they have to be continuously refined to meet the growing requirements. Two different areas of application were analysed. In structural reliability probabilistic approaches have been introduced in some cases for the calculation of the reliability of structures or components. A new computer program has been developed based upon numerical integration in several variables. In systems reliability Monte Carlo simulation programs are used especially in analysis of very complex systems. In order to increase the applicability of the programs variance reduction techniques can be applied to speed up the calculation process. Variance reduction techniques have been studied and procedures for implementation of importance sampling are suggested. (author)

  2. Phylo.io: Interactive Viewing and Comparison of Large Phylogenetic Trees on the Web.

    Science.gov (United States)

    Robinson, Oscar; Dylus, David; Dessimoz, Christophe

    2016-08-01

    Phylogenetic trees are pervasively used to depict evolutionary relationships. Increasingly, researchers need to visualize large trees and compare multiple large trees inferred for the same set of taxa (reflecting uncertainty in the tree inference or genuine discordance among the loci analyzed). Existing tree visualization tools are however not well suited to these tasks. In particular, side-by-side comparison of trees can prove challenging beyond a few dozen taxa. Here, we introduce Phylo.io, a web application to visualize and compare phylogenetic trees side-by-side. Its distinctive features are: highlighting of similarities and differences between two trees, automatic identification of the best matching rooting and leaf order, scalability to large trees, high usability, multiplatform support via standard HTML5 implementation, and possibility to store and share visualizations. The tool can be freely accessed at http://phylo.io and can easily be embedded in other web servers. The code for the associated JavaScript library is available at https://github.com/DessimozLab/phylo-io under an MIT open source license. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. Systems reliability/structural reliability

    International Nuclear Information System (INIS)

    Green, A.E.

    1980-01-01

    The question of reliability technology using quantified techniques is considered for systems and structures. Systems reliability analysis has progressed to a viable and proven methodology whereas this has yet to be fully achieved for large scale structures. Structural loading variants over the half-time of the plant are considered to be more difficult to analyse than for systems, even though a relatively crude model may be a necessary starting point. Various reliability characteristics and environmental conditions are considered which enter this problem. The rare event situation is briefly mentioned together with aspects of proof testing and normal and upset loading conditions. (orig.)

  4. Comparison of reliability of five patellar position indices at various stifle joint angles in pelvic limbs obtained from cadavers of red foxes (Vulpes vulpes)

    DEFF Research Database (Denmark)

    Miles, James E; Nielsen, Dorte H; Jensen, Bente Rona

    2012-01-01

    To compare 5 patellar position indices at various stifle joint angles in cadavers of red foxes, determine measurement reliability, and assess the suitability of these indices for clinical use.......To compare 5 patellar position indices at various stifle joint angles in cadavers of red foxes, determine measurement reliability, and assess the suitability of these indices for clinical use....

  5. Human reliability

    International Nuclear Information System (INIS)

    Bubb, H.

    1992-01-01

    This book resulted from the activity of Task Force 4.2 - 'Human Reliability'. This group was established on February 27th, 1986, at the plenary meeting of the Technical Reliability Committee of VDI, within the framework of the joint committee of VDI on industrial systems technology - GIS. It is composed of representatives of industry, representatives of research institutes, of technical control boards and universities, whose job it is to study how man fits into the technical side of the world of work and to optimize this interaction. In a total of 17 sessions, information from the part of ergonomy dealing with human reliability in using technical systems at work was exchanged, and different methods for its evaluation were examined and analyzed. The outcome of this work was systematized and compiled in this book. (orig.) [de

  6. Microelectronics Reliability

    Science.gov (United States)

    2017-01-17

    inverters  connected in a chain. ................................................. 5  Figure 3  Typical graph showing frequency versus square root of...developing an experimental  reliability estimating methodology that could both illuminate the  lifetime  reliability of advanced devices,  circuits and...or  FIT of the device. In other words an accurate estimate of the device  lifetime  was found and thus the  reliability  that  can  be  conveniently

  7. Reliability evaluation of non-reparable three-state systems using Markov model and its comparison with the UGF and the recursive methods

    International Nuclear Information System (INIS)

    Pourkarim Guilani, Pedram; Sharifi, Mani; Niaki, S.T.A.; Zaretalab, Arash

    2014-01-01

    In multi-state systems (MSS) reliability problems, it is assumed that the components of each subsystem have different performance rates with certain probabilities. This leads into extensive computational efforts involved in using the commonly employed universal generation function (UGF) and the recursive algorithm to obtain reliability of systems consisting of a large number of components. This research deals with evaluating non-repairable three-state systems reliability and proposes a novel method based on a Markov process for which an appropriate state definition is provided. It is shown that solving the derived differential equations significantly reduces the computational time compared to the UGF and the recursive algorithm. - Highlights: • Reliability evaluation of a non-repairable three-state systems is aimed. • A novel method based on a Markov process is proposed. • An appropriate state definition is provided. • Computational time is significantly less compared to the ones in the UGF and the recursive methods

  8. RTE - 2015 Reliability Report. Summary

    International Nuclear Information System (INIS)

    2016-01-01

    Every year, RTE produces a reliability report for the past year. This report includes a number of results from previous years so that year-to-year comparisons can be drawn and long-term trends analysed. The 2015 report underlines the major factors that have impacted on the reliability of the electrical power system, without focusing exclusively on Significant System Events (ESS). It describes various factors which contribute to present and future reliability and the numerous actions implemented by RTE to ensure reliability today and in the future, as well as the ways in which the various parties involved in the electrical power system interact across the whole European interconnected network

  9. Redefining reliability

    International Nuclear Information System (INIS)

    Paulson, S.L.

    1995-01-01

    Want to buy some reliability? The question would have been unthinkable in some markets served by the natural gas business even a few years ago, but in the new gas marketplace, industrial, commercial and even some residential customers have the opportunity to choose from among an array of options about the kind of natural gas service they need--and are willing to pay for. The complexities of this brave new world of restructuring and competition have sent the industry scrambling to find ways to educate and inform its customers about the increased responsibility they will have in determining the level of gas reliability they choose. This article discusses the new options and the new responsibilities of customers, the needed for continuous education, and MidAmerican Energy Company's experiment in direct marketing of natural gas

  10. Solar g-modes? Comparison of detected asymptotic g-mode frequencies with solar model predictions

    Science.gov (United States)

    Wood, Suzannah Rebecca; Guzik, Joyce Ann; Mussack, Katie; Bradley, Paul A.

    2018-06-01

    After many years of searching for solar gravity modes, Fossat et al. (2017) reported detection of the nearly equally spaced high-order g-modes periods using a 15-year time series of GOLF data from the SOHO spacecraft. Here we report progress towards and challenges associated with calculating and comparing g-mode period predictions for several previously published standard solar models using various abundance mixtures and opacities, as well as the predictions for some non-standard models incorporating early mass loss, and compare with the periods reported by Fossat et al (2017). Additionally, we have a side-by-side comparison of results of different stellar pulsation codes for calculating g-mode predictions. These comparisons will allow for testing of nonstandard physics input that affect the core, including an early more massive Sun and dynamic electron screening.

  11. Reliability and comparison of gain values with occurrence of saccades in the EyeSeeCam video head impulse test (vHIT)

    DEFF Research Database (Denmark)

    Hviid Korsager, Leise Elisabeth; Schmidt, Jesper Hvass; Faber, Christian

    2016-01-01

    . There is a lack of knowledge regarding the reliability of the two parameters. The objective was to investigate the reliability of vHIT by comparing gain values between examiners on the same subjects, and to see how differences affected the occurrence of saccades. SUBJECTS: 25 subjects who had undergone cochlear...... coefficient (ICC) of the gain values between examiners ranged from 0.62 to 0.70. Differences in gain values amongst examiners did not seem to affect the occurrence of saccades in the same patient. The occurrence of saccades, therefore, seems to be more reliable than the gain value in the evaluation......The vHIT (video head impulse test) investigates the vestibular function in two ways: a VOR (vestibulo-ocular reflex) gain value and a head impulse diagram. From the diagram covert and overt saccades can be detected. Evaluation of the vestibular function based on vHIT depends on both parameters...

  12. Reliability and Validity of the Computerized Revised Token Test: Comparison of Reading and Listening Versions in Persons with and without Aphasia

    Science.gov (United States)

    McNeil, Malcolm R.; Pratt, Sheila R.; Szuminsky, Neil; Sung, Jee Eun; Fossett, Tepanta R. D.; Fassbinder, Wiltrud; Lim, Kyoung Yuel

    2015-01-01

    Purpose: This study assessed the reliability and validity of intermodality associations and differences in persons with aphasia (PWA) and healthy controls (HC) on a computerized listening and 3 reading versions of the Revised Token Test (RTT; McNeil & Prescott, 1978). Method: Thirty PWA and 30 HC completed the test versions, including a…

  13. Assessing the accuracy and reliability of ultrasonographic three-dimensional parathyroid volume measurement in a patient with secondary hyperparathyroidism: a comparison with the two-dimensional conventional method

    Energy Technology Data Exchange (ETDEWEB)

    You, Sung Hye; Son, Gyu Ri; Lee, Nam Joon [Dept. of Radiology, Korea University Anam Hospital, Seoul (Korea, Republic of); Suh, Sangil; Ryoo, In Seon; Seol, Hae Young [Dept. of Radiology, Korea University Guro Hospital, Seoul (Korea, Republic of); Lee, Young Hen; Seo, Hyung Suk [Dept. of Radiology, Korea University Ansan Hospital, Ansan (Korea, Republic of)

    2017-01-15

    The purpose of this study was to investigate the accuracy and reliability of the semi-automated ultrasonographic volume measurement tool, virtual organ computer-aided analysis (VOCAL), for measuring the volume of parathyroid glands. Volume measurements for 40 parathyroid glands were performed in patients with secondary hyperparathyroidism caused by chronic renal failure. The volume of the parathyroid glands was measured twice by experienced radiologists by two-dimensional (2D) and three-dimensional (3D) methods using conventional sonograms and the VOCAL with 30°angle increments before parathyroidectomy. The specimen volume was also measured postoperatively. Intraclass correlation coefficients (ICCs) and the absolute percentage error were used for estimating the reproducibility and accuracy of the two different methods. The ICC value between two measurements of the 2D method and the 3D method was 0.956 and 0.999, respectively. The mean absolute percentage error of the 2D method and the 3D VOCAL technique was 29.56% and 5.78%, respectively. For accuracy and reliability, the plots of the 3D method showed a more compact distribution than those of the 2D method on the Bland-Altman graph. The rotational VOCAL method for measuring the parathyroid gland is more accurate and reliable than the conventional 2D measurement. This VOCAL method could be used as a more reliable follow-up imaging modality in a patient with hyperparathyroidism.

  14. Assessing the accuracy and reliability of ultrasonographic three-dimensional parathyroid volume measurement in a patient with secondary hyperparathyroidism: a comparison with the two-dimensional conventional method

    Directory of Open Access Journals (Sweden)

    Sung-Hye You

    2017-01-01

    Full Text Available Purpose The purpose of this study was to investigate the accuracy and reliability of the semi-automated ultrasonographic volume measurement tool, virtual organ computer-aided analysis (VOCAL, for measuring the volume of parathyroid glands. Methods Volume measurements for 40 parathyroid glands were performed in patients with secondary hyperparathyroidism caused by chronic renal failure. The volume of the parathyroid glands was measured twice by experienced radiologists by two-dimensional (2D and three-dimensional (3D methods using conventional sonograms and the VOCAL with 30°angle increments before parathyroidectomy. The specimen volume was also measured postoperatively. Intraclass correlation coefficients (ICCs and the absolute percentage error were used for estimating the reproducibility and accuracy of the two different methods. Results The ICC value between two measurements of the 2D method and the 3D method was 0.956 and 0.999, respectively. The mean absolute percentage error of the 2D method and the 3D VOCAL technique was 29.56% and 5.78%, respectively. For accuracy and reliability, the plots of the 3D method showed a more compact distribution than those of the 2D method on the Bland-Altman graph. Conclusion The rotational VOCAL method for measuring the parathyroid gland is more accurate and reliable than the conventional 2D measurement. This VOCAL method could be used as a more reliable follow-up imaging modality in a patient with hyperparathyroidism.

  15. Assessing the accuracy and reliability of ultrasonographic three-dimensional parathyroid volume measurement in a patient with secondary hyperparathyroidism: a comparison with the two-dimensional conventional method

    International Nuclear Information System (INIS)

    You, Sung Hye; Son, Gyu Ri; Lee, Nam Joon; Suh, Sangil; Ryoo, In Seon; Seol, Hae Young; Lee, Young Hen; Seo, Hyung Suk

    2017-01-01

    The purpose of this study was to investigate the accuracy and reliability of the semi-automated ultrasonographic volume measurement tool, virtual organ computer-aided analysis (VOCAL), for measuring the volume of parathyroid glands. Volume measurements for 40 parathyroid glands were performed in patients with secondary hyperparathyroidism caused by chronic renal failure. The volume of the parathyroid glands was measured twice by experienced radiologists by two-dimensional (2D) and three-dimensional (3D) methods using conventional sonograms and the VOCAL with 30°angle increments before parathyroidectomy. The specimen volume was also measured postoperatively. Intraclass correlation coefficients (ICCs) and the absolute percentage error were used for estimating the reproducibility and accuracy of the two different methods. The ICC value between two measurements of the 2D method and the 3D method was 0.956 and 0.999, respectively. The mean absolute percentage error of the 2D method and the 3D VOCAL technique was 29.56% and 5.78%, respectively. For accuracy and reliability, the plots of the 3D method showed a more compact distribution than those of the 2D method on the Bland-Altman graph. The rotational VOCAL method for measuring the parathyroid gland is more accurate and reliable than the conventional 2D measurement. This VOCAL method could be used as a more reliable follow-up imaging modality in a patient with hyperparathyroidism

  16. A Review and Comparison of the Reliabilities of the MMPI-2, MCMI-III, and PAI Presented in Their Respective Test Manuals

    Science.gov (United States)

    Wise, Edward A.; Streiner, David L.; Walfish, Steven

    2010-01-01

    This article provides a review of the literature to determine the most frequently used personality tests. Based on this review, internal consistency and test-retest reliability coefficients from the test manuals for the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Millon Clinical Multiaxial Inventory-III (MCMI-III), and Personality…

  17. Reliability of Oronasal Fistula Classification.

    Science.gov (United States)

    Sitzman, Thomas J; Allori, Alexander C; Matic, Damir B; Beals, Stephen P; Fisher, David M; Samson, Thomas D; Marcus, Jeffrey R; Tse, Raymond W

    2018-01-01

    Objective Oronasal fistula is an important complication of cleft palate repair that is frequently used to evaluate surgical quality, yet reliability of fistula classification has never been examined. The objective of this study was to determine the reliability of oronasal fistula classification both within individual surgeons and between multiple surgeons. Design Using intraoral photographs of children with repaired cleft palate, surgeons rated the location of palatal fistulae using the Pittsburgh Fistula Classification System. Intrarater and interrater reliability scores were calculated for each region of the palate. Participants Eight cleft surgeons rated photographs obtained from 29 children. Results Within individual surgeons reliability for each region of the Pittsburgh classification ranged from moderate to almost perfect (κ = .60-.96). By contrast, reliability between surgeons was lower, ranging from fair to substantial (κ = .23-.70). Between-surgeon reliability was lowest for the junction of the soft and hard palates (κ = .23). Within-surgeon and between-surgeon reliability were almost perfect for the more general classification of fistula in the secondary palate (κ = .95 and κ = .83, respectively). Conclusions This is the first reliability study of fistula classification. We show that the Pittsburgh Fistula Classification System is reliable when used by an individual surgeon, but less reliable when used among multiple surgeons. Comparisons of fistula occurrence among surgeons may be subject to less bias if they use the more general classification of "presence or absence of fistula of the secondary palate" rather than the Pittsburgh Fistula Classification System.

  18. Cluster-based upper body marker models for three-dimensional kinematic analysis: Comparison with an anatomical model and reliability analysis.

    Science.gov (United States)

    Boser, Quinn A; Valevicius, Aïda M; Lavoie, Ewen B; Chapman, Craig S; Pilarski, Patrick M; Hebert, Jacqueline S; Vette, Albert H

    2018-04-27

    Quantifying angular joint kinematics of the upper body is a useful method for assessing upper limb function. Joint angles are commonly obtained via motion capture, tracking markers placed on anatomical landmarks. This method is associated with limitations including administrative burden, soft tissue artifacts, and intra- and inter-tester variability. An alternative method involves the tracking of rigid marker clusters affixed to body segments, calibrated relative to anatomical landmarks or known joint angles. The accuracy and reliability of applying this cluster method to the upper body has, however, not been comprehensively explored. Our objective was to compare three different upper body cluster models with an anatomical model, with respect to joint angles and reliability. Non-disabled participants performed two standardized functional upper limb tasks with anatomical and cluster markers applied concurrently. Joint angle curves obtained via the marker clusters with three different calibration methods were compared to those from an anatomical model, and between-session reliability was assessed for all models. The cluster models produced joint angle curves which were comparable to and highly correlated with those from the anatomical model, but exhibited notable offsets and differences in sensitivity for some degrees of freedom. Between-session reliability was comparable between all models, and good for most degrees of freedom. Overall, the cluster models produced reliable joint angles that, however, cannot be used interchangeably with anatomical model outputs to calculate kinematic metrics. Cluster models appear to be an adequate, and possibly advantageous alternative to anatomical models when the objective is to assess trends in movement behavior. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. The reliability and validity of the informant AD8 by comparison with a series of cognitive assessment tools in primary healthcare.

    Science.gov (United States)

    Shaik, Muhammad Amin; Xu, Xin; Chan, Qun Lin; Hui, Richard Jor Yeong; Chong, Steven Shih Tsze; Chen, Christopher Li-Hsian; Dong, YanHong

    2016-03-01

    The validity and reliability of the informant AD8 in primary healthcare has not been established. Therefore, the present study examined the validity and reliability of the informant AD8 in government subsidized primary healthcare centers in Singapore. Eligible patients (≥60 years old) were recruited from primary healthcare centers and their informants received the AD8. Patient-informant dyads who agreed for further cognitive assessments received the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Clinical Dementia Rating (CDR), and a locally validated formal neuropsychological battery at a research center in a tertiary hospital. 1,082 informants completed AD8 assessment at two primary healthcare centers. Of these, 309 patients-informant dyads were further assessed, of whom 243 (78.6%) were CDR = 0; 22 (7.1%) were CDR = 0.5; and 44 (14.2%) were CDR≥1. The mean administration time of the informant AD8 was 2.3 ± 1.0 minutes. The informant AD8 demonstrated good internal consistency (Cronbach's α = 0.85); inter-rater reliability (Intraclass Correlation Coefficient (ICC) = 0.85); and test-retest reliability (weighted κ = 0.80). Concurrent validity, as measured by the correlation between total AD8 scores and CDR global (R = 0.65, p validity, as measured by convergent validity (R ≥ 0.4) between individual items of AD8 with CDR and neuropsychological domains was acceptable. The informant AD8 demonstrated good concurrent and construct validity and is a reliable measure to detect cognitive dysfunction in primary healthcare.

  20. Validity and reliability of the session-RPE method for quantifying training in Australian football: a comparison of the CR10 and CR100 scales.

    Science.gov (United States)

    Scott, Tannath J; Black, Cameron R; Quinn, John; Coutts, Aaron J

    2013-01-01

    The purpose of this study was to examine and compare the criterion validity and test-retest reliability of the CR10 and CR100 rating of perceived exertion (RPE) scales for team sport athletes that undertake high-intensity, intermittent exercise. Twenty-one male Australian football (AF) players (age: 19.0 ± 1.8 years, body mass: 83.92 ± 7.88 kg) participated the first part (part A) of this study, which examined the construct validity of the session-RPE (sRPE) method for quantifying training load in AF. Ten male athletes (age: 16.1 ± 0.5 years) participated in the second part of the study (part B), which compared the test-retest reliability of the CR10 and CR100 RPE scales. In part A, the validity of the sRPE method was assessed by examining the relationships between sRPE, and objective measures of internal (i.e., heart rate) and external training load (i.e., distance traveled), collected from AF training sessions. Part B of the study assessed the reliability of sRPE through examining the test-retest reliability of sRPE during 3 different intensities of controlled intermittent running (10, 11.5, and 13 km·h(-1)). Results from part A demonstrated strong correlations for CR10- and CR100-derived sRPE with measures of internal training load (Banisters TRIMP and Edwards TRIMP) (CR10: r = 0.83 and 0.83, and CR100: r = 0.80 and 0.81, p training load (distance, higher speed running and player load) for both the CR10 (r = 0.81, 0.71, and 0.83) and CR100 (r = 0.78, 0.69, and 0.80) were significant (p reliability for both the CR10 (31.9% CV) and CR100 (38.6% CV) RPE scales after short bouts of intermittent running. Collectively, these results suggest both CR10- and CR100-derived sRPE methods have good construct validity for assessing training load in AF. The poor levels of reliability revealed under field testing indicate that the sRPE method may not be sensible to detecting small changes in exercise intensity during brief intermittent running bouts. Despite this limitation

  1. Contribution of subtraction ictal SPECT coregistered to MRI to epilepsy surgery. A multicenter study

    International Nuclear Information System (INIS)

    Matsuda, Hiroshi; Matsuda, Kazumi; Nakamura, Fumihiro

    2009-01-01

    in predicting good surgical outcome. A SISCOM technique of ictal and interictal SPECT images provides higher predictive value of good surgical outcome and more reliability on the diagnosis of the epileptogenic focus than side-by-side comparison in medically intractable partial epilepsy. (author)

  2. Accuracy, intra- and inter-unit reliability, and comparison between GPS and UWB-based position-tracking systems used for time-motion analyses in soccer.

    Science.gov (United States)

    Bastida Castillo, Alejandro; Gómez Carmona, Carlos D; De la Cruz Sánchez, Ernesto; Pino Ortega, José

    2018-05-01

    There is interest in the accuracy and inter-unit reliability of position-tracking systems to monitor players. Research into this technology, although relatively recent, has grown exponentially in the last years, and it is difficult to find professional team sport that does not use Global Positioning System (GPS) technology at least. The aim of this study is to know the accuracy of both GPS-based and Ultra Wide Band (UWB)-based systems on a soccer field and their inter- and intra-unit reliability. A secondary aim is to compare them for practical applications in sport science. Following institutional ethical approval and familiarization, 10 healthy and well-trained former soccer players (20 ± 1.6 years, 1.76 ± 0.08 cm, and 69.5 ± 9.8 kg) performed three course tests: (i) linear course, (ii) circular course, and (iii) a zig-zag course, all using UWB and GPS technologies. The average speed and distance covered were compared with timing gates and the real distance as references. The UWB technology showed better accuracy (bias: 0.57-5.85%), test-retest reliability (%TEM: 1.19), and inter-unit reliability (bias: 0.18) in determining distance covered than the GPS technology (bias: 0.69-6.05%; %TEM: 1.47; bias: 0.25) overall. Also, UWB showed better results (bias: 0.09; ICC: 0.979; bias: 0.01) for mean velocity measurement than GPS (bias: 0.18; ICC: 0.951; bias: 0.03).

  3. An Introduction To Reliability

    International Nuclear Information System (INIS)

    Park, Kyoung Su

    1993-08-01

    This book introduces reliability with definition of reliability, requirement of reliability, system of life cycle and reliability, reliability and failure rate such as summary, reliability characteristic, chance failure, failure rate which changes over time, failure mode, replacement, reliability in engineering design, reliability test over assumption of failure rate, and drawing of reliability data, prediction of system reliability, conservation of system, failure such as summary and failure relay and analysis of system safety.

  4. The Comparative Reliability and Feasibility of the Past-Year Canadian Diet History Questionnaire II: Comparison of the Paper and Web Versions.

    Science.gov (United States)

    Lo Siou, Geraldine; Csizmadi, Ilona; Boucher, Beatrice A; Akawung, Alianu K; Whelan, Heather K; Sharma, Michelle; Al Rajabi, Ala; Vena, Jennifer E; Kirkpatrick, Sharon I; Koushik, Anita; Massarelli, Isabelle; Rondeau, Isabelle; Robson, Paula J

    2017-02-13

    Advances in technology-enabled dietary assessment include the advent of web-based food frequency questionnaires, which may reduce costs and researcher burden but may introduce new challenges related to internet connectivity and computer literacy. The purpose of this study was to evaluate the intra- and inter-version reliability, feasibility and acceptability of the paper and web Canadian Diet History Questionnaire II (CDHQ-II) in a sub-sample of 648 adults (aged 39-81 years) recruited from Alberta's Tomorrow Project. Participants were randomly assigned to one of two groups: (1) paper, web, paper; or (2) web, paper, web over a six-week period. With few exceptions, no statistically significant differences in mean nutrient intake were found in the intra- and inter-version reliability analyses. The majority of participants indicated future willingness to complete the CDHQ-II online, and 59% indicated a preference for the web over the paper version. Findings indicate that, in this population of adults drawn from an existing cohort, the CDHQ-II may be administered in paper or web modalities (increasing flexibility for questionnaire delivery), and the nutrient estimates obtained with either version are comparable. We recommend that other studies explore the feasibility and reliability of different modes of administration of dietary assessment instruments prior to widespread implementation.

  5. The Comparative Reliability and Feasibility of the Past-Year Canadian Diet History Questionnaire II: Comparison of the Paper and Web Versions

    Science.gov (United States)

    Lo Siou, Geraldine; Csizmadi, Ilona; Boucher, Beatrice A.; Akawung, Alianu K.; Whelan, Heather K.; Sharma, Michelle; Al Rajabi, Ala; Vena, Jennifer E.; Kirkpatrick, Sharon I.; Koushik, Anita; Massarelli, Isabelle; Rondeau, Isabelle; Robson, Paula J.

    2017-01-01

    Advances in technology-enabled dietary assessment include the advent of web-based food frequency questionnaires, which may reduce costs and researcher burden but may introduce new challenges related to internet connectivity and computer literacy. The purpose of this study was to evaluate the intra- and inter-version reliability, feasibility and acceptability of the paper and web Canadian Diet History Questionnaire II (CDHQ-II) in a sub-sample of 648 adults (aged 39–81 years) recruited from Alberta’s Tomorrow Project. Participants were randomly assigned to one of two groups: (1) paper, web, paper; or (2) web, paper, web over a six-week period. With few exceptions, no statistically significant differences in mean nutrient intake were found in the intra- and inter-version reliability analyses. The majority of participants indicated future willingness to complete the CDHQ-II online, and 59% indicated a preference for the web over the paper version. Findings indicate that, in this population of adults drawn from an existing cohort, the CDHQ-II may be administered in paper or web modalities (increasing flexibility for questionnaire delivery), and the nutrient estimates obtained with either version are comparable. We recommend that other studies explore the feasibility and reliability of different modes of administration of dietary assessment instruments prior to widespread implementation. PMID:28208819

  6. Aerospace reliability applied to biomedicine.

    Science.gov (United States)

    Lalli, V. R.; Vargo, D. J.

    1972-01-01

    An analysis is presented that indicates that the reliability and quality assurance methodology selected by NASA to minimize failures in aerospace equipment can be applied directly to biomedical devices to improve hospital equipment reliability. The Space Electric Rocket Test project is used as an example of NASA application of reliability and quality assurance (R&QA) methods. By analogy a comparison is made to show how these same methods can be used in the development of transducers, instrumentation, and complex systems for use in medicine.

  7. Is quantitative coronary angiography reliable in assessing the late lumen loss of the everolimus-eluting bioresorbable polylactide scaffold in comparison with the cobalt-chromium metallic stent?

    NARCIS (Netherlands)

    Sotomi, Yohei; Onuma, Yoshinobu; Miyazaki, Yosuke; Asano, Taku; Katagiri, Yuki; Tenekecioglu, Erhan; Jonker, Hans; Dijkstra, Jouke; de Winter, Robbert J.; Wykrzykowska, Joanna J.; Stone, Gregg W.; Popma, Jeffrey J.; Kozuma, Ken; Tanabe, Kengo; Serruys, Patrick W.; Kimura, Takeshi

    2017-01-01

    Aims: Immediately after stent/scaffold implantation, quantitative coronary angiography (QCA) in comparison to optical coherence tomography (OCT) more severely underestimates the lumen diameter (LD) in Absorb than in XIENCE. This OCT-QCA discrepancy has not been evaluated at long-term follow-up. The

  8. The validity and reliability of the cross-national comparison of degree programme levels in European countries : What have students learnt?

    NARCIS (Netherlands)

    Rexwinkel, Trudy; Haenen, Jacques; Pilot, Albert

    2017-01-01

    A cross-national comparison of degree programme levels became relevant when the borders of European countries opened for students and graduates, and higher education institutions were restructured into bachelor’s and master’s programmes. This new situation foregrounded the questions of what students

  9. Ultrasound estimates of muscle quality in older adults: reliability and comparison of Photoshop and ImageJ for the grayscale analysis of muscle echogenicity

    Directory of Open Access Journals (Sweden)

    Michael O. Harris-Love

    2016-02-01

    Full Text Available Background. Quantitative diagnostic ultrasound imaging has been proposed as a method of estimating muscle quality using measures of echogenicity. The Rectangular Marquee Tool (RMT and the Free Hand Tool (FHT are two types of editing features used in Photoshop and ImageJ for determining a region of interest (ROI within an ultrasound image. The primary objective of this study is to determine the intrarater and interrater reliability of Photoshop and ImageJ for the estimate of muscle tissue echogenicity in older adults via grayscale histogram analysis. The secondary objective is to compare the mean grayscale values obtained using both the RMT and FHT methods across both image analysis platforms. Methods. This cross-sectional observational study features 18 community-dwelling men (age = 61.5 ± 2.32 years. Longitudinal views of the rectus femoris were captured using B-mode ultrasound. The ROI for each scan was selected by 2 examiners using the RMT and FHT methods from each software program. Their reliability is assessed using intraclass correlation coefficients (ICCs and the standard error of the measurement (SEM. Measurement agreement for these values is depicted using Bland-Altman plots. A paired t-test is used to determine mean differences in echogenicity expressed as grayscale values using the RMT and FHT methods to select the post-image acquisition ROI. The degree of association among ROI selection methods and image analysis platforms is analyzed using the coefficient of determination (R2. Results. The raters demonstrated excellent intrarater and interrater reliability using the RMT and FHT methods across both platforms (lower bound 95% CI ICC = .97–.99, p < .001. Mean differences between the echogenicity estimates obtained with the RMT and FHT methods was .87 grayscale levels (95% CI [.54–1.21], p < .0001 using data obtained with both programs. The SEM for Photoshop was .97 and 1.05 grayscale levels when using the RMT and FHT ROI selection

  10. A comparison of seminar and computer based training on the accuracy and reliability of raters using the Children's Global Assessment Scale (CGAS).

    Science.gov (United States)

    Lundh, Anna; Kowalski, Jan; Sundberg, Carl Johan; Landén, Mikael

    2012-11-01

    The aim of this study was to compare two methods to conduct CGAS rater training. A total of 648 raters were randomized to training (CD or seminar), and rated five cases before and 12 months after training. The ICC at baseline/end of study was 0.71/0.78 (seminar), 0.76/0.78 (CD), and 0.67/0.79 (comparison). There were no differences in training effect in terms of agreement with expert ratings, which speaks in favor of using the less resource-demanding CD. However, the effect was modest in both groups, and untrained comparison group improved of the same order of magnitude, which proposes more extensive training.

  11. Visualizing request-flow comparison to aid performance diagnosis in distributed systems.

    Science.gov (United States)

    Sambasivan, Raja R; Shafer, Ilari; Mazurek, Michelle L; Ganger, Gregory R

    2013-12-01

    Distributed systems are complex to develop and administer, and performance problem diagnosis is particularly challenging. When performance degrades, the problem might be in any of the system's many components or could be a result of poor interactions among them. Recent research efforts have created tools that automatically localize the problem to a small number of potential culprits, but research is needed to understand what visualization techniques work best for helping distributed systems developers understand and explore their results. This paper compares the relative merits of three well-known visualization approaches (side-by-side, diff, and animation) in the context of presenting the results of one proven automated localization technique called request-flow comparison. Via a 26-person user study, which included real distributed systems developers, we identify the unique benefits that each approach provides for different problem types and usage modes.

  12. Coronary calcium screening with dual-source CT: reliability of ungated, high-pitch chest CT in comparison with dedicated calcium-scoring CT

    Energy Technology Data Exchange (ETDEWEB)

    Hutt, Antoine; Faivre, Jean-Baptiste; Remy, Jacques; Remy-Jardin, Martine [CHRU et Universite de Lille, Department of Thoracic Imaging, Hospital Calmette (EA 2694), Lille (France); Duhamel, Alain; Deken, Valerie [CHRU et Universite de Lille, Department of Biostatistics (EA 2694), Lille (France); Molinari, Francesco [Centre Hospitalier General de Tourcoing, Department of Radiology, Tourcoing (France)

    2016-06-15

    To investigate the reliability of ungated, high-pitch dual-source CT for coronary artery calcium (CAC) screening. One hundred and eighty-five smokers underwent a dual-source CT examination with acquisition of two sets of images during the same session: (a) ungated, high-pitch and high-temporal resolution acquisition over the entire thorax (i.e., chest CT); (b) prospectively ECG-triggered acquisition over the cardiac cavities (i.e., cardiac CT). Sensitivity and specificity of chest CT for detecting positive CAC scores were 96.4 % and 100 %, respectively. There was excellent inter-technique agreement for determining the quantitative CAC score (ICC = 0.986). The mean difference between the two techniques was 11.27, representing 1.81 % of the average of the two techniques. The inter-technique agreement for categorizing patients into the four ranks of severity was excellent (weighted kappa = 0.95; 95 % CI 0.93-0.98). The inter-technique differences for quantitative CAC scores did not correlate with BMI (r = 0.05, p = 0.575) or heart rate (r = -0.06, p = 0.95); 87.2 % of them were explained by differences at the level of the right coronary artery (RCA: 0.8718; LAD: 0.1008; LCx: 0.0139; LM: 0.0136). Ungated, high-pitch dual-source CT is a reliable imaging mode for CAC screening in the conditions of routine chest CT examinations. (orig.)

  13. Postpartum Bonding Disorder: Factor Structure, Validity, Reliability and a Model Comparison of the Postnatal Bonding Questionnaire in Japanese Mothers of Infants

    Directory of Open Access Journals (Sweden)

    Yukiko Ohashi

    2016-08-01

    Full Text Available Negative attitudes of mothers towards their infant is conceptualized as postpartum bonding disorder, which leads to serious health problems in perinatal health care. However, its measurement still remains to be standardized. Our aim was to examine and confirm the psychometric properties of the Postnatal Bonding Questionnaire (PBQ in Japanese mothers. We distributed a set of questionnaires to community mothers and studied 392 mothers who returned the questionnaires at 1 month after childbirth. Our model was compared with three other models derived from previous studies. In a randomly halved sample, an exploratory factor analysis yielded a three-factor structure: Anger and Restrictedness, Lack of Affection, and Rejection and Fear. This factor structure was cross-validated by a confirmatory factor analysis using the other halved sample. The three subscales showed satisfactory internal consistency. The three PBQ subscale scores were correlated with depression and psychological abuse scores. Their test–retest reliability between day 5 and 1 month after childbirth was measured by intraclass correlation coefficients between 0.76 and 0.83. The Akaike Information Criteria of our model was better than the original four-factor model of Brockington. The present study indicates that the PBQ is a reliable and valid measure of bonding difficulties of Japanese mothers with neonates.

  14. Ultrasound estimates of muscle quality in older adults: reliability and comparison of Photoshop and ImageJ for the grayscale analysis of muscle echogenicity.

    Science.gov (United States)

    Harris-Love, Michael O; Seamon, Bryant A; Teixeira, Carla; Ismail, Catheeja

    2016-01-01

    Background. Quantitative diagnostic ultrasound imaging has been proposed as a method of estimating muscle quality using measures of echogenicity. The Rectangular Marquee Tool (RMT) and the Free Hand Tool (FHT) are two types of editing features used in Photoshop and ImageJ for determining a region of interest (ROI) within an ultrasound image. The primary objective of this study is to determine the intrarater and interrater reliability of Photoshop and ImageJ for the estimate of muscle tissue echogenicity in older adults via grayscale histogram analysis. The secondary objective is to compare the mean grayscale values obtained using both the RMT and FHT methods across both image analysis platforms. Methods. This cross-sectional observational study features 18 community-dwelling men (age = 61.5 ± 2.32 years). Longitudinal views of the rectus femoris were captured using B-mode ultrasound. The ROI for each scan was selected by 2 examiners using the RMT and FHT methods from each software program. Their reliability is assessed using intraclass correlation coefficients (ICCs) and the standard error of the measurement (SEM). Measurement agreement for these values is depicted using Bland-Altman plots. A paired t-test is used to determine mean differences in echogenicity expressed as grayscale values using the RMT and FHT methods to select the post-image acquisition ROI. The degree of association among ROI selection methods and image analysis platforms is analyzed using the coefficient of determination (R (2)). Results. The raters demonstrated excellent intrarater and interrater reliability using the RMT and FHT methods across both platforms (lower bound 95% CI ICC = .97-.99, p Photoshop was .97 and 1.05 grayscale levels when using the RMT and FHT ROI selection methods, respectively. Comparatively, the SEM values were .72 and .81 grayscale levels, respectively, when using the RMT and FHT ROI selection methods in ImageJ. Uniform coefficients of determination (R (2) = .96

  15. Identification of Nasal Bone Fractures on Conventional Radiography and Facial CT: Comparison of the Diagnostic Accuracy in Different Imaging Modalities and Analysis of Interobserver Reliability

    International Nuclear Information System (INIS)

    Baek, Hye Jin; Kim, Dong Wook; Ryu, Ji Hwa; Lee, Yoo Jin

    2013-01-01

    There has been no study to compare the diagnostic accuracy of an experienced radiologist with a trainee in nasal bone fracture. To compare the diagnostic accuracy between conventional radiography and computed tomography (CT) for the identification of nasal bone fractures and to evaluate the interobserver reliability between a staff radiologist and a trainee. A total of 108 patients who underwent conventional radiography and CT after acute nasal trauma were included in this retrospective study. Two readers, a staff radiologist and a second-year resident, independently assessed the results of the imaging studies. Of the 108 patients, the presence of a nasal bone fracture was confirmed in 88 (81.5%) patients. The number of non-depressed fractures was higher than the number of depressed fractures. In nine (10.2%) patients, nasal bone fractures were only identified on conventional radiography, including three depressed and six non-depressed fractures. CT was more accurate as compared to conventional radiography for the identification of nasal bone fractures as determined by both readers (P <0.05), all diagnostic indices of an experienced radiologist were similar to or higher than those of a trainee, and κ statistics showed moderate agreement between the two diagnostic tools for both readers. There was no statistical difference in the assessment of interobserver reliability for both imaging modalities in the identification of nasal bone fractures. For the identification of nasal bone fractures, CT was significantly superior to conventional radiography. Although a staff radiologist showed better values in the identification of nasal bone fracture and differentiation between depressed and non-depressed fractures than a trainee, there was no statistically significant difference in the interpretation of conventional radiography and CT between a radiologist and a trainee

  16. Comparison of the reliability of two hydronephrosis grading systems: The Society for Foetal Urology grading system vs. the Onen grading system

    International Nuclear Information System (INIS)

    Kim, S.-Y.; Kim, M.-J.; Yoon, C.S.; Lee, M.S.; Han, K.H.; Lee, M.-J.

    2013-01-01

    Aim: To compare the reliability of the conventional ultrasonography grading system for hydronephrosis as suggested by the Society for Fetal Urology (SFU) in 1993 and that developed by Onen in 2007. Materials and methods: One hundred and eighty kidneys in 90 paediatric patients were assessed by four radiologists using each of the two grading systems twice. The SFU system was graded 0–4 (0 = no hydronephrosis; 1 = visualized only renal pelvis; 2 = plus a few caliceal dilatation; 3 = all calyceal dilatation; 4 = plus parenchymal thinning). The Onen system was graded 0–4 (0 = no hydronephrosis; 1 = only renal pelvic dilatation; 2 = plus caliceal dilatation; 3 = plus 50% renal parenchymal loss). Cohen's kappa statistic was used to estimate intra- and interobserver agreement. The weighted least-squares approach was used to compare the intra-observer agreement, and bootstrapping was used to compare the interobserver agreement between the two systems. Results: Intra-observer agreement was substantial to almost perfect in both the SFU (κ 0.79–0.95) and the Onen (κ 0.66–0.97) grading system without difference. The overall interobserver agreement was substantial in both the SFU (κ 0.61–0.68) and the Onen (κ 0.66–0.76) grading system. However, interobserver agreement was fair to moderate for SFU grades 1 and 2 and Onen grades 2 and 3. Conclusion: Both the SFU and Onen grading system are reliable with good intra- and interobserver agreement. However, decreased interobserver agreement was demonstrated for SFU grades 1 and 2 and Onen grades 2 and 3

  17. Reliability of reactor materials

    International Nuclear Information System (INIS)

    Toerroenen, K.; Aho-Mantila, I.

    1986-05-01

    This report is the final technical report of the fracture mechanics part of the Reliability of Reactor Materials Programme, which was carried out at the Technical Research Centre of Finland (VTT) through the years 1981 to 1983. Research and development work was carried out in five major areas, viz. statistical treatment and modelling of cleavage fracture, crack arrest, ductile fracture, instrumented impact testing as well as comparison of numerical and experimental elastic-plastic fracture mechanics. In the area of cleavage fracture the critical variables affecting the fracture of steels are considered in the frames of a statistical model, so called WST-model. Comparison of fracture toughness values predicted by the model and corresponding experimental values shows excellent agreement for a variety of microstructures. different posibilities for using the model are discussed. The development work in the area of crack arrest testing was concentrated in the crack starter properties, test arrangement and computer control. A computerized elastic-plastic fracture testing method with a variety of test specimen geometries in a large temperature range was developed for a routine stage. Ductile fracture characteristics of reactor pressure vessel steel A533B and comparable weld material are given. The features of a new, patented instrumented impact tester are described. Experimental and theoretical comparisons between the new and conventional testers indicated clearly the improvements achieved with the new tester. A comparison of numerical and experimental elastic-plastic fracture mechanics capabilities at VTT was carried out. The comparison consisted of two-dimensional linear elastic as well as elastic-plastic finite element analysis of four specimen geometries and equivalent experimental tests. (author)

  18. Frontiers of reliability

    CERN Document Server

    Basu, Asit P; Basu, Sujit K

    1998-01-01

    This volume presents recent results in reliability theory by leading experts in the world. It will prove valuable for researchers, and users of reliability theory. It consists of refereed invited papers on a broad spectrum of topics in reliability. The subjects covered include Bayesian reliability, Bayesian reliability modeling, confounding in a series system, DF tests, Edgeworth approximation to reliability, estimation under random censoring, fault tree reduction for reliability, inference about changes in hazard rates, information theory and reliability, mixture experiment, mixture of Weibul

  19. Assessment of peak oxygen uptake during handcycling: Test-retest reliability and comparison of a ramp-incremented and perceptually-regulated exercise test.

    Science.gov (United States)

    Hutchinson, Michael J; Paulson, Thomas A W; Eston, Roger; Goosey-Tolfrey, Victoria L

    2017-01-01

    To examine the reliability of a perceptually-regulated maximal exercise test (PRETmax) to measure peak oxygen uptake ([Formula: see text]) during handcycle exercise and to compare peak responses to those derived from a ramp-incremented protocol (RAMP). Twenty recreationally active individuals (14 male, 6 female) completed four trials across a 2-week period, using a randomised, counterbalanced design. Participants completed two RAMP protocols (20 W·min-1) in week 1, followed by two PRETmax in week 2, or vice versa. The PRETmax comprised five, 2-min stages clamped at Ratings of Perceived Exertion (RPE) 11, 13, 15, 17 and 20. Participants changed power output (PO) as often as required to maintain target RPE. Gas exchange variables (oxygen uptake, carbon dioxide production, minute ventilation), heart rate (HR) and PO were collected throughout. Differentiated RPE were collected at the end of each stage throughout trials. For relative [Formula: see text], coefficient of variation (CV) was equal to 4.1% and 4.8%, with ICC(3,1) of 0.92 and 0.85 for repeated measures from PRETmax and RAMP, respectively. Measurement error was 0.15 L·min-1 and 2.11 ml·kg-1·min-1 in PRETmax and 0.16 L·min-1 and 2.29 ml·kg-1·min-1 during RAMP for determining absolute and relative [Formula: see text], respectively. The difference in [Formula: see text] between PRETmax and RAMP was tending towards statistical significance (26.2 ± 5.1 versus 24.3 ± 4.0 ml·kg-1·min-1, P = 0.055). The 95% LoA were -1.9 ± 4.1 (-9.9 to 6.2) ml·kg-1·min-1. The PRETmax can be used as a reliable test to measure [Formula: see text] during handcycle exercise in recreationally active participants. Whilst PRETmax tended towards significantly greater [Formula: see text] values than RAMP, the difference is smaller than measurement error of determining [Formula: see text] from PRETmax and RAMP.

  20. Non-echoplanar diffusion-weighted MRI in children and adolescents with cholesteatoma: reliability and pitfalls in comparison to middle ear surgery

    International Nuclear Information System (INIS)

    Kalle, Thekla von; Amrhein, Peter; Koitschev, Assen

    2015-01-01

    Currently, there is only limited and contradictory evidence of the role of diffusion-weighted MRI (DW-MRI) in the management of children with cholesteatoma. To provide surgically controlled data that may allow to replace second-look surgery by non-echoplanar DW-MRI in children. Fifty-five children and adolescents with a median age of 8.6 years (2.2-17.7 years) underwent 61 preoperative half-Fourier acquisition single-shot turbo spin-echo (HASTE) DW-MRI of their petrous bone. Surgical interventions followed within 24 h (79%), within 5 months (20%) or at 18 months (1 case). Surgery detected a cholesteatoma or retraction pocket in 41 of 61 cases (67%). In 49 cases (80%), the MR result was confirmed by surgical findings. Two MR findings were false-positive and 10 false-negative (including cholesteatomas <4 mm). HASTE DW-MRI alone had a sensitivity of 76% and a specificity of 90%. The positive predictive value was 94%, the negative predictive value 64%. In combination with preoperative otoscopy, sensitivity was 90% and negative predictive value 82%. DW-MRI correctly detected the majority of lesions but could not reliably exclude small cholesteatomas and empty retraction pockets. We would therefore not generally recommend MR as a substitute for second-look surgery. (orig.)

  1. Non-echoplanar diffusion-weighted MRI in children and adolescents with cholesteatoma: reliability and pitfalls in comparison to middle ear surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kalle, Thekla von [Olgahospital Klinikum Stuttgart, Pediatric Radiology, Radiologisches Institut, Stuttgart (Germany); Amrhein, Peter; Koitschev, Assen [Olgahospital Klinikum Stuttgart, Division of Pediatric Otorhinolaryngology and Otology, Department of Otorhinolaryngology, Stuttgart (Germany)

    2015-07-15

    Currently, there is only limited and contradictory evidence of the role of diffusion-weighted MRI (DW-MRI) in the management of children with cholesteatoma. To provide surgically controlled data that may allow to replace second-look surgery by non-echoplanar DW-MRI in children. Fifty-five children and adolescents with a median age of 8.6 years (2.2-17.7 years) underwent 61 preoperative half-Fourier acquisition single-shot turbo spin-echo (HASTE) DW-MRI of their petrous bone. Surgical interventions followed within 24 h (79%), within 5 months (20%) or at 18 months (1 case). Surgery detected a cholesteatoma or retraction pocket in 41 of 61 cases (67%). In 49 cases (80%), the MR result was confirmed by surgical findings. Two MR findings were false-positive and 10 false-negative (including cholesteatomas <4 mm). HASTE DW-MRI alone had a sensitivity of 76% and a specificity of 90%. The positive predictive value was 94%, the negative predictive value 64%. In combination with preoperative otoscopy, sensitivity was 90% and negative predictive value 82%. DW-MRI correctly detected the majority of lesions but could not reliably exclude small cholesteatomas and empty retraction pockets. We would therefore not generally recommend MR as a substitute for second-look surgery. (orig.)

  2. Reliability of a CAD/CAM Surgical Guide for Implant Placement: An In Vitro Comparison of Surgeons' Experience Levels and Implant Sites.

    Science.gov (United States)

    Park, Su-Jung; Leesungbok, Richard; Cui, Taixing; Lee, Suk Won; Ahn, Su-Jin

    This in vitro study evaluated the reliability of a surgical guide with regard to different levels of operator surgical experience and implant site. A stereolithographic surgical guide for epoxy resin mandibles with three edentulous molar sites was produced using a computer-aided design/computer-assisted manufacture (CAD/CAM) system. Two surgeons with and two surgeons without implant surgery experience placed implants in a model either using or not using the CAD/CAM surgical guide. Four groups were created: inexperienced surgeon without the guide (group 1); experienced surgeon without the guide (group 2); inexperienced surgeon with the guide (group 3); and experienced surgeon with the guide (group 4). Planned implants and placed implants were superimposed using digital software, and deviation parameters were calculated. There were no significant differences in any of the deviation parameters between the groups when using the surgical guide. With respect to the implant sites, there were no significant differences among the groups in any parameter. Use of the CAD/CAM surgical guide reduced discrepancies among operators performing implant surgery regardless of their level of experience. Whether or not the guide was used, differences in the anterior-posterior implant site in the molar area did not affect the accuracy of implant placement.

  3. Validity and reliability of haemoglobin colour scale and its comparison with clinical signs in diagnosing anaemia in pregnancy in Ahmedabad, India.

    Science.gov (United States)

    Bala, D V; Vyas, S; Shukla, A; Tiwari, H; Bhatt, G; Gupta, K

    2012-07-01

    This study compared the validity of the haemoglobin colour scale (HCS) and clinical signs in diagnosing anaemia against Sahli's haemoglobinometer method as the gold standard, and assessed the reliability of HCS. The sample comprised 129 pregnant women recruited from 6 urban health centres in Ahmedabad. The prevalence of anaemia was 69.8% by Sahli's method, 78.3% by HCS and 89.9% by clinical signs; there was no statistically significant difference between Sahli's method and HCS whereas there was between Sahlis method and clinical signs. The mean haemoglobin level by Sahli's method and HCS differed significantly. The sensitivity, specificity, positive predictive value and negative predictive value of HCS was 83.3%, 33.3%, 74.3% and 46.4% respectively and that of clinical signs was 91.1%, 12.8%, 70.7% and 38.5% respectively. Interobserver agreement for HCS was moderate (K = 0.43). Clinical signs are better than HCS for diagnosing anaemia. HCS can be used in the field provided assessors are adequately trained.

  4. Secondary dentine as a sole parameter for age estimation: Comparison and reliability of qualitative and quantitative methods among North Western adult Indians

    Directory of Open Access Journals (Sweden)

    Jasbir Arora

    2016-06-01

    Full Text Available The indestructible nature of teeth against most of the environmental abuses makes its use in disaster victim identification (DVI. The present study has been undertaken to examine the reliability of Gustafson’s qualitative method and Kedici’s quantitative method of measuring secondary dentine for age estimation among North Western adult Indians. 196 (M = 85; F = 111 single rooted teeth were collected from the Department of Oral Health Sciences, PGIMER, Chandigarh. Ground sections were prepared and the amount of secondary dentine formed was scored qualitatively according to Gustafson’s (0–3 scoring system (method 1 and quantitatively following Kedici’s micrometric measurement method (method 2. Out of 196 teeth 180 samples (M = 80; F = 100 were found to be suitable for measuring secondary dentine following Kedici’s method. Absolute mean error of age was calculated by both methodologies. Results clearly showed that in pooled data, method 1 gave an error of ±10.4 years whereas method 2 exhibited an error of approximately ±13 years. A statistically significant difference was noted in absolute mean error of age between two methods of measuring secondary dentine for age estimation. Further, it was also revealed that teeth extracted for periodontal reasons severely decreased the accuracy of Kedici’s method however, the disease had no effect while estimating age by Gustafson’s method. No significant gender differences were noted in the absolute mean error of age by both methods which suggest that there is no need to separate data on the basis of gender.

  5. 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.

  6. Objective evaluation of cervical vertebral bone age' its reliability in comparison with hand-wrist bone age: by TW3 method.

    Science.gov (United States)

    Prasad, Cms Krishna; Reddy, Vamsi Nilay; Sreedevi, Gojja; Ponnada, Swaroopa Rani; Priya, K Padma; Naik, B Raveendra

    2013-09-01

    The aim of this study was to establish the validity of a new method for evaluating skeletal maturation by assessing the 3rd and 4th cervical vertebrae seen in the cephalometric radiograph. This study consisted of a sample of 50 patients in the age group of 8 to 14 years of age. Chronologically, they were divided into six groups, based on the age consisting of a minimum of six to a maximum of 10 subjects. All the patients included in the study were females. The selected subjects were clinically examined and then age and date of birth of the patient in years and months was noted. Then lateral cephalograms and hand-wrist radiographs of the patient were taken on the same day with good clarity and contrast. The results suggested that cervical vertebral bone age on cephalometric radiographs calculated with this method is as reliable at estimating bone age as is the Tanner-Whitehouse 3 (TW3) method on hand-wrist radiographs. By determining the cervical vertebral bone age, skeletal maturity can be evaluated in a detailed and objective manner with cephalometric radiographs. The ability to accurately appraise skeletal maturity from cervical vertebral maturation, without the need for additional radiographs, has the potential to improve orthodontic diagnostic and therapeutic decisions. The technique's simplicity and ease of use should encourage this method as a frst level diagnostic tool to assess skeletal maturation. Clinical signifcance: This study revealed that the timing and sequence of ossifcation of the bones in hand and wrist and cervical vertebrae were able to relate the skeletal development of the various skeletal maturity indicators to a child's development. This method provided a mean with which one can determine the skeletal maturity of a person and thereby determine whether the possibility of potential growth existed.

  7. System Reliability Engineering

    International Nuclear Information System (INIS)

    Lim, Tae Jin

    2005-02-01

    This book tells of reliability engineering, which includes quality and reliability, reliability data, importance of reliability engineering, reliability and measure, the poisson process like goodness of fit test and the poisson arrival model, reliability estimation like exponential distribution, reliability of systems, availability, preventive maintenance such as replacement policies, minimal repair policy, shock models, spares, group maintenance and periodic inspection, analysis of common cause failure, and analysis model of repair effect.

  8. Protective role of 3-nitrotyrosine against gamma radiation-induced DNA strand breaks: A comparison study with tyrosine

    International Nuclear Information System (INIS)

    Shi Weiqun; Ni Meinan; Kong Fuquan; Sui Li; Hu Jia; Xu Diandou; Li Yanmei

    2008-01-01

    3-Nitrotyrosine(3-NY) has been reported as a potential source of reactive oxygen species (ROSs). In this work, plasmid pBR322 DNA was irradiated by gamma rays in aqueous solution in presence and absence of 3-NY, DNA strand breaks were analyzed by neutral electrophoresis followed by quantification with image analysis software. It was found that the presence of 3-NY could effectively reduce radiation-induced DNA strand breaks. A side-by-side comparison was performed between 3-NY and tyrosine, the results showed that the protective role 3-NY was comparable with tyrosine, which might imply that protein tyrosine nitration might not significantly decrease its ability as a free radical scavenger

  9. The Use of Bayesian Networks to Assess the Quality of Evidence from Research Synthesis: 2. Inter-Rater Reliability and Comparison with Standard GRADE Assessment.

    Directory of Open Access Journals (Sweden)

    Alexis Llewellyn

    Full Text Available The grades of recommendation, assessment, development and evaluation (GRADE approach is widely implemented in systematic reviews, health technology assessment and guideline development organisations throughout the world. We have previously reported on the development of the Semi-Automated Quality Assessment Tool (SAQAT, which enables a semi-automated validity assessment based on GRADE criteria. The main advantage to our approach is the potential to improve inter-rater agreement of GRADE assessments particularly when used by less experienced researchers, because such judgements can be complex and challenging to apply without training. This is the first study examining the inter-rater agreement of the SAQAT.We conducted two studies to compare: a the inter-rater agreement of two researchers using the SAQAT independently on 28 meta-analyses and b the inter-rater agreement between a researcher using the SAQAT (who had no experience of using GRADE and an experienced member of the GRADE working group conducting a standard GRADE assessment on 15 meta-analyses.There was substantial agreement between independent researchers using the Quality Assessment Tool for all domains (for example, overall GRADE rating: weighted kappa 0.79; 95% CI 0.65 to 0.93. Comparison between the SAQAT and a standard GRADE assessment suggested that inconsistency was parameterised too conservatively by the SAQAT. Therefore the tool was amended. Following amendment we found fair-to-moderate agreement between the standard GRADE assessment and the SAQAT (for example, overall GRADE rating: weighted kappa 0.35; 95% CI 0.09 to 0.87.Despite a need for further research, the SAQAT may aid consistent application of GRADE, particularly by less experienced researchers.

  10. INTRA- AND INTER-OBSERVER RELIABILITY IN SELECTION OF THE HEART RATE DEFLECTION POINT DURING INCREMENTAL EXERCISE: COMPARISON TO A COMPUTER-GENERATED DEFLECTION POINT

    Directory of Open Access Journals (Sweden)

    Bridget A. Duoos

    2002-12-01

    Full Text Available This study was designed to 1 determine the relative frequency of occurrence of a heart rate deflection point (HRDP, when compared to a linear relationship, during progressive exercise, 2 measure the reproducibility of a visual assessment of a heart rate deflection point (HRDP, both within and between observers 3 compare visual and computer-assessed deflection points. Subjects consisted of 73 competitive male cyclists with mean age of 31.4 ± 6.3 years, mean height 178.3 ± 4.8 cm. and weight 74.0 ± 4.4 kg. Tests were conducted on an electrically-braked cycle ergometer beginning at 25 watts and progressing 25 watts per minute to fatigue. Heart Rates were recorded the last 10 seconds of each stage and at fatigue. Scatter plots of heart rate versus watts were computer-generated and given to 3 observers on two different occasions. A computer program was developed to assess if data points were best represented by a single line or two lines. The HRDP represented the intersection of the two lines. Results of this study showed that 1 computer-assessed HRDP showed that 44 of 73 subjects (60.3% had scatter plots best represented by a straight line with no HRDP 2in those subjects having HRDP, all 3 observers showed significant differences(p = 0.048, p = 0.007, p = 0.001 in reproducibility of their HRDP selection. Differences in HRDP selection were significant for two of the three comparisons between observers (p = 0.002, p = 0.305, p = 0.0003 Computer-generated HRDP was significantly different than visual HRDP for 2 of 3 observers (p = 0.0016, p = 0.513, p = 0.0001. It is concluded that 1 HRDP occurs in a minority of subjects 2 significant differences exist, both within and between observers, in selection of HRDP and 3 differences in agreement between visual and computer-generated HRDP would indicate that, when HRDP exists, it should be computer-assessed

  11. AMSAA Reliability Growth Guide

    National Research Council Canada - National Science Library

    Broemm, William

    2000-01-01

    ... has developed reliability growth methodology for all phases of the process, from planning to tracking to projection. The report presents this methodology and associated reliability growth concepts.

  12. A reliability simulation language for reliability analysis

    International Nuclear Information System (INIS)

    Deans, N.D.; Miller, A.J.; Mann, D.P.

    1986-01-01

    The results of work being undertaken to develop a Reliability Description Language (RDL) which will enable reliability analysts to describe complex reliability problems in a simple, clear and unambiguous way are described. Component and system features can be stated in a formal manner and subsequently used, along with control statements to form a structured program. The program can be compiled and executed on a general-purpose computer or special-purpose simulator. (DG)

  13. Measuring reliability under epistemic uncertainty: Review on non-probabilistic reliability metrics

    Directory of Open Access Journals (Sweden)

    Kang Rui

    2016-06-01

    Full Text Available In this paper, a systematic review of non-probabilistic reliability metrics is conducted to assist the selection of appropriate reliability metrics to model the influence of epistemic uncertainty. Five frequently used non-probabilistic reliability metrics are critically reviewed, i.e., evidence-theory-based reliability metrics, interval-analysis-based reliability metrics, fuzzy-interval-analysis-based reliability metrics, possibility-theory-based reliability metrics (posbist reliability and uncertainty-theory-based reliability metrics (belief reliability. It is pointed out that a qualified reliability metric that is able to consider the effect of epistemic uncertainty needs to (1 compensate the conservatism in the estimations of the component-level reliability metrics caused by epistemic uncertainty, and (2 satisfy the duality axiom, otherwise it might lead to paradoxical and confusing results in engineering applications. The five commonly used non-probabilistic reliability metrics are compared in terms of these two properties, and the comparison can serve as a basis for the selection of the appropriate reliability metrics.

  14. An empirical comparison of respondent-driven sampling, time location sampling, and snowball sampling for behavioral surveillance in men who have sex with men, Fortaleza, Brazil.

    Science.gov (United States)

    Kendall, Carl; Kerr, Ligia R F S; Gondim, Rogerio C; Werneck, Guilherme L; Macena, Raimunda Hermelinda Maia; Pontes, Marta Kerr; Johnston, Lisa G; Sabin, Keith; McFarland, Willi

    2008-07-01

    Obtaining samples of populations at risk for HIV challenges surveillance, prevention planning, and evaluation. Methods used include snowball sampling, time location sampling (TLS), and respondent-driven sampling (RDS). Few studies have made side-by-side comparisons to assess their relative advantages. We compared snowball, TLS, and RDS surveys of men who have sex with men (MSM) in Forteleza, Brazil, with a focus on the socio-economic status (SES) and risk behaviors of the samples to each other, to known AIDS cases and to the general population. RDS produced a sample with wider inclusion of lower SES than snowball sampling or TLS-a finding of health significance given the majority of AIDS cases reported among MSM in the state were low SES. RDS also achieved the sample size faster and at lower cost. For reasons of inclusion and cost-efficiency, RDS is the sampling methodology of choice for HIV surveillance of MSM in Fortaleza.

  15. Comparison of five automated hematology analyzers in a university hospital setting: Abbott Cell-Dyn Sapphire, Beckman Coulter DxH 800, Siemens Advia 2120i, Sysmex XE-5000, and Sysmex XN-2000.

    Science.gov (United States)

    Bruegel, Mathias; Nagel, Dorothea; Funk, Manuela; Fuhrmann, Petra; Zander, Johannes; Teupser, Daniel

    2015-06-01

    Various types of automated hematology analyzers are used in clinical laboratories. Here, we performed a side-by-side comparison of five current top of the range routine hematology analyzers in the setting of a university hospital central laboratory. Complete blood counts (CBC), differentials, reticulocyte and nucleated red blood cell (NRBC) counts of 349 patient samples, randomly taken out of routine diagnostics, were analyzed with Cell-Dyn Sapphire (Abbott), DxH 800 (Beckman Coulter), Advia 2120i (Siemens), XE-5000 and XN-2000 (Sysmex). Inter-instrument comparison of CBCs including reticulocyte and NRBC counts and investigation of flagging quality in relation to microscopy were performed with the complete set of samples. Inter-instrument comparison of five-part differential was performed using samples without atypical cells in blood smear (n=292). Automated five-part differentials and NRBCs were additionally compared with microscopy. The five analyzers showed a good concordance for basic blood count parameters. Correlations between instruments were less well for reticulocyte counts, NRBCs, and differentials. The poorest concordance for NRBCs with microscopy was observed for Advia 2120i (Kendall's τb=0.37). The highest flagging sensitivity for blasts was observed for XN-2000 (97% compared to 65%-76% for other analyzers), whereas overall specificity was comparable between different instruments. To the best of our knowledge, this is the most comprehensive side-by-side comparison of five current top of the range routine hematology analyzers. Variable analyzer quality and parameter specific limitations must be considered in defining laboratory algorithms in clinical practice.

  16. Finite element reliability analysis of fatigue life

    International Nuclear Information System (INIS)

    Harkness, H.H.; Belytschko, T.; Liu, W.K.

    1992-01-01

    Fatigue reliability is addressed by the first-order reliability method combined with a finite element method. Two-dimensional finite element models of components with cracks in mode I are considered with crack growth treated by the Paris law. Probability density functions of the variables affecting fatigue are proposed to reflect a setting where nondestructive evaluation is used, and the Rosenblatt transformation is employed to treat non-Gaussian random variables. Comparisons of the first-order reliability results and Monte Carlo simulations suggest that the accuracy of the first-order reliability method is quite good in this setting. Results show that the upper portion of the initial crack length probability density function is crucial to reliability, which suggests that if nondestructive evaluation is used, the probability of detection curve plays a key role in reliability. (orig.)

  17. Reliability data banks

    International Nuclear Information System (INIS)

    Cannon, A.G.; Bendell, A.

    1991-01-01

    Following an introductory chapter on Reliability, what is it, why it is needed, how it is achieved and measured, the principles of reliability data bases and analysis methodologies are the subject of the next two chapters. Achievements due to the development of data banks are mentioned for different industries in the next chapter, FACTS, a comprehensive information system for industrial safety and reliability data collection in process plants are covered next. CREDO, the Central Reliability Data Organization is described in the next chapter and is indexed separately, as is the chapter on DANTE, the fabrication reliability Data analysis system. Reliability data banks at Electricite de France and IAEA's experience in compiling a generic component reliability data base are also separately indexed. The European reliability data system, ERDS, and the development of a large data bank come next. The last three chapters look at 'Reliability data banks, - friend foe or a waste of time'? and future developments. (UK)

  18. Suncor maintenance and reliability

    Energy Technology Data Exchange (ETDEWEB)

    Little, S. [Suncor Energy, Calgary, AB (Canada)

    2006-07-01

    Fleet maintenance and reliability at Suncor Energy was discussed in this presentation, with reference to Suncor Energy's primary and support equipment fleets. This paper also discussed Suncor Energy's maintenance and reliability standard involving people, processes and technology. An organizational maturity chart that graphed organizational learning against organizational performance was illustrated. The presentation also reviewed the maintenance and reliability framework; maintenance reliability model; the process overview of the maintenance and reliability standard; a process flow chart of maintenance strategies and programs; and an asset reliability improvement process flow chart. An example of an improvement initiative was included, with reference to a shovel reliability review; a dipper trip reliability investigation; bucket related failures by type and frequency; root cause analysis of the reliability process; and additional actions taken. Last, the presentation provided a graph of the results of the improvement initiative and presented the key lessons learned. tabs., figs.

  19. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  20. Human Reliability Program Overview

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, Michael

    2012-09-25

    This presentation covers the high points of the Human Reliability Program, including certification/decertification, critical positions, due process, organizational structure, program components, personnel security, an overview of the US DOE reliability program, retirees and academia, and security program integration.

  1. Power electronics reliability analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mark A.; Atcitty, Stanley

    2009-12-01

    This report provides the DOE and industry with a general process for analyzing power electronics reliability. The analysis can help with understanding the main causes of failures, downtime, and cost and how to reduce them. One approach is to collect field maintenance data and use it directly to calculate reliability metrics related to each cause. Another approach is to model the functional structure of the equipment using a fault tree to derive system reliability from component reliability. Analysis of a fictitious device demonstrates the latter process. Optimization can use the resulting baseline model to decide how to improve reliability and/or lower costs. It is recommended that both electric utilities and equipment manufacturers make provisions to collect and share data in order to lay the groundwork for improving reliability into the future. Reliability analysis helps guide reliability improvements in hardware and software technology including condition monitoring and prognostics and health management.

  2. Reliability of software

    International Nuclear Information System (INIS)

    Kopetz, H.

    1980-01-01

    Common factors and differences in the reliability of hardware and software; reliability increase by means of methods of software redundancy. Maintenance of software for long term operating behavior. (HP) [de

  3. Reliable Design Versus Trust

    Science.gov (United States)

    Berg, Melanie; LaBel, Kenneth A.

    2016-01-01

    This presentation focuses on reliability and trust for the users portion of the FPGA design flow. It is assumed that the manufacturer prior to hand-off to the user tests FPGA internal components. The objective is to present the challenges of creating reliable and trusted designs. The following will be addressed: What makes a design vulnerable to functional flaws (reliability) or attackers (trust)? What are the challenges for verifying a reliable design versus a trusted design?

  4. Pocket Handbook on Reliability

    Science.gov (United States)

    1975-09-01

    exponencial distributions Weibull distribution, -xtimating reliability, confidence intervals, relia- bility growth, 0. P- curves, Bayesian analysis. 20 A S...introduction for those not familiar with reliability and a good refresher for those who are currently working in the area. LEWIS NERI, CHIEF...includes one or both of the following objectives: a) prediction of the current system reliability, b) projection on the system reliability for someI future

  5. Principles of Bridge Reliability

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, Andrzej S.

    The paper gives a brief introduction to the basic principles of structural reliability theory and its application to bridge engineering. Fundamental concepts like failure probability and reliability index are introduced. Ultimate as well as serviceability limit states for bridges are formulated......, and as an example the reliability profile and a sensitivity analyses for a corroded reinforced concrete bridge is shown....

  6. Reliability technology and nuclear power

    International Nuclear Information System (INIS)

    Garrick, B.J.; Kaplan, S.

    1976-01-01

    This paper reviews some of the history and status of nuclear reliability and the evolution of this subject from art towards science. It shows that that probability theory is the appropriate and essential mathematical language of this subject. The authors emphasize that it is more useful to view probability not as a $prime$frequency$prime$, i.e., not as the result of a statistical experiment, but rather as a measure of state of confidence or a state of knowledge. They also show that the probabilistic, quantitative approach has a considerable history of application in the electric power industry in the area of power system planning. Finally, the authors show that the decision theory notion of utility provides a point of view from which risks, benefits, safety, and reliability can be viewed in a unified way thus facilitating understanding, comparison, and communication. 29 refs

  7. Reliable computer systems.

    Science.gov (United States)

    Wear, L L; Pinkert, J R

    1993-11-01

    In this article, we looked at some decisions that apply to the design of reliable computer systems. We began with a discussion of several terms such as testability, then described some systems that call for highly reliable hardware and software. The article concluded with a discussion of methods that can be used to achieve higher reliability in computer systems. Reliability and fault tolerance in computers probably will continue to grow in importance. As more and more systems are computerized, people will want assurances about the reliability of these systems, and their ability to work properly even when sub-systems fail.

  8. Human factor reliability program

    International Nuclear Information System (INIS)

    Knoblochova, L.

    2017-01-01

    The human factor's reliability program was at Slovenske elektrarne, a.s. (SE) nuclear power plants. introduced as one of the components Initiatives of Excellent Performance in 2011. The initiative's goal was to increase the reliability of both people and facilities, in response to 3 major areas of improvement - Need for improvement of the results, Troubleshooting support, Supporting the achievement of the company's goals. The human agent's reliability program is in practice included: - Tools to prevent human error; - Managerial observation and coaching; - Human factor analysis; -Quick information about the event with a human agent; -Human reliability timeline and performance indicators; - Basic, periodic and extraordinary training in human factor reliability(authors)

  9. Benchmark Comparison of Cloud Analytics Methods Applied to Earth Observations

    Science.gov (United States)

    Lynnes, Chris; Little, Mike; Huang, Thomas; Jacob, Joseph; Yang, Phil; Kuo, Kwo-Sen

    2016-01-01

    Cloud computing has the potential to bring high performance computing capabilities to the average science researcher. However, in order to take full advantage of cloud capabilities, the science data used in the analysis must often be reorganized. This typically involves sharding the data across multiple nodes to enable relatively fine-grained parallelism. This can be either via cloud-based file systems or cloud-enabled databases such as Cassandra, Rasdaman or SciDB. Since storing an extra copy of data leads to increased cost and data management complexity, NASA is interested in determining the benefits and costs of various cloud analytics methods for real Earth Observation cases. Accordingly, NASA's Earth Science Technology Office and Earth Science Data and Information Systems project have teamed with cloud analytics practitioners to run a benchmark comparison on cloud analytics methods using the same input data and analysis algorithms. We have particularly looked at analysis algorithms that work over long time series, because these are particularly intractable for many Earth Observation datasets which typically store data with one or just a few time steps per file. This post will present side-by-side cost and performance results for several common Earth observation analysis operations.

  10. Benchmark Comparison of Cloud Analytics Methods Applied to Earth Observations

    Science.gov (United States)

    Lynnes, C.; Little, M. M.; Huang, T.; Jacob, J. C.; Yang, C. P.; Kuo, K. S.

    2016-12-01

    Cloud computing has the potential to bring high performance computing capabilities to the average science researcher. However, in order to take full advantage of cloud capabilities, the science data used in the analysis must often be reorganized. This typically involves sharding the data across multiple nodes to enable relatively fine-grained parallelism. This can be either via cloud-based filesystems or cloud-enabled databases such as Cassandra, Rasdaman or SciDB. Since storing an extra copy of data leads to increased cost and data management complexity, NASA is interested in determining the benefits and costs of various cloud analytics methods for real Earth Observation cases. Accordingly, NASA's Earth Science Technology Office and Earth Science Data and Information Systems project have teamed with cloud analytics practitioners to run a benchmark comparison on cloud analytics methods using the same input data and analysis algorithms. We have particularly looked at analysis algorithms that work over long time series, because these are particularly intractable for many Earth Observation datasets which typically store data with one or just a few time steps per file. This post will present side-by-side cost and performance results for several common Earth observation analysis operations.

  11. Population-based mammography screening: comparison of screen-film and full-field digital mammography with soft-copy reading--Oslo I study.

    Science.gov (United States)

    Skaane, Per; Young, Kari; Skjennald, Arnulf

    2003-12-01

    To compare screen-film and full-field digital mammography with soft-copy reading in a population-based screening program. Full-field digital and screen-film mammography were performed in 3,683 women aged 50-69 years. Two standard views of each breast were acquired with each modality. Images underwent independent double reading with use of a five-point rating scale for probability of cancer. Recall rates and positive predictive values were calculated. Cancer detection rates determined with both modalities were compared by using the McNemar test for paired proportions. Retrospective side-by-side analysis for conspicuity of cancers was performed by an external independent radiologist group with experience in both modalities. In 3,683 cases, 31 cancers were detected. Screen-film mammography depicted 28 (0.76%) malignancies, and full-field digital mammography depicted 23 (0.62%) malignancies. The difference between cancer detection rates was not significant (P =.23). The recall rate for full-field digital mammography (4.6%; 168 of 3,683 cases) was slightly higher than that for screen-film mammography (3.5%; 128 of 3,683 cases). The positive predictive value based on needle biopsy results was 46% for screen-film mammography and 39% for full-field digital mammography. Side-by-side image comparison for cancer conspicuity led to classification of 19 cancers as equal for probability of malignancy, six cancers as slightly better demonstrated at screen-film mammography, and six cancers as slightly better demonstrated at full-field digital mammography. There was no statistically significant difference in cancer detection rate between screen-film and full-field digital mammography. Cancer conspicuity was equal with both modalities. Full-field digital mammography with soft-copy reading is comparable to screen-film mammography in population-based screening.

  12. Reliability and safety engineering

    CERN Document Server

    Verma, Ajit Kumar; Karanki, Durga Rao

    2016-01-01

    Reliability and safety are core issues that must be addressed throughout the life cycle of engineering systems. Reliability and Safety Engineering presents an overview of the basic concepts, together with simple and practical illustrations. The authors present reliability terminology in various engineering fields, viz.,electronics engineering, software engineering, mechanical engineering, structural engineering and power systems engineering. The book describes the latest applications in the area of probabilistic safety assessment, such as technical specification optimization, risk monitoring and risk informed in-service inspection. Reliability and safety studies must, inevitably, deal with uncertainty, so the book includes uncertainty propagation methods: Monte Carlo simulation, fuzzy arithmetic, Dempster-Shafer theory and probability bounds. Reliability and Safety Engineering also highlights advances in system reliability and safety assessment including dynamic system modeling and uncertainty management. Cas...

  13. Human reliability analysis

    International Nuclear Information System (INIS)

    Dougherty, E.M.; Fragola, J.R.

    1988-01-01

    The authors present a treatment of human reliability analysis incorporating an introduction to probabilistic risk assessment for nuclear power generating stations. They treat the subject according to the framework established for general systems theory. Draws upon reliability analysis, psychology, human factors engineering, and statistics, integrating elements of these fields within a systems framework. Provides a history of human reliability analysis, and includes examples of the application of the systems approach

  14. Reliability of electronic systems

    International Nuclear Information System (INIS)

    Roca, Jose L.

    2001-01-01

    Reliability techniques have been developed subsequently as a need of the diverse engineering disciplines, nevertheless they are not few those that think they have been work a lot on reliability before the same word was used in the current context. Military, space and nuclear industries were the first ones that have been involved in this topic, however not only in these environments it is that it has been carried out this small great revolution in benefit of the increase of the reliability figures of the products of those industries, but rather it has extended to the whole industry. The fact of the massive production, characteristic of the current industries, drove four decades ago, to the fall of the reliability of its products, on one hand, because the massively itself and, for other, to the recently discovered and even not stabilized industrial techniques. Industry should be changed according to those two new requirements, creating products of medium complexity and assuring an enough reliability appropriated to production costs and controls. Reliability began to be integral part of the manufactured product. Facing this philosophy, the book describes reliability techniques applied to electronics systems and provides a coherent and rigorous framework for these diverse activities providing a unifying scientific basis for the entire subject. It consists of eight chapters plus a lot of statistical tables and an extensive annotated bibliography. Chapters embrace the following topics: 1- Introduction to Reliability; 2- Basic Mathematical Concepts; 3- Catastrophic Failure Models; 4-Parametric Failure Models; 5- Systems Reliability; 6- Reliability in Design and Project; 7- Reliability Tests; 8- Software Reliability. This book is in Spanish language and has a potentially diverse audience as a text book from academic to industrial courses. (author)

  15. Operational safety reliability research

    International Nuclear Information System (INIS)

    Hall, R.E.; Boccio, J.L.

    1986-01-01

    Operating reactor events such as the TMI accident and the Salem automatic-trip failures raised the concern that during a plant's operating lifetime the reliability of systems could degrade from the design level that was considered in the licensing process. To address this concern, NRC is sponsoring the Operational Safety Reliability Research project. The objectives of this project are to identify the essential tasks of a reliability program and to evaluate the effectiveness and attributes of such a reliability program applicable to maintaining an acceptable level of safety during the operating lifetime at the plant

  16. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  17. Comparison Results on the Basic Phenomena between CAP and CONTEMPT-LT

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Kim, Min Ki; Lee, Byung Chul [FNC Tech., SNU, Seoul (Korea, Republic of); Ha, Sang Jun; Choi, Hoon [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2011-10-15

    A development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. As a part of this project, CAP (Containment Analysis Package) code has been developing for the containment safety and performance analysis side by side with SPACE. CAP Beta version has been released lately and validation processes are under way currently. Code by code comparison activity is scheduled in the validation processes and the first comparable code is CONTEMPT-LT. CONTEMPT-LT was developed to predict the longterm behavior of water-cooled nuclear reactor containment systems subjected to postulated loss-ofcoolant accident (LOCA) conditions. CONTEMPT-LT calculates the time variation of compartment pressures, temperatures, mass and energy inventories, heat structure temperature distributions, and energy exchange with adjacent compartments, leakage on containment response. Models are provided for fan cooler and cooling spray as engineered safety systems. Any compartment may have both a liquid pool region and an air-vapor atmosphere region above the pool. Each region is assumed to have a uniform temperature, but the temperatures of the two regions may be different. As mentioned above, CONTEMP-LT has the similar code features and it, therefore, is expected to show the similar analysis performance with CAP. In this study, the code performances were compared for the same phenomena between CAP and CONTEMPT-LT. Code comparison is carried out through two stages; separate and integral effect comparison

  18. Comparison Results on the Basic Phenomena between CAP and CONTEMPT-LT

    International Nuclear Information System (INIS)

    Choo, Yeon Joon; Hong, Soon Joon; Hwang, Su Hyun; Kim, Min Ki; Lee, Byung Chul; Ha, Sang Jun; Choi, Hoon

    2011-01-01

    A development project for the domestic design code was launched to be used for the safety and performance analysis of pressurized light water reactors. As a part of this project, CAP (Containment Analysis Package) code has been developing for the containment safety and performance analysis side by side with SPACE. CAP Beta version has been released lately and validation processes are under way currently. Code by code comparison activity is scheduled in the validation processes and the first comparable code is CONTEMPT-LT. CONTEMPT-LT was developed to predict the longterm behavior of water-cooled nuclear reactor containment systems subjected to postulated loss-ofcoolant accident (LOCA) conditions. CONTEMPT-LT calculates the time variation of compartment pressures, temperatures, mass and energy inventories, heat structure temperature distributions, and energy exchange with adjacent compartments, leakage on containment response. Models are provided for fan cooler and cooling spray as engineered safety systems. Any compartment may have both a liquid pool region and an air-vapor atmosphere region above the pool. Each region is assumed to have a uniform temperature, but the temperatures of the two regions may be different. As mentioned above, CONTEMP-LT has the similar code features and it, therefore, is expected to show the similar analysis performance with CAP. In this study, the code performances were compared for the same phenomena between CAP and CONTEMPT-LT. Code comparison is carried out through two stages; separate and integral effect comparison

  19. Potential benefit of a simultaneous, side-by-side display of contrast MDCT and echocardiography over routine sequential imaging for assessment of adult congenital heart disease: A preliminary study.

    Science.gov (United States)

    Oe, Hiroki; Watanabe, Nobuhisa; Miyoshi, Toru; Osawa, Kazuhiro; Akagi, Teiji; Kanazawa, Susumu; Ito, Hiroshi

    2018-06-18

    Management of adult congenital heart disease (ACHD) patients requires understanding of its complex morphology and functional features. An innovative imaging technique has been developed to display a virtual multi-planar reconstruction obtained from contrast-enhanced multidetector-computed tomography (MDCT) corresponding to the same cross-sectional image from transthoracic echocardiography (TTE). The aim of this study is to assess the usefulness of this imaging technology in ACHD patients. This study consisted of 46 consecutive patients (30 women; mean age, 52±18 years old) with ACHD who had undergone contrast MDCT. All patients underwent TTE within a week of MDCT. An experienced sonographer who did not know the results of MDCT conducted a diagnosis using TTE and, then, using the new imaging technology. We studied whether this imaging technology provided additional or unexpected findings or makes more accurate diagnosis. In this imaging technology, MDCT cross-section provides higher-resolution image to the deep compared to corresponding TTE image. Depending on the MDCT section which can be arbitrarily set under the echo guide, we can diagnose unexpected or incremental lesions or more accurately assess the severity of the lesion in 27 patients (59%) compared to TTE study alone. This imaging technology was useful in the following situations: CONCLUSIONS: This integrated imaging technology provides incremental role over TTE in complex anatomy, and allows functional information in ACHD patients. Copyright © 2018 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  20. Investigating Reliabilities of Intraindividual Variability Indicators

    Science.gov (United States)

    Wang, Lijuan; Grimm, Kevin J.

    2012-01-01

    Reliabilities of the two most widely used intraindividual variability indicators, "ISD[superscript 2]" and "ISD", are derived analytically. Both are functions of the sizes of the first and second moments of true intraindividual variability, the size of the measurement error variance, and the number of assessments within a burst. For comparison,…

  1. Improving machinery reliability

    CERN Document Server

    Bloch, Heinz P

    1998-01-01

    This totally revised, updated and expanded edition provides proven techniques and procedures that extend machinery life, reduce maintenance costs, and achieve optimum machinery reliability. This essential text clearly describes the reliability improvement and failure avoidance steps practiced by best-of-class process plants in the U.S. and Europe.

  2. LED system reliability

    NARCIS (Netherlands)

    Driel, W.D. van; Yuan, C.A.; Koh, S.; Zhang, G.Q.

    2011-01-01

    This paper presents our effort to predict the system reliability of Solid State Lighting (SSL) applications. A SSL system is composed of a LED engine with micro-electronic driver(s) that supplies power to the optic design. Knowledge of system level reliability is not only a challenging scientific

  3. Integrated system reliability analysis

    DEFF Research Database (Denmark)

    Gintautas, Tomas; Sørensen, John Dalsgaard

    Specific targets: 1) The report shall describe the state of the art of reliability and risk-based assessment of wind turbine components. 2) Development of methodology for reliability and risk-based assessment of the wind turbine at system level. 3) Describe quantitative and qualitative measures...

  4. Reliability of neural encoding

    DEFF Research Database (Denmark)

    Alstrøm, Preben; Beierholm, Ulrik; Nielsen, Carsten Dahl

    2002-01-01

    The reliability with which a neuron is able to create the same firing pattern when presented with the same stimulus is of critical importance to the understanding of neuronal information processing. We show that reliability is closely related to the process of phaselocking. Experimental results f...

  5. Design reliability engineering

    International Nuclear Information System (INIS)

    Buden, D.; Hunt, R.N.M.

    1989-01-01

    Improved design techniques are needed to achieve high reliability at minimum cost. This is especially true of space systems where lifetimes of many years without maintenance are needed and severe mass limitations exist. Reliability must be designed into these systems from the start. Techniques are now being explored to structure a formal design process that will be more complete and less expensive. The intent is to integrate the best features of design, reliability analysis, and expert systems to design highly reliable systems to meet stressing needs. Taken into account are the large uncertainties that exist in materials, design models, and fabrication techniques. Expert systems are a convenient method to integrate into the design process a complete definition of all elements that should be considered and an opportunity to integrate the design process with reliability, safety, test engineering, maintenance and operator training. 1 fig

  6. Bayesian methods in reliability

    Science.gov (United States)

    Sander, P.; Badoux, R.

    1991-11-01

    The present proceedings from a course on Bayesian methods in reliability encompasses Bayesian statistical methods and their computational implementation, models for analyzing censored data from nonrepairable systems, the traits of repairable systems and growth models, the use of expert judgment, and a review of the problem of forecasting software reliability. Specific issues addressed include the use of Bayesian methods to estimate the leak rate of a gas pipeline, approximate analyses under great prior uncertainty, reliability estimation techniques, and a nonhomogeneous Poisson process. Also addressed are the calibration sets and seed variables of expert judgment systems for risk assessment, experimental illustrations of the use of expert judgment for reliability testing, and analyses of the predictive quality of software-reliability growth models such as the Weibull order statistics.

  7. Comparison of Reliability and Validity of the Breast Cancer depression anxiety stress scales (DASS- 21) with the Beck Depression Inventory-(BDI-II) and Hospital Anxiety and Depression Scale (HADS)

    OpenAIRE

    Bener A; Alsulaiman R; Doodson LG; El Ayoubi HR

    2016-01-01

    Background: No study has been conducted to determine the reliability and validity of the Depression, Anxiety and Stress Scale (DASS-21), Hospital Anxiety and Depression [HADS] and Beck Depression Inventory (BDI-II) among the Arab Breast Cancer population. Aim: The aim of this study was to compare the reliability and validity of the Depression, Anxiety, and Stress scale (DASS-21), the Beck Depression Inventory-(BDI-II) and Hospital Anxiety and Depression Scale (HADS) among Breast Cancer women ...

  8. Evaluation of structural reliability using simulation methods

    Directory of Open Access Journals (Sweden)

    Baballëku Markel

    2015-01-01

    Full Text Available Eurocode describes the 'index of reliability' as a measure of structural reliability, related to the 'probability of failure'. This paper is focused on the assessment of this index for a reinforced concrete bridge pier. It is rare to explicitly use reliability concepts for design of structures, but the problems of structural engineering are better known through them. Some of the main methods for the estimation of the probability of failure are the exact analytical integration, numerical integration, approximate analytical methods and simulation methods. Monte Carlo Simulation is used in this paper, because it offers a very good tool for the estimation of probability in multivariate functions. Complicated probability and statistics problems are solved through computer aided simulations of a large number of tests. The procedures of structural reliability assessment for the bridge pier and the comparison with the partial factor method of the Eurocodes have been demonstrated in this paper.

  9. Reliability of construction materials

    International Nuclear Information System (INIS)

    Merz, H.

    1976-01-01

    One can also speak of reliability with respect to materials. While for reliability of components the MTBF (mean time between failures) is regarded as the main criterium, this is replaced with regard to materials by possible failure mechanisms like physical/chemical reaction mechanisms, disturbances of physical or chemical equilibrium, or other interactions or changes of system. The main tasks of the reliability analysis of materials therefore is the prediction of the various failure reasons, the identification of interactions, and the development of nondestructive testing methods. (RW) [de

  10. Structural Reliability Methods

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Madsen, H. O.

    The structural reliability methods quantitatively treat the uncertainty of predicting the behaviour and properties of a structure given the uncertain properties of its geometry, materials, and the actions it is supposed to withstand. This book addresses the probabilistic methods for evaluation...... of structural reliability, including the theoretical basis for these methods. Partial safety factor codes under current practice are briefly introduced and discussed. A probabilistic code format for obtaining a formal reliability evaluation system that catches the most essential features of the nature...... of the uncertainties and their interplay is the developed, step-by-step. The concepts presented are illustrated by numerous examples throughout the text....

  11. Reliability and mechanical design

    International Nuclear Information System (INIS)

    Lemaire, Maurice

    1997-01-01

    A lot of results in mechanical design are obtained from a modelisation of physical reality and from a numerical solution which would lead to the evaluation of needs and resources. The goal of the reliability analysis is to evaluate the confidence which it is possible to grant to the chosen design through the calculation of a probability of failure linked to the retained scenario. Two types of analysis are proposed: the sensitivity analysis and the reliability analysis. Approximate methods are applicable to problems related to reliability, availability, maintainability and safety (RAMS)

  12. Approach to reliability assessment

    International Nuclear Information System (INIS)

    Green, A.E.; Bourne, A.J.

    1975-01-01

    Experience has shown that reliability assessments can play an important role in the early design and subsequent operation of technological systems where reliability is at a premium. The approaches to and techniques for such assessments, which have been outlined in the paper, have been successfully applied in variety of applications ranging from individual equipments to large and complex systems. The general approach involves the logical and systematic establishment of the purpose, performance requirements and reliability criteria of systems. This is followed by an appraisal of likely system achievment based on the understanding of different types of variational behavior. A fundamental reliability model emerges from the correlation between the appropriate Q and H functions for performance requirement and achievement. This model may cover the complete spectrum of performance behavior in all the system dimensions

  13. Reliability and maintainability assessment factors for reliable fault-tolerant systems

    Science.gov (United States)

    Bavuso, S. J.

    1984-01-01

    A long term goal of the NASA Langley Research Center is the development of a reliability assessment methodology of sufficient power to enable the credible comparison of the stochastic attributes of one ultrareliable system design against others. This methodology, developed over a 10 year period, is a combined analytic and simulative technique. An analytic component is the Computer Aided Reliability Estimation capability, third generation, or simply CARE III. A simulative component is the Gate Logic Software Simulator capability, or GLOSS. The numerous factors that potentially have a degrading effect on system reliability and the ways in which these factors that are peculiar to highly reliable fault tolerant systems are accounted for in credible reliability assessments. Also presented are the modeling difficulties that result from their inclusion and the ways in which CARE III and GLOSS mitigate the intractability of the heretofore unworkable mathematics.

  14. The rating reliability calculator

    Directory of Open Access Journals (Sweden)

    Solomon David J

    2004-04-01

    Full Text Available Abstract Background Rating scales form an important means of gathering evaluation data. Since important decisions are often based on these evaluations, determining the reliability of rating data can be critical. Most commonly used methods of estimating reliability require a complete set of ratings i.e. every subject being rated must be rated by each judge. Over fifty years ago Ebel described an algorithm for estimating the reliability of ratings based on incomplete data. While his article has been widely cited over the years, software based on the algorithm is not readily available. This paper describes an easy-to-use Web-based utility for estimating the reliability of ratings based on incomplete data using Ebel's algorithm. Methods The program is available public use on our server and the source code is freely available under GNU General Public License. The utility is written in PHP, a common open source imbedded scripting language. The rating data can be entered in a convenient format on the user's personal computer that the program will upload to the server for calculating the reliability and other statistics describing the ratings. Results When the program is run it displays the reliability, number of subject rated, harmonic mean number of judges rating each subject, the mean and standard deviation of the averaged ratings per subject. The program also displays the mean, standard deviation and number of ratings for each subject rated. Additionally the program will estimate the reliability of an average of a number of ratings for each subject via the Spearman-Brown prophecy formula. Conclusion This simple web-based program provides a convenient means of estimating the reliability of rating data without the need to conduct special studies in order to provide complete rating data. I would welcome other researchers revising and enhancing the program.

  15. Structural systems reliability analysis

    International Nuclear Information System (INIS)

    Frangopol, D.

    1975-01-01

    For an exact evaluation of the reliability of a structure it appears necessary to determine the distribution densities of the loads and resistances and to calculate the correlation coefficients between loads and between resistances. These statistical characteristics can be obtained only on the basis of a long activity period. In case that such studies are missing the statistical properties formulated here give upper and lower bounds of the reliability. (orig./HP) [de

  16. Reliability and maintainability

    International Nuclear Information System (INIS)

    1994-01-01

    Several communications in this conference are concerned with nuclear plant reliability and maintainability; their titles are: maintenance optimization of stand-by Diesels of 900 MW nuclear power plants; CLAIRE: an event-based simulation tool for software testing; reliability as one important issue within the periodic safety review of nuclear power plants; design of nuclear building ventilation by the means of functional analysis; operation characteristic analysis for a power industry plant park, as a function of influence parameters

  17. Reliability data book

    International Nuclear Information System (INIS)

    Bento, J.P.; Boerje, S.; Ericsson, G.; Hasler, A.; Lyden, C.O.; Wallin, L.; Poern, K.; Aakerlund, O.

    1985-01-01

    The main objective for the report is to improve failure data for reliability calculations as parts of safety analyses for Swedish nuclear power plants. The work is based primarily on evaluations of failure reports as well as information provided by the operation and maintenance staff of each plant. In the report are presented charts of reliability data for: pumps, valves, control rods/rod drives, electrical components, and instruments. (L.E.)

  18. Multidisciplinary System Reliability Analysis

    Science.gov (United States)

    Mahadevan, Sankaran; Han, Song; Chamis, Christos C. (Technical Monitor)

    2001-01-01

    The objective of this study is to develop a new methodology for estimating the reliability of engineering systems that encompass multiple disciplines. The methodology is formulated in the context of the NESSUS probabilistic structural analysis code, developed under the leadership of NASA Glenn Research Center. The NESSUS code has been successfully applied to the reliability estimation of a variety of structural engineering systems. This study examines whether the features of NESSUS could be used to investigate the reliability of systems in other disciplines such as heat transfer, fluid mechanics, electrical circuits etc., without considerable programming effort specific to each discipline. In this study, the mechanical equivalence between system behavior models in different disciplines are investigated to achieve this objective. A new methodology is presented for the analysis of heat transfer, fluid flow, and electrical circuit problems using the structural analysis routines within NESSUS, by utilizing the equivalence between the computational quantities in different disciplines. This technique is integrated with the fast probability integration and system reliability techniques within the NESSUS code, to successfully compute the system reliability of multidisciplinary systems. Traditional as well as progressive failure analysis methods for system reliability estimation are demonstrated, through a numerical example of a heat exchanger system involving failure modes in structural, heat transfer and fluid flow disciplines.

  19. Comparison of SISEC code simulations with earthquake data of ordinary and base-isolated buildings

    International Nuclear Information System (INIS)

    Wang, C.Y.; Gvildys, J.

    1991-01-01

    At Argonne National Laboratory (ANL), a 3-D computer program SISEC (Seismic Isolation System Evaluation Code) is being developed for simulating the system response of isolated and ordinary structures (Wang et al. 1991). This paper describes comparison of SISEC code simulations with building response data of actual earthquakes. To ensure the accuracy of analytical simulations, recorded data of full-size reinforced concrete structures located in Sendai, Japan are used in this benchmark comparison. The test structures consist of two three-story buildings, one base-isolated and the other one ordinary founded. They were constructed side by side to investigate the effect of base isolation on the acceleration response. Among 20 earthquakes observed since April 1989, complete records of three representative earthquakes, no.2, no.6, and no.17, are used for the code validation presented in this paper. Correlations of observed and calculated accelerations at all instrument locations are made. Also, relative response characteristics of ordinary and isolated building structures are investigated. (J.P.N.)

  20. Analysis and Application of Reliability

    International Nuclear Information System (INIS)

    Jeong, Hae Seong; Park, Dong Ho; Kim, Jae Ju

    1999-05-01

    This book tells of analysis and application of reliability, which includes definition, importance and historical background of reliability, function of reliability and failure rate, life distribution and assumption of reliability, reliability of unrepaired system, reliability of repairable system, sampling test of reliability, failure analysis like failure analysis by FEMA and FTA, and cases, accelerated life testing such as basic conception, acceleration and acceleration factor, and analysis of accelerated life testing data, maintenance policy about alternation and inspection.

  1. The Americleft Speech Project: A Training and Reliability Study.

    Science.gov (United States)

    Chapman, Kathy L; Baylis, Adriane; Trost-Cardamone, Judith; Cordero, Kelly Nett; Dixon, Angela; Dobbelsteyn, Cindy; Thurmes, Anna; Wilson, Kristina; Harding-Bell, Anne; Sweeney, Triona; Stoddard, Gregory; Sell, Debbie

    2016-01-01

    To describe the results of two reliability studies and to assess the effect of training on interrater reliability scores. The first study (1) examined interrater and intrarater reliability scores (weighted and unweighted kappas) and (2) compared interrater reliability scores before and after training on the use of the Cleft Audit Protocol for Speech-Augmented (CAPS-A) with British English-speaking children. The second study examined interrater and intrarater reliability on a modified version of the CAPS-A (CAPS-A Americleft Modification) with American and Canadian English-speaking children. Finally, comparisons were made between the interrater and intrarater reliability scores obtained for Study 1 and Study 2. The participants were speech-language pathologists from the Americleft Speech Project. In Study 1, interrater reliability scores improved for 6 of the 13 parameters following training on the CAPS-A protocol. Comparison of the reliability results for the two studies indicated lower scores for Study 2 compared with Study 1. However, this appeared to be an artifact of the kappa statistic that occurred due to insufficient variability in the reliability samples for Study 2. When percent agreement scores were also calculated, the ratings appeared similar across Study 1 and Study 2. The findings of this study suggested that improvements in interrater reliability could be obtained following a program of systematic training. However, improvements were not uniform across all parameters. Acceptable levels of reliability were achieved for those parameters most important for evaluation of velopharyngeal function.

  2. Reliability-based Assessment of Fatigue Life for Bridges

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    2012-01-01

    The reliability level for bridges is discussed based on a comparison of the reliability levels proposed and used by e.g. JCSS, ISO, NKB and Eurocodes. The influence of reserve capacity by which failure of a specific detail does not lead to structural collapse is investigated. The results show...

  3. A comparative study on the reliability criteria determination

    International Nuclear Information System (INIS)

    Jerng, Dong Wook; Ju, Tae Young

    2009-01-01

    There are two methods to determine the reliability criteria for maintenance effectiveness monitoring; using the failure probability, and the importance from PRA. Comparisons of the results from these two methods provides an insight on the relevancy of setting the reliability criteria to improve the maintenance effectiveness. (author)

  4. A general software reliability process simulation technique

    Science.gov (United States)

    Tausworthe, Robert C.

    1991-01-01

    The structure and rationale of the generalized software reliability process, together with the design and implementation of a computer program that simulates this process are described. Given assumed parameters of a particular project, the users of this program are able to generate simulated status timelines of work products, numbers of injected anomalies, and the progress of testing, fault isolation, repair, validation, and retest. Such timelines are useful in comparison with actual timeline data, for validating the project input parameters, and for providing data for researchers in reliability prediction modeling.

  5. Swimming pool reactor reliability and safety analysis

    International Nuclear Information System (INIS)

    Li Zhaohuan

    1997-01-01

    A reliability and safety analysis of Swimming Pool Reactor in China Institute of Atomic Energy is done by use of event/fault tree technique. The paper briefly describes the analysis model, analysis code and main results. Meanwhile it also describes the impact of unassigned operation status on safety, the estimation of effectiveness of defense tactics in maintenance against common cause failure, the effectiveness of recovering actions on the system reliability, the comparison of occurrence frequencies of the core damage by use of generic and specific data

  6. Safety and reliability criteria

    International Nuclear Information System (INIS)

    O'Neil, R.

    1978-01-01

    Nuclear power plants and, in particular, reactor pressure boundary components have unique reliability requirements, in that usually no significant redundancy is possible, and a single failure can give rise to possible widespread core damage and fission product release. Reliability may be required for availability or safety reasons, but in the case of the pressure boundary and certain other systems safety may dominate. Possible Safety and Reliability (S and R) criteria are proposed which would produce acceptable reactor design. Without some S and R requirement the designer has no way of knowing how far he must go in analysing his system or component, or whether his proposed solution is likely to gain acceptance. The paper shows how reliability targets for given components and systems can be individually considered against the derived S and R criteria at the design and construction stage. Since in the case of nuclear pressure boundary components there is often very little direct experience on which to base reliability studies, relevant non-nuclear experience is examined. (author)

  7. Proposed reliability cost model

    Science.gov (United States)

    Delionback, L. M.

    1973-01-01

    The research investigations which were involved in the study include: cost analysis/allocation, reliability and product assurance, forecasting methodology, systems analysis, and model-building. This is a classic example of an interdisciplinary problem, since the model-building requirements include the need for understanding and communication between technical disciplines on one hand, and the financial/accounting skill categories on the other. The systems approach is utilized within this context to establish a clearer and more objective relationship between reliability assurance and the subcategories (or subelements) that provide, or reenforce, the reliability assurance for a system. Subcategories are further subdivided as illustrated by a tree diagram. The reliability assurance elements can be seen to be potential alternative strategies, or approaches, depending on the specific goals/objectives of the trade studies. The scope was limited to the establishment of a proposed reliability cost-model format. The model format/approach is dependent upon the use of a series of subsystem-oriented CER's and sometimes possible CTR's, in devising a suitable cost-effective policy.

  8. Reliability Centered Maintenance - Methodologies

    Science.gov (United States)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  9. Issues in cognitive reliability

    International Nuclear Information System (INIS)

    Woods, D.D.; Hitchler, M.J.; Rumancik, J.A.

    1984-01-01

    This chapter examines some problems in current methods to assess reactor operator reliability at cognitive tasks and discusses new approaches to solve these problems. The two types of human failures are errors in the execution of an intention and errors in the formation/selection of an intention. Topics considered include the types of description, error correction, cognitive performance and response time, the speed-accuracy tradeoff function, function based task analysis, and cognitive task analysis. One problem of human reliability analysis (HRA) techniques in general is the question of what are the units of behavior whose reliability are to be determined. A second problem for HRA is that people often detect and correct their errors. The use of function based analysis, which maps the problem space for plant control, is recommended

  10. Reliability issues in PACS

    Science.gov (United States)

    Taira, Ricky K.; Chan, Kelby K.; Stewart, Brent K.; Weinberg, Wolfram S.

    1991-07-01

    Reliability is an increasing concern when moving PACS from the experimental laboratory to the clinical environment. Any system downtime may seriously affect patient care. The authors report on the several classes of errors encountered during the pre-clinical release of the PACS during the past several months and present the solutions implemented to handle them. The reliability issues discussed include: (1) environmental precautions, (2) database backups, (3) monitor routines of critical resources and processes, (4) hardware redundancy (networks, archives), and (5) development of a PACS quality control program.

  11. Reliability Parts Derating Guidelines

    Science.gov (United States)

    1982-06-01

    226-30, October 1974. 66 I, 26. "Reliability of GAAS Injection Lasers", De Loach , B. C., Jr., 1973 IEEE/OSA Conference on Laser Engineering and...Vol. R-23, No. 4, 226-30, October 1974. 28. "Reliability of GAAS Injection Lasers", De Loach , B. C., Jr., 1973 IEEE/OSA Conference on Laser...opnatien ot 󈨊 deg C, mounted on a 4-inach square 0.250~ inch thick al~loy alum~nusi panel.. This mounting technique should be L~ ken into cunoidur~tiou

  12. Weibull distribution in reliability data analysis in nuclear power plant

    International Nuclear Information System (INIS)

    Ma Yingfei; Zhang Zhijian; Zhang Min; Zheng Gangyang

    2015-01-01

    Reliability is an important issue affecting each stage of the life cycle ranging from birth to death of a product or a system. The reliability engineering includes the equipment failure data processing, quantitative assessment of system reliability and maintenance, etc. Reliability data refers to the variety of data that describe the reliability of system or component during its operation. These data may be in the form of numbers, graphics, symbols, texts and curves. Quantitative reliability assessment is the task of the reliability data analysis. It provides the information related to preventing, detect, and correct the defects of the reliability design. Reliability data analysis under proceed with the various stages of product life cycle and reliability activities. Reliability data of Systems Structures and Components (SSCs) in Nuclear Power Plants is the key factor of probabilistic safety assessment (PSA); reliability centered maintenance and life cycle management. The Weibull distribution is widely used in reliability engineering, failure analysis, industrial engineering to represent manufacturing and delivery times. It is commonly used to model time to fail, time to repair and material strength. In this paper, an improved Weibull distribution is introduced to analyze the reliability data of the SSCs in Nuclear Power Plants. An example is given in the paper to present the result of the new method. The Weibull distribution of mechanical equipment for reliability data fitting ability is very strong in nuclear power plant. It's a widely used mathematical model for reliability analysis. The current commonly used methods are two-parameter and three-parameter Weibull distribution. Through comparison and analysis, the three-parameter Weibull distribution fits the data better. It can reflect the reliability characteristics of the equipment and it is more realistic to the actual situation. (author)

  13. Columbus safety and reliability

    Science.gov (United States)

    Longhurst, F.; Wessels, H.

    1988-10-01

    Analyses carried out to ensure Columbus reliability, availability, and maintainability, and operational and design safety are summarized. Failure modes/effects/criticality is the main qualitative tool used. The main aspects studied are fault tolerance, hazard consequence control, risk minimization, human error effects, restorability, and safe-life design.

  14. Reliability versus reproducibility

    International Nuclear Information System (INIS)

    Lautzenheiser, C.E.

    1976-01-01

    Defect detection and reproducibility of results are two separate but closely related subjects. It is axiomatic that a defect must be detected from examination to examination or reproducibility of results is very poor. On the other hand, a defect can be detected on each of subsequent examinations for higher reliability and still have poor reproducibility of results

  15. Power transformer reliability modelling

    NARCIS (Netherlands)

    Schijndel, van A.

    2010-01-01

    Problem description Electrical power grids serve to transport and distribute electrical power with high reliability and availability at acceptable costs and risks. These grids play a crucial though preferably invisible role in supplying sufficient power in a convenient form. Today’s society has

  16. Designing reliability into accelerators

    International Nuclear Information System (INIS)

    Hutton, A.

    1992-08-01

    For the next generation of high performance, high average luminosity colliders, the ''factories,'' reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis

  17. Proof tests on reliability

    International Nuclear Information System (INIS)

    Mishima, Yoshitsugu

    1983-01-01

    In order to obtain public understanding on nuclear power plants, tests should be carried out to prove the reliability and safety of present LWR plants. For example, the aseismicity of nuclear power plants must be verified by using a large scale earthquake simulator. Reliability test began in fiscal 1975, and the proof tests on steam generators and on PWR support and flexure pins against stress corrosion cracking have already been completed, and the results have been internationally highly appreciated. The capacity factor of the nuclear power plant operation in Japan rose to 80% in the summer of 1983, and considering the period of regular inspection, it means the operation of almost full capacity. Japanese LWR technology has now risen to the top place in the world after having overcome the defects. The significance of the reliability test is to secure the functioning till the age limit is reached, to confirm the correct forecast of deteriorating process, to confirm the effectiveness of the remedy to defects and to confirm the accuracy of predicting the behavior of facilities. The reliability of nuclear valves, fuel assemblies, the heat affected zones in welding, reactor cooling pumps and electric instruments has been tested or is being tested. (Kako, I.)

  18. Reliability and code level

    NARCIS (Netherlands)

    Kasperski, M.; Geurts, C.P.W.

    2005-01-01

    The paper describes the work of the IAWE Working Group WBG - Reliability and Code Level, one of the International Codification Working Groups set up at ICWE10 in Copenhagen. The following topics are covered: sources of uncertainties in the design wind load, appropriate design target values for the

  19. Reliability of Plastic Slabs

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    1989-01-01

    In the paper it is shown how upper and lower bounds for the reliability of plastic slabs can be determined. For the fundamental case it is shown that optimal bounds of a deterministic and a stochastic analysis are obtained on the basis of the same failure mechanisms and the same stress fields....

  20. Reliability based structural design

    NARCIS (Netherlands)

    Vrouwenvelder, A.C.W.M.

    2014-01-01

    According to ISO 2394, structures shall be designed, constructed and maintained in such a way that they are suited for their use during the design working life in an economic way. To fulfil this requirement one needs insight into the risk and reliability under expected and non-expected actions. A

  1. Travel time reliability modeling.

    Science.gov (United States)

    2011-07-01

    This report includes three papers as follows: : 1. Guo F., Rakha H., and Park S. (2010), "A Multi-state Travel Time Reliability Model," : Transportation Research Record: Journal of the Transportation Research Board, n 2188, : pp. 46-54. : 2. Park S.,...

  2. Reliability and Model Fit

    Science.gov (United States)

    Stanley, Leanne M.; Edwards, Michael C.

    2016-01-01

    The purpose of this article is to highlight the distinction between the reliability of test scores and the fit of psychometric measurement models, reminding readers why it is important to consider both when evaluating whether test scores are valid for a proposed interpretation and/or use. It is often the case that an investigator judges both the…

  3. Parametric Mass Reliability Study

    Science.gov (United States)

    Holt, James P.

    2014-01-01

    The International Space Station (ISS) systems are designed based upon having redundant systems with replaceable orbital replacement units (ORUs). These ORUs are designed to be swapped out fairly quickly, but some are very large, and some are made up of many components. When an ORU fails, it is replaced on orbit with a spare; the failed unit is sometimes returned to Earth to be serviced and re-launched. Such a system is not feasible for a 500+ day long-duration mission beyond low Earth orbit. The components that make up these ORUs have mixed reliabilities. Components that make up the most mass-such as computer housings, pump casings, and the silicon board of PCBs-typically are the most reliable. Meanwhile components that tend to fail the earliest-such as seals or gaskets-typically have a small mass. To better understand the problem, my project is to create a parametric model that relates both the mass of ORUs to reliability, as well as the mass of ORU subcomponents to reliability.

  4. Comparison of Software Models for Energy Savings from Cool Roofs

    Energy Technology Data Exchange (ETDEWEB)

    New, Joshua Ryan [ORNL; Miller, William A [ORNL; Huang, Yu (Joe) [White Box Technologies; Levinson, Ronnen [Lawrence Berkeley National Laboratory (LBNL)

    2014-01-01

    A web-based Roof Savings Calculator (RSC) has been deployed for the United States Department of Energy as an industry-consensus tool to help building owners, manufacturers, distributors, contractors and researchers easily run complex roof and attic simulations. This tool employs modern web technologies, usability design, and national average defaults as an interface to annual simulations of hour-by-hour, whole-building performance using the world-class simulation tools DOE-2.1E and AtticSim in order to provide estimated annual energy and cost savings. In addition to cool reflective roofs, RSC simulates multiple roof and attic configurations including different roof slopes, above sheathing ventilation, radiant barriers, low-emittance roof surfaces, duct location, duct leakage rates, multiple substrate types, and insulation levels. A base case and energy-efficient alternative can be compared side-by-side to estimate monthly energy. RSC was benchmarked against field data from demonstration homes in Ft. Irwin, California; while cooling savings were similar, heating penalty varied significantly across different simulation engines. RSC results reduce cool roofing cost-effectiveness thus mitigating expected economic incentives for this countermeasure to the urban heat island effect. This paper consolidates comparison of RSC s projected energy savings to other simulation engines including DOE-2.1E, AtticSim, Micropas, and EnergyPlus, and presents preliminary analyses. RSC s algorithms for capturing radiant heat transfer and duct interaction in the attic assembly are considered major contributing factors to increased cooling savings and heating penalties. Comparison to previous simulation-based studies, analysis on the force multiplier of RSC cooling savings and heating penalties, the role of radiative heat exchange in an attic assembly, and changes made for increased accuracy of the duct model are included.

  5. Reliability analysis of visual ranking of coronary artery calcification on low-dose CT of the thorax for lung cancer screening: comparison with ECG-gated calcium scoring CT.

    Science.gov (United States)

    Kim, Yoon Kyung; Sung, Yon Mi; Cho, So Hyun; Park, Young Nam; Choi, Hye-Young

    2014-12-01

    Coronary artery calcification (CAC) is frequently detected on low-dose CT (LDCT) of the thorax. Concurrent assessment of CAC and lung cancer screening using LDCT is beneficial in terms of cost and radiation dose reduction. The aim of our study was to evaluate the reliability of visual ranking of positive CAC on LDCT compared to Agatston score (AS) on electrocardiogram (ECG)-gated calcium scoring CT. We studied 576 patients who were consecutively registered for health screening and undergoing both LDCT and ECG-gated calcium scoring CT. We excluded subjects with an AS of zero. The final study cohort included 117 patients with CAC (97 men; mean age, 53.4 ± 8.5). AS was used as the gold standard (mean score 166.0; range 0.4-3,719.3). Two board-certified radiologists and two radiology residents participated in an observer performance study. Visual ranking of CAC was performed according to four categories (1-10, 11-100, 101-400, and 401 or higher) for coronary artery disease risk stratification. Weighted kappa statistics were used to measure the degree of reliability on visual ranking of CAC on LDCT. The degree of reliability on visual ranking of CAC on LDCT compared to ECG-gated calcium scoring CT was excellent for board-certified radiologists and good for radiology residents. A high degree of association was observed with 71.6% of visual rankings in the same category as the Agatston category and 98.9% varying by no more than one category. Visual ranking of positive CAC on LDCT is reliable for predicting AS rank categorization.

  6. Neck Flexor and Extensor Muscle Endurance in Subclinical Neck Pain: Intrarater Reliability, Standard Error of Measurement, Minimal Detectable Change, and Comparison With Asymptomatic Participants in a University Student Population.

    Science.gov (United States)

    Lourenço, Ana S; Lameiras, Carina; Silva, Anabela G

    2016-01-01

    The aims of this study were to assess intrarater reliability and to calculate the standard error of measurement (SEM) and minimal detectable change (MDC) for deep neck flexor and neck extensor muscle endurance tests, and compare the results between individuals with and without subclinical neck pain. Participants were students of the University of Aveiro reporting subclinical neck pain and asymptomatic participants matched for sex and age to the neck pain group. Data on endurance capacity of the deep neck flexors and neck extensors were collected by a blinded assessor using the deep neck flexor endurance test and the extensor endurance test, respectively. Intraclass correlation coefficients (ICCs), SEM, and MDC were calculated for measurements taken within a session by the same assessor. Differences between groups for endurance capacity were investigated using a Mann-Whitney U test. The deep neck flexor endurance test (ICC = 0.71; SEM = 6.91 seconds; MDC = 19.15 seconds) and neck extensor endurance test (ICC = 0.73; SEM = 9.84 minutes; MDC = 2.34 minutes) are reliable. No significant differences were found between participants with and without neck pain for both tests of muscle endurance (P > .05). The endurance capacity of the deep neck flexors and neck extensors can be reliably measured in participants with subclinical neck pain. However, the wide SEM and MDC might limit the sensitivity of these tests. Copyright © 2016. Published by Elsevier Inc.

  7. White Matter Lesion Assessment in Patients with Cognitive Impairment and Healthy Controls: Reliability Comparisons between Visual Rating, a Manual, and an Automatic Volumetrical MRI Method—The Gothenburg MCI Study

    Directory of Open Access Journals (Sweden)

    Erik Olsson

    2013-01-01

    Full Text Available Age-related white matter lesions (WML are a risk factor for stroke, cognitive decline, and dementia. Different requirements are imposed on methods for the assessment of WML in clinical settings and for research purposes, but reliability analysis is of major importance. In this study, WML assessment with three different methods was evaluated. In the Gothenburg mild cognitive impairment study, MRI scans from 152 participants were used to assess WML with the Fazekas visual rating scale on T2 images, a manual volumetric method on FLAIR images, and FreeSurfer volumetry on T1 images. Reliability was acceptable for all three methods. For low WML volumes (2/3 of the patients, reliability was overall lower and nonsignificant for the manual volumetric method. Unreliability in the assessment of patients with low WML with manual volumetry may mainly be due to intensity variation in the FLAIR sequence used; hence, intensity standardization and normalization methods must be used for more accurate assessments. The FreeSurfer segmentations resulted in smaller WML volumes than the volumes acquired with the manual method and showed deviations from visible hypointensities in the T1 images, which quite likely reduces validity.

  8. Reliability Approach of a Compressor System using Reliability Block ...

    African Journals Online (AJOL)

    pc

    2018-03-05

    Mar 5, 2018 ... This paper presents a reliability analysis of such a system using reliability ... Keywords-compressor system, reliability, reliability block diagram, RBD .... the same structure has been kept with the three subsystems: air flow, oil flow and .... and Safety in Engineering Design", Springer, 2009. [3] P. O'Connor ...

  9. Reliability in the utility computing era: Towards reliable Fog computing

    DEFF Research Database (Denmark)

    Madsen, Henrik; Burtschy, Bernard; Albeanu, G.

    2013-01-01

    This paper considers current paradigms in computing and outlines the most important aspects concerning their reliability. The Fog computing paradigm as a non-trivial extension of the Cloud is considered and the reliability of the networks of smart devices are discussed. Combining the reliability...... requirements of grid and cloud paradigms with the reliability requirements of networks of sensor and actuators it follows that designing a reliable Fog computing platform is feasible....

  10. RTE - Reliability report 2016

    International Nuclear Information System (INIS)

    2017-06-01

    Every year, RTE produces a reliability report for the past year. This document lays out the main factors that affected the electrical power system's operational reliability in 2016 and the initiatives currently under way intended to ensure its reliability in the future. Within a context of the energy transition, changes to the European interconnected network mean that RTE has to adapt on an on-going basis. These changes include the increase in the share of renewables injecting an intermittent power supply into networks, resulting in a need for flexibility, and a diversification in the numbers of stakeholders operating in the energy sector and changes in the ways in which they behave. These changes are dramatically changing the structure of the power system of tomorrow and the way in which it will operate - particularly the way in which voltage and frequency are controlled, as well as the distribution of flows, the power system's stability, the level of reserves needed to ensure supply-demand balance, network studies, assets' operating and control rules, the tools used and the expertise of operators. The results obtained in 2016 are evidence of a globally satisfactory level of reliability for RTE's operations in somewhat demanding circumstances: more complex supply-demand balance management, cross-border schedules at interconnections indicating operation that is closer to its limits and - most noteworthy - having to manage a cold spell just as several nuclear power plants had been shut down. In a drive to keep pace with the changes expected to occur in these circumstances, RTE implemented numerous initiatives to ensure high levels of reliability: - maintaining investment levels of euro 1.5 billion per year; - increasing cross-zonal capacity at borders with our neighbouring countries, thus bolstering the security of our electricity supply; - implementing new mechanisms (demand response, capacity mechanism, interruptibility, etc.); - involvement in tests or projects

  11. Waste package reliability analysis

    International Nuclear Information System (INIS)

    Pescatore, C.; Sastre, C.

    1983-01-01

    Proof of future performance of a complex system such as a high-level nuclear waste package over a period of hundreds to thousands of years cannot be had in the ordinary sense of the word. The general method of probabilistic reliability analysis could provide an acceptable framework to identify, organize, and convey the information necessary to satisfy the criterion of reasonable assurance of waste package performance according to the regulatory requirements set forth in 10 CFR 60. General principles which may be used to evaluate the qualitative and quantitative reliability of a waste package design are indicated and illustrated with a sample calculation of a repository concept in basalt. 8 references, 1 table

  12. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L; Duru, Ph; Koch, J M; Revol, J L; Van Vaerenbergh, P; Volpe, A M; Clugnet, K; Dely, A; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  13. Human Reliability Program Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Landers, John; Rogers, Erin; Gerke, Gretchen

    2014-05-18

    A Human Reliability Program (HRP) is designed to protect national security as well as worker and public safety by continuously evaluating the reliability of those who have access to sensitive materials, facilities, and programs. Some elements of a site HRP include systematic (1) supervisory reviews, (2) medical and psychological assessments, (3) management evaluations, (4) personnel security reviews, and (4) training of HRP staff and critical positions. Over the years of implementing an HRP, the Department of Energy (DOE) has faced various challenges and overcome obstacles. During this 4-day activity, participants will examine programs that mitigate threats to nuclear security and the insider threat to include HRP, Nuclear Security Culture (NSC) Enhancement, and Employee Assistance Programs. The focus will be to develop an understanding of the need for a systematic HRP and to discuss challenges and best practices associated with mitigating the insider threat.

  14. Reliability and construction control

    Directory of Open Access Journals (Sweden)

    Sherif S. AbdelSalam

    2016-06-01

    Full Text Available The goal of this study was to determine the most reliable and efficient combination of design and construction methods required for vibro piles. For a wide range of static and dynamic formulas, the reliability-based resistance factors were calculated using EGYPT database, which houses load test results for 318 piles. The analysis was extended to introduce a construction control factor that determines the variation between the pile nominal capacities calculated using static versus dynamic formulae. From the major outcomes, the lowest coefficient of variation is associated with Davisson’s criterion, and the resistance factors calculated for the AASHTO method are relatively high compared with other methods. Additionally, the CPT-Nottingham and Schmertmann method provided the most economic design. Recommendations related to a pile construction control factor were also presented, and it was found that utilizing the factor can significantly reduce variations between calculated and actual capacities.

  15. Scyllac equipment reliability analysis

    International Nuclear Information System (INIS)

    Gutscher, W.D.; Johnson, K.J.

    1975-01-01

    Most of the failures in Scyllac can be related to crowbar trigger cable faults. A new cable has been designed, procured, and is currently undergoing evaluation. When the new cable has been proven, it will be worked into the system as quickly as possible without causing too much additional down time. The cable-tip problem may not be easy or even desirable to solve. A tightly fastened permanent connection that maximizes contact area would be more reliable than the plug-in type of connection in use now, but it would make system changes and repairs much more difficult. The balance of the failures have such a low occurrence rate that they do not cause much down time and no major effort is underway to eliminate them. Even though Scyllac was built as an experimental system and has many thousands of components, its reliability is very good. Because of this the experiment has been able to progress at a reasonable pace

  16. Improving Power Converter Reliability

    DEFF Research Database (Denmark)

    Ghimire, Pramod; de Vega, Angel Ruiz; Beczkowski, Szymon

    2014-01-01

    of a high-power IGBT module during converter operation, which may play a vital role in improving the reliability of the power converters. The measured voltage is used to estimate the module average junction temperature of the high and low-voltage side of a half-bridge IGBT separately in every fundamental......The real-time junction temperature monitoring of a high-power insulated-gate bipolar transistor (IGBT) module is important to increase the overall reliability of power converters for industrial applications. This article proposes a new method to measure the on-state collector?emitter voltage...... is measured in a wind power converter at a low fundamental frequency. To illustrate more, the test method as well as the performance of the measurement circuit are also presented. This measurement is also useful to indicate failure mechanisms such as bond wire lift-off and solder layer degradation...

  17. Accelerator reliability workshop

    International Nuclear Information System (INIS)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D.

    2002-01-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop

  18. Safety and reliability assessment

    International Nuclear Information System (INIS)

    1979-01-01

    This report contains the papers delivered at the course on safety and reliability assessment held at the CSIR Conference Centre, Scientia, Pretoria. The following topics were discussed: safety standards; licensing; biological effects of radiation; what is a PWR; safety principles in the design of a nuclear reactor; radio-release analysis; quality assurance; the staffing, organisation and training for a nuclear power plant project; event trees, fault trees and probability; Automatic Protective Systems; sources of failure-rate data; interpretation of failure data; synthesis and reliability; quantification of human error in man-machine systems; dispersion of noxious substances through the atmosphere; criticality aspects of enrichment and recovery plants; and risk and hazard analysis. Extensive examples are given as well as case studies

  19. Multi-model comparison of CO2 emissions peaking in China: Lessons from CEMF01 study

    Directory of Open Access Journals (Sweden)

    Oleg Lugovoy

    2018-03-01

    Full Text Available The paper summarizes results of the China Energy Modeling Forum's (CEMF first study. Carbon emissions peaking scenarios, consistent with China's Paris commitment, have been simulated with seven national and industry-level energy models and compared. The CO2 emission trends in the considered scenarios peak from 2015 to 2030 at the level of 9–11 Gt. Sector-level analysis suggests that total emissions pathways before 2030 will be determined mainly by dynamics of emissions in the electric power industry and transportation sector. Both sectors will experience significant increase in demand, but have low-carbon alternative options for development. Based on a side-by-side comparison of modeling input and results, conclusions have been drawn regarding the sources of emissions projections differences, which include data, views on economic perspectives, or models' structure and theoretical framework. Some suggestions have been made regarding energy models' development priorities for further research. Keywords: Carbon emissions projections, Climate change, CO2 emissions peak, China's Paris commitment, Top-Down energy models, Bottom-Up energy models, Multi model comparative study, China Energy Modeling Forum (CEMF

  20. Analysis of DOE s Roof Savings Calculator with Comparison to other Simulation Engines

    Energy Technology Data Exchange (ETDEWEB)

    New, Joshua Ryan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huang, Yu [White Box Technologies, Salt Lake City, UT (United States); Levinson, Ronnen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mellot, Joe [The Garland Company, Cleveland, OH (United States); Sanyal, Jibonananda [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Childs, Kenneth W [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-01-01

    A web-based Roof Savings Calculator (RSC) has been deployed for the Department of Energy as an industry-consensus tool to help building owners, manufacturers, distributors, contractors and researchers easily run complex roof and attic simulations. This tool employs the latest web technologies and usability design to provide an easy input interface to an annual simulation of hour-by-hour, whole-building performance using the world-class simulation tools DOE-2.1E and AtticSim. Building defaults were assigned based on national averages and can provide estimated annual energy and cost savings after the user selects nothing more than building location. In addition to cool reflective roofs, the RSC tool can simulate multiple roof and attic configurations including different roof slopes, above sheathing ventilation, radiant barriers, low-emittance surfaces, HVAC duct location, duct leakage rates, multiple layers of building materials, ceiling and deck insulation levels, and other parameters. A base case and energy-efficient alternative can be compared side-by-side to generate an energy/cost savings estimate between two buildings. The RSC tool was benchmarked against field data for demonstration homes in Ft. Irwin, CA. However, RSC gives different energy savings estimates than previous cool roof simulation tools so more thorough software and empirical validation proved necessary. This report consolidates much of the preliminary analysis for comparison of RSC s projected energy savings to that from other simulation engines.

  1. Reliability of Circumplex Axes

    Directory of Open Access Journals (Sweden)

    Micha Strack

    2013-06-01

    Full Text Available We present a confirmatory factor analysis (CFA procedure for computing the reliability of circumplex axes. The tau-equivalent CFA variance decomposition model estimates five variance components: general factor, axes, scale-specificity, block-specificity, and item-specificity. Only the axes variance component is used for reliability estimation. We apply the model to six circumplex types and 13 instruments assessing interpersonal and motivational constructs—Interpersonal Adjective List (IAL, Interpersonal Adjective Scales (revised; IAS-R, Inventory of Interpersonal Problems (IIP, Impact Messages Inventory (IMI, Circumplex Scales of Interpersonal Values (CSIV, Support Action Scale Circumplex (SAS-C, Interaction Problems With Animals (IPI-A, Team Role Circle (TRC, Competing Values Leadership Instrument (CV-LI, Love Styles, Organizational Culture Assessment Instrument (OCAI, Customer Orientation Circle (COC, and System for Multi-Level Observation of Groups (behavioral adjectives; SYMLOG—in 17 German-speaking samples (29 subsamples, grouped by self-report, other report, and metaperception assessments. The general factor accounted for a proportion ranging from 1% to 48% of the item variance, the axes component for 2% to 30%; and scale specificity for 1% to 28%, respectively. Reliability estimates varied considerably from .13 to .92. An application of the Nunnally and Bernstein formula proposed by Markey, Markey, and Tinsley overestimated axes reliabilities in cases of large-scale specificities but otherwise works effectively. Contemporary circumplex evaluations such as Tracey’s RANDALL are sensitive to the ratio of the axes and scale-specificity components. In contrast, the proposed model isolates both components.

  2. The cost of reliability

    International Nuclear Information System (INIS)

    Ilic, M.

    1998-01-01

    In this article the restructuring process under way in the US power industry is being revisited from the point of view of transmission system provision and reliability was rolled into the average cost of electricity to all, it is not so obvious how is this cost managed in the new industry. A new MIT approach to transmission pricing is here suggested as a possible solution [it

  3. Software reliability studies

    Science.gov (United States)

    Hoppa, Mary Ann; Wilson, Larry W.

    1994-01-01

    There are many software reliability models which try to predict future performance of software based on data generated by the debugging process. Our research has shown that by improving the quality of the data one can greatly improve the predictions. We are working on methodologies which control some of the randomness inherent in the standard data generation processes in order to improve the accuracy of predictions. Our contribution is twofold in that we describe an experimental methodology using a data structure called the debugging graph and apply this methodology to assess the robustness of existing models. The debugging graph is used to analyze the effects of various fault recovery orders on the predictive accuracy of several well-known software reliability algorithms. We found that, along a particular debugging path in the graph, the predictive performance of different models can vary greatly. Similarly, just because a model 'fits' a given path's data well does not guarantee that the model would perform well on a different path. Further we observed bug interactions and noted their potential effects on the predictive process. We saw that not only do different faults fail at different rates, but that those rates can be affected by the particular debugging stage at which the rates are evaluated. Based on our experiment, we conjecture that the accuracy of a reliability prediction is affected by the fault recovery order as well as by fault interaction.

  4. SGHWR fuel performance, safety and reliability

    International Nuclear Information System (INIS)

    Pickman, D.O.; Inglis, G.H.

    1977-05-01

    The design principles involved in fuel pins and elements need to take account of the sometimes conflicting requirements of safety and reliability. The principal factors involved in this optimisation are discussed and it is shown from fuel irradiation experience in the Winfrith SGHWR that the necessary bias towards safety has not resulted in a reliability level lower than that shown by other successful water reactor designs. Reliability has important economic implications. By a detailed evaluation of SGHWR fuel defects it is shown that very few defects can be shown to be related to design, rating, or burn-up. This demonstrates that economic aspects have not over-ridden necessary criteria that most be met to achieve the desirable reliability level. It is possible that large scale experience on SGHWR fuel may eventually demonstrate that the balance is too much in favour of reliability and consideration may be given to whether design changes favouring economy could be achieved without compromising safety. The safety criteria applied to SGHWR fuel are designed to avoid any possibility of a temperature runaway in any credible accident situation. the philosophy and supporting experimental work programme are outlines and the fuel design features which particularly contribute to maximising safety margins are outlined. Reference is made to the new 60-pin fuel element to be used in the commercial SGHWRs and to its comparison in design and performance aspects with the 36-pin element that has been used to date in the Winfrith SGHWR. (author)

  5. Reliability of lifeline networks under seismic hazard

    International Nuclear Information System (INIS)

    Selcuk, A. Sevtap; Yuecemen, M. Semih

    1999-01-01

    Lifelines, such as pipelines, transportation, communication and power transmission systems, are networks which extend spatially over large geographical regions. The quantification of the reliability (survival probability) of a lifeline under seismic threat requires attention, as the proper functioning of these systems during or after a destructive earthquake is vital. In this study, a lifeline is idealized as an equivalent network with the capacity of its elements being random and spatially correlated and a comprehensive probabilistic model for the assessment of the reliability of lifelines under earthquake loads is developed. The seismic hazard that the network is exposed to is described by a probability distribution derived by using the past earthquake occurrence data. The seismic hazard analysis is based on the 'classical' seismic hazard analysis model with some modifications. An efficient algorithm developed by Yoo and Deo (Yoo YB, Deo N. A comparison of algorithms for terminal pair reliability. IEEE Transactions on Reliability 1988; 37: 210-215) is utilized for the evaluation of the network reliability. This algorithm eliminates the CPU time and memory capacity problems for large networks. A comprehensive computer program, called LIFEPACK is coded in Fortran language in order to carry out the numerical computations. Two detailed case studies are presented to show the implementation of the proposed model

  6. Reliability and accuracy of Crystaleye spectrophotometric system.

    Science.gov (United States)

    Chen, Li; Tan, Jian Guo; Zhou, Jian Feng; Yang, Xu; Du, Yang; Wang, Fang Ping

    2010-01-01

    to develop an in vitro shade-measuring model to evaluate the reliability and accuracy of the Crystaleye spectrophotometric system, a newly developed spectrophotometer. four shade guides, VITA Classical, VITA 3D-Master, Chromascop and Vintage Halo NCC, were measured with the Crystaleye spectrophotometer in a standardised model, ten times for 107 shade tabs. The shade-matching results and the CIE L*a*b* values of the cervical, body and incisal regions for each measurement were automatically analysed using the supporting software. Reliability and accuracy were calculated for each shade tab both in percentage and in colour difference (ΔE). Difference was analysed by one-way ANOVA in the cervical, body and incisal regions. range of reliability was 88.81% to 98.97% and 0.13 to 0.24 ΔE units, and that of accuracy was 44.05% to 91.25% and 1.03 to 1.89 ΔE units. Significant differences in reliability and accuracy were found between the body region and the cervical and incisal regions. Comparisons made among regions and shade guides revealed that evaluation in ΔE was prone to disclose the differences. measurements with the Crystaleye spectrophotometer had similar, high reliability in different shade guides and regions, indicating predictable repeated measurements. Accuracy in the body region was high and less variable compared with the cervical and incisal regions.

  7. Investment in new product reliability

    International Nuclear Information System (INIS)

    Murthy, D.N.P.; Rausand, M.; Virtanen, S.

    2009-01-01

    Product reliability is of great importance to both manufacturers and customers. Building reliability into a new product is costly, but the consequences of inadequate product reliability can be costlier. This implies that manufacturers need to decide on the optimal investment in new product reliability by achieving a suitable trade-off between the two costs. This paper develops a framework and proposes an approach to help manufacturers decide on the investment in new product reliability.

  8. Reliability evaluation of a natural circulation system

    International Nuclear Information System (INIS)

    Jafari, Jalil; D'Auria, Francesco; Kazeminejad, Hossein; Davilu, Hadi

    2003-01-01

    This paper discusses a reliability study performed with reference to a passive thermohydraulic natural circulation (NC) system, named TTL-1. A methodology based on probabilistic techniques has been applied with the main purpose to optimize the system design. The obtained results have been adopted to estimate the thermal-hydraulic reliability (TH-R) of the same system. A total of 29 relevant parameters (including nominal values and plausible ranges of variations) affecting the design and the NC performance of the TTL-1 loop are identified and a probability of occurrence is assigned for each value based on expert judgment. Following procedures established for the uncertainty evaluation of thermal-hydraulic system codes results, 137 system configurations have been selected and each configuration has been analyzed via the Relap5 best-estimate code. The reference system configuration and the failure criteria derived from the 'mission' of the passive system are adopted for the evaluation of the system TH-R. Four different definitions of a less-than-unity 'reliability-values' (where unity represents the maximum achievable reliability) are proposed for the performance of the selected passive system. This is normally considered fully reliable, i.e. reliability-value equal one, in typical Probabilistic Safety Assessment (PSA) applications in nuclear reactor safety. The two 'point' TH-R values for the considered NC system were found equal to 0.70 and 0.85, i.e. values comparable with the reliability of a pump installed in an 'equivalent' forced circulation (active) system having the same 'mission'. The design optimization study was completed by a regression analysis addressing the output of the 137 calculations: heat losses, undetected leakage, loop length, riser diameter, and equivalent diameter of the test section have been found as the most important parameters bringing to the optimal system design and affecting the TH-R. As added values for this work, the comparison has

  9. Comparison of the reliability of subjective evaluation and quantitative measurements of MR signal intensity in inflammations of the intratemporal facial nerve; Vergleich der Reliabilitaet von subjektiver Beurteilung und quantitativer Messung der MR-Signalintensitaet bei Entzuendungen des intratemporalen N. facialis

    Energy Technology Data Exchange (ETDEWEB)

    Kress, B. [Universitaetsklinikum Heidelberg, Abt. Neuroradiologie (Germany); Abt. Neuroradiologie, Neurologische Klinik, Universitaetsklinik Heidelberg (Germany); Griesbeck, F. [Abt. Neurologie/Psychiatrie, Bundeswehrkrankenhaus Ulm (Germany); Stippich, C.; Sartor, K. [Abt. Neuroradiologie, Neurologische Klinik, Universitaetsklinik Heidelberg (Germany); Baehren, W. [Universitaetsklinikum Heidelberg, Abt. Neuroradiologie (Germany)

    2003-01-01

    Purpose: To compare in a single-blind study the reliability of quantitative measurements and subjective evaluations of contrast enhancement of the facial nerve in patients with idiopathic facial paralysis. Materials and Methods: Magnetic resonance images with a 0.7 mm slice thickness (surface coil) were obtained in patients with idiopathic facial paralysis before and after administration of Gd-DTPA, 0.1 mmol/kg. The five intratemporal segments of the facial nerve were quantitatively measured and subjectively assessed by five radiologists as to the degree of enhancement. The results were compared as to the reliability of both methods. Results: Using the quantitative measuring method, 175 measurements were calculated from a total of 350 regions of interest. At all 35 measured sites, the five quantitative measurements produced identical results. In contrast, the subjective assessment of the five radiologists arrived at a majority consensus in only 16 sites. A complete agreement was not reached for any measured site. Conclusion: The measured quantitative increase in signal intensity after administration of contrast medium is more reliable than subjective assessment. The quantitative method enables reproducible signal intensity measurements even for different window settings and can be easily and swiftly performed at the workstation. (orig.) [German] Untersuchungsziel: In einer einfach geblindeten Untersuchung sollte geprueft werden, wie hoch die Reliabilitaet der quantitativen Messung des Kontrastmittelanstieges im N. facialis bei idiopathischer Fazialisparese im Vergleich zur subjektiven Einschaetzung ist. Methodik: Bei 7 Patienten mit idiopathischer Fazialisparese wurde eine MRT in Duennschichttechnik (0,7 mm, nativ und nach Gabe von 0,1 mmol GdDTPA/kg) unter Verwendung einer Oberflaechenspule durchgefuehrt. 5 intratemporale Abschnitte des N. facialis wurden sowohl quantitativ als auch subjektiv durch 5 Radiologen beurteilt, und die Methoden wurden im Hinblick auf

  10. Nuclear performance and reliability

    International Nuclear Information System (INIS)

    Rothwell, G.

    1993-01-01

    If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive. There has been a significant improvement in nuclear power plant performance, due largely to a decline in the forced outage rate and a dramatic drop in the average number of forced outages per fuel cycle. If fewer forced outages are a sign of improved safety, nuclear power plants have become safer and more productive over time. To encourage further increases in performance, regulatory incentive schemes should reward reactor operators for improved reliability and safety, as well as for improved performance

  11. [How Reliable is Neuronavigation?].

    Science.gov (United States)

    Stieglitz, Lennart Henning

    2016-02-17

    Neuronavigation plays a central role in modern neurosurgery. It allows visualizing instruments and three-dimensional image data intraoperatively and supports spatial orientation. Thus it allows to reduce surgical risks and speed up complex surgical procedures. The growing availability and importance of neuronavigation makes clear how relevant it is to know about its reliability and accuracy. Different factors may influence the accuracy during the surgery unnoticed, misleading the surgeon. Besides the best possible optimization of the systems themselves, a good knowledge about its weaknesses is mandatory for every neurosurgeon.

  12. The value of reliability

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Karlström, Anders

    2010-01-01

    We derive the value of reliability in the scheduling of an activity of random duration, such as travel under congested conditions. Using a simple formulation of scheduling utility, we show that the maximal expected utility is linear in the mean and standard deviation of trip duration, regardless...... of the form of the standardised distribution of trip durations. This insight provides a unification of the scheduling model and models that include the standard deviation of trip duration directly as an argument in the cost or utility function. The results generalise approximately to the case where the mean...

  13. Interactive reliability assessment using an integrated reliability data bank

    International Nuclear Information System (INIS)

    Allan, R.N.; Whitehead, A.M.

    1986-01-01

    The logical structure, techniques and practical application of a computer-aided technique based on a microcomputer using floppy disc Random Access Files is described. This interactive computational technique is efficient if the reliability prediction program is coupled directly to a relevant source of data to create an integrated reliability assessment/reliability data bank system. (DG)

  14. Load Control System Reliability

    Energy Technology Data Exchange (ETDEWEB)

    Trudnowski, Daniel [Montana Tech of the Univ. of Montana, Butte, MT (United States)

    2015-04-03

    This report summarizes the results of the Load Control System Reliability project (DOE Award DE-FC26-06NT42750). The original grant was awarded to Montana Tech April 2006. Follow-on DOE awards and expansions to the project scope occurred August 2007, January 2009, April 2011, and April 2013. In addition to the DOE monies, the project also consisted of matching funds from the states of Montana and Wyoming. Project participants included Montana Tech; the University of Wyoming; Montana State University; NorthWestern Energy, Inc., and MSE. Research focused on two areas: real-time power-system load control methodologies; and, power-system measurement-based stability-assessment operation and control tools. The majority of effort was focused on area 2. Results from the research includes: development of fundamental power-system dynamic concepts, control schemes, and signal-processing algorithms; many papers (including two prize papers) in leading journals and conferences and leadership of IEEE activities; one patent; participation in major actual-system testing in the western North American power system; prototype power-system operation and control software installed and tested at three major North American control centers; and, the incubation of a new commercial-grade operation and control software tool. Work under this grant certainly supported the DOE-OE goals in the area of “Real Time Grid Reliability Management.”

  15. Microprocessor hardware reliability

    Energy Technology Data Exchange (ETDEWEB)

    Wright, R I

    1982-01-01

    Microprocessor-based technology has had an impact in nearly every area of industrial electronics and many applications have important safety implications. Microprocessors are being used for the monitoring and control of hazardous processes in the chemical, oil and power generation industries, for the control and instrumentation of aircraft and other transport systems and for the control of industrial machinery. Even in the field of nuclear reactor protection, where designers are particularly conservative, microprocessors are used to implement certain safety functions and may play increasingly important roles in protection systems in the future. Where microprocessors are simply replacing conventional hard-wired control and instrumentation systems no new hazards are created by their use. In the field of robotics, however, the microprocessor has opened up a totally new technology and with it has created possible new and as yet unknown hazards. The paper discusses some of the design and manufacturing techniques which may be used to enhance the reliability of microprocessor based systems and examines the available reliability data on lsi/vlsi microcircuits. 12 references.

  16. Supply chain reliability modelling

    Directory of Open Access Journals (Sweden)

    Eugen Zaitsev

    2012-03-01

    Full Text Available Background: Today it is virtually impossible to operate alone on the international level in the logistics business. This promotes the establishment and development of new integrated business entities - logistic operators. However, such cooperation within a supply chain creates also many problems related to the supply chain reliability as well as the optimization of the supplies planning. The aim of this paper was to develop and formulate the mathematical model and algorithms to find the optimum plan of supplies by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Methods: The mathematical model and algorithms to find the optimum plan of supplies were developed and formulated by using economic criterion and the model for the probability evaluating of non-failure operation of supply chain. Results and conclusions: The problem of ensuring failure-free performance of goods supply channel analyzed in the paper is characteristic of distributed network systems that make active use of business process outsourcing technologies. The complex planning problem occurring in such systems that requires taking into account the consumer's requirements for failure-free performance in terms of supply volumes and correctness can be reduced to a relatively simple linear programming problem through logical analysis of the structures. The sequence of the operations, which should be taken into account during the process of the supply planning with the supplier's functional reliability, was presented.

  17. OSS reliability measurement and assessment

    CERN Document Server

    Yamada, Shigeru

    2016-01-01

    This book analyses quantitative open source software (OSS) reliability assessment and its applications, focusing on three major topic areas: the Fundamentals of OSS Quality/Reliability Measurement and Assessment; the Practical Applications of OSS Reliability Modelling; and Recent Developments in OSS Reliability Modelling. Offering an ideal reference guide for graduate students and researchers in reliability for open source software (OSS) and modelling, the book introduces several methods of reliability assessment for OSS including component-oriented reliability analysis based on analytic hierarchy process (AHP), analytic network process (ANP), and non-homogeneous Poisson process (NHPP) models, the stochastic differential equation models and hazard rate models. These measurement and management technologies are essential to producing and maintaining quality/reliable systems using OSS.

  18. Transit ridership, reliability, and retention.

    Science.gov (United States)

    2008-10-01

    This project explores two major components that affect transit ridership: travel time reliability and rider : retention. It has been recognized that transit travel time reliability may have a significant impact on : attractiveness of transit to many ...

  19. Travel reliability inventory for Chicago.

    Science.gov (United States)

    2013-04-01

    The overarching goal of this research project is to enable state DOTs to document and monitor the reliability performance : of their highway networks. To this end, a computer tool, TRIC, was developed to produce travel reliability inventories from : ...

  20. 2017 NREL Photovoltaic Reliability Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-15

    NREL's Photovoltaic (PV) Reliability Workshop (PVRW) brings together PV reliability experts to share information, leading to the improvement of PV module reliability. Such improvement reduces the cost of solar electricity and promotes investor confidence in the technology -- both critical goals for moving PV technologies deeper into the electricity marketplace.

  1. AECL's reliability and maintainability program

    International Nuclear Information System (INIS)

    Wolfe, W.A.; Nieuwhof, G.W.E.

    1976-05-01

    AECL's reliability and maintainability program for nuclear generating stations is described. How the various resources of the company are organized to design and construct stations that operate reliably and safely is shown. Reliability and maintainability includes not only special mathematically oriented techniques, but also the technical skills and organizational abilities of the company. (author)

  2. Reliability of chromogenic in situ hybridization for epidermal growth factor receptor gene copy number detection in non-small-cell lung carcinomas: a comparison with fluorescence in situ hybridization study.

    Science.gov (United States)

    Yoo, Seol Bong; Lee, Hyun Ju; Park, Jung Ok; Choe, Gheeyoung; Chung, Doo Hyun; Seo, Jeong-Wook; Chung, Jin-Haeng

    2010-03-01

    Fluorescence in situ hybridization (FISH) has been known to be the most representative and standardized test for assessing gene amplification. However, FISH requires a fluorescence microscope, the signals are labile and rapidly fade over time. Recently, chromogenic in situ hybridization (CISH) has emerged as a potential alternative to FISH. The aim of this study is to test the reliability of CISH technique for the detection of epidermal growth factor receptor (EGFR) gene amplification in non-small-cell lung carcinomas (NSCLC), to compare CISH results with FISH. A total of 277 formalin-fixed and paraffin embedded NSCLC tissue samples were retrieved from the surgical pathology archives at Seoul National University Bundang Hospital. CISH and FISH examinations were performed to test EGFR gene amplification status. There was high concordance in the assessment of EGFR gene copy number between CISH and FISH tests (Kappa coefficient=0.83). Excellent concordance was shown between two observers on the interpretation of the CISH results (Kappa coefficient=0.90). In conclusion, CISH result is highly reproducible, accurate and practical method to determine EGFR gene amplification in NSCLC. In addition, CISH allows a concurrent analysis of histological features of the tumors and gene copy numbers.

  3. Business of reliability

    Science.gov (United States)

    Engel, Pierre

    1999-12-01

    The presentation is organized around three themes: (1) The decrease of reception equipment costs allows non-Remote Sensing organization to access a technology until recently reserved to scientific elite. What this means is the rise of 'operational' executive agencies considering space-based technology and operations as a viable input to their daily tasks. This is possible thanks to totally dedicated ground receiving entities focusing on one application for themselves, rather than serving a vast community of users. (2) The multiplication of earth observation platforms will form the base for reliable technical and financial solutions. One obstacle to the growth of the earth observation industry is the variety of policies (commercial versus non-commercial) ruling the distribution of the data and value-added products. In particular, the high volume of data sales required for the return on investment does conflict with traditional low-volume data use for most applications. Constant access to data sources supposes monitoring needs as well as technical proficiency. (3) Large volume use of data coupled with low- cost equipment costs is only possible when the technology has proven reliable, in terms of application results, financial risks and data supply. Each of these factors is reviewed. The expectation is that international cooperation between agencies and private ventures will pave the way for future business models. As an illustration, the presentation proposes to use some recent non-traditional monitoring applications, that may lead to significant use of earth observation data, value added products and services: flood monitoring, ship detection, marine oil pollution deterrent systems and rice acreage monitoring.

  4. Study of redundant Models in reliability prediction of HXMT's HES

    International Nuclear Information System (INIS)

    Wang Jinming; Liu Congzhan; Zhang Zhi; Ji Jianfeng

    2010-01-01

    Two redundant equipment structures of HXMT's HES are proposed firstly, the block backup and dual system cold-redundancy. Then prediction of the reliability is made by using parts count method. Research of comparison and analysis is also performed on the two proposals. A conclusion is drawn that a higher reliability and longer service life could be offered by taking a redundant equipment structure of block backup. (authors)

  5. Reliability Based Management of Marine Fouling

    DEFF Research Database (Denmark)

    Faber, Michael Havbro; Hansen, Peter Friis

    1999-01-01

    The present paper describes the results of a recent study on the application of methods from structural reliability to optimise management of marine fouling on jacket type structures.In particular the study addresses effects on the structural response by assessment and quantification of uncertain......The present paper describes the results of a recent study on the application of methods from structural reliability to optimise management of marine fouling on jacket type structures.In particular the study addresses effects on the structural response by assessment and quantification...... of uncertainties of a set of parameters. These are the seasonal variation of marine fouling parameters, the wave loading (taking into account the seasonal variation in sea-state statistics), and the effects of spatial variations and seasonal effects of marine fouling parameters. Comparison of design values...

  6. Modeling high-Power Accelerators Reliability-SNS LINAC (SNS-ORNL); MAX LINAC (MYRRHA)

    International Nuclear Information System (INIS)

    Pitigoi, A. E.; Fernandez Ramos, P.

    2013-01-01

    Improving reliability has recently become a very important objective in the field of particle accelerators. The particle accelerators in operation are constantly undergoing modifications, and improvements are implemented using new technologies, more reliable components or redundant schemes (to obtain more reliability, strength, more power, etc.) A reliability model of SNS (Spallation Neutron Source) LINAC has been developed within MAX project and analysis of the accelerator systems reliability has been performed within the MAX project, using the Risk Spectrum reliability analysis software. The analysis results have been evaluated by comparison with the SNS operational data. Results and conclusions are presented in this paper, oriented to identify design weaknesses and provide recommendations for improving reliability of MYRRHA linear accelerator. The SNS reliability model developed for the MAX preliminary design phase indicates possible avenues for further investigation that could be needed to improve the reliability of the high-power accelerators, in view of the future reliability targets of ADS accelerators.

  7. Electronics reliability calculation and design

    CERN Document Server

    Dummer, Geoffrey W A; Hiller, N

    1966-01-01

    Electronics Reliability-Calculation and Design provides an introduction to the fundamental concepts of reliability. The increasing complexity of electronic equipment has made problems in designing and manufacturing a reliable product more and more difficult. Specific techniques have been developed that enable designers to integrate reliability into their products, and reliability has become a science in its own right. The book begins with a discussion of basic mathematical and statistical concepts, including arithmetic mean, frequency distribution, median and mode, scatter or dispersion of mea

  8. Reliability of a semi-automated 3D-CT measuring method for tunnel diameters after anterior cruciate ligament reconstruction: A comparison between soft-tissue single-bundle allograft vs. autograft.

    Science.gov (United States)

    Robbrecht, Cedric; Claes, Steven; Cromheecke, Michiel; Mahieu, Peter; Kakavelakis, Kyriakos; Victor, Jan; Bellemans, Johan; Verdonk, Peter

    2014-10-01

    Post-operative widening of tibial and/or femoral bone tunnels is a common observation after ACL reconstruction, especially with soft-tissue grafts. There are no studies comparing tunnel widening in hamstring autografts versus tibialis anterior allografts. The goal of this study was to observe the difference in tunnel widening after the use of allograft vs. autograft for ACL reconstruction, by measuring it with a novel 3-D computed tomography based method. Thirty-five ACL-deficient subjects were included, underwent anatomic single-bundle ACL reconstruction and were evaluated at one year after surgery with the use of 3-D CT imaging. Three independent observers semi-automatically delineated femoral and tibial tunnel outlines, after which a best-fit cylinder was derived and the tunnel diameter was determined. Finally, intra- and inter-observer reliability of this novel measurement protocol was defined. In femoral tunnels, the intra-observer ICC was 0.973 (95% CI: 0.922-0.991) and the inter-observer ICC was 0.992 (95% CI: 0.982-0.996). In tibial tunnels, the intra-observer ICC was 0.955 (95% CI: 0.875-0.985). The combined inter-observer ICC was 0.970 (95% CI: 0.987-0.917). Tunnel widening was significantly higher in allografts compared to autografts, in the tibial tunnels (p=0.013) as well as in the femoral tunnels (p=0.007). To our knowledge, this novel, semi-automated 3D-computed tomography image processing method has shown to yield highly reproducible results for the measurement of bone tunnel diameter and area. This series showed a significantly higher amount of tunnel widening observed in the allograft group at one-year follow-up. Level II, Prospective comparative study. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Mathematical reliability an expository perspective

    CERN Document Server

    Mazzuchi, Thomas; Singpurwalla, Nozer

    2004-01-01

    In this volume consideration was given to more advanced theoretical approaches and novel applications of reliability to ensure that topics having a futuristic impact were specifically included. Topics like finance, forensics, information, and orthopedics, as well as the more traditional reliability topics were purposefully undertaken to make this collection different from the existing books in reliability. The entries have been categorized into seven parts, each emphasizing a theme that seems poised for the future development of reliability as an academic discipline with relevance. The seven parts are networks and systems; recurrent events; information and design; failure rate function and burn-in; software reliability and random environments; reliability in composites and orthopedics, and reliability in finance and forensics. Embedded within the above are some of the other currently active topics such as causality, cascading, exchangeability, expert testimony, hierarchical modeling, optimization and survival...

  10. A comparison of two cloudwater/fogwater collectors: The rotating arm collector and the caltech active strand cloudwater collector

    Science.gov (United States)

    Collett, Jeffrey L.; Daube, Bruce C.; Munger, J. William; Hoffmann, Michael R.

    A side-by-side comparison of the Rotating Arm Collector (RAC) and the Caltech Active Strand Cloudwater Collector (CASCC) was conducted at an elevated coastal site near the eastern end of the Santa Barbara Channel in southern California. The CASCC was observed to collect cloudwater at rates of up to 8.5 ml min -1. The ratio of cloudwater collection rates was found to be close to the theoretical prediction of 4.2:1 (CASCC:RAC) over a wide range of liquid water contents (LWC). At low LWC, however, this ratio climbed rapidly, possibly reflecting a predominance of small droplets under these conditions, coupled with a greater collection efficiency of small droplets by the CASCC. Cloudwater samples collected by the RAC had significantly higher concentrations of Na +, Ca 2+, Mg 2+ and Cl - than those collected by the CASCC. These higher concentrations may be due to differences in the chemical composition of large vs small droplets. No significant differences were observed in concentrations of NO 3-, SO 42- or NH 4+ in samples collected by the two instruments.

  11. Reliability model for common mode failures in redundant safety systems

    International Nuclear Information System (INIS)

    Fleming, K.N.

    1974-12-01

    A method is presented for computing the reliability of redundant safety systems, considering both independent and common mode type failures. The model developed for the computation is a simple extension of classical reliability theory. The feasibility of the method is demonstrated with the use of an example. The probability of failure of a typical diesel-generator emergency power system is computed based on data obtained from U. S. diesel-generator operating experience. The results are compared with reliability predictions based on the assumption that all failures are independent. The comparison shows a significant increase in the probability of redundant system failure, when common failure modes are considered. (U.S.)

  12. Of plants and reliability

    International Nuclear Information System (INIS)

    Schneider Horst

    2009-01-01

    Behind the political statements made about the transformer event at the Kruemmel nuclear power station (KKK) in the summer of 2009 there are fundamental issues of atomic law. Pursuant to Articles 20 and 28 of its Basic Law, Germany is a state in which the rule of law applies. Consequently, the aspects of atomic law associated with the incident merit a closer look, all the more so as the items concerned have been known for many years. Important aspects in the debate about the Kruemmel nuclear power plant are the fact that the transformer is considered part of the nuclear power station under atomic law and thus a ''plant'' subject to surveillance by the nuclear regulatory agencies, on the one hand, and the reliability under atomic law of the operator and the executive personnel responsible, on the other hand. Both ''plant'' and ''reliability'' are terms focusing on nuclear safety. Hence the question to what extent safety was affected in the Kruemmel incident. The classification of the event as 0 = no or only a very slight safety impact on the INES scale (INES = International Nuclear Event Scale) should not be used to put aside the safety issue once and for all. Points of fact and their technical significance must be considered prior to any legal assessment. Legal assessments and regulations are associated with facts and circumstances. Any legal examination is based on the facts as determined and elucidated. Any other procedure would be tantamount to an inadmissible legal advance conviction. Now, what is the position of political statements, i.e. political assessments and political responsibility? If everything is done the correct way, they come at the end, after exploration of the facts and evaluation under applicable law. Sometimes things are handled differently, with consequences which are not very helpful. In the light of the provisions about the rule of law as laid down in the Basic Law, the new federal government should be made to observe the proper sequence of

  13. Instrument comparison for Aerosolized Titanium Dioxide

    Science.gov (United States)

    Ranpara, Anand

    Recent toxicological studies have shown that the surface area of ultrafine particles (UFP i.e., particles with diameters less than 0.1 micrometer) has a stronger correlation with adverse health effects than does mass of these particles. Ultrafine titanium dioxide (TiO2) particles are widely used in industry, and their use is associated with adverse health outcomes, such as micro vascular dysfunctions and pulmonary damages. The primary aim of this experimental study was to compare a variety of laboratory and industrial hygiene (IH) field study instruments all measuring the same aerosolized TiO2. The study also observed intra-instrument variability between measurements made by two apparently identical devices of the same type of instrument placed side-by-side. The types of instruments studied were (1) DustTrak(TM) DRX, (2) Personal Data RAMs(TM) (PDR), (3) GRIMM, (4) Diffusion charger (DC) and (5) Scanning Mobility Particle Sizer (SMPS). Two devices of each of the four IH field study instrument types were used to measure six levels of mass concentration of fine and ultrafine TiO2 aerosols in controlled chamber tests. Metrics evaluated included real-time mass, active surface area and number/geometric surface area distributions, and off-line gravimetric mass and morphology on filters. DustTrak(TM) DRXs and PDRs were used for mass concentration measurements. DCs were used for active surface area concentration measurements. GRIMMs were used for number concentration measurements. SMPS was used for inter-instrument comparisons of surface area and number concentrations. The results indicated that two apparently identical devices of each DRX and PDR were statistically not different with each other for all the trials of both the sizes of powder (p < 5%). Mean difference between mass concentrations measured by two DustTrak DRX devices was smaller than that measured by two PDR devices. DustTrak DRX measurements were closer to the reference method, gravimetric mass concentration

  14. Multinomial-exponential reliability function: a software reliability model

    International Nuclear Information System (INIS)

    Saiz de Bustamante, Amalio; Saiz de Bustamante, Barbara

    2003-01-01

    The multinomial-exponential reliability function (MERF) was developed during a detailed study of the software failure/correction processes. Later on MERF was approximated by a much simpler exponential reliability function (EARF), which keeps most of MERF mathematical properties, so the two functions together makes up a single reliability model. The reliability model MERF/EARF considers the software failure process as a non-homogeneous Poisson process (NHPP), and the repair (correction) process, a multinomial distribution. The model supposes that both processes are statistically independent. The paper discusses the model's theoretical basis, its mathematical properties and its application to software reliability. Nevertheless it is foreseen model applications to inspection and maintenance of physical systems. The paper includes a complete numerical example of the model application to a software reliability analysis

  15. Quality assurance and reliability

    International Nuclear Information System (INIS)

    Normand, J.; Charon, M.

    1975-01-01

    Concern for obtaining high-quality products which will function properly when required to do so is nothing new - it is one manifestation of a conscientious attitude to work. However, the complexity and cost of equipment and the consequences of even temporary immobilization are such that it has become necessary to make special arrangements for obtaining high-quality products and examining what one has obtained. Each unit within an enterprise must examine its own work or arrange for it to be examined; a unit whose specific task is quality assurance is responsible for overall checking, but does not relieve other units of their responsibility. Quality assurance is a form of mutual assistance within an enterprise, designed to remove the causes of faults as far as possible. It begins very early in a project and continues through the ordering stage, construction, start-up trials and operation. Quality and hence reliability are the direct result of what is done at all stages of a project. They depend on constant attention to detail, for even a minor piece of poor workmanship can, in the case of an essential item of equipment, give rise to serious operational difficulties

  16. Dependent systems reliability estimation by structural reliability approach

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard

    2014-01-01

    Estimation of system reliability by classical system reliability methods generally assumes that the components are statistically independent, thus limiting its applicability in many practical situations. A method is proposed for estimation of the system reliability with dependent components, where...... the leading failure mechanism(s) is described by physics of failure model(s). The proposed method is based on structural reliability techniques and accounts for both statistical and failure effect correlations. It is assumed that failure of any component is due to increasing damage (fatigue phenomena...... identification. Application of the proposed method can be found in many real world systems....

  17. An accurate and efficient reliability-based design optimization using the second order reliability method and improved stability transformation method

    Science.gov (United States)

    Meng, Zeng; Yang, Dixiong; Zhou, Huanlin; Yu, Bo

    2018-05-01

    The first order reliability method has been extensively adopted for reliability-based design optimization (RBDO), but it shows inaccuracy in calculating the failure probability with highly nonlinear performance functions. Thus, the second order reliability method is required to evaluate the reliability accurately. However, its application for RBDO is quite challenge owing to the expensive computational cost incurred by the repeated reliability evaluation and Hessian calculation of probabilistic constraints. In this article, a new improved stability transformation method is proposed to search the most probable point efficiently, and the Hessian matrix is calculated by the symmetric rank-one update. The computational capability of the proposed method is illustrated and compared to the existing RBDO approaches through three mathematical and two engineering examples. The comparison results indicate that the proposed method is very efficient and accurate, providing an alternative tool for RBDO of engineering structures.

  18. Field reliability of electronic systems

    International Nuclear Information System (INIS)

    Elm, T.

    1984-02-01

    This report investigates, through several examples from the field, the reliability of electronic units in a broader sense. That is, it treats not just random parts failure, but also inadequate reliability design and (externally and internally) induced failures. The report is not meant to be merely an indication of the state of the art for the reliability prediction methods we know, but also as a contribution to the investigation of man-machine interplay in the operation and repair of electronic equipment. The report firmly links electronics reliability to safety and risk analyses approaches with a broader, system oriented view of reliability prediction and with postfailure stress analysis. It is intended to reveal, in a qualitative manner, the existence of symptom and cause patterns. It provides a background for further investigations to identify the detailed mechanisms of the faults and the remedical actions and precautions for achieving cost effective reliability. (author)

  19. Reliability Assessment Of Wind Turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2014-01-01

    Reduction of cost of energy for wind turbines are very important in order to make wind energy competitive compared to other energy sources. Therefore the turbine components should be designed to have sufficient reliability but also not be too costly (and safe). This paper presents models...... for uncertainty modeling and reliability assessment of especially the structural components such as tower, blades, substructure and foundation. But since the function of a wind turbine is highly dependent on many electrical and mechanical components as well as a control system also reliability aspects...... of these components are discussed and it is described how there reliability influences the reliability of the structural components. Two illustrative examples are presented considering uncertainty modeling, reliability assessment and calibration of partial safety factors for structural wind turbine components exposed...

  20. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2014-01-01

    This book shows how to build in, evaluate, and demonstrate reliability and availability of components, equipment, systems. It presents the state-of-theart of reliability engineering, both in theory and practice, and is based on the author's more than 30 years experience in this field, half in industry and half as Professor of Reliability Engineering at the ETH, Zurich. The structure of the book allows rapid access to practical results. This final edition extend and replace all previous editions. New are, in particular, a strategy to mitigate incomplete coverage, a comprehensive introduction to human reliability with design guidelines and new models, and a refinement of reliability allocation, design guidelines for maintainability, and concepts related to regenerative stochastic processes. The set of problems for homework has been extended. Methods & tools are given in a way that they can be tailored to cover different reliability requirement levels and be used for safety analysis. Because of the Appendice...

  1. Reliability of Wireless Sensor Networks

    Science.gov (United States)

    Dâmaso, Antônio; Rosa, Nelson; Maciel, Paulo

    2014-01-01

    Wireless Sensor Networks (WSNs) consist of hundreds or thousands of sensor nodes with limited processing, storage, and battery capabilities. There are several strategies to reduce the power consumption of WSN nodes (by increasing the network lifetime) and increase the reliability of the network (by improving the WSN Quality of Service). However, there is an inherent conflict between power consumption and reliability: an increase in reliability usually leads to an increase in power consumption. For example, routing algorithms can send the same packet though different paths (multipath strategy), which it is important for reliability, but they significantly increase the WSN power consumption. In this context, this paper proposes a model for evaluating the reliability of WSNs considering the battery level as a key factor. Moreover, this model is based on routing algorithms used by WSNs. In order to evaluate the proposed models, three scenarios were considered to show the impact of the power consumption on the reliability of WSNs. PMID:25157553

  2. The value of service reliability

    OpenAIRE

    Benezech , Vincent; Coulombel , Nicolas

    2013-01-01

    International audience; This paper studies the impact of service frequency and reliability on the choice of departure time and the travel cost of transit users. When the user has (α, β, γ) scheduling preferences, we show that the optimal head start decreases with service reliability, as expected. It does not necessarily decrease with service frequency, however. We derive the value of service headway (VoSH) and the value of service reliability (VoSR), which measure the marginal effect on the e...

  3. Distribution-Independent Reliable Learning

    OpenAIRE

    Kanade, Varun; Thaler, Justin

    2014-01-01

    We study several questions in the reliable agnostic learning framework of Kalai et al. (2009), which captures learning tasks in which one type of error is costlier than others. A positive reliable classifier is one that makes no false positive errors. The goal in the positive reliable agnostic framework is to output a hypothesis with the following properties: (i) its false positive error rate is at most $\\epsilon$, (ii) its false negative error rate is at most $\\epsilon$ more than that of the...

  4. Reliability of visual and instrumental color matching.

    Science.gov (United States)

    Igiel, Christopher; Lehmann, Karl Martin; Ghinea, Razvan; Weyhrauch, Michael; Hangx, Ysbrand; Scheller, Herbert; Paravina, Rade D

    2017-09-01

    The aim of this investigation was to evaluate intra-rater and inter-rater reliability of visual and instrumental shade matching. Forty individuals with normal color perception participated in this study. The right maxillary central incisor of a teaching model was prepared and restored with 10 feldspathic all-ceramic crowns of different shades. A shade matching session consisted of the observer (rater) visually selecting the best match by using VITA classical A1-D4 (VC) and VITA Toothguide 3D Master (3D) shade guides and the VITA Easyshade Advance intraoral spectrophotometer (ES) to obtain both VC and 3D matches. Three shade matching sessions were held with 4 to 6 weeks between sessions. Intra-rater reliability was assessed based on the percentage of agreement for the three sessions for the same observer, whereas the inter-rater reliability was calculated as mean percentage of agreement between different observers. The Fleiss' Kappa statistical analysis was used to evaluate visual inter-rater reliability. The mean intra-rater reliability for the visual shade selection was 64(11) for VC and 48(10) for 3D. The corresponding ES values were 96(4) for both VC and 3D. The percentages of observers who matched the same shade with VC and 3D were 55(10) and 43(12), respectively, while corresponding ES values were 88(8) for VC and 92(4) for 3D. The results for visual shade matching exhibited a high to moderate level of inconsistency for both intra-rater and inter-rater comparisons. The VITA Easyshade Advance intraoral spectrophotometer exhibited significantly better reliability compared with visual shade selection. This study evaluates the ability of observers to consistently match the same shade visually and with a dental spectrophotometer in different sessions. The intra-rater and inter-rater reliability (agreement of repeated shade matching) of visual and instrumental tooth color matching strongly suggest the use of color matching instruments as a supplementary tool in

  5. Level III Reliability methods feasible for complex structures

    NARCIS (Netherlands)

    Waarts, P.H.; Boer, A. de

    2001-01-01

    The paper describes the comparison between three types of reliability methods: code type level I used by a designer, full level I and a level III method. Two cases that are typical for civil engineering practise, a cable-stayed subjected to traffic load and the installation of a soil retaining sheet

  6. Comparability and Reliability Considerations of Adequate Yearly Progress

    Science.gov (United States)

    Maier, Kimberly S.; Maiti, Tapabrata; Dass, Sarat C.; Lim, Chae Young

    2012-01-01

    The purpose of this study is to develop an estimate of Adequate Yearly Progress (AYP) that will allow for reliable and valid comparisons among student subgroups, schools, and districts. A shrinkage-type estimator of AYP using the Bayesian framework is described. Using simulated data, the performance of the Bayes estimator will be compared to…

  7. Erratum: Comparative Analysis of Some Reliability Characteristics of ...

    African Journals Online (AJOL)

    ... are analyzed using kolmogorov's forward equation method. Comparisons are performed for specific values of system parameters. Finally, the configurations are ranked based on MTSF and ( AV(∞)) and the results show that configuration 3 is optimal. Keywords: Reliability, Availability, Deterioration, Repair, Replacement.

  8. Power plant reliability calculation with Markov chain models

    International Nuclear Information System (INIS)

    Senegacnik, A.; Tuma, M.

    1998-01-01

    In the paper power plant operation is modelled using continuous time Markov chains with discrete state space. The model is used to compute the power plant reliability and the importance and influence of individual states, as well as the transition probabilities between states. For comparison the model is fitted to data for coal and nuclear power plants recorded over several years. (orig.) [de

  9. Design methodologies for reliability of SSL LED boards

    NARCIS (Netherlands)

    Jakovenko, J.; Formánek, J.; Perpiñà, X.; Jorda, X.; Vellvehi, M.; Werkhoven, R.J.; Husák, M.; Kunen, J.M.G.; Bancken, P.; Bolt, P.J.; Gasse, A.

    2013-01-01

    This work presents a comparison of various LED board technologies from thermal, mechanical and reliability point of view provided by an accurate 3-D modelling. LED boards are proposed as a possible technology replacement of FR4 LED boards used in 400 lumen retrofit SSL lamps. Presented design

  10. Reliability in automotive ethernet networks

    DEFF Research Database (Denmark)

    Soares, Fabio L.; Campelo, Divanilson R.; Yan, Ying

    2015-01-01

    This paper provides an overview of in-vehicle communication networks and addresses the challenges of providing reliability in automotive Ethernet in particular.......This paper provides an overview of in-vehicle communication networks and addresses the challenges of providing reliability in automotive Ethernet in particular....

  11. Estimation of Bridge Reliability Distributions

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    In this paper it is shown how the so-called reliability distributions can be estimated using crude Monte Carlo simulation. The main purpose is to demonstrate the methodology. Therefor very exact data concerning reliability and deterioration are not needed. However, it is intended in the paper to ...

  12. Reliability of wind turbine subassemblies

    NARCIS (Netherlands)

    Spinato, F.; Tavner, P.J.; Bussel, van G.J.W.; Koutoulakos, E.

    2009-01-01

    We have investigated the reliability of more than 6000 modern onshore wind turbines and their subassemblies in Denmark and Germany over 11 years and particularly changes in reliability of generators, gearboxes and converters in a subset of 650 turbines in Schleswig Holstein, Germany. We first start

  13. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2010-01-01

    Presenting a solid overview of reliability engineering, this volume enables readers to build and evaluate the reliability of various components, equipment and systems. Current applications are presented, and the text itself is based on the author's 30 years of experience in the field.

  14. Reliability-Based Optimization in Structural Engineering

    DEFF Research Database (Denmark)

    Enevoldsen, I.; Sørensen, John Dalsgaard

    1994-01-01

    In this paper reliability-based optimization problems in structural engineering are formulated on the basis of the classical decision theory. Several formulations are presented: Reliability-based optimal design of structural systems with component or systems reliability constraints, reliability...

  15. Reliability-Based Code Calibration

    DEFF Research Database (Denmark)

    Faber, M.H.; Sørensen, John Dalsgaard

    2003-01-01

    The present paper addresses fundamental concepts of reliability based code calibration. First basic principles of structural reliability theory are introduced and it is shown how the results of FORM based reliability analysis may be related to partial safety factors and characteristic values....... Thereafter the code calibration problem is presented in its principal decision theoretical form and it is discussed how acceptable levels of failure probability (or target reliabilities) may be established. Furthermore suggested values for acceptable annual failure probabilities are given for ultimate...... and serviceability limit states. Finally the paper describes the Joint Committee on Structural Safety (JCSS) recommended procedure - CodeCal - for the practical implementation of reliability based code calibration of LRFD based design codes....

  16. Photovoltaic performance and reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Mrig, L. [ed.

    1993-12-01

    This workshop was the sixth in a series of workshops sponsored by NREL/DOE under the general subject of photovoltaic testing and reliability during the period 1986--1993. PV performance and PV reliability are at least as important as PV cost, if not more. In the US, PV manufacturers, DOE laboratories, electric utilities, and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in the field were brought together to exchange the technical knowledge and field experience as related to current information in this evolving field of PV reliability. The papers presented here reflect this effort since the last workshop held in September, 1992. The topics covered include: cell and module characterization, module and system testing, durability and reliability, system field experience, and standards and codes.

  17. Reliability of drivers in urban intersections.

    Science.gov (United States)

    Gstalter, Herbert; Fastenmeier, Wolfgang

    2010-01-01

    The concept of human reliability has been widely used in industrial settings by human factors experts to optimise the person-task fit. Reliability is estimated by the probability that a task will successfully be completed by personnel in a given stage of system operation. Human Reliability Analysis (HRA) is a technique used to calculate human error probabilities as the ratio of errors committed to the number of opportunities for that error. To transfer this notion to the measurement of car driver reliability the following components are necessary: a taxonomy of driving tasks, a definition of correct behaviour in each of these tasks, a list of errors as deviations from the correct actions and an adequate observation method to register errors and opportunities for these errors. Use of the SAFE-task analysis procedure recently made it possible to derive driver errors directly from the normative analysis of behavioural requirements. Driver reliability estimates could be used to compare groups of tasks (e.g. different types of intersections with their respective regulations) as well as groups of drivers' or individual drivers' aptitudes. This approach was tested in a field study with 62 drivers of different age groups. The subjects drove an instrumented car and had to complete an urban test route, the main features of which were 18 intersections representing six different driving tasks. The subjects were accompanied by two trained observers who recorded driver errors using standardized observation sheets. Results indicate that error indices often vary between both the age group of drivers and the type of driving task. The highest error indices occurred in the non-signalised intersection tasks and the roundabout, which exactly equals the corresponding ratings of task complexity from the SAFE analysis. A comparison of age groups clearly shows the disadvantage of older drivers, whose error indices in nearly all tasks are significantly higher than those of the other groups

  18. 18 CFR 39.5 - Reliability Standards.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Reliability Standards... RELIABILITY STANDARDS § 39.5 Reliability Standards. (a) The Electric Reliability Organization shall file each Reliability Standard or modification to a Reliability Standard that it proposes to be made effective under...

  19. Reliability Evaluation Of The City Transport Buses Under Actual Conditions

    Directory of Open Access Journals (Sweden)

    Rymarz Joanna

    2015-12-01

    Full Text Available The purpose of this paper was to present a reliability comparison of two types of city transport buses. Case study on the example of the well-known brands of city buses: Solaris Urbino 12 and Mercedes-Benz 628 Conecto L used at Municipal Transport Company in Lublin was presented in details. A reliability index for the most failure parts and complex systems for the period of time failures was determined. The analysis covered damages of the following systems: engine, electrical system, pneumatic system, brake system, driving system, central heating and air-conditioning and doors. Reliability was analyzed based on Weibull model. It has been demonstrated, that during the operation significant reliability differences occur between the buses produced nowadays.

  20. North American Electric Reliability Council (NERC) Reliability Coordinators

    Data.gov (United States)

    Department of Homeland Security — ERC is an international regulatory authority that works to improve the reliability of the bulk power system in North America. NERC works with many different regional...

  1. Calculating system reliability with SRFYDO

    Energy Technology Data Exchange (ETDEWEB)

    Morzinski, Jerome [Los Alamos National Laboratory; Anderson - Cook, Christine M [Los Alamos National Laboratory; Klamann, Richard M [Los Alamos National Laboratory

    2010-01-01

    SRFYDO is a process for estimating reliability of complex systems. Using information from all applicable sources, including full-system (flight) data, component test data, and expert (engineering) judgment, SRFYDO produces reliability estimates and predictions. It is appropriate for series systems with possibly several versions of the system which share some common components. It models reliability as a function of age and up to 2 other lifecycle (usage) covariates. Initial output from its Exploratory Data Analysis mode consists of plots and numerical summaries so that the user can check data entry and model assumptions, and help determine a final form for the system model. The System Reliability mode runs a complete reliability calculation using Bayesian methodology. This mode produces results that estimate reliability at the component, sub-system, and system level. The results include estimates of uncertainty, and can predict reliability at some not-too-distant time in the future. This paper presents an overview of the underlying statistical model for the analysis, discusses model assumptions, and demonstrates usage of SRFYDO.

  2. 78 FR 41339 - Electric Reliability Organization Proposal To Retire Requirements in Reliability Standards

    Science.gov (United States)

    2013-07-10

    ...] Electric Reliability Organization Proposal To Retire Requirements in Reliability Standards AGENCY: Federal... Reliability Standards identified by the North American Electric Reliability Corporation (NERC), the Commission-certified Electric Reliability Organization. FOR FURTHER INFORMATION CONTACT: Kevin Ryan (Legal Information...

  3. New Approaches to Reliability Assessment

    DEFF Research Database (Denmark)

    Ma, Ke; Wang, Huai; Blaabjerg, Frede

    2016-01-01

    of energy. New approaches for reliability assessment are being taken in the design phase of power electronics systems based on the physics-of-failure in components. In this approach, many new methods, such as multidisciplinary simulation tools, strength testing of components, translation of mission profiles......, and statistical analysis, are involved to enable better prediction and design of reliability for products. This article gives an overview of the new design flow in the reliability engineering of power electronics from the system-level point of view and discusses some of the emerging needs for the technology...

  4. Some remarks on software reliability

    International Nuclear Information System (INIS)

    Gonzalez Hernando, J.; Sanchez Izquierdo, J.

    1978-01-01

    Trend in modern NPPCI is toward a broad use of programmable elements. Some aspects concerning present status of programmable digital systems reliability are reported. Basic differences between software and hardware concept require a specific approach in all the reliability topics concerning software systems. The software reliability theory was initialy developed upon hardware models analogies. At present this approach is changing and specific models are being developed. The growing use of programmable systems necessitates emphasizing the importance of more adequate regulatory requirements to include this technology in NPPCI. (author)

  5. Reliability evaluation of power systems

    CERN Document Server

    Billinton, Roy

    1996-01-01

    The Second Edition of this well-received textbook presents over a decade of new research in power system reliability-while maintaining the general concept, structure, and style of the original volume. This edition features new chapters on the growing areas of Monte Carlo simulation and reliability economics. In addition, chapters cover the latest developments in techniques and their application to real problems. The text also explores the progress occurring in the structure, planning, and operation of real power systems due to changing ownership, regulation, and access. This work serves as a companion volume to Reliability Evaluation of Engineering Systems: Second Edition (1992).

  6. Integrating reliability analysis and design

    International Nuclear Information System (INIS)

    Rasmuson, D.M.

    1980-10-01

    This report describes the Interactive Reliability Analysis Project and demonstrates the advantages of using computer-aided design systems (CADS) in reliability analysis. Common cause failure problems require presentations of systems, analysis of fault trees, and evaluation of solutions to these. Results have to be communicated between the reliability analyst and the system designer. Using a computer-aided design system saves time and money in the analysis of design. Computer-aided design systems lend themselves to cable routing, valve and switch lists, pipe routing, and other component studies. At EG and G Idaho, Inc., the Applicon CADS is being applied to the study of water reactor safety systems

  7. Double Pass 595 nm Pulsed Dye Laser Does Not Enhance the Efficacy of Port Wine Stains Compared with Single Pass: A Randomized Comparison with Histological Examination.

    Science.gov (United States)

    Yu, Wenxin; Zhu, Jiafang; Wang, Lizhen; Qiu, Yajing; Chen, Yijie; Yang, Xi; Chang, Lei; Ma, Gang; Lin, Xiaoxi

    2018-03-27

    To compare the efficacy and safety of double-pass pulsed dye laser (DWL) and single-pass PDL (SWL) in treating virgin port wine stain (PWS). The increase in the extent of vascular damage attributed to the use of double-pass techniques for PWS remains inconclusive. A prospective, side-by-side comparison with a histological study for virgin PWS is still lacking. Twenty-one patients (11 flat PWS, 10 hypertrophic PWS) with untreated PWS underwent 3 treatments at 2-month intervals. Each PWS was divided into three treatment sites: SWL, DWL, and untreated control. Chromametric and visual evaluation of the efficacy and evaluation of side effects were conducted 3 months after final treatment. Biopsies were taken at the treated sites immediately posttreatment. Chromametric and visual evaluation suggested that DWL sites showed no significant improvement compared with SWL (p > 0.05) in treating PWS. The mean depth of photothermal damage to the vessels was limited to a maximum of 0.36-0.41 mm in both SWL and DWL sides. Permanent side effects were not observed in any patients. Double-pass PDL does not enhance PWS clearance. To improve the clearance of PWS lesions, either the depth of laser penetration should be increased or greater photothermal damage to vessels should be generated.

  8. Comparison between human cord blood serum and platelet-rich plasma supplementation for Human Wharton's Jelly Stem Cells and dermal fibroblasts culture

    Directory of Open Access Journals (Sweden)

    Hashemi SS

    2016-08-01

    Full Text Available We carried out a side-by-side comparison of the effects of Human cord blood serum (HcbS versus embryonic PRP on Human Wharton's Jelly Stem Cells(hWMSCand dermal fibroblasts proliferation. Human umbilical cord blood was collected to prepare activated serum (HCS and platelet-rich plasma (CPRP.Wharton's Jelly Stem Cells and dermal fibroblasts were cultured in complete medium with10% CPRP, 10%HCSor 10% fetal bovine serumand control (serum-free media.The efficiency of the protocols was evaluated in terms of the number of adherent cells and their expansion and Cell proliferation. We showed that proliferation of fibroblasts and mesenchymal stem cells in the presence of cord blood serum and platelet-rich plasma significantly more than the control group (p≤0/05. As an alternative to FBS, cord blood serum has been proved as an effective component in cell tissue culture applications and embraced a vast future in clinical applications of regenerative medicine. However, there is still a need to explore the potential of HCS and its safe applications in humanized cell therapy or tissue engineering.

  9. Comparisons of phenotype and immunomodulatory capacity among rhesus bone-marrow-derived mesenchymal stem/stromal cells, multipotent adult progenitor cells, and dermal fibroblasts

    Science.gov (United States)

    Wang, Qi; Clarkson, Christina; Graham, Melanie; Donahue, Robert; Hering, Bernhard J.; Verfaillie, Catherine M.; Bansal-Pakala, Pratima; O'Brien, Timothy D.

    2015-01-01

    Background Potent immunomodulatory effects have been reported for mesenchymal stem/stromal cells (MSCs), multipotent adult progenitor cells (MAPCs), and fibroblasts. However, side-by-side comparisons of these cells specifically regarding immunophenotype, gene expression, and suppression of proliferation of CD4+ and CD8+ lymphocyte populations have not been reported. Methods We developed MAPC and MSC lines from rhesus macaque bone marrow and fibroblast cell lines from rhesus dermis and assessed phenotypes based upon differentiation potential, flow cytometric analysis of immunophenotype, and quantitative RT-PCR analysis of gene expression. Using allogeneic lymphocyte proliferation assays, we compared the in vitro immunomodulatory potency of each cell type. Results and Conclusions Extensive phenotypic similarities exist among each cell type, although immunosuppressive potencies are distinct. MAPCs are most potent, and fibroblasts are the least potent cell type. All three cell types demonstrated immunomodulatory capacity such that each may have potential therapeutic applications such as in organ transplantation, where reduced local immune response is desirable. PMID:24825538

  10. ASSESSING AND COMBINING RELIABILITY OF PROTEIN INTERACTION SOURCES

    Science.gov (United States)

    LEACH, SONIA; GABOW, AARON; HUNTER, LAWRENCE; GOLDBERG, DEBRA S.

    2008-01-01

    Integrating diverse sources of interaction information to create protein networks requires strategies sensitive to differences in accuracy and coverage of each source. Previous integration approaches calculate reliabilities of protein interaction information sources based on congruity to a designated ‘gold standard.’ In this paper, we provide a comparison of the two most popular existing approaches and propose a novel alternative for assessing reliabilities which does not require a gold standard. We identify a new method for combining the resultant reliabilities and compare it against an existing method. Further, we propose an extrinsic approach to evaluation of reliability estimates, considering their influence on the downstream tasks of inferring protein function and learning regulatory networks from expression data. Results using this evaluation method show 1) our method for reliability estimation is an attractive alternative to those requiring a gold standard and 2) the new method for combining reliabilities is less sensitive to noise in reliability assignments than the similar existing technique. PMID:17990508

  11. Reliability of the standard goniometry and diagrammatic recording of finger joint angles: a comparative study with healthy subjects and non-professional raters.

    Science.gov (United States)

    Macionis, Valdas

    2013-01-09

    Diagrammatic recording of finger joint angles by using two criss-crossed paper strips can be a quick substitute to the standard goniometry. As a preliminary step toward clinical validation of the diagrammatic technique, the current study employed healthy subjects and non-professional raters to explore whether reliability estimates of the diagrammatic goniometry are comparable with those of the standard procedure. The study included two procedurally different parts, which were replicated by assigning 24 medical students to act interchangeably as 12 subjects and 12 raters. A larger component of the study was designed to compare goniometers side-by-side in measurement of finger joint angles varying from subject to subject. In the rest of the study, the instruments were compared by parallel evaluations of joint angles similar for all subjects in a situation of simulated change of joint range of motion over time. The subjects used special guides to position the joints of their left ring finger at varying angles of flexion and extension. The obtained diagrams of joint angles were converted to numerical values by computerized measurements. The statistical approaches included calculation of appropriate intraclass correlation coefficients, standard errors of measurements, proportions of measurement differences of 5 or less degrees, and significant differences between paired observations. Reliability estimates were similar for both goniometers. Intra-rater and inter-rater intraclass correlation coefficients ranged from 0.69 to 0.93. The corresponding standard errors of measurements ranged from 2.4 to 4.9 degrees. Repeated measurements of a considerable number of raters fell within clinically non-meaningful 5 degrees of each other in proportions comparable with a criterion value of 0.95. Data collected with both instruments could be similarly interpreted in a simulated situation of change of joint range of motion over time. The paper goniometer and the standard goniometer can

  12. Reliability analysis of shutdown system

    International Nuclear Information System (INIS)

    Kumar, C. Senthil; John Arul, A.; Pal Singh, Om; Suryaprakasa Rao, K.

    2005-01-01

    This paper presents the results of reliability analysis of Shutdown System (SDS) of Indian Prototype Fast Breeder Reactor. Reliability analysis carried out using Fault Tree Analysis predicts a value of 3.5 x 10 -8 /de for failure of shutdown function in case of global faults and 4.4 x 10 -8 /de for local faults. Based on 20 de/y, the frequency of shutdown function failure is 0.7 x 10 -6 /ry, which meets the reliability target, set by the Indian Atomic Energy Regulatory Board. The reliability is limited by Common Cause Failure (CCF) of actuation part of SDS and to a lesser extent CCF of electronic components. The failure frequency of individual systems is -3 /ry, which also meets the safety criteria. Uncertainty analysis indicates a maximum error factor of 5 for the top event unavailability

  13. Measures of differences in reliability

    International Nuclear Information System (INIS)

    Doksum, K.A.

    1975-01-01

    Measures of differences in reliability of two systems are considered in the scale model, location-scale model, and a nonparametric model. In each model, estimates and confidence intervals are given and some of their properties discussed

  14. Transportation reliability and trip satisfaction.

    Science.gov (United States)

    2012-10-01

    Travel delays and associated costs have become a major problem in Michigan over the : past several decades as congestion has continued to increase, creating significant negative : impacts on travel reliability on many roadways throughout the State. T...

  15. Reliability Analysis of Wind Turbines

    DEFF Research Database (Denmark)

    Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

    2008-01-01

    In order to minimise the total expected life-cycle costs of a wind turbine it is important to estimate the reliability level for all components in the wind turbine. This paper deals with reliability analysis for the tower and blades of onshore wind turbines placed in a wind farm. The limit states...... consideres are in the ultimate limit state (ULS) extreme conditions in the standstill position and extreme conditions during operating. For wind turbines, where the magnitude of the loads is influenced by the control system, the ultimate limit state can occur in both cases. In the fatigue limit state (FLS......) the reliability level for a wind turbine placed in a wind farm is considered, and wake effects from neighbouring wind turbines is taken into account. An illustrative example with calculation of the reliability for mudline bending of the tower is considered. In the example the design is determined according...

  16. Reliability issues at the LHC

    CERN Multimedia

    CERN. Geneva. Audiovisual Unit; Gillies, James D

    2002-01-01

    The Lectures on reliability issues at the LHC will be focused on five main Modules on five days. Module 1: Basic Elements in Reliability Engineering Some basic terms, definitions and methods, from components up to the system and the plant, common cause failures and human factor issues. Module 2: Interrelations of Reliability & Safety (R&S) Reliability and risk informed approach, living models, risk monitoring. Module 3: The ideal R&S Process for Large Scale Systems From R&S goals via the implementation into the system to the proof of the compliance. Module 4: Some Applications of R&S on LHC Master logic, anatomy of risk, cause - consequence diagram, decomposition and aggregation of the system. Module 5: Lessons learned from R&S Application in various Technologies Success stories, pitfalls, constrains in data and methods, limitations per se, experienced in aviation, space, process, nuclear, offshore and transport systems and plants. The Lectures will reflect in summary the compromise in...

  17. On Bayesian System Reliability Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen Ringi, M

    1995-05-01

    The view taken in this thesis is that reliability, the probability that a system will perform a required function for a stated period of time, depends on a person`s state of knowledge. Reliability changes as this state of knowledge changes, i.e. when new relevant information becomes available. Most existing models for system reliability prediction are developed in a classical framework of probability theory and they overlook some information that is always present. Probability is just an analytical tool to handle uncertainty, based on judgement and subjective opinions. It is argued that the Bayesian approach gives a much more comprehensive understanding of the foundations of probability than the so called frequentistic school. A new model for system reliability prediction is given in two papers. The model encloses the fact that component failures are dependent because of a shared operational environment. The suggested model also naturally permits learning from failure data of similar components in non identical environments. 85 refs.

  18. On Bayesian System Reliability Analysis

    International Nuclear Information System (INIS)

    Soerensen Ringi, M.

    1995-01-01

    The view taken in this thesis is that reliability, the probability that a system will perform a required function for a stated period of time, depends on a person's state of knowledge. Reliability changes as this state of knowledge changes, i.e. when new relevant information becomes available. Most existing models for system reliability prediction are developed in a classical framework of probability theory and they overlook some information that is always present. Probability is just an analytical tool to handle uncertainty, based on judgement and subjective opinions. It is argued that the Bayesian approach gives a much more comprehensive understanding of the foundations of probability than the so called frequentistic school. A new model for system reliability prediction is given in two papers. The model encloses the fact that component failures are dependent because of a shared operational environment. The suggested model also naturally permits learning from failure data of similar components in non identical environments. 85 refs

  19. As reliable as the sun

    Science.gov (United States)

    Leijtens, J. A. P.

    2017-11-01

    Fortunately there is almost nothing as reliable as the sun which can consequently be utilized as a very reliable source of spacecraft power. In order to harvest this power, the solar panels have to be pointed towards the sun as accurately and reliably as possible. To this extend, sunsensors are available on almost every satellite to support vital sun-pointing capability throughout the mission, even in the deployment and save mode phases of the satellites life. Given the criticality of the application one would expect that after more than 50 years of sun sensor utilisation, such sensors would be fully matured and optimised. In actual fact though, the majority of sunsensors employed are still coarse sunsensors which have a proven extreme reliability but present major issues regarding albedo sensitivity and pointing accuracy.

  20. Steam generator reliability improvement project

    International Nuclear Information System (INIS)

    Blomgren, J.C.; Green, S.J.

    1987-01-01

    Upon successful completion of its research and development technology transfer program, the Electric Power Research Institute's Steam Generator Owners Group (SGOG II) will disband in December 1986 and be replaced in January 1987 by a successor project, the Steam Generator Reliability Project (SGRP). The new project, funded in the EPRI base program, will continue the emphasis on reliability and life extension that was carried forward by SGOG II. The objectives of SGOG II have been met. Causes and remedies have been identified for tubing corrosion problems, such as stress corrosion cracking and pitting, and steam generator technology has been improved in areas such as tube wear prediction and nondestructive evaluation (NDE). These actions have led to improved reliability of steam generators. Now the owners want to continue with a centrally managed program that builds on what has been learned. The goal is to continue to improve steam generator reliability and solve small problems before they become large problems

  1. Steam generator reliability improvement project

    International Nuclear Information System (INIS)

    Blomgren, J.C.; Green, S.J.

    1987-01-01

    Upon successful completion of its research and development technology transfer program, the Electric Power Research Institute's (EPRI's) Steam Generator Owners Group (SGOG II) will disband in December 1986, and be replaced in January 1987, by a successor project, the Steam Generator Reliability Project (SGRP). The new project, funded in the EPRI base program, will continue to emphasize reliability and life extension, which were carried forward by SGOG II. The objectives of SGOG II have been met. Causes and remedies have been identified for tubing corrosion problems such as stress corrosion cracking and pitting, and steam generator technology has been improved in areas such as tube wear prediction and nondestructive evaluation. These actions have led to improved reliability of steam generators. Now the owners want to continue with a centrally managed program that builds on what has been learned. The goal is to continue to improve steam generator reliability and to solve small problems before they become large problems

  2. Reliability analysis in intelligent machines

    Science.gov (United States)

    Mcinroy, John E.; Saridis, George N.

    1990-01-01

    Given an explicit task to be executed, an intelligent machine must be able to find the probability of success, or reliability, of alternative control and sensing strategies. By using concepts for information theory and reliability theory, new techniques for finding the reliability corresponding to alternative subsets of control and sensing strategies are proposed such that a desired set of specifications can be satisfied. The analysis is straightforward, provided that a set of Gaussian random state variables is available. An example problem illustrates the technique, and general reliability results are presented for visual servoing with a computed torque-control algorithm. Moreover, the example illustrates the principle of increasing precision with decreasing intelligence at the execution level of an intelligent machine.

  3. Innovations in power systems reliability

    CERN Document Server

    Santora, Albert H; Vaccaro, Alfredo

    2011-01-01

    Electrical grids are among the world's most reliable systems, yet they still face a host of issues, from aging infrastructure to questions of resource distribution. Here is a comprehensive and systematic approach to tackling these contemporary challenges.

  4. Reliability analysis and operator modelling

    International Nuclear Information System (INIS)

    Hollnagel, Erik

    1996-01-01

    The paper considers the state of operator modelling in reliability analysis. Operator models are needed in reliability analysis because operators are needed in process control systems. HRA methods must therefore be able to account both for human performance variability and for the dynamics of the interaction. A selected set of first generation HRA approaches is briefly described in terms of the operator model they use, their classification principle, and the actual method they propose. In addition, two examples of second generation methods are also considered. It is concluded that first generation HRA methods generally have very simplistic operator models, either referring to the time-reliability relationship or to elementary information processing concepts. It is argued that second generation HRA methods must recognise that cognition is embedded in a context, and be able to account for that in the way human reliability is analysed and assessed

  5. Reliability and Maintainability (RAM) Training

    Science.gov (United States)

    Lalli, Vincent R. (Editor); Malec, Henry A. (Editor); Packard, Michael H. (Editor)

    2000-01-01

    The theme of this manual is failure physics-the study of how products, hardware, software, and systems fail and what can be done about it. The intent is to impart useful information, to extend the limits of production capability, and to assist in achieving low-cost reliable products. In a broader sense the manual should do more. It should underscore the urgent need CI for mature attitudes toward reliability. Five of the chapters were originally presented as a classroom course to over 1000 Martin Marietta engineers and technicians. Another four chapters and three appendixes have been added, We begin with a view of reliability from the years 1940 to 2000. Chapter 2 starts the training material with a review of mathematics and a description of what elements contribute to product failures. The remaining chapters elucidate basic reliability theory and the disciplines that allow us to control and eliminate failures.

  6. Development of reliable pavement models.

    Science.gov (United States)

    2011-05-01

    The current report proposes a framework for estimating the reliability of a given pavement structure as analyzed by : the Mechanistic-Empirical Pavement Design Guide (MEPDG). The methodology proposes using a previously fit : response surface, in plac...

  7. Cost analysis of reliability investigations

    International Nuclear Information System (INIS)

    Schmidt, F.

    1981-01-01

    Taking Epsteins testing theory as a basis, premisses are formulated for the selection of cost-optimized reliability inspection plans. Using an example, the expected testing costs and inspection time periods of various inspection plan types, standardized on the basis of the exponential distribution, are compared. It can be shown that sequential reliability tests usually involve lower costs than failure or time-fixed tests. The most 'costly' test is to be expected with the inspection plan type NOt. (orig.) [de

  8. Nonparametric predictive inference in reliability

    International Nuclear Information System (INIS)

    Coolen, F.P.A.; Coolen-Schrijner, P.; Yan, K.J.

    2002-01-01

    We introduce a recently developed statistical approach, called nonparametric predictive inference (NPI), to reliability. Bounds for the survival function for a future observation are presented. We illustrate how NPI can deal with right-censored data, and discuss aspects of competing risks. We present possible applications of NPI for Bernoulli data, and we briefly outline applications of NPI for replacement decisions. The emphasis is on introduction and illustration of NPI in reliability contexts, detailed mathematical justifications are presented elsewhere

  9. Accelerator Availability and Reliability Issues

    Energy Technology Data Exchange (ETDEWEB)

    Steve Suhring

    2003-05-01

    Maintaining reliable machine operations for existing machines as well as planning for future machines' operability present significant challenges to those responsible for system performance and improvement. Changes to machine requirements and beam specifications often reduce overall machine availability in an effort to meet user needs. Accelerator reliability issues from around the world will be presented, followed by a discussion of the major factors influencing machine availability.

  10. Power peaking nuclear reliability factors

    International Nuclear Information System (INIS)

    Hassan, H.A.; Pegram, J.W.; Mays, C.W.; Romano, J.J.; Woods, J.J.; Warren, H.D.

    1977-11-01

    The Calculational Nuclear Reliability Factor (CNRF) assigned to the limiting power density calculated in reactor design has been determined. The CNRF is presented as a function of the relative power density of the fuel assembly and its radial local. In addition, the Measurement Nuclear Reliability Factor (MNRF) for the measured peak hot pellet power in the core has been evaluated. This MNRF is also presented as a function of the relative power density and radial local within the fuel assembly

  11. Travel Time Reliability in Indiana

    OpenAIRE

    Martchouk, Maria; Mannering, Fred L.; Singh, Lakhwinder

    2010-01-01

    Travel time and travel time reliability are important performance measures for assessing traffic condition and extent of congestion on a roadway. This study first uses a floating car technique to assess travel time and travel time reliability on a number of Indiana highways. Then the study goes on to describe the use of Bluetooth technology to collect real travel time data on a freeway and applies it to obtain two weeks of data on Interstate 69 in Indianapolis. An autoregressive model, estima...

  12. Transmission reliability faces future challenges

    International Nuclear Information System (INIS)

    Beaty, W.

    1993-01-01

    The recently published Washington International Energy Group's 1993 Electric Utility Outlook states that nearly one-third (31 percent) of U.S. utility executives expect reliability to decrease in the near future. Electric power system stability is crucial to reliability. Stability analysis determines whether a system will stay intact under normal operating conditions, during minor disturbances such as load fluctuations, and during major disturbances when one or more parts of the system fails. All system elements contribute to reliability or the lack of it. However, this report centers on the transmission segment of the electric system. The North American Electric Reliability Council (NERC) says the transmission systems as planned will be adequate over the next 10 years. However, delays in building new lines and increasing demands for transmission services are serious concerns. Reliability concerns exist in the Mid-Continent Area Power Pool and the Mid-America Interconnected Network regions where transmission facilities have not been allowed to be constructed as planned. Portions of the transmission systems in other regions are loaded at or near their limits. NERC further states that utilities must be allowed to complete planned generation and transmission as scheduled. A reliable supply of electricity also depends on adhering to established operating criteria. Factors that could complicate operations include: More interchange schedules resulting from increased transmission services. Increased line loadings in portions of the transmission systems. Proliferation of non-utility generators

  13. MEMS reliability: coming of age

    Science.gov (United States)

    Douglass, Michael R.

    2008-02-01

    In today's high-volume semiconductor world, one could easily take reliability for granted. As the MOEMS/MEMS industry continues to establish itself as a viable alternative to conventional manufacturing in the macro world, reliability can be of high concern. Currently, there are several emerging market opportunities in which MOEMS/MEMS is gaining a foothold. Markets such as mobile media, consumer electronics, biomedical devices, and homeland security are all showing great interest in microfabricated products. At the same time, these markets are among the most demanding when it comes to reliability assurance. To be successful, each company developing a MOEMS/MEMS device must consider reliability on an equal footing with cost, performance and manufacturability. What can this maturing industry learn from the successful development of DLP technology, air bag accelerometers and inkjet printheads? This paper discusses some basic reliability principles which any MOEMS/MEMS device development must use. Examples from the commercially successful and highly reliable Digital Micromirror Device complement the discussion.

  14. Fuel reliability experience in Finland

    International Nuclear Information System (INIS)

    Kekkonen, L.

    2015-01-01

    Four nuclear reactors have operated in Finland now for 35-38 years. The two VVER-440 units at Loviisa Nuclear Power Plant are operated by Fortum and two BWR’s in Olkiluoto are operated by Teollisuuden Voima Oyj (TVO). The fuel reliability experience of the four reactors operating currently in Finland has been very good and the fuel failure rates have been very low. Systematic inspection of spent fuel assemblies, and especially all failed assemblies, is a good practice that is employed in Finland in order to improve fuel reliability and operational safety. Investigation of the root cause of fuel failures is important in developing ways to prevent similar failures in the future. The operational and fuel reliability experience at the Loviisa Nuclear Power Plant has been reported also earlier in the international seminars on WWER Fuel Performance, Modelling and Experimental Support. In this paper the information on fuel reliability experience at Loviisa NPP is updated and also a short summary of the fuel reliability experience at Olkiluoto NPP is given. Keywords: VVER-440, fuel reliability, operational experience, poolside inspections, fuel failure identification. (author)

  15. Reliability issues : a Canadian perspective

    International Nuclear Information System (INIS)

    Konow, H.

    2004-01-01

    A Canadian perspective of power reliability issues was presented. Reliability depends on adequacy of supply and a framework for standards. The challenges facing the electric power industry include new demand, plant replacement and exports. It is expected that demand will by 670 TWh by 2020, with 205 TWh coming from new plants. Canada will require an investment of $150 billion to meet this demand and the need is comparable in the United States. As trade grows, the challenge becomes a continental issue and investment in the bi-national transmission grid will be essential. The 5 point plan of the Canadian Electricity Association is to: (1) establish an investment climate to ensure future electricity supply, (2) move government and industry towards smart and effective regulation, (3) work to ensure a sustainable future for the next generation, (4) foster innovation and accelerate skills development, and (5) build on the strengths of an integrated North American system to maximize opportunity for Canadians. The CEA's 7 measures that enhance North American reliability were listed with emphasis on its support for a self-governing international organization for developing and enforcing mandatory reliability standards. CEA also supports the creation of a binational Electric Reliability Organization (ERO) to identify and solve reliability issues in the context of a bi-national grid. tabs., figs

  16. Performances and reliabilities comparisons by multidimensional statistic studies

    International Nuclear Information System (INIS)

    Coudray, R.

    1993-01-01

    After an overview of the methods utilizables in this type of analyse, we insist on the method used in the experience return for the French PWR 900 MWe chemical and volume control system pump. 7 figs., 3 tabs., 8 refs

  17. Reliability of cause of death coding: an international comparison.

    Science.gov (United States)

    Antini, Carmen; Rajs, Danuta; Muñoz-Quezada, María Teresa; Mondaca, Boris Andrés Lucero; Heiss, Gerardo

    2015-07-01

    This study evaluates the agreement of nosologic coding of cardiovascular causes of death between a Chilean coder and one in the United States, in a stratified random sample of death certificates of persons aged ≥ 60, issued in 2008 in the Valparaíso and Metropolitan regions, Chile. All causes of death were converted to ICD-10 codes in parallel by both coders. Concordance was analyzed with inter-coder agreement and Cohen's kappa coefficient by level of specification ICD-10 code for the underlying cause and the total causes of death coding. Inter-coder agreement was 76.4% for all causes of death and 80.6% for the underlying cause (agreement at the four-digit level), with differences by the level of specification of the ICD-10 code, by line of the death certificate, and by number of causes of death per certificate. Cohen's kappa coefficient was 0.76 (95%CI: 0.68-0.84) for the underlying cause and 0.75 (95%CI: 0.74-0.77) for the total causes of death. In conclusion, causes of death coding and inter-coder agreement for cardiovascular diseases in two regions of Chile are comparable to an external benchmark and with reports from other countries.

  18. Performance and Reliability of Wind Turbines: A Review

    Directory of Open Access Journals (Sweden)

    Sebastian Pfaffel

    2017-11-01

    Full Text Available Performance (availability and yield and reliability of wind turbines can make the difference between success and failure of wind farm projects and these factors are vital to decrease the cost of energy. During the last years, several initiatives started to gather data on the performance and reliability of wind turbines on- and offshore and published findings in different journals and conferences. Even though the scopes of the different initiatives are similar, every initiative follows a different approach and results are therefore difficult to compare. The present paper faces this issue, collects results of different initiatives and harmonizes the results. A short description and assessment of every considered data source is provided. To enable this comparison, the existing reliability characteristics are mapped to a system structure according to the Reference Designation System for Power Plants (RDS-PP®. The review shows a wide variation in the performance and reliability metrics of the individual initiatives. Especially the comparison on onshore wind turbines reveals significant differences between the results. Only a few publications are available on offshore wind turbines and the results show an increasing performance and reliability of offshore wind turbines since the first offshore wind farms were erected and monitored.

  19. Statistical reliability analyses of two wood plastic composite extrusion processes

    International Nuclear Information System (INIS)

    Crookston, Kevin A.; Mark Young, Timothy; Harper, David; Guess, Frank M.

    2011-01-01

    Estimates of the reliability of wood plastic composites (WPC) are explored for two industrial extrusion lines. The goal of the paper is to use parametric and non-parametric analyses to examine potential differences in the WPC metrics of reliability for the two extrusion lines that may be helpful for use by the practitioner. A parametric analysis of the extrusion lines reveals some similarities and disparities in the best models; however, a non-parametric analysis reveals unique and insightful differences between Kaplan-Meier survival curves for the modulus of elasticity (MOE) and modulus of rupture (MOR) of the WPC industrial data. The distinctive non-parametric comparisons indicate the source of the differences in strength between the 10.2% and 48.0% fractiles [3,183-3,517 MPa] for MOE and for MOR between the 2.0% and 95.1% fractiles [18.9-25.7 MPa]. Distribution fitting as related to selection of the proper statistical methods is discussed with relevance to estimating the reliability of WPC. The ability to detect statistical differences in the product reliability of WPC between extrusion processes may benefit WPC producers in improving product reliability and safety of this widely used house-decking product. The approach can be applied to many other safety and complex system lifetime comparisons.

  20. Failure mode and effect analysis experimental reliability determination for the CANDU reactor equipment

    International Nuclear Information System (INIS)

    Vieru, G.

    1996-01-01

    This paper describes the experimental tests performed in order to prove the reliability parameters for certain equipment manufactured in INR Pitesti, for NPP Cernavoda. The tests were provided by Technical Specifications and test procedures. A comparison, referring to the reliability parameters, between Canadian equipment and INR manufactured equipment ones is also given. The results of tests and conclusions are shown. (author)

  1. Notions of reliability: considering the importance of difference in guiding patients to health care Web sites.

    Science.gov (United States)

    Adams, S A; De Bont, A A

    2003-01-01

    This article analyzes the efforts of three organizations to provide a standard that guides Internet users to reliable health care sites. Comparison of health Internet sites, interviews and document studies. In comparing these approaches, three different constructions of reliability are identified. The resulting possibilities and restrictions of these constructions for users that are searching for health information on the Internet are revealed.

  2. Comparison of non-O157 Shiga toxin-producing E. coli detection systems

    Science.gov (United States)

    Category: methodology improvements Objective: To identify strengths and weaknesses of commercial Shiga toxin-producing E. coli detection systems and kits in a side by side fashion. Experimental Design: Three commercial Shiga toxin-producing E. coli detection tests (BAX, GDS, and GeneDisc) and two t...

  3. Long term reliability analysis of standby diesel generators

    International Nuclear Information System (INIS)

    Winfield, D.J.

    1988-01-01

    The long term reliability of 11 diesel generators of 125 to 250 kV A size has been analysed from 26 years of data base information on individual diesel service as standby power supplies for the Chalk River research reactor facilities. Failure to start on demand and failure to run data is presented and failure by diesel subsystem and multiple failures are also analysed. A brief comparison is made with reliability studies of larger diesel generator units used for standby power service in nuclear power plants. (author)

  4. CRL research reactor diesel generator reliability study 1960 - 1992

    International Nuclear Information System (INIS)

    Winfield, D.J.; McCauley, G.M.

    1994-07-01

    A data base has been provided for the Chalk River Laboratories (CRL) research reactor diesel generator reliability, for use in risk assessment studies of CRL research reactors. Data from 1960 to end of 1992 have been collected, representing 358 diesel generator years of experience. The data is used to provide failure-to-start probabilities and failure-to-run rates. Data is also classified according to subsystem failures, multiple failures and common cause failures. Comparisons with other recent studies of nuclear power plant diesel generator reliability have been made. This revision updates the 1989 September report. (author). 14 refs., 13 tabs., 10 figs

  5. CRNL research reactor diesel generator reliability study 1960-1985

    International Nuclear Information System (INIS)

    Winfield, D.J.

    1989-09-01

    A data base has been provided for the CRNL research reactor diesel generator reliability, for use in risk assessment studies of CRNL research reactors. Data from 1960 to the present have been collected, representing 281 diesel generator years of experience. The data is used to provide failure-to-start probabilities and failure-to-run rates. Data is also classified according to subsystem failures, multiple failures and common cause failures. Comparisons with other recent studies of nuclear power plant diesel generator reliability have been made

  6. Predicting risk and human reliability: a new approach

    International Nuclear Information System (INIS)

    Duffey, R.; Ha, T.-S.

    2009-01-01

    Learning from experience describes human reliability and skill acquisition, and the resulting theory has been validated by comparison against millions of outcome data from multiple industries and technologies worldwide. The resulting predictions were used to benchmark the classic first generation human reliability methods adopted in probabilistic risk assessments. The learning rate, probabilities and response times are also consistent with the existing psychological models for human learning and error correction. The new approach also implies a finite lower bound probability that is not predicted by empirical statistical distributions that ignore the known and fundamental learning effects. (author)

  7. Reliability analysis techniques in power plant design

    International Nuclear Information System (INIS)

    Chang, N.E.

    1981-01-01

    An overview of reliability analysis techniques is presented as applied to power plant design. The key terms, power plant performance, reliability, availability and maintainability are defined. Reliability modeling, methods of analysis and component reliability data are briefly reviewed. Application of reliability analysis techniques from a design engineering approach to improving power plant productivity is discussed. (author)

  8. Seismic stops vs. snubbers, a reliable alternative

    International Nuclear Information System (INIS)

    Cloud, R.L.; Anderson, P.H.; Leung, J.S.M.

    1988-01-01

    The Seismic Stops methodology has been developed to provide a reliable alternative for providing seismic support to nuclear power plant piping. The concept is based on using rigid passive supports with large clearances. These gaps permit unrestrained thermal expansion while limiting excessive seismic displacements. This type of restraint has performed successfully in fossil fueled power plants. A simplified production analysis tool has been developed which evaluates the nonlinear piping response including the effect of the gapped supports. The methodology utilizes the response spectrum approach and has been incorporated into a piping analysis computer program RLCA-GAP. Full scale shake table tests of piping specimens were performed to provide test correlation with the developed methodology. Analyses using RLCA-GAP were in good agreement with test results. A sample piping system was evaluated using the Seismic Stops methodology to replace the existing snubbers with passive gapped supports. To provide further correlation data, the sample system was also evaluated using nonlinear time history analysis. The correlation comparisons showed RLCA-GAP to be a viable methodology and a reliable alternative for snubber optimization and elimination. (orig.)

  9. Reliability and accuracy of four dental shade-matching devices.

    Science.gov (United States)

    Kim-Pusateri, Seungyee; Brewer, Jane D; Davis, Elaine L; Wee, Alvin G

    2009-03-01

    There are several electronic shade-matching instruments available for clinical use, but the reliability and accuracy of these instruments have not been thoroughly investigated. The purpose of this in vitro study was to evaluate the reliability and accuracy of 4 dental shade-matching instruments in a standardized environment. Four shade-matching devices were tested: SpectroShade, ShadeVision, VITA Easyshade, and ShadeScan. Color measurements were made of 3 commercial shade guides (Vitapan Classical, Vitapan 3D-Master, and Chromascop). Shade tabs were placed in the middle of a gingival matrix (Shofu GUMY) with shade tabs of the same nominal shade from additional shade guides placed on both sides. Measurements were made of the central region of the shade tab positioned inside a black box. For the reliability assessment, each shade tab from each of the 3 shade guide types was measured 10 times. For the accuracy assessment, each shade tab from 10 guides of each of the 3 types evaluated was measured once. Differences in reliability and accuracy were evaluated using the Standard Normal z test (2 sided) (alpha=.05) with Bonferroni correction. Reliability of devices was as follows: ShadeVision, 99.0%; SpectroShade, 96.9%; VITA Easyshade, 96.4%; and ShadeScan, 87.4%. A significant difference in reliability was found between ShadeVision and ShadeScan (P=.008). All other comparisons showed similar reliability. Accuracy of devices was as follows: VITA Easyshade, 92.6%; ShadeVision, 84.8%; SpectroShade, 80.2%; and ShadeScan, 66.8%. Significant differences in accuracy were found between all device pairs (Preliability (over 96%), indicating predictable shade values from repeated measurements. However, there was more variability in accuracy among devices (67-93%), and differences in accuracy were seen with most device comparisons.

  10. Reliability analysis under epistemic uncertainty

    International Nuclear Information System (INIS)

    Nannapaneni, Saideep; Mahadevan, Sankaran

    2016-01-01

    This paper proposes a probabilistic framework to include both aleatory and epistemic uncertainty within model-based reliability estimation of engineering systems for individual limit states. Epistemic uncertainty is considered due to both data and model sources. Sparse point and/or interval data regarding the input random variables leads to uncertainty regarding their distribution types, distribution parameters, and correlations; this statistical uncertainty is included in the reliability analysis through a combination of likelihood-based representation, Bayesian hypothesis testing, and Bayesian model averaging techniques. Model errors, which include numerical solution errors and model form errors, are quantified through Gaussian process models and included in the reliability analysis. The probability integral transform is used to develop an auxiliary variable approach that facilitates a single-level representation of both aleatory and epistemic uncertainty. This strategy results in an efficient single-loop implementation of Monte Carlo simulation (MCS) and FORM/SORM techniques for reliability estimation under both aleatory and epistemic uncertainty. Two engineering examples are used to demonstrate the proposed methodology. - Highlights: • Epistemic uncertainty due to data and model included in reliability analysis. • A novel FORM-based approach proposed to include aleatory and epistemic uncertainty. • A single-loop Monte Carlo approach proposed to include both types of uncertainties. • Two engineering examples used for illustration.

  11. Emergency diesel generator reliability program

    International Nuclear Information System (INIS)

    Serkiz, A.W.

    1989-01-01

    The need for an emergency diesel generator (EDG) reliability program has been established by 10 CFR Part 50, Section 50.63, Loss of All Alternating Current Power, which requires that utilities assess their station blackout duration and recovery capability. EDGs are the principal emergency ac power sources for coping with a station blackout. Regulatory Guide 1.155, Station Blackout, identifies a need for (1) an EDG reliability equal to or greater than 0.95, and (2) an EDG reliability program to monitor and maintain the required levels. The resolution of Generic Safety Issue (GSI) B-56 embodies the identification of a suitable EDG reliability program structure, revision of pertinent regulatory guides and Tech Specs, and development of an Inspection Module. Resolution of B-56 is coupled to the resolution of Unresolved Safety Issue (USI) A-44, Station Blackout, which resulted in the station blackout rule, 10 CFR 50.63 and Regulatory Guide 1.155, Station Blackout. This paper discusses the principal elements of an EDG reliability program developed for resolving GSI B-56 and related matters

  12. Comparison of Strategies for Climate Change Adaptation of Water Supply and Flood Control Reservoirs

    Science.gov (United States)

    Ng, T. L.; Yang, P.; Bhushan, R.

    2016-12-01

    With climate change, streamflows are expected to become more fluctuating, with more frequent and intense floods and droughts. This complicates reservoir operation, which is highly sensitive to inflow variability. We make a comparative evaluation of three strategies for adapting reservoirs to climate-induced shifts in streamflow patterns. Specifically, we examine the effectiveness of (i) expanding the capacities of reservoirs by way of new off-stream reservoirs, (ii) introducing wastewater reclamation to augment supplies, and (iii) improving real-time streamflow forecasts for more optimal decision-making. The first two are hard strategies involving major infrastructure modifications, while the third a soft strategy entailing adjusting the system operation. A comprehensive side-by-side comparison of the three strategies is as yet lacking in the literature despite the many past studies investigating the strategies individually. To this end, we developed an adaptive forward-looking linear program that solves to yield the optimal decisions for the current time as a function of an ensemble forecast of future streamflows. Solving the model repeatedly on a rolling basis with regular updating of the streamflow forecast simulates the system behavior over the entire operating horizon. Results are generated for two hypothetical water supply and flood control reservoirs of differing inflows and demands. Preliminary findings suggest that of the three strategies, improving streamflow forecasts to be most effective in mitigating the effects of climate change. We also found that, in average terms, both additional reservoir capacity and wastewater reclamation have potential to reduce water shortage and downstream flooding. However, in the worst case, the potential of the former to reduce water shortage is limited, and similarly so the potential of the latter to reduce downstream flooding.

  13. The serotonin transporter in rhesus monkey brain: comparison of DASB and citalopram binding sites

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Zhizhen [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States)]. E-mail: zhizhen_zeng@merck.com; Chen, T.-B. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Miller, Patricia J. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Dean, Dennis [Labeled Compound Synthesis Group, Drug Metabolism, Merck Research Laboratories, Rahway, NJ 07065-0900 (United States); Tang, Y.S. [Labeled Compound Synthesis Group, Drug Metabolism, Merck Research Laboratories, Rahway, NJ 07065-0900 (United States); Sur, Cyrille [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States); Williams, David L. [Imaging Department, Merck Research Laboratories, West Point, PA 19486 (United States)

    2006-05-15

    We have characterized the interaction of the serotonin transporter ligand [{sup 3}H]-N,N-dimethyl-2-(2-amino-4-cyanophenylthio)-benzylamine (DASB) with rhesus monkey brain in vitro using tissue homogenate binding and autoradiographic mapping. [{sup 3}H]-DASB, a tritiated version of the widely used [{sup 11}C] positron emission tomography tracer, was found to selectively bind to a single population of sites with high affinity (K {sub d}=0.20{+-}0.04 nM). The serotonin transporter density (B {sub max}) obtained for rhesus frontal cortex was found to be 66{+-}8 fmol/mg protein using [{sup 3}H]-DASB, similar to the B {sub max} value obtained using the reference radioligand [{sup 3}H]-citalopram, a well-characterized and highly selective serotonin reuptake inhibitor (83{+-}22 fmol/mg protein). Specific binding sites of both [{sup 3}H]-DASB and [{sup 3}H]-citalopram were similarly and nonuniformly distributed throughout the rhesus central nervous system, in a pattern consistent with serotonin transporter localization reported for human brain. Regional serotonin transporter densities, estimated from optical densities of the autoradiographic images, were well correlated between the two radioligands. Finally, DASB and fluoxetine showed dose-dependent full inhibition of [{sup 3}H]-citalopram binding in a competition autoradiographic study, with K {sub i} values in close agreement with those obtained from rhesus brain homogenates. This side-by-side comparison of [{sup 3}H]-DASB and [{sup 3}H]-citalopram binding sites in rhesus tissue homogenates and in adjacent rhesus brain slices provides additional support for the use of [{sup 11}C]-DASB to assess the availability and distribution of serotonin transporters in nonhuman primates.

  14. Comparison of cell-based assays for the identification and evaluation of competitive CXCR4 inhibitors.

    Directory of Open Access Journals (Sweden)

    Anneleen Van Hout

    Full Text Available The chemokine receptor CXCR4 is activated by its unique chemokine ligand CXCL12 and regulates many physiological and developmental processes such as hematopoietic cell trafficking. CXCR4 is also one of the main co-receptors for human immunodeficiency virus (HIV entry. Dysfunction of the CXCL12/CXCR4 axis contributes to several human pathologies, including cancer and inflammatory diseases. Consequently, inhibition of CXCR4 activation is recognized as an attractive target for therapeutic intervention. In this regard, numerous agents modifying CXCR4 activity have been evaluated in in vitro experimental studies and pre-clinical models. Here, we evaluated a CXCL12 competition binding assay for its potential as a valuable initial screen for functional and competitive CXCR4 inhibitors. In total, 11 structurally diverse compounds were included in a side-by-side comparison of in vitro CXCR4 cell-based assays, such as CXCL12 competition binding, CXCL12-induced calcium signaling, CXCR4 internalization, CXCL12-guided cell migration and CXCR4-specific HIV-1 replication experiments. Our data indicated that agents that inhibit CXCL12 binding, i.e. the anti-CXCR4 peptide analogs T22, T140 and TC14012 and the small molecule antagonists AMD3100, AMD3465, AMD11070 and IT1t showed inhibitory activity with consistent relative potencies in all further applied CXCR4-related assays. Accordingly, agents exerting no or very weak receptor binding (i.e., CTCE-9908, WZ811, Me6TREN and gambogic acid showed no or very poor anti-CXCR4 inhibitory activity. Thus, CXCL12 competition binding studies were proven to be highly valuable as an initial screening assay and indicative for the pharmacological and functional profile of competitive CXCR4 antagonists, which will help the design of new potent CXCR4 inhibitors.

  15. The serotonin transporter in rhesus monkey brain: comparison of DASB and citalopram binding sites

    International Nuclear Information System (INIS)

    Zeng Zhizhen; Chen, T.-B.; Miller, Patricia J.; Dean, Dennis; Tang, Y.S.; Sur, Cyrille; Williams, David L.

    2006-01-01

    We have characterized the interaction of the serotonin transporter ligand [ 3 H]-N,N-dimethyl-2-(2-amino-4-cyanophenylthio)-benzylamine (DASB) with rhesus monkey brain in vitro using tissue homogenate binding and autoradiographic mapping. [ 3 H]-DASB, a tritiated version of the widely used [ 11 C] positron emission tomography tracer, was found to selectively bind to a single population of sites with high affinity (K d =0.20±0.04 nM). The serotonin transporter density (B max ) obtained for rhesus frontal cortex was found to be 66±8 fmol/mg protein using [ 3 H]-DASB, similar to the B max value obtained using the reference radioligand [ 3 H]-citalopram, a well-characterized and highly selective serotonin reuptake inhibitor (83±22 fmol/mg protein). Specific binding sites of both [ 3 H]-DASB and [ 3 H]-citalopram were similarly and nonuniformly distributed throughout the rhesus central nervous system, in a pattern consistent with serotonin transporter localization reported for human brain. Regional serotonin transporter densities, estimated from optical densities of the autoradiographic images, were well correlated between the two radioligands. Finally, DASB and fluoxetine showed dose-dependent full inhibition of [ 3 H]-citalopram binding in a competition autoradiographic study, with K i values in close agreement with those obtained from rhesus brain homogenates. This side-by-side comparison of [ 3 H]-DASB and [ 3 H]-citalopram binding sites in rhesus tissue homogenates and in adjacent rhesus brain slices provides additional support for the use of [ 11 C]-DASB to assess the availability and distribution of serotonin transporters in nonhuman primates

  16. Reliability and continuous regeneration model

    Directory of Open Access Journals (Sweden)

    Anna Pavlisková

    2006-06-01

    Full Text Available The failure-free function of an object is very important for the service. This leads to the interest in the determination of the object reliability and failure intensity. The reliability of an element is defined by the theory of probability.The element durability T is a continuous random variate with the probability density f. The failure intensity (tλ is a very important reliability characteristics of the element. Often it is an increasing function, which corresponds to the element ageing. We disposed of the data about a belt conveyor failures recorded during the period of 90 months. The given ses behaves according to the normal distribution. By using a mathematical analysis and matematical statistics, we found the failure intensity function (tλ. The function (tλ increases almost linearly.

  17. Reliability Based Ship Structural Design

    DEFF Research Database (Denmark)

    Dogliani, M.; Østergaard, C.; Parmentier, G.

    1996-01-01

    This paper deals with the development of different methods that allow the reliability-based design of ship structures to be transferred from the area of research to the systematic application in current design. It summarises the achievements of a three-year collaborative research project dealing...... with developments of models of load effects and of structural collapse adopted in reliability formulations which aim at calibrating partial safety factors for ship structural design. New probabilistic models of still-water load effects are developed both for tankers and for containerships. New results are presented...... structure of several tankers and containerships. The results of the reliability analysis were the basis for the definition of a target safety level which was used to asses the partial safety factors suitable for in a new design rules format to be adopted in modern ship structural design. Finally...

  18. Structural Optimization with Reliability Constraints

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    1986-01-01

    During the last 25 years considerable progress has been made in the fields of structural optimization and structural reliability theory. In classical deterministic structural optimization all variables are assumed to be deterministic. Due to the unpredictability of loads and strengths of actual......]. In this paper we consider only structures which can be modelled as systems of elasto-plastic elements, e.g. frame and truss structures. In section 2 a method to evaluate the reliability of such structural systems is presented. Based on a probabilistic point of view a modern structural optimization problem...... is formulated in section 3. The formulation is a natural extension of the commonly used formulations in determinstic structural optimization. The mathematical form of the optimization problem is briefly discussed. In section 4 two new optimization procedures especially designed for the reliability...

  19. Reliability assessment of Wind turbines

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2015-01-01

    Wind turbines can be considered as structures that are in between civil engineering structures and machines since they consist of structural components and many electrical and machine components together with a control system. Further, a wind turbine is not a one-of-a-kind structure...... but manufactured in series production based on many component tests, some prototype tests and zeroseries wind turbines. These characteristics influence the reliability assessment where focus in this paper is on the structural components. Levelized Cost Of Energy is very important for wind energy, especially when...... comparing to other energy sources. Therefore much focus is on cost reductions and improved reliability both for offshore and onshore wind turbines. The wind turbine components should be designed to have sufficient reliability level with respect to both extreme and fatigue loads but also not be too costly...

  20. Reliability Modeling of Wind Turbines

    DEFF Research Database (Denmark)

    Kostandyan, Erik

    Cost reductions for offshore wind turbines are a substantial requirement in order to make offshore wind energy more competitive compared to other energy supply methods. During the 20 – 25 years of wind turbines useful life, Operation & Maintenance costs are typically estimated to be a quarter...... for Operation & Maintenance planning. Concentrating efforts on development of such models, this research is focused on reliability modeling of Wind Turbine critical subsystems (especially the power converter system). For reliability assessment of these components, structural reliability methods are applied...... to one third of the total cost of energy. Reduction of Operation & Maintenance costs will result in significant cost savings and result in cheaper electricity production. Operation & Maintenance processes mainly involve actions related to replacements or repair. Identifying the right times when...

  1. Component reliability for electronic systems

    CERN Document Server

    Bajenescu, Titu-Marius I

    2010-01-01

    The main reason for the premature breakdown of today's electronic products (computers, cars, tools, appliances, etc.) is the failure of the components used to build these products. Today professionals are looking for effective ways to minimize the degradation of electronic components to help ensure longer-lasting, more technically sound products and systems. This practical book offers engineers specific guidance on how to design more reliable components and build more reliable electronic systems. Professionals learn how to optimize a virtual component prototype, accurately monitor product reliability during the entire production process, and add the burn-in and selection procedures that are the most appropriate for the intended applications. Moreover, the book helps system designers ensure that all components are correctly applied, margins are adequate, wear-out failure modes are prevented during the expected duration of life, and system interfaces cannot lead to failure.

  2. Reliable computation from contextual correlations

    Science.gov (United States)

    Oestereich, André L.; Galvão, Ernesto F.

    2017-12-01

    An operational approach to the study of computation based on correlations considers black boxes with one-bit inputs and outputs, controlled by a limited classical computer capable only of performing sums modulo-two. In this setting, it was shown that noncontextual correlations do not provide any extra computational power, while contextual correlations were found to be necessary for the deterministic evaluation of nonlinear Boolean functions. Here we investigate the requirements for reliable computation in this setting; that is, the evaluation of any Boolean function with success probability bounded away from 1 /2 . We show that bipartite CHSH quantum correlations suffice for reliable computation. We also prove that an arbitrarily small violation of a multipartite Greenberger-Horne-Zeilinger noncontextuality inequality also suffices for reliable computation.

  3. Reliability Characteristics of Power Plants

    Directory of Open Access Journals (Sweden)

    Zbynek Martinek

    2017-01-01

    Full Text Available This paper describes the phenomenon of reliability of power plants. It gives an explanation of the terms connected with this topic as their proper understanding is important for understanding the relations and equations which model the possible real situations. The reliability phenomenon is analysed using both the exponential distribution and the Weibull distribution. The results of our analysis are specific equations giving information about the characteristics of the power plants, the mean time of operations and the probability of failure-free operation. Equations solved for the Weibull distribution respect the failures as well as the actual operating hours. Thanks to our results, we are able to create a model of dynamic reliability for prediction of future states. It can be useful for improving the current situation of the unit as well as for creating the optimal plan of maintenance and thus have an impact on the overall economics of the operation of these power plants.

  4. Product reliability and the reliability of its emanating operational processes.

    NARCIS (Netherlands)

    Sonnemans, P.J.M.; Geudens, W.H.J.M.

    1999-01-01

    This paper addresses the problem of proper reliability management in business operations today, facing increasing demands on essential business drivers such as time to market, quality and financial profit. In this paper a general method is described of how to achieve product quality in a highly

  5. Power Electronics Packaging Reliability | Transportation Research | NREL

    Science.gov (United States)

    Packaging Reliability Power Electronics Packaging Reliability A photo of a piece of power electronics laboratory equipment. NREL power electronics packaging reliability research investigates the electronics packaging around a semiconductor switching device determines the electrical, thermal, and

  6. Reliability Assessment of Concrete Bridges

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Middleton, C. R.

    This paper is partly based on research performed for the Highways Agency, London, UK under the project DPU/9/44 "Revision of Bridge Assessment Rules Based on Whole Life Performance: concrete bridges". It contains the details of a methodology which can be used to generate Whole Life (WL) reliability...... profiles. These WL reliability profiles may be used to establish revised rules for concrete bridges. This paper is to some extend based on Thoft-Christensen et. al. [1996], Thoft-Christensen [1996] et. al. and Thoft-Christensen [1996]....

  7. Metrological Reliability of Medical Devices

    Science.gov (United States)

    Costa Monteiro, E.; Leon, L. F.

    2015-02-01

    The prominent development of health technologies of the 20th century triggered demands for metrological reliability of physiological measurements comprising physical, chemical and biological quantities, essential to ensure accurate and comparable results of clinical measurements. In the present work, aspects concerning metrological reliability in premarket and postmarket assessments of medical devices are discussed, pointing out challenges to be overcome. In addition, considering the social relevance of the biomeasurements results, Biometrological Principles to be pursued by research and innovation aimed at biomedical applications are proposed, along with the analysis of their contributions to guarantee the innovative health technologies compliance with the main ethical pillars of Bioethics.

  8. The problem of software reliability

    International Nuclear Information System (INIS)

    Ballard, G.M.

    1989-01-01

    The state of the art in safety and reliability assessment of the software of industrial computer systems is reviewed and likely progress over the next few years is identified and compared with the perceived needs of the user. Some of the current projects contributing to the development of new techniques for assessing software reliability are described. One is the software test and evaluation method which looked at the faults within and between two manufacturers specifications, faults in the codes and inconsistencies between the codes and specifications. The results are given. (author)

  9. Safety and reliability in Europe

    International Nuclear Information System (INIS)

    Colombo, A.G.

    1985-01-01

    This volume contains the papers presented at the ESRA Pre-Launching Meeting. The meeting was attended by about eighty European reliability and safety experts from industry, research organizations and universities. This meeting was dealing with the following subjects: the historical perspective of safety and reliability in Europe and to the aims of ESRA. Status and Trends in Research and Development; Codes, Standards and Regulations; Academic and Technical Training. National and international Organizations. Twenty six papers have been analyzed and abstracted for inclusion in the data base

  10. Photovoltaic power system reliability considerations

    Science.gov (United States)

    Lalli, V. R.

    1980-01-01

    This paper describes an example of how modern engineering and safety techniques can be used to assure the reliable and safe operation of photovoltaic power systems. This particular application was for a solar cell power system demonstration project in Tangaye, Upper Volta, Africa. The techniques involve a definition of the power system natural and operating environment, use of design criteria and analysis techniques, an awareness of potential problems via the inherent reliability and FMEA methods, and use of a fail-safe and planned spare parts engineering philosophy.

  11. Reliability in the design phase

    International Nuclear Information System (INIS)

    Siahpush, A.S.; Hills, S.W.; Pham, H.; Majumdar, D.

    1991-12-01

    A study was performed to determine the common methods and tools that are available to calculated or predict a system's reliability. A literature review and software survey are included. The desired product of this developmental work is a tool for the system designer to use in the early design phase so that the final design will achieve the desired system reliability without lengthy testing and rework. Three computer programs were written which provide the first attempt at fulfilling this need. The programs are described and a case study is presented for each one. This is a continuing effort which will be furthered in FY-1992. 10 refs

  12. FRELIB, Failure Reliability Index Calculation

    International Nuclear Information System (INIS)

    Parkinson, D.B.; Oestergaard, C.

    1984-01-01

    1 - Description of problem or function: Calculation of the reliability index given the failure boundary. A linearization point (design point) is found on the failure boundary for a stationary reliability index (min) and a stationary failure probability density function along the failure boundary, provided that the basic variables are normally distributed. 2 - Method of solution: Iteration along the failure boundary which must be specified - together with its partial derivatives with respect to the basic variables - by the user in a subroutine FSUR. 3 - Restrictions on the complexity of the problem: No distribution information included (first-order-second-moment-method). 20 basic variables (could be extended)

  13. 76 FR 58101 - Electric Reliability Organization Interpretation of Transmission Operations Reliability Standard

    Science.gov (United States)

    2011-09-20

    ....C. Cir. 2009). \\4\\ Mandatory Reliability Standards for the Bulk-Power System, Order No. 693, FERC... for maintaining real and reactive power balance. \\14\\ Electric Reliability Organization Interpretation...; Order No. 753] Electric Reliability Organization Interpretation of Transmission Operations Reliability...

  14. Issues in benchmarking human reliability analysis methods: A literature review

    International Nuclear Information System (INIS)

    Boring, Ronald L.; Hendrickson, Stacey M.L.; Forester, John A.; Tran, Tuan Q.; Lois, Erasmia

    2010-01-01

    There is a diversity of human reliability analysis (HRA) methods available for use in assessing human performance within probabilistic risk assessments (PRA). Due to the significant differences in the methods, including the scope, approach, and underlying models, there is a need for an empirical comparison investigating the validity and reliability of the methods. To accomplish this empirical comparison, a benchmarking study comparing and evaluating HRA methods in assessing operator performance in simulator experiments is currently underway. In order to account for as many effects as possible in the construction of this benchmarking study, a literature review was conducted, reviewing past benchmarking studies in the areas of psychology and risk assessment. A number of lessons learned through these studies is presented in order to aid in the design of future HRA benchmarking endeavors.

  15. Issues in benchmarking human reliability analysis methods : a literature review.

    Energy Technology Data Exchange (ETDEWEB)

    Lois, Erasmia (US Nuclear Regulatory Commission); Forester, John Alan; Tran, Tuan Q. (Idaho National Laboratory, Idaho Falls, ID); Hendrickson, Stacey M. Langfitt; Boring, Ronald L. (Idaho National Laboratory, Idaho Falls, ID)

    2008-04-01

    There is a diversity of human reliability analysis (HRA) methods available for use in assessing human performance within probabilistic risk assessment (PRA). Due to the significant differences in the methods, including the scope, approach, and underlying models, there is a need for an empirical comparison investigating the validity and reliability of the methods. To accomplish this empirical comparison, a benchmarking study is currently underway that compares HRA methods with each other and against operator performance in simulator studies. In order to account for as many effects as possible in the construction of this benchmarking study, a literature review was conducted, reviewing past benchmarking studies in the areas of psychology and risk assessment. A number of lessons learned through these studies are presented in order to aid in the design of future HRA benchmarking endeavors.

  16. Fatigue Reliability under Random Loads

    DEFF Research Database (Denmark)

    Talreja, R.

    1979-01-01

    We consider the problem of estimating the probability of survival (non-failure) and the probability of safe operation (strength greater than a limiting value) of structures subjected to random loads. These probabilities are formulated in terms of the probability distributions of the loads...... propagation stage. The consequences of this behaviour on the fatigue reliability are discussed....

  17. Forecasting reliability of transformer populations

    NARCIS (Netherlands)

    Schijndel, van A.; Wetzer, J.; Wouters, P.A.A.F.

    2007-01-01

    The expected replacement wave in the current power grid faces asset managers with challenging questions. Setting up a replacement strategy and planning calls for a forecast of the long term component reliability. For transformers the future failure probability can be predicted based on the ongoing

  18. Teaming up to improve reliability

    International Nuclear Information System (INIS)

    Malone, E.A.; Ayres, D.J.; Lear, R.C. van

    1989-01-01

    Responding to increasingly stringent regulatory requirements, Babcock and Wilcox has teamed up with three specialist companies to provide services for nuclear utilities aiming to improve the performance of their valves and actuators. The services, which are outlined here, include inspection, repair, overhaul and valve and actuator reliability programmes. (author)

  19. Nonelectronic Parts Reliability Data 1991

    Science.gov (United States)

    1991-05-01

    Characterization & Failure Analysis Techniques 100.00 130.Ot_00, ______ MFAT_1 &2 Combined set ofMFAT-1_andMFAT-2 200 00 300,00 _ _ ____ FTA ...Device Reliability - 1988 10000 12000 ___ CRTA- FMD Failure Mode Distribution Critical Technology Review Assessment 10000 12000 ___ NONOP-1

  20. INCREASED RELIABILITY OF ELECTRIC BLASTING

    OpenAIRE

    Kashuba, Oleh Ivanovych; Skliarov, L I; Skliarov, A L

    2017-01-01

    The problems of improving reliability of an electric blasting method using electric detonators with nichrome filament bridges. It was revealed that in the calculation of the total resistance of the explosive network it is necessary to increase to 24% of the nominal value

  1. Reliability Analysis of Money Habitudes

    Science.gov (United States)

    Delgadillo, Lucy M.; Bushman, Brittani S.

    2015-01-01

    Use of the Money Habitudes exercise has gained popularity among various financial professionals. This article reports on the reliability of this resource. A survey administered to young adults at a western state university was conducted, and each Habitude or "domain" was analyzed using Cronbach's alpha procedures. Results showed all six…

  2. Proposed Reliability/Cost Model

    Science.gov (United States)

    Delionback, L. M.

    1982-01-01

    New technique estimates cost of improvement in reliability for complex system. Model format/approach is dependent upon use of subsystem cost-estimating relationships (CER's) in devising cost-effective policy. Proposed methodology should have application in broad range of engineering management decisions.

  3. Reliability in the Rasch Model

    Czech Academy of Sciences Publication Activity Database

    Martinková, Patrícia; Zvára, K.

    2007-01-01

    Roč. 43, č. 3 (2007), s. 315-326 ISSN 0023-5954 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : Cronbach's alpha * Rasch model * reliability Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 0.552, year: 2007 http://dml.cz/handle/10338.dmlcz/135776

  4. On the NPP structural reliability

    International Nuclear Information System (INIS)

    Klemin, A.I.; Polyakov, E.F.

    1980-01-01

    Reviewed are the main statements peculiarities and possibilities of the first branch guiding technical material (GTM) ''The methods of calculation of structural reliability of NPP and its systems at the stage of projecting''. It is stated, that in GTM presented are recomendations on the calculation of reliability of such specific systems, as the system of the reactor control and protection the system of measuring instruments and automatics and safe systems. GTM are based on analytical methods of modern theory of realibility with the Use of metodology of minimal cross sections of complex systems. It is stressed, that the calculations on the proposed methods permit to calculate a wide complex of reliability parameters, reflecting separately or together prorerties of NPP dependability and maintainability. For NPP, operating by a variable schedule of leading, aditionally considered are parameters, characterizing reliability with account of the proposed regime of power change, i.e. taking into account failures, caused by decrease of the obtained power lower, than the reguired or increase of the required power higher, than the obtained

  5. System reliability of corroding pipelines

    International Nuclear Information System (INIS)

    Zhou Wenxing

    2010-01-01

    A methodology is presented in this paper to evaluate the time-dependent system reliability of a pipeline segment that contains multiple active corrosion defects and is subjected to stochastic internal pressure loading. The pipeline segment is modeled as a series system with three distinctive failure modes due to corrosion, namely small leak, large leak and rupture. The internal pressure is characterized as a simple discrete stochastic process that consists of a sequence of independent and identically distributed random variables each acting over a period of one year. The magnitude of a given sequence follows the annual maximum pressure distribution. The methodology is illustrated through a hypothetical example. Furthermore, the impact of the spatial variability of the pressure loading and pipe resistances associated with different defects on the system reliability is investigated. The analysis results suggest that the spatial variability of pipe properties has a negligible impact on the system reliability. On the other hand, the spatial variability of the internal pressure, initial defect sizes and defect growth rates can have a significant impact on the system reliability.

  6. Reliability Assessment of Transformerless PV Inverters considering Mission Profiles

    Directory of Open Access Journals (Sweden)

    Yongheng Yang

    2015-01-01

    Full Text Available Due to the small volume and high efficiency, transformerless inverters have gained much popularity in grid-connected PV applications, where minimizing leakage current injection is mandatory. This can be achieved by either modifying the modulation schemes or adding extra power switching devices, resulting in an uneven distribution of the power losses on the switching devices. Consequently, the device thermal loading is redistributed and thus may alter the entire inverter reliability performance, especially under a long-term operation. In this consideration, this paper assesses the device reliability of three transformerless inverters under a yearly mission profile (i.e., solar irradiance and ambient temperature. The mission profile is translated to device thermal loading, which is used for lifetime prediction. Comparison results reveal the lifetime mismatches among the power switching devices operating under the same condition, which offers new thoughts for a robust design and a reliable operation of grid-connected transformerless PV inverters with high efficiency.

  7. Comparing two reliability upper bounds for multistate systems

    International Nuclear Information System (INIS)

    Meng, Fan C.

    2005-01-01

    The path-cut reliability bound due to Esary and Proschan [J. Am. Stat. Assoc. 65 (1970) 329] and the minimax reliability bound due to Barlow and Proschan [Statistical Theory of Reliability and Life Testing: Probability Models, 1981] for binary systems have been generalized to multistate systems by Block and Savits [J. Appl. Probab. 19 (1982) 391]. Some comparison results concerning the two multistate lower bounds for various types of multistate systems are given by Meng [Probab. Eng. Inform. Sci. 16 (2002) 485]. In this note we compare the two multistate upper bounds and present results which generalize some previous ones obtained by Maymin [J. Stat. Plan. Inference 16 (1987) 337] for binary systems. Examples are given to illustrate our results

  8. Reliability factors of tube-to-tubesheet joints

    International Nuclear Information System (INIS)

    Sang, Z.F.; Zhu, Y.Z.; Widera, G.E.O.

    1992-01-01

    The main purpose of this paper is to provide an applicable method to establish reliability factors for expanded tube-to-tubesheet joints. The paper also reports on the results of a preliminary study to validate experimentally the reliability efficiencies listed in Table A-2 of Appendix A of Section VIII, Division 1, of the ASME Boiler and Pressure Vessel Code. A comparison between the actual reliability factors f r , determined from testing the damage strength of the joint and calculated according to Appendix A-4 of the ASME Code, and those of Table A-2 is carried out. The results are discussed in light of the restrictions inherent in Table A-2. It is confirmed that some existing values of f r are conservative while others are less so. (orig.)

  9. Gearbox Reliability Collaborative High-Speed Shaft Calibration

    Energy Technology Data Exchange (ETDEWEB)

    Keller, J.; McNiff, B.

    2014-09-01

    Instrumentation has been added to the high-speed shaft, pinion, and tapered roller bearing pair of the Gearbox Reliability Collaborative gearbox to measure loads and temperatures. The new shaft bending moment and torque instrumentation was calibrated and the purpose of this document is to describe this calibration process and results, such that the raw shaft bending and torque signals can be converted to the proper engineering units and coordinate system reference for comparison to design loads and simulation model predictions.

  10. AFSC/FMA/NPRB Halibut Bycatch Video Field Test

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data arise from a field test of electronic monitoring (EM) of vessels participating in the Pacific halibut fishery off Alaska. A side-by-side comparison was...

  11. Comparison of two new angiogenesis PET tracers 68Ga-NODAGA-E[c(RGDyK)]2 and 64Cu-NODAGA-E[c(RGDyK)]2; in vivo imaging studies in human xenograft tumors

    DEFF Research Database (Denmark)

    Oxbøl, Jytte; Brandt-Larsen, Malene; Schjøth-Eskesen, Christina

    2014-01-01

    INTRODUCTION: The aim of this study was to synthesize and perform a side-by-side comparison of two new tumor-angiogenesis PET tracers (68)Ga-NODAGA-E[c(RGDyK)](2) and (64)Cu-NODAGA-E[c(RGDyK)](2) in vivo using human xenograft tumors in mice. Human radiation burden was estimated to evaluate...... potential for future use as clinical PET tracers for imaging of neo-angiogenesis. METHODS: A (68)Ge/(68)Ga generator was used for the synthesis of (68)Ga-NODAGA-E[c(RGDyK)](2). (68)Ga and (64)Cu labeled NODAGA-E[c(RGDyK)](2) tracers were administrated in nude mice bearing either human glioblastoma (U87MG......) or human neuroendocrine (H727) xenograft tumors. PET/CT scans at 3 time points were used for calculating the tracer uptake in tumors (%ID/g), integrin αVβ3 target specificity was shown by blocking with cold NODAGA-E[c(RGDyK)](2), and biodistribution in normal organs were also examined. From biodistribution...

  12. Exact reliability quantification of highly reliable systems with maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Bris, Radim, E-mail: radim.bris@vsb.c [VSB-Technical University Ostrava, Faculty of Electrical Engineering and Computer Science, Department of Applied Mathematics, 17. listopadu 15, 70833 Ostrava-Poruba (Czech Republic)

    2010-12-15

    When a system is composed of highly reliable elements, exact reliability quantification may be problematic, because computer accuracy is limited. Inaccuracy can be due to different aspects. For example, an error may be made when subtracting two numbers that are very close to each other, or at the process of summation of many very different numbers, etc. The basic objective of this paper is to find a procedure, which eliminates errors made by PC when calculations close to an error limit are executed. Highly reliable system is represented by the use of directed acyclic graph which is composed from terminal nodes, i.e. highly reliable input elements, internal nodes representing subsystems and edges that bind all of these nodes. Three admissible unavailability models of terminal nodes are introduced, including both corrective and preventive maintenance. The algorithm for exact unavailability calculation of terminal nodes is based on merits of a high-performance language for technical computing MATLAB. System unavailability quantification procedure applied to a graph structure, which considers both independent and dependent (i.e. repeatedly occurring) terminal nodes is based on combinatorial principle. This principle requires summation of a lot of very different non-negative numbers, which may be a source of an inaccuracy. That is why another algorithm for exact summation of such numbers is designed in the paper. The summation procedure uses benefits from a special number system with the base represented by the value 2{sup 32}. Computational efficiency of the new computing methodology is compared with advanced simulation software. Various calculations on systems from references are performed to emphasize merits of the methodology.

  13. Reliability on the move: safety and reliability in transportation

    International Nuclear Information System (INIS)

    Guy, G.B.

    1989-01-01

    The development of transportation has been a significant factor in the development of civilisation as a whole. Our technical ability to move people and goods now seems virtually limitless when one considers for example the achievements of the various space programmes. Yet our current achievements rely heavily on high standards of safety and reliability from equipment and the human component of transportation systems. Recent failures have highlighted our dependence on equipment and human reliability. This book represents the proceedings of the 1989 Safety and Reliability Society symposium held at Bath on 11-12 October 1989. The structure of the book follows the structure of the symposium itself and the papers selected represent current thinking the the wide field of transportation, and the areas of rail (6 papers, three on railway signalling), air including space (two papers), road (one paper), road and rail (two papers) and sea (three papers) are covered. There are four papers concerned with general transport issues. Three papers concerned with the transport of radioactive materials are indexed separately. (author)

  14. Robust Reliability or reliable robustness? - Integrated consideration of robustness and reliability aspects

    DEFF Research Database (Denmark)

    Kemmler, S.; Eifler, Tobias; Bertsche, B.

    2015-01-01

    products are and vice versa. For a comprehensive understanding and to use existing synergies between both domains, this paper discusses the basic principles of Reliability- and Robust Design theory. The development of a comprehensive model will enable an integrated consideration of both domains...

  15. 78 FR 38311 - Reliability Technical Conference Agenda

    Science.gov (United States)

    2013-06-26

    ... issues related to the reliability of the Bulk-Power System. The agenda for this conference is attached... Reliability Technical Docket No. AD13-6-000 Conference. North American Electric Docket No. RC11-6-004 Reliability Corporation. North American Electric Docket No. RR13-2-000 Reliability Corporation. Not...

  16. 78 FR 63036 - Transmission Planning Reliability Standards

    Science.gov (United States)

    2013-10-23

    ... Reliability Standards for the Bulk Power System, 130 FERC ] 61,200 (2010). \\8\\ Mandatory Reliability Standards... electric system operations across normal and contingency conditions. We also find that Reliability Standard... Reliability Standards for the Bulk Power System, 131 FERC ] 61,231 at P 21. Comments 24. NERC supports the...

  17. Medical device reliability and associated areas

    National Research Council Canada - National Science Library

    Dhillon, Balbir S

    2000-01-01

    .... Although the history of reliability engineering can be traced back to World War II, the application of reliability engineering concepts to medical devices is a fairly recent idea that goes back to the latter part of the 1960s when many publications on medical device reliability emerged. Today, a large number of books on general reliability have been...

  18. Human factors reliability Benchmark exercise

    International Nuclear Information System (INIS)

    Poucet, A.

    1989-06-01

    The Joint Research Centre of the European Commission has organized a Human Factors Reliability Benchmark Exercise (HF-RBE) with the aim of assessing the state of the art in human reliability modelling and assessment. Fifteen teams from eleven countries, representing industry, utilities, licensing organisations and research institutes, participated in the HF-RBE. The HF-RBE was organized around two study cases: (1) analysis of routine functional Test and Maintenance (T and M) procedures: with the aim of assessing the probability of test induced failures, the probability of failures to remain unrevealed and the potential to initiate transients because of errors performed in the test; (2) analysis of human actions during an operational transient: with the aim of assessing the probability that the operators will correctly diagnose the malfunctions and take proper corrective action. This report contains the final summary reports produced by the participants in the exercise

  19. Gearbox Reliability Collaborative Bearing Calibration

    Energy Technology Data Exchange (ETDEWEB)

    van Dam, J.

    2011-10-01

    NREL has initiated the Gearbox Reliability Collaborative (GRC) to investigate the root cause of the low wind turbine gearbox reliability. The GRC follows a multi-pronged approach based on a collaborative of manufacturers, owners, researchers and consultants. The project combines analysis, field testing, dynamometer testing, condition monitoring, and the development and population of a gearbox failure database. At the core of the project are two 750kW gearboxes that have been redesigned and rebuilt so that they are representative of the multi-megawatt gearbox topology currently used in the industry. These gearboxes are heavily instrumented and are tested in the field and on the dynamometer. This report discusses the bearing calibrations of the gearboxes.

  20. RELIABILITY OF LENTICULAR EXPANSION COMPENSATORS

    Directory of Open Access Journals (Sweden)

    Gabriel BURLACU,

    2011-11-01

    Full Text Available Axial lenticular compensators are made to take over the longitudinal heat expansion, shock , vibration and noise, made elastic connections for piping systems. In order to have a long life for installations it is necessary that all elements, including lenticular compensators, have a good reliability. This desire can be did by technology of manufactoring and assembly of compensators, the material for lenses and by maintenance.of compensator

  1. PWR system reliability improvement activities

    International Nuclear Information System (INIS)

    Yoshikawa, Yuichiro

    1985-01-01

    In Japan lacking in energy resources, it is our basic energy policy to accelerate the development program of nuclear power, thereby reducing our dependence. As referred to in the foregoing, every effort has been exerted on our part to improve the PWR system reliability by dint of the so-called 'HOMEMADE' TQC activities, which is our brain-child as a result of applying to the energy industry the quality control philosophy developed in the field of manufacturing industry

  2. Reliability of Composite Dichotomous Measurements

    Czech Academy of Sciences Publication Activity Database

    Martinková, Patrícia; Zvára, Karel

    2010-01-01

    Roč. 6, č. 2 (2010), s. 103-109 ISSN 1801-5603 R&D Projects: GA MŠk(CZ) 1M06014 Institutional research plan: CEZ:AV0Z10300504 Keywords : reliability * binary data * logistic regression * Cronbach alpha * Rasch model * myocardial perfusion diagnosis Subject RIV: BB - Applied Statistics, Operational Research http://www.ejbi.cz/articles/201012/65/1.html

  3. TFTR CAMAC power supplies reliability

    International Nuclear Information System (INIS)

    Camp, R.A.; Bergin, W.

    1989-01-01

    Since the expected life of the Tokamak Fusion Test Reactor (TFTR) has been extended into the early 1990's, the issues of equipment wear-out, when to refurbish/replace, and the costs associated with these decisions, must be faced. The management of the maintenance of the TFTR Central Instrumentation, Control and Data Acquisition System (CICADA) power supplies within the CAMAC network is a case study of a set of systems to monitor repairable systems reliability, costs, and results of action. The CAMAC network is composed of approximately 500 racks, each with its own power supply. By using a simple reliability estimator on a coarse time interval, in conjunction with determining the root cause of individual failures, a cost effective repair and maintenance program has been realized. This paper describes the estimator, some of the specific causes for recurring failures and their correction, and the subsequent effects on the reliability estimator. By extension of this program the authors can assess the continued viability of CAMAC power supplies into the future, predicting wear-out and developing cost effective refurbishment/replacement policies. 4 refs., 3 figs., 1 tab

  4. Reliability in individual monitoring service.

    Science.gov (United States)

    Mod Ali, N

    2011-03-01

    As a laboratory certified to ISO 9001:2008 and accredited to ISO/IEC 17025, the Secondary Standard Dosimetry Laboratory (SSDL)-Nuclear Malaysia has incorporated an overall comprehensive system for technical and quality management in promoting a reliable individual monitoring service (IMS). Faster identification and resolution of issues regarding dosemeter preparation and issuing of reports, personnel enhancement, improved customer satisfaction and overall efficiency of laboratory activities are all results of the implementation of an effective quality system. Review of these measures and responses to observed trends provide continuous improvement of the system. By having these mechanisms, reliability of the IMS can be assured in the promotion of safe behaviour at all levels of the workforce utilising ionising radiation facilities. Upgradation of in the reporting program through a web-based e-SSDL marks a major improvement in Nuclear Malaysia's IMS reliability on the whole. The system is a vital step in providing a user friendly and effective occupational exposure evaluation program in the country. It provides a higher level of confidence in the results generated for occupational dose monitoring of the IMS, thus, enhances the status of the radiation protection framework of the country.

  5. Reliability engineering theory and practice

    CERN Document Server

    Birolini, Alessandro

    2017-01-01

    This book shows how to build in and assess reliability, availability, maintainability, and safety (RAMS) of components, equipment, and systems. It presents the state of the art of reliability (RAMS) engineering, in theory & practice, and is based on over 30 years author's experience in this field, half in industry and half as Professor of Reliability Engineering at the ETH, Zurich. The book structure allows rapid access to practical results. Methods & tools are given in a way that they can be tailored to cover different RAMS requirement levels. Thanks to Appendices A6 - A8 the book is mathematically self-contained, and can be used as a textbook or as a desktop reference with a large number of tables (60), figures (210), and examples / exercises^ 10,000 per year since 2013) were the motivation for this final edition, the 13th since 1985, including German editions. Extended and carefully reviewed to improve accuracy, it represents the continuous improvement effort to satisfy reader's needs and confidenc...

  6. Operator reliability assessment system (OPERAS)

    International Nuclear Information System (INIS)

    Singh, A.; Spurgin, A.J.; Martin, T.; Welsch, J.; Hallam, J.W.

    1991-01-01

    OPERAS is a personal-computer (PC) based software to collect and process simulator data on control-room operators responses during requalification training scenarios. The data collection scheme is based upon approach developed earlier during the EPRI Operator Reliability Experiments project. The software allows automated data collection from simulator, thus minimizing simulator staff time and resources to collect, maintain and process data which can be useful in monitoring, assessing and enhancing the progress of crew reliability and effectiveness. The system is designed to provide the data and output information in the form of user-friendly charts, tables and figures for use by plant staff. OPERAS prototype software has been implemented at the Diablo Canyon (PWR) and Millstone (BWR) plants and is currently being used to collect operator response data. Data collected from similator include plant-state variables such as reactor pressure and temperature, malfunction, times at which annunciators are activated, operator actions and observations of crew behavior by training staff. The data and systematic analytical results provided by the OPERAS system can contribute to increase objectivity by the utility probabilistic risk analysis (PRA) and training staff in monitoring and assessing reliability of their crews

  7. Human factors reliability benchmark exercise

    International Nuclear Information System (INIS)

    Poucet, A.

    1989-08-01

    The Joint Research Centre of the European Commission has organised a Human Factors Reliability Benchmark Exercise (HF-RBE) with the aim of assessing the state of the art in human reliability modelling and assessment. Fifteen teams from eleven countries, representing industry, utilities, licensing organisations and research institutes, participated in the HF-RBE. The HF-RBE was organised around two study cases: (1) analysis of routine functional Test and Maintenance (TPM) procedures: with the aim of assessing the probability of test induced failures, the probability of failures to remain unrevealed and the potential to initiate transients because of errors performed in the test; (2) analysis of human actions during an operational transient: with the aim of assessing the probability that the operators will correctly diagnose the malfunctions and take proper corrective action. This report summarises the contributions received from the participants and analyses these contributions on a comparative basis. The aim of this analysis was to compare the procedures, modelling techniques and quantification methods used, to obtain insight in the causes and magnitude of the variability observed in the results, to try to identify preferred human reliability assessment approaches and to get an understanding of the current state of the art in the field identifying the limitations that are still inherent to the different approaches

  8. OPTIMUM DESIGN OF EXPERIMENTS FOR ACCELERATED RELIABILITY TESTING

    Directory of Open Access Journals (Sweden)

    Sebastian Marian ZAHARIA

    2014-05-01

    Full Text Available In this paper is presented a case study that demonstrates how design to experiments (DOE information can be used to design better accelerated reliability tests. In the case study described in this paper, will be done a comparison and optimization between main accelerated reliability test plans (3 Level Best Standard Plan, 3 Level Best Compromise Plan, 3 Level Best Equal Expected Number Failing Plan, 3 Level 4:2:1 Allocation Plan. Before starting an accelerated reliability test, it is advisable to have a plan that helps in accurately estimating reliability at operating conditions while minimizing test time and costs. A test plan should be used to decide on the appropriate stress levels that should be used (for each stress type and the amount of the test units that need to be allocated to the different stress levels (for each combination of the different stress types' levels. For the case study it used ALTA 7 software what provides a complete analysis for data from accelerated reliability tests

  9. Inference on the reliability of Weibull distribution with multiply Type-I censored data

    International Nuclear Information System (INIS)

    Jia, Xiang; Wang, Dong; Jiang, Ping; Guo, Bo

    2016-01-01

    In this paper, we focus on the reliability of Weibull distribution under multiply Type-I censoring, which is a general form of Type-I censoring. In multiply Type-I censoring in this study, all units in the life testing experiment are terminated at different times. Reliability estimation with the maximum likelihood estimate of Weibull parameters is conducted. With the delta method and Fisher information, we propose a confidence interval for reliability and compare it with the bias-corrected and accelerated bootstrap confidence interval. Furthermore, a scenario involving a few expert judgments of reliability is considered. A method is developed to generate extended estimations of reliability according to the original judgments and transform them to estimations of Weibull parameters. With Bayes theory and the Monte Carlo Markov Chain method, a posterior sample is obtained to compute the Bayes estimate and credible interval for reliability. Monte Carlo simulation demonstrates that the proposed confidence interval outperforms the bootstrap one. The Bayes estimate and credible interval for reliability are both satisfactory. Finally, a real example is analyzed to illustrate the application of the proposed methods. - Highlights: • We focus on reliability of Weibull distribution under multiply Type-I censoring. • The proposed confidence interval for the reliability is superior after comparison. • The Bayes estimates with a few expert judgements on reliability are satisfactory. • We specify the cases where the MLEs do not exist and present methods to remedy it. • The distribution of estimate of reliability should be used for accurate estimate.

  10. Computer Model to Estimate Reliability Engineering for Air Conditioning Systems

    International Nuclear Information System (INIS)

    Afrah Al-Bossly, A.; El-Berry, A.; El-Berry, A.

    2012-01-01

    Reliability engineering is used to predict the performance and optimize design and maintenance of air conditioning systems. Air conditioning systems are expose to a number of failures. The failures of an air conditioner such as turn on, loss of air conditioner cooling capacity, reduced air conditioning output temperatures, loss of cool air supply and loss of air flow entirely can be due to a variety of problems with one or more components of an air conditioner or air conditioning system. Forecasting for system failure rates are very important for maintenance. This paper focused on the reliability of the air conditioning systems. Statistical distributions that were commonly applied in reliability settings: the standard (2 parameter) Weibull and Gamma distributions. After distributions parameters had been estimated, reliability estimations and predictions were used for evaluations. To evaluate good operating condition in a building, the reliability of the air conditioning system that supplies conditioned air to the several The company's departments. This air conditioning system is divided into two, namely the main chilled water system and the ten air handling systems that serves the ten departments. In a chilled-water system the air conditioner cools water down to 40-45 degree F (4-7 degree C). The chilled water is distributed throughout the building in a piping system and connected to air condition cooling units wherever needed. Data analysis has been done with support a computer aided reliability software, this is due to the Weibull and Gamma distributions indicated that the reliability for the systems equal to 86.012% and 77.7% respectively. A comparison between the two important families of distribution functions, namely, the Weibull and Gamma families was studied. It was found that Weibull method performed for decision making.

  11. Reliability analysis of minimum energy on target for laser facilities with more beam lines

    International Nuclear Information System (INIS)

    Chen Guangyu

    2008-01-01

    Shot reliability performance measures of laser facilities with more beam lines pertain to three categories: minimum-energy-on-target, power balance, and shot diagnostics. Accounting for symmetry of NIF beam line design and similarity of subset reliability in a same partition, a fault tree of meeting minimum-energy-on-target for the large laser facility shot of type K and a simplified method are presented, which are used to analyze hypothetic reliability of partition subsets in order to get trends of influences increasing number of beam lines and diverse shot types of large laser facilities on their shot reliability. Finally, it finds that improving component reliability is more crucial for laser facilities with more beam lines in comparison with those with beam lines and functional diversity from design flexibility is greatly helpful for improving shot reliability. (authors)

  12. An Energy-Based Limit State Function for Estimation of Structural Reliability in Shock Environments

    Directory of Open Access Journals (Sweden)

    Michael A. Guthrie

    2013-01-01

    Full Text Available limit state function is developed for the estimation of structural reliability in shock environments. This limit state function uses peak modal strain energies to characterize environmental severity and modal strain energies at failure to characterize the structural capacity. The Hasofer-Lind reliability index is briefly reviewed and its computation for the energy-based limit state function is discussed. Applications to two degree of freedom mass-spring systems and to a simple finite element model are considered. For these examples, computation of the reliability index requires little effort beyond a modal analysis, but still accounts for relevant uncertainties in both the structure and environment. For both examples, the reliability index is observed to agree well with the results of Monte Carlo analysis. In situations where fast, qualitative comparison of several candidate designs is required, the reliability index based on the proposed limit state function provides an attractive metric which can be used to compare and control reliability.

  13. Quantitative measurement of hypertrophic scar: interrater reliability and concurrent validity.

    Science.gov (United States)

    Nedelec, Bernadette; Correa, José A; Rachelska, Grazyna; Armour, Alexis; LaSalle, Léo

    2008-01-01

    Research into the pathophysiology and treatment of hypertrophic scar (HSc) remains limited by the heterogeneity of scar and the imprecision with which its severity is measured. The objective of this study was to test the interrater reliability and concurrent validity of the Cutometer measurement of elasticity, the Mexameter measurement of erythema and pigmentation, and total thickness measure of the DermaScan C relative to the modified Vancouver Scar Scale (mVSS) in patient-matched normal skin, normal scar, and HSc. Three independent investigators evaluated 128 sites (severe HSc, moderate or mild HSc, donor site, and normal skin) on 32 burn survivors using all of the above measurement tools. The intraclass correlation coefficient, which was used to measure interrater reliability, reflects the inherent amount of error in the measure and is considered acceptable when it is >0.75. Interrater reliability of the totals of the height, pliability, and vascularity subscales of the mVSS fell below the acceptable limit ( congruent with0.50). The individual subscales of the mVSS fell well below the acceptable level (0.89) for each study site with the exception of severe scar. Mexameter and DermaScan C reliability measurements were acceptable for all sites (>0.82). Concurrent validity correlations with the mVSS were significant except for the comparison of the mVSS pliability subscale and the Cutometer maximum deformation measure comparison in severe scar. In conclusion, the Mexameter and DermaScan C measurements of scar color and thickness of all sites, as well as the Cutometer measurement of elasticity in all but the most severe scars shows high interrater reliability. Their significant concurrent validity with the mVSS confirms that these tools are measuring the same traits as the mVSS, and in a more objective way.

  14. Comparison of three different methods for the detection of circulating tumor cells in mice with lung metastasis.

    Science.gov (United States)

    Xu, Weifeng; Wu, Bing; Fu, Lengxi; Chen, Junying; Wang, Zeng; Huang, Fei; Chen, Jinrong; Zhang, Mei; Zhang, Zhenhuan; Lin, Jingan; Lan, Ruilong; Chen, Ruiqing; Chen, Wei; Chen, Long; Hong, Jinsheng; Zhang, Weijian; Ding, Yuxiong; Okunieff, Paul; Lin, Jianhua; Zhang, Lurong

    2017-06-01

    Circulating tumor cells (CTCs) represent the key step of cancer cell dissemination. The alteration of CTCs correlates with the treatment outcome and prognosis. To enrich and identify CTCs from billions of blood cells renders a very challenging task, which triggers development of several methods, including lysis of RBC plus negative or positive enrichment using antibodies, and filter membrane or spiral microfluidics to capture CTCs. To compare the advantages of different enrichment methods for CTCs, we utilized the 4T1 breast cancer cells transfected with both green fluorescent protein (GFP) and luciferase to trace CTCs in the experimental lung metastasis model. Three methods were used to detect CTCs at the same time: bioluminescence assay, smearing method, and membrane filter method. The in vivo alive mouse imaging was used to dynamically monitor the growth of lung metastases. The sensitivity and accuracy of three detection methods were compared side-by-side. Our results showed that 1) the sensitivity of bioluminescence assay was the highest, but there was no information of CTC morphology; 2) the smearing method and membrane filter method could observe the detail of CTC morphology, such as in single or in cluster, while their sensitivity was lower than bioluminescence assay; 3) A dynamic observation at a 7-day intervals, the lung metastatic cancer grew at a log speed, while CTCs were increased at a low speed. This might be due to the activated immune cells eliminating the CTCs at a speed much faster than CTCs were generated. This comparison of three CTC detection methods in mouse model suggests that bioluminescence assay could be used in quantitative study of the effect of certain agent on the suppression of CTCs, while GFP-based morphological assays could be used to study the dissemination mechanism of CTCs. The combination of both bioluminescence assay and GFP-based assay would generate more information for quantity and quality of CTCs.

  15. Evaluation of the Ortho-Clinical Diagnostics Vitros ECi Anti-HCV test: comparison with three other methods.

    Science.gov (United States)

    Watterson, Jeannette M; Stallcup, Paulina; Escamilla, David; Chernay, Patrick; Reyes, Alfred; Trevino, Sylvia C

    2007-01-01

    After observing a high incidence of low positive hepatitis C virus (HCV) antibody screens by the Ortho-Clinical Vitros ECi test (Orthoclinical Diagnostics, Raritan, NJ), we compared results against those obtained using another chemiluminescent analyzer, as well as two U.S. Food and Drug Administration (FDA)-approved confirmatory methodologies. To ascertain the true anti-HCV status of samples deemed low-positive by the Ortho-Clinical Vitros ECi test, we tested samples using the ADVIA Centaur HCV screen test (Siemens Medical Solutions Diagnostics), the Chiron recombinant immunoblot assay (RIBA) test (Chiron Corp., Emeryville, CA), and the Roche COBAS Amplicor HCV qualitative test (Roche Diagnostics, Indianapolis, IN) in a series of studies. Of 94 specimens positive by Vitros ECi, 19% were observed to be negative by Centaur. A separate study of 91 samples with signal-to-cutoff (s/co) values less than 8.0 showed that all but one was negative for HCV ribonucleic acid (RNA). In comparison with RIBA, 100% (77) samples positive by the Vitros ECi test with s/co values less than 12.0 were negative or indeterminate by RIBA. A final study comparing all four methods side-by-side showed 63% disagreement by Centaur for Vitros ECi low-positive samples, 75% disagreement by RIBA, and 97% disagreement by polymerase chain reaction (PCR). In conclusion, the Ortho-Clinical Vitros ECi Anti-HCV test yields a high rate of false-positive results in the low s/co range in our patient population. (c) 2007 Wiley-Liss, Inc.

  16. 76 FR 23171 - Electric Reliability Organization Interpretations of Interconnection Reliability Operations and...

    Science.gov (United States)

    2011-04-26

    ... Reliability Standards for the Bulk-Power System, Order No. 693, FERC Stats. & Regs. ] 31,242, order on reh'g...-Power System reliability may request an interpretation of a Reliability Standard.\\7\\ The ERO's standards... information in its reliability assessments. The Reliability Coordinator must monitor Bulk Electric System...

  17. 76 FR 66055 - North American Electric Reliability Corporation; Order Approving Interpretation of Reliability...

    Science.gov (United States)

    2011-10-25

    ...\\ Mandatory Reliability Standards for the Bulk-Power System, Order No. 693, FERC Stats. & Regs. ] 31,242... materially affected'' by Bulk-Power System reliability may request an interpretation of a Reliability... Electric Reliability Corporation; Order Approving Interpretation of Reliability Standard; Before...

  18. Improved reliability of power modules

    DEFF Research Database (Denmark)

    Baker, Nick; Liserre, Marco; Dupont, Laurent

    2014-01-01

    Power electronic systems play an increasingly important role in providing high-efficiency power conversion for adjustable-speed drives, power-quality correction, renewable-energy systems, energy-storage systems, and electric vehicles. However, they are often presented with demanding operating...... environments that challenge the reliability aspects of power electronic techniques. For example, increasingly thermally stressful environments are seen in applications such as electric vehicles, where ambient temperatures under the hood exceed 150 °C, while some wind turbine applications can place large...

  19. A Survey of Network Reliability.

    Science.gov (United States)

    1983-07-01

    STATEMENT A. Atoyed for public releosel Oo . Distibution Unlimited JULY 1983 ORC 83-5 This research was supported by the Air Force Office of Scientific ...cONTso.oSoo oaoCC NaME ara AOoM It. REPORT DATE United States Air Force July 1983 Air Force Office of Scientific Research IL NUNeen or s Boiling Air Force Base...One node in K is designated the root and the reliability problem is to calculate the probability that the root can comunicate with the remaining K C V

  20. Application of reliability methods in Ontario Hydro

    International Nuclear Information System (INIS)

    Jeppesen, R.; Ravishankar, T.J.

    1985-01-01

    Ontario Hydro have established a reliability program in support of its substantial nuclear program. Application of the reliability program to achieve both production and safety goals is described. The value of such a reliability program is evident in the record of Ontario Hydro's operating nuclear stations. The factors which have contributed to the success of the reliability program are identified as line management's commitment to reliability; selective and judicious application of reliability methods; establishing performance goals and monitoring the in-service performance; and collection, distribution, review and utilization of performance information to facilitate cost-effective achievement of goals and improvements. (orig.)

  1. Towards Reliable Integrated Services for Dependable Systems

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Ravn, Anders Peter; Izadi-Zamanabadi, Roozbeh

    Reliability issues for various technical systems are discussed and focus is directed towards distributed systems, where communication facilities are vital to maintain system functionality. Reliability in communication subsystems is considered as a resource to be shared among a number of logical c...... applications residing on alternative routes. Details are provided for the operation of RRRSVP based on reliability slack calculus. Conclusions summarize the considerations and give directions for future research....... connections and a reliability management framework is suggested. We suggest a network layer level reliability management protocol RRSVP (Reliability Resource Reservation Protocol) as a counterpart of the RSVP for bandwidth and time resource management. Active and passive standby redundancy by background...

  2. Towards Reliable Integrated Services for Dependable Systems

    DEFF Research Database (Denmark)

    Schiøler, Henrik; Ravn, Anders Peter; Izadi-Zamanabadi, Roozbeh

    2003-01-01

    Reliability issues for various technical systems are discussed and focus is directed towards distributed systems, where communication facilities are vital to maintain system functionality. Reliability in communication subsystems is considered as a resource to be shared among a number of logical c...... applications residing on alternative routes. Details are provided for the operation of RRRSVP based on reliability slack calculus. Conclusions summarize the considerations and give directions for future research....... connections and a reliability management framework is suggested. We suggest a network layer level reliability management protocol RRSVP (Reliability Resource Reservation Protocol) as a counterpart of the RSVP for bandwidth and time resource management. Active and passive standby redundancy by background...

  3. Projected cost comparison of nuclear electricity

    International Nuclear Information System (INIS)

    Juhn, P.E.; Hu, C.W.

    2000-01-01

    Comparison of electricity generation costs has been done in the late years through a large co-operation between several organisations. The studies are aiming to provide reliable comparison of electricity generating costs of nuclear and conventional base load power plants. This paper includes the result of the joint IAEA/OECD study published in 1997. (author)

  4. Reliability studies in research reactors

    International Nuclear Information System (INIS)

    Albuquerque, Tob Rodrigues de

    2013-01-01

    Fault trees and event trees are widely used in industry to model and to evaluate the reliability of safety systems. Detailed analyzes in nuclear installations require the combination of these two techniques. This study uses the methods of FT (Fault Tree) and ET (Event Tree) to accomplish the PSA (Probabilistic Safety Assessment) in research reactors. According to IAEA (lnternational Atomic Energy Agency), the PSA is divided into Level 1, Level 2 and Level 3. At the Level 1, conceptually, the security systems perform to prevent the occurrence of accidents, At the Level 2, once accidents happened, this Level seeks to minimize consequences, known as stage management of accident, and at Level 3 accident impacts are determined. This study focuses on analyzing the Level 1, and searching through the acquisition of knowledge, the consolidation of methodologies for future reliability studies. The Greek Research Reactor, GRR-1, is a case example. The LOCA (Loss of Coolant Accident) was chosen as the initiating event and from it, using ET, possible accidental sequences were developed, which could lead damage to the core. Moreover, for each of affected systems, probabilities of each event top of FT were developed and evaluated in possible accidental sequences. Also, the estimates of importance measures for basic events are presented in this work. The studies of this research were conducted using a commercial computational tool SAPHIRE. Additionally, achieved results thus were considered satisfactory for the performance or the failure of analyzed systems. (author)

  5. Highly reliable TOFD UT Technique

    International Nuclear Information System (INIS)

    Acharya, G.D.; Trivedi, S.A.R.; Pai, K.B.

    2003-01-01

    The high performance of the time of flight diffraction technique (TOFD) with regard to the detection capabilities of weld defects such as crack, slag, lack of fusion has led to a rapidly increasing acceptance of the technique as a pre?service inspection tool. Since the early 1990s TOFD has been applied to several projects, where it replaced the commonly used radiographic testing. The use of TOM lead to major time savings during new build and replacement projects. At the same time the TOFD technique was used as base line inspection, which enables monitoring in the future for critical welds, but also provides documented evidence for life?time. The TOFD technique as the ability to detect and simultaneously size flows of nearly any orientation within the weld and heat affected zone. TOM is recognized as a reliable, proven technique for detection and sizing of defects and proven to be a time saver, resulting in shorter shutdown periods and construction project times. Thus even in cases where inspection price of TOFD per welds is higher, in the end it will result in significantly lower overall costs and improve quality. This paper deals with reliability, economy, acceptance criteria and field experience. It also covers comparative study between radiography technique Vs. TOFD. (Author)

  6. Demonstration of reliability centered maintenance

    International Nuclear Information System (INIS)

    Schwan, C.A.; Morgan, T.A.

    1991-04-01

    Reliability centered maintenance (RCM) is an approach to preventive maintenance planning and evaluation that has been used successfully by other industries, most notably the airlines and military. Now EPRI is demonstrating RCM in the commercial nuclear power industry. Just completed are large-scale, two-year demonstrations at Rochester Gas ampersand Electric (Ginna Nuclear Power Station) and Southern California Edison (San Onofre Nuclear Generating Station). Both demonstrations were begun in the spring of 1988. At each plant, RCM was performed on 12 to 21 major systems. Both demonstrations determined that RCM is an appropriate means to optimize a PM program and improve nuclear plant preventive maintenance on a large scale. Such favorable results had been suggested by three earlier EPRI pilot studies at Florida Power ampersand Light, Duke Power, and Southern California Edison. EPRI selected the Ginna and San Onofre sites because, together, they represent a broad range of utility and plant size, plant organization, plant age, and histories of availability and reliability. Significant steps in each demonstration included: selecting and prioritizing plant systems for RCM evaluation; performing the RCM evaluation steps on selected systems; evaluating the RCM recommendations by a multi-disciplinary task force; implementing the RCM recommendations; establishing a system to track and verify the RCM benefits; and establishing procedures to update the RCM bases and recommendations with time (a living program). 7 refs., 1 tab

  7. Reliability Estimation Based Upon Test Plan Results

    National Research Council Canada - National Science Library

    Read, Robert

    1997-01-01

    The report contains a brief summary of aspects of the Maximus reliability point and interval estimation technique as it has been applied to the reliability of a device whose surveillance tests contain...

  8. Identifying factors influencing reliability of professional systems

    NARCIS (Netherlands)

    Balasubramanian, A.; Kevrekidis, K.; Sonnemans, P.J.M.; Newby, M.J.

    2008-01-01

    Modern product development strategies call for a more proactive approach to fight intense global competition in terms of technological innovation, shorter time to market, quality and reliability and accommodative price. From a reliability engineering perspective, development managers would like to

  9. Optimal, Reliability-Based Code Calibration

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard

    2002-01-01

    Reliability based code calibration is considered in this paper. It is described how the results of FORM based reliability analysis may be related to the partial safety factors and characteristic values. The code calibration problem is presented in a decision theoretical form and it is discussed how...... of reliability based code calibration of LRFD based design codes....

  10. Structural reliability assessment capability in NESSUS

    Science.gov (United States)

    Millwater, H.; Wu, Y.-T.

    1992-07-01

    The principal capabilities of NESSUS (Numerical Evaluation of Stochastic Structures Under Stress), an advanced computer code developed for probabilistic structural response analysis, are reviewed, and its structural reliability assessed. The code combines flexible structural modeling tools with advanced probabilistic algorithms in order to compute probabilistic structural response and resistance, component reliability and risk, and system reliability and risk. An illustrative numerical example is presented.

  11. 78 FR 58492 - Generator Verification Reliability Standards

    Science.gov (United States)

    2013-09-24

    ... power capability that is available for planning models and bulk electric system reliability assessments... of generator equipment needed to support Bulk-Power System reliability and enhance coordination of... support Bulk-Power System reliability and will ensure that accurate data is verified and made available...

  12. 77 FR 26714 - Transmission Planning Reliability Standards

    Science.gov (United States)

    2012-05-07

    ... Reliability Standards for the Bulk-Power System, Order No. 693, FERC Stats. & Regs. ] 31,242, order on reh'g... Standards for the Bulk Power System, 130 FERC ] 61,200 (2010) (March 2010 Order). \\12\\ Mandatory Reliability... excluded from future planning assessments and its potential impact to bulk electric system reliability...

  13. 18 CFR 39.11 - Reliability reports.

    Science.gov (United States)

    2010-04-01

    ... Electric Reliability Organization shall conduct assessments of the adequacy of the Bulk-Power System in... assessments as determined by the Commission of the reliability of the Bulk-Power System in North America and... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Reliability reports. 39...

  14. 2015 NREL Photovoltaic Module Reliability Workshops

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    NREL's Photovoltaic (PV) Module Reliability Workshop (PVMRW) brings together PV reliability experts to share information, leading to the improvement of PV module reliability. Such improvement reduces the cost of solar electricity and promotes investor confidence in the technology--both critical goals for moving PV technologies deeper into the electricity marketplace.

  15. 2016 NREL Photovoltaic Module Reliability Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-07

    NREL's Photovoltaic (PV) Module Reliability Workshop (PVMRW) brings together PV reliability experts to share information, leading to the improvement of PV module reliability. Such improvement reduces the cost of solar electricity and promotes investor confidence in the technology - both critical goals for moving PV technologies deeper into the electricity marketplace.

  16. Space transportation main engine reliability and safety

    Science.gov (United States)

    Monk, Jan C.

    1991-01-01

    Viewgraphs are used to illustrate the reliability engineering and aerospace safety of the Space Transportation Main Engine (STME). A technology developed is called Total Quality Management (TQM). The goal is to develop a robust design. Reducing process variability produces a product with improved reliability and safety. Some engine system design characteristics are identified which improves reliability.

  17. Reliability models for Space Station power system

    Science.gov (United States)

    Singh, C.; Patton, A. D.; Kim, Y.; Wagner, H.

    1987-01-01

    This paper presents a methodology for the reliability evaluation of Space Station power system. The two options considered are the photovoltaic system and the solar dynamic system. Reliability models for both of these options are described along with the methodology for calculating the reliability indices.

  18. Monitoring Travel Time Reliability on Freeways

    NARCIS (Netherlands)

    Tu, Huizhao

    2008-01-01

    Travel time and travel time reliability are important attributes of a trip. The current measures of reliability have in common that in general they all relate to the variability of travel times. However, travel time reliability does not only rely on variability but also on the stability of travel

  19. 46 CFR 169.619 - Reliability.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Reliability. 169.619 Section 169.619 Shipping COAST... Electrical Steering Systems § 169.619 Reliability. (a) Except where the OCMI judges it impracticable, the... be below that necessary for the safe navigation of the vessel. (c) The strength and reliability of...

  20. Human reliability assessment in context

    International Nuclear Information System (INIS)

    Hollnagel, Erik

    2005-01-01

    Human Reliability Assessment (HRA) is conducted on the unspoken premise that 'human error' is a meaningful concept and that it can be associated with individual actions. The basis for this assumption it found in the origin of HRA, as a necessary extension of PSA to account for the impact of failures emanating from human actions. Although it was natural to model HRA on PSA, a large number of studies have shown that the premises are wrong, specifically that human and technological functions cannot be decomposed in the same manner. The general experience from accident studies also indicates that action failures are a function of the context, and that it is the variability of the context rather than the 'human error probability' that is the much sought for signal. Accepting this will have significant consequences for the way in which HRA, and ultimately also PSA, should be pursued