Academic literature on the topic 'Weighted Differences Method'
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Journal articles on the topic "Weighted Differences Method"
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Løseth, Lars O., Lasse Amundsen, and Arne J. Jenssen. "A solution to the airwave-removal problem in shallow-water marine EM." GEOPHYSICS 75, no. 5 (September 2010): A37—A42. http://dx.doi.org/10.1190/1.3475359.
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A new method is presented for removing the airwave in shallow-water electromagnetic (EM) data. By using pairs of receivers or pairs of source points along a towline and forming weighted differences of an EM field component, the airwave is significantly attenuated. The weights are related to the geometric spreading of the airwave. Specifically, the horizontal electric and magnetic field components are weighted with the horizontal offset to the power of three before their differences are calculated. One can also first calculate difference data without weights in the common-source domain to remove correlated noise and then use the resulting data to perform a second-order difference with weights. In this case, the weights should equal the horizontal offset to the power of four. Moreover, the weighted difference data can be integrated to obtain an estimate of the physical field void of the airwave. Additionally, the airwave contribution to the physical field can be estimated. The theory behind the method is presented and demonstrated on a real controlled-source EM (CSEM) data set.
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Setyawan, Agus, Florentina Yuni Arini, and Isa Akhlis. "Comparative Analysis of Simple Additive Weighting Method and Weighted Product Method to New Employee Recruitment Decision Support System (DSS) at PT. Warta Media Nusantara." Scientific Journal of Informatics 4, no. 1 (May 10, 2017): 34–42. http://dx.doi.org/10.15294/sji.v4i1.8458.
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Issue handling of inadvertence situations in the decision-making process of recruiting new employees at PT. Warta Media Nusantara that use criteria value of interviews, field test, a psychological test and medical check-up requires Multi Attribute Decision Making (MADM) as an auxiliary method of decision-making on the prospective eligible employee to be accepted in the company. There are various MADM methods, such as Simple Additive Weighting (SAW) method and Weighted Product (WP) method. Both of these methods are known as the most common method used in handling MADM issues, so in this study both methods are applied to the DSS and analyzed the differences in terms of obtained results and the execution time required for each method. The results of the study of the application of SAW and WP methods in the recruitment of new employees DSS there are some differences in the results of the candidates rank order and the differences in execution time of each method. The differences in rank order of these methods are due to the effects of alternative values, weighting criteria, and the calculation method. WP method is able to provide more rigorous result than SAW method, while the difference in execution time of SAW and WP methods explains that the execution time of SAW method relatively quick because SAW calculation method has a simpler process than the process of WP calculation methods
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Abolhasani Foroughi, Amin, Roohollah Salahi, Alireza Nikseresht, Hora Heidari, Masoume Nazeri, and Ali Khorsand. "Comparison of diffusion-weighted imaging and enhanced T1-weighted sequencing in patients with multiple sclerosis." Neuroradiology Journal 30, no. 4 (April 28, 2017): 347–51. http://dx.doi.org/10.1177/1971400916678224.
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Introduction The purpose of this study was to assess whether demographic, brain anatomical regions and contrast enhancement show differences in multiple sclerosis (MS) patients with increased diffusion lesions (ID group) compared with diffusion restriction (DR group). Method MRI protocol comprised T1- and T2-weighted sequences with and without gadolinium (Gd), and sagittal three-dimensional FLAIR sequence, DWI and ADC maps were prospectively performed in 126 MS patients from January to December 2015. The investigation was conducted to evaluate differences in demographic, cord and brain regional, technical, and positive or negative Gd contrast imaging parameters in two groups of ID and DR. Statistical analysis was performed by using SPSS. Results A total of 9.6% of patients showed DR. In the DR group, 66.6% of the patients showed contrast enhancement of plaques, whereas 29.2% of the IR group showed enhancement of plaques. The most prevalent group was non-enhanced plaques in the ID group, followed by Gd-enhanced plaques in the ID group. Patients in the ID group (90.4%) were significantly more than in the DR group (9.6%). Out of the 40 patients with Gd-enhanced plaques, 80.5% was from the ID group and 19.5% from the DR group. Conclusion MRI of the brain, unlike of the cord, with Gd demonstrates significant difference in enhancement between the two groups ( p < 0.05). No significant difference was seen in demographic, cord and brain regional, and technical parameters, EDSS, disease duration, and attack rate as well as demographic and regional parameters between the ID and decrease diffusion groups ( p > 0.05).
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Pusdiktasari, Zerlita Fahdha, Rahma Fitriani, and Eni Sumarminingsih. "An Improved Weighted Median Algorithm for Spatial Outliers Detection." ComTech: Computer, Mathematics and Engineering Applications 13, no. 2 (November 25, 2022): 111–21. http://dx.doi.org/10.21512/comtech.v13i2.7821.
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A spatial outlier is an object that significantly deviates from its surrounding neighbors. The median algorithm is one of the spatial outlier methods, which is robust. However, it assumes that all spatial objects have the same characteristics. Meanwhile, the Average Difference Algorithm (AvgDiff) has accommodated the differences in spatial characteristics, but it does not use statistical tests to determine the status of an object, whether it is an outlier or not. The research developed an improved version of the median algorithm and AvgDiff, called the Weighted Median Algorithm (WMA) which combined the advantages of the two methods. From the median algorithm, WMA adopted median and statistical test concepts. Meanwhile, from AvgDiff, WMA adopted the concept of using differences in objects’ spatial characteristics as weights. A combination of the two advantages was innovated by calculating WMA’s neighborhood score using a weighted median. Then, a simulation was conducted to analyze the accuracy of the method. The result confirms that when objects have heterogeneous spatial characteristics, WMA performs better than the median algorithm. The accuracy of WMA is not much higher than AvgDiff, but the use of WMA can prevent a serious false detection problem. The methods can be applied to an incidence rate of Covid-19 data in East Java.
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Shi, X., L. Lu, S. Yang, G. Huang, and Z. Zhao. "Object-oriented change detection based on weighted polarimetric scattering differences on POLSAR images." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-7/W4 (June 26, 2015): 149–54. http://dx.doi.org/10.5194/isprsarchives-xl-7-w4-149-2015.
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For wide application of change detection with SAR imagery, current processing technologies and methods are mostly based on pixels. It is difficult for pixel-based technologies to utilize spatial characteristics of images and topological relations of objects. Object-oriented technology takes objects as processing unit, which takes advantage of the shape and texture information of image. It can greatly improve the efficiency and reliability of change detection. Recently, with the development of polarimetric synthetic aperture radar (PolSAR), more backscattering features on different polarization state can be available for usage of object-oriented change detection study. In this paper, the object-oriented strategy will be employed. Considering the fact that the different target or target's state behaves different backscattering characteristics dependent on polarization state, an object-oriented change detection method that based on weighted polarimetric scattering difference of PolSAR images is proposed. The method operates on the objects generated by generalized statistical region merging (GSRM) segmentation processing. The merit of GSRM method is that image segmentation is executed on polarimetric coherence matrix, which takes full advantages of polarimetric backscattering features. And then, the measurement of polarimetric scattering difference is constructed by combining the correlation of covariance matrix and the difference of scattering power. Through analysing the effects of the covariance matrix correlation and the scattering echo power difference on the polarimetric scattering difference, the weighted method is used to balance the influences caused by the two parts, so that more reasonable weights can be chosen to decrease the false alarm rate. The effectiveness of the algorithm that proposed in this letter is tested by detection of the growth of crops with two different temporal radarsat-2 fully PolSAR data. First, objects are produced by GSRM algorithm based on the coherent matrix in the pre-processing. Then, the corresponding patches are extracted in two temporal images to measure the differences of objects. To detect changes of patches, a difference map is created by means of weighted polarization scattering difference. Finally, the result of change detection can be obtained by threshold determining. The experiments show that this approach is feasible and effective, and a reasonable choice of weights can improve the detection accuracy significantly.
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Zare, Mohsen, Maxime Norval, Julie Bodin, and Yves Roquelaure. "Differences between risk situations identified using a self-reported questionnaire and an observational method." Work 68, no. 3 (March 26, 2021): 759–69. http://dx.doi.org/10.3233/wor-203409.
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Background: This study investigates work-related musculoskeletal disorders risk estimation by frequently as used as ergonomic methods in the field. Objective: To identify the difference in risk estimation by an in-house observational method and a self-reported questionnaire, and to evaluate the complementary aspects of these methods. Methods: A sample of 15 operators who worked on the assembly workstations was selected from a truck manufacturing plant. The risk assessment of these workstations (28 scenarios) was performed by the observational method and the self-reported questionnaire. The agreement between both methods to identify risk situations was measured with the weighted Kappa coefficient. Results: The observational method and the self-reported questionnaire deployed on the same activity estimated different risk situations. Conclusion: This analysis does not reveal that one tool is more powerful than the other one, but shows the probability of different risk estimation. The complementary effect of each method might be considered for further investigation concerning musculoskeletal risk factors.
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Ashpreet and Mantosh Biswas. "Impulse Noise Detection and Removal Method Based on Modified Weighted Median." International Journal of Software Innovation 8, no. 2 (April 2020): 38–53. http://dx.doi.org/10.4018/ijsi.2020040103.
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Impulse noise generally occurs because of bit errors in progression of image acquisition and transmission. It is well known that median filtering method is an impulse noise removal method. Lots of modified median filters have been proposed in the last decades to improve the methods for noise suppression and detail preservation, which have their own deficiencies while identifying and restoring noise pixels. In this article, after deeply analyzing the reasons, such as decreased noise detection and noise removal accuracy that forms the basis of the deficiencies, this article proposes a modified weighted median filter method for color images corrupted by salt-and-pepper noise. In this method, a pixel is classified into either “noise free pixel” or “noise pixel” by checking the center pixel in the current filtering window with the extreme values (0 or 255) for an 8-bit image using noise detection step. Directional differences and the number of “good” pixels in the current filtering window modify the detected noise pixels. Simulation effects on considered test images reveal the proposed method to be improved over state-of-the-art de-noising methods in terms of PSNR and SSIM with pictorial comparative analysis.
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Salimi, Negin, and Jafar Rezaei. "Measuring efficiency of university-industry Ph.D. projects using best worst method." Scientometrics 109, no. 3 (September 17, 2016): 1911–38. http://dx.doi.org/10.1007/s11192-016-2121-0.
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AbstractA collaborative Ph.D. project, carried out by a doctoral candidate, is a type of collaboration between university and industry. Due to the importance of such projects, researchers have considered different ways to evaluate the success, with a focus on the outputs of these projects. However, what has been neglected is the other side of the coin—the inputs. The main aim of this study is to incorporate both the inputs and outputs of these projects into a more meaningful measure called efficiency. A ratio of the weighted sum of outputs over the weighted sum of inputs identifies the efficiency of a Ph.D. project. The weights of the inputs and outputs can be identified using a multi-criteria decision-making (MCDM) method. Data on inputs and outputs are collected from 51 Ph.D. candidates who graduated from Eindhoven University of Technology. The weights are identified using a new MCDM method called Best Worst Method (BWM). Because there may be differences in the opinion of Ph.D. candidates and supervisors on weighing the inputs and outputs, data for BWM are collected from both groups. It is interesting to see that there are differences in the level of efficiency from the two perspectives, because of the weight differences. Moreover, a comparison between the efficiency scores of these projects and their success scores reveals differences that may have significant implications. A sensitivity analysis divulges the most contributing inputs and outputs.
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Gipson, Geoffrey T., Kay S. Tatsuoka, Brian C. Sweatman, and Susan C. Connor. "Weighted least-squares deconvolution method for discovery of group differences between complex biofluid 1H NMR spectra." Journal of Magnetic Resonance 183, no. 2 (December 2006): 269–77. http://dx.doi.org/10.1016/j.jmr.2006.09.003.
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Baumann, Philipp Sebastian, Leila Cammoun, Philippe Conus, Kim Quang Do, Pierre Marquet, Djalel Meskaldji, Reto Meuli, Jean-Philippe Thiran, and Patric Hagmann. "High b-value diffusion-weighted imaging: A sensitive method to reveal white matter differences in schizophrenia." Psychiatry Research: Neuroimaging 201, no. 2 (February 2012): 144–51. http://dx.doi.org/10.1016/j.pscychresns.2011.08.003.
Full textDissertations / Theses on the topic "Weighted Differences Method"
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Böhme, Christian, Anton Holmberg, and Lind Martin Nilsson. "Numerical Analysis of the Two Dimensional Wave Equation : Using Weighted Finite Differences for Homogeneous and Hetrogeneous Media." Thesis, Uppsala universitet, Avdelningen för beräkningsvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-412798.
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This thesis discusses properties arising when finite differences are implemented forsolving the two dimensional wave equation on media with various properties. Both homogeneous and heterogeneous surfaces are considered. The time derivative of the wave equation is discretised using a weighted central difference scheme, dependenton a variable parameter gamma. Stability and convergence properties are studied forsome different values of gamma. The report furthermore features an introduction to solving large sparse linear systems of equations, using so-called multigrid methods.The linear systems emerge from the finite difference discretisation scheme. Aconclusion is drawn stating that values of gamma in the unconditionally stable region provides the best computational efficiency. This holds true as the multigrid based numerical solver exhibits optimal or near optimal scaling properties.
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Acharya, Arjun R. "Free energy differences : representations, estimators, and sampling strategies." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/602.
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In this thesis we examine methodologies for determining free energy differences (FEDs) of phases via Monte Carlo simulation. We identify and address three generic issues that arise in FED calculations; the choice of representation, the choice of estimator, and the choice of sampling strategy. In addition we discuss how the classical framework may be extended to take into account quantum effects. Key words: Phase Mapping, Phase Switch, Lattice Switch, Simulated Tempering, Multi-stage, Weighted Histogram Analysis Method, Fast Growth, Jarzynski method, Umbrella, Multicanonical, Path Integral Monte Carlo, Path Sampling, Multihamiltonian, fluctuation theorem.
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Meglicki, Zdzislaw, and Zdzislaw Meglicki [gustav@perth ovpit indiana edu]. "Analysis and Applications of Smoothed Particle Magnetohydrodynamics." The Australian National University. Research School of Physical Sciences, 1995. http://thesis.anu.edu.au./public/adt-ANU20080901.114053.
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Smoothed Particle Hydrodynamics (SPH) is analysed as the weighted residual method. In particular the analysis focuses on the collocation aspect of the method. Using Monte Carlo experiments we demonstrate that SPH is highly sensitive to node disorder, especially in its symmetrised energy and momentum conserving form. This aspect of the method is related to low [Beta] MHD instabilities observed by other authors. A remedy in the form of the Weighted Differences Method is suggested, which addresses this problem to some extent, but at a cost of losing automatic conservation of energy and momentum.
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The Weighted Differences Method is used to simulate propagation of Alfven and magnetosonic wave fronts in [Beta] = 0 plasma, and the results are compared with data obtained with the NCSA Zeus3D code with the Method of Characteristics (MOC) module.
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SPH is then applied to two interesting astrophysical situations: accretion on to a white dwarf in a compact binary system, which results in a formation of an accretion disk, and gravitational collapse of a magnetised vortex. Both models are 3 dimensional.
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The accretion disk which forms in the binary star model is characterised by turbulent flow: the Karman vortex street is observed behind the stream-disk interaction region. The shock that forms at the point of stream-disk interaction is controlled by the means of particle merges, whereas Monaghan-Lattanzio artificial viscosity is used to simulate Smagorinsky closure.
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The evolution of the collapsing magnetised vortex ends up in the formation of an expanding ring in the symmetry plane of the system. We observe the presence of spiralling inward motion towards the centre of attraction. That final state compares favourably with the observed qualitative and quantitative characteristics of the circumnuclear disk in the Galactic Centre. That simulation has also been verified with the NCSA Zeus3D run.
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In conclusions we contrast the result of our Monte Carlo experiments with the results delivered by our production runs. We also compare SPH and Weighted Differences against the new generation of conservative finite differences methods, such as the Godunov method and the Piecewise Parabolic Method. We conclude that although SPH cannot match the accuracy and performance of those methods, it appears to have some advantage in simulation of rotating flows, which are of special interest to astrophysics.
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Keele, John Wiliam. "Estimation of (co)variance components by weighted and unweighted symmetric differences squared, and selected MIVQUE's : relationships between methods and relative efficiencies /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487266011223482.
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Valenta, Václav. "Řešení parciálních diferenciálních rovnic s využitím aposteriorního odhadu chyby." Doctoral thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2016. http://www.nusl.cz/ntk/nusl-412549.
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This thesis deals with gradient calculation in triangulation nodes using weighted average of gradients of neighboring elements. This gradient is then used for a posteriori error estimation which produce better solution of partial differential equations. This work presents two common methods - Finite elements method and Finite difference method.
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Tsul, Pei Chun, and 崔培均. "The Differences Between Popolation Mean Weighted and Unweighted Estimates with Simulation Method in Sample Survey." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/06391446323415783337.
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碩士國立交通大學
管理科學研究所
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This Review of thesis is to disscuss the differences between population mean weighted and unweighted estimates with simulation method , which the population is constituent of Normal distribution , Uniform distribution and Gamma distribution. Provide management and statistical analysis degree members to understand ,it will be very dangerous when they misuse statisticalanalysis methods. In order to choice the proper statistical analysis methods , so we must know well the sample''s situation of theSurvey from beginningto end.
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Meglicki, Zdzislaw. "Analysis and Applications of Smoothed Particle Magnetohydrodynamics." Phd thesis, 1995. http://hdl.handle.net/1885/49346.
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Smoothed Particle Hydrodynamics (SPH) is analysed as the weighted residual method. In particular the analysis focuses on the collocation aspect of the method. Using Monte Carlo experiments we demonstrate that SPH is highly sensitive to node disorder, especially in its symmetrised energy and momentum conserving form. This aspect of the method is related to low [Beta] MHD instabilities observed by other authors. A remedy in the form of the Weighted Differences Method is suggested, which addresses this problem to some extent, but at a cost of losing automatic conservation of energy and momentum. ¶ The Weighted Differences Method is used to simulate propagation of Alfven and magnetosonic wave fronts in [Beta] = 0 plasma, and the results are compared with data obtained with the NCSA Zeus3D code with the Method of Characteristics (MOC) module. ¶ SPH is then applied to two interesting astrophysical situations: accretion on to a white dwarf in a compact binary system, which results in a formation of an accretion disk, and gravitational collapse of a magnetised vortex. Both models are 3 dimensional. ¶ ...
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Aydogdu, Elif Can. "Three dimensional heterogeneous finite element method for static multi‐group neutron diffusion." Thesis, 2010. http://hdl.handle.net/10155/116.
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Because current full‐core neutronic‐calculations use two‐group neutron diffusion and
rely on homogenizing fuel assemblies, reconstructing pin powers from such a calculation
is an elaborate and not very accurate process; one which becomes more difficult with
increased core heterogeneity. A three‐dimensional Heterogeneous Finite Element
Method (HFEM) is developed to address the limitations of current methods by offering
fine‐group energy representation and fuel‐pin‐level spatial detail at modest
computational cost. The calculational cost of the method is roughly equal to the
calculational cost of the Finite Differences Method (FDM) using one mesh box per fuel
assembly and a comparable number of energy groups. Pin‐level fluxes are directly
obtained from the method’s results without the need for reconstruction schemes.UOIT
Books on the topic "Weighted Differences Method"
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Allen, Michael P., and Dominic J. Tildesley. Advanced Monte Carlo methods. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198803195.003.0009.
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This chapter describes the ways in which the Monte Carlo importance sampling method may be adapted to improve the calculation of ensemble averages, particularly those associated with free energy differences. These approaches include umbrella sampling, non-Boltzmann sampling, the Wang–Landau method, and nested sampling. In addition, a range of special techniques have been developed to accelerate the simulation of flexible molecules, such as polymers. These approaches are illustrated with scientific examples and program code. The chapter also explains the analysis of such simulations using techniques such as weighted histograms, and acceptance ratio calculations. Practical advice on selection of methods, parameters, and the direction in which to make comparisons, are given. Monte Carlo methods for modelling phase equilibria and chemical reactions at equilibrium are described.
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Chang-Qing, Hu, Shu Chi-Wang, and Institute for Computer Applications in Science and Engineering., eds. A technique of treating negative weights in WENO schemes. Hampton, VA: Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 2000.
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Levin, Ines, and Betsy Sinclair. Causal Inference with Complex Survey Designs. Edited by Lonna Rae Atkeson and R. Michael Alvarez. Oxford University Press, 2016. http://dx.doi.org/10.1093/oxfordhb/9780190213299.013.4.
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This article discusses methods that combine survey weighting and propensity score matching to estimate population average treatment effects. Beginning with an overview of causal inference techniques that incorporate data from complex surveys and the usefulness of survey weights, it then considers approaches for incorporating survey weights into three matching algorithms, along with their respective methodologies: nearest-neighbor matching, subclassification matching, and propensity score weighting. It also presents the results of a Monte Carlo simulation study that illustrates the benefits of incorporating survey weights into propensity score matching procedures, as well as the problems that arise when survey weights are ignored. Finally, it explores the differences between population-based inferences and sample-based inferences using real-world data from the 2012 panel of The American Panel Survey (TAPS). The article highlights the impact of social media usage on political participation, when such impact is not actually apparent in the target population.
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Gow, James, and Benedict Wilkinson. Introduction. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190851163.003.0001.
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Freedman is a figure of significant distinction; who has had real world influence, yet whose theoretical depth and development has been largely overlooked. Is there anything distinctive in Freedman’s approach, or even the roots of a school of thought? How can we make sense of the extensive and diverse record, and can we bring coherence to it? Is there a common thread running through it? How far does it have theoretical weight? Is there something more than chance and personality involved? How can we make sense of this record of conducting and supporting research that makes a difference in a way that also suggests coherence and a scholarly identity? Has a distinctive working method – a school of thought – emerged around ‘war studies’, without actually being given a name, under the leading influence of Freedman for thirty years? This is the challenge outlined in this chapter and the volume it introduces.
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Skiba, Grzegorz. Fizjologiczne, żywieniowe i genetyczne uwarunkowania właściwości kości rosnących świń. The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 2020. http://dx.doi.org/10.22358/mono_gs_2020.
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Bones are multifunctional passive organs of movement that supports soft tissue and directly attached muscles. They also protect internal organs and are a reserve of calcium, phosphorus and magnesium. Each bone is covered with periosteum, and the adjacent bone surfaces are covered by articular cartilage. Histologically, the bone is an organ composed of many different tissues. The main component is bone tissue (cortical and spongy) composed of a set of bone cells and intercellular substance (mineral and organic), it also contains fat, hematopoietic (bone marrow) and cartilaginous tissue. Bones are a tissue that even in adult life retains the ability to change shape and structure depending on changes in their mechanical and hormonal environment, as well as self-renewal and repair capabilities. This process is called bone turnover. The basic processes of bone turnover are: • bone modeling (incessantly changes in bone shape during individual growth) following resorption and tissue formation at various locations (e.g. bone marrow formation) to increase mass and skeletal morphology. This process occurs in the bones of growing individuals and stops after reaching puberty • bone remodeling (processes involve in maintaining bone tissue by resorbing and replacing old bone tissue with new tissue in the same place, e.g. repairing micro fractures). It is a process involving the removal and internal remodeling of existing bone and is responsible for maintaining tissue mass and architecture of mature bones. Bone turnover is regulated by two types of transformation: • osteoclastogenesis, i.e. formation of cells responsible for bone resorption • osteoblastogenesis, i.e. formation of cells responsible for bone formation (bone matrix synthesis and mineralization) Bone maturity can be defined as the completion of basic structural development and mineralization leading to maximum mass and optimal mechanical strength. The highest rate of increase in pig bone mass is observed in the first twelve weeks after birth. This period of growth is considered crucial for optimizing the growth of the skeleton of pigs, because the degree of bone mineralization in later life stages (adulthood) depends largely on the amount of bone minerals accumulated in the early stages of their growth. The development of the technique allows to determine the condition of the skeletal system (or individual bones) in living animals by methods used in human medicine, or after their slaughter. For in vivo determination of bone properties, Abstract 10 double energy X-ray absorptiometry or computed tomography scanning techniques are used. Both methods allow the quantification of mineral content and bone mineral density. The most important property from a practical point of view is the bone’s bending strength, which is directly determined by the maximum bending force. The most important factors affecting bone strength are: • age (growth period), • gender and the associated hormonal balance, • genotype and modification of genes responsible for bone growth • chemical composition of the body (protein and fat content, and the proportion between these components), • physical activity and related bone load, • nutritional factors: – protein intake influencing synthesis of organic matrix of bone, – content of minerals in the feed (CA, P, Zn, Ca/P, Mg, Mn, Na, Cl, K, Cu ratio) influencing synthesis of the inorganic matrix of bone, – mineral/protein ratio in the diet (Ca/protein, P/protein, Zn/protein) – feed energy concentration, – energy source (content of saturated fatty acids - SFA, content of polyun saturated fatty acids - PUFA, in particular ALA, EPA, DPA, DHA), – feed additives, in particular: enzymes (e.g. phytase releasing of minerals bounded in phytin complexes), probiotics and prebiotics (e.g. inulin improving the function of the digestive tract by increasing absorption of nutrients), – vitamin content that regulate metabolism and biochemical changes occurring in bone tissue (e.g. vitamin D3, B6, C and K). This study was based on the results of research experiments from available literature, and studies on growing pigs carried out at the Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences. The tests were performed in total on 300 pigs of Duroc, Pietrain, Puławska breeds, line 990 and hybrids (Great White × Duroc, Great White × Landrace), PIC pigs, slaughtered at different body weight during the growth period from 15 to 130 kg. Bones for biomechanical tests were collected after slaughter from each pig. Their length, mass and volume were determined. Based on these measurements, the specific weight (density, g/cm3) was calculated. Then each bone was cut in the middle of the shaft and the outer and inner diameters were measured both horizontally and vertically. Based on these measurements, the following indicators were calculated: • cortical thickness, • cortical surface, • cortical index. Abstract 11 Bone strength was tested by a three-point bending test. The obtained data enabled the determination of: • bending force (the magnitude of the maximum force at which disintegration and disruption of bone structure occurs), • strength (the amount of maximum force needed to break/crack of bone), • stiffness (quotient of the force acting on the bone and the amount of displacement occurring under the influence of this force). Investigation of changes in physical and biomechanical features of bones during growth was performed on pigs of the synthetic 990 line growing from 15 to 130 kg body weight. The animals were slaughtered successively at a body weight of 15, 30, 40, 50, 70, 90, 110 and 130 kg. After slaughter, the following bones were separated from the right half-carcass: humerus, 3rd and 4th metatarsal bone, femur, tibia and fibula as well as 3rd and 4th metatarsal bone. The features of bones were determined using methods described in the methodology. Describing bone growth with the Gompertz equation, it was found that the earliest slowdown of bone growth curve was observed for metacarpal and metatarsal bones. This means that these bones matured the most quickly. The established data also indicate that the rib is the slowest maturing bone. The femur, humerus, tibia and fibula were between the values of these features for the metatarsal, metacarpal and rib bones. The rate of increase in bone mass and length differed significantly between the examined bones, but in all cases it was lower (coefficient b <1) than the growth rate of the whole body of the animal. The fastest growth rate was estimated for the rib mass (coefficient b = 0.93). Among the long bones, the humerus (coefficient b = 0.81) was characterized by the fastest rate of weight gain, however femur the smallest (coefficient b = 0.71). The lowest rate of bone mass increase was observed in the foot bones, with the metacarpal bones having a slightly higher value of coefficient b than the metatarsal bones (0.67 vs 0.62). The third bone had a lower growth rate than the fourth bone, regardless of whether they were metatarsal or metacarpal. The value of the bending force increased as the animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. The rate of change in the value of this indicator increased at a similar rate as the body weight changes of the animals in the case of the fibula and the fourth metacarpal bone (b value = 0.98), and more slowly in the case of the metatarsal bone, the third metacarpal bone, and the tibia bone (values of the b ratio 0.81–0.85), and the slowest femur, humerus and rib (value of b = 0.60–0.66). Bone stiffness increased as animals grew. Regardless of the growth point tested, the highest values were observed for the humerus, tibia and femur, smaller for the metatarsal and metacarpal bone, and the lowest for the fibula and rib. Abstract 12 The rate of change in the value of this indicator changed at a faster rate than the increase in weight of pigs in the case of metacarpal and metatarsal bones (coefficient b = 1.01–1.22), slightly slower in the case of fibula (coefficient b = 0.92), definitely slower in the case of the tibia (b = 0.73), ribs (b = 0.66), femur (b = 0.59) and humerus (b = 0.50). Bone strength increased as animals grew. Regardless of the growth point tested, bone strength was as follows femur > tibia > humerus > 4 metacarpal> 3 metacarpal> 3 metatarsal > 4 metatarsal > rib> fibula. The rate of increase in strength of all examined bones was greater than the rate of weight gain of pigs (value of the coefficient b = 2.04–3.26). As the animals grew, the bone density increased. However, the growth rate of this indicator for the majority of bones was slower than the rate of weight gain (the value of the coefficient b ranged from 0.37 – humerus to 0.84 – fibula). The exception was the rib, whose density increased at a similar pace increasing the body weight of animals (value of the coefficient b = 0.97). The study on the influence of the breed and the feeding intensity on bone characteristics (physical and biomechanical) was performed on pigs of the breeds Duroc, Pietrain, and synthetic 990 during a growth period of 15 to 70 kg body weight. Animals were fed ad libitum or dosed system. After slaughter at a body weight of 70 kg, three bones were taken from the right half-carcass: femur, three metatarsal, and three metacarpal and subjected to the determinations described in the methodology. The weight of bones of animals fed aa libitum was significantly lower than in pigs fed restrictively All bones of Duroc breed were significantly heavier and longer than Pietrain and 990 pig bones. The average values of bending force for the examined bones took the following order: III metatarsal bone (63.5 kg) <III metacarpal bone (77.9 kg) <femur (271.5 kg). The feeding system and breed of pigs had no significant effect on the value of this indicator. The average values of the bones strength took the following order: III metatarsal bone (92.6 kg) <III metacarpal (107.2 kg) <femur (353.1 kg). Feeding intensity and breed of animals had no significant effect on the value of this feature of the bones tested. The average bone density took the following order: femur (1.23 g/cm3) <III metatarsal bone (1.26 g/cm3) <III metacarpal bone (1.34 g / cm3). The density of bones of animals fed aa libitum was higher (P<0.01) than in animals fed with a dosing system. The density of examined bones within the breeds took the following order: Pietrain race> line 990> Duroc race. The differences between the “extreme” breeds were: 7.2% (III metatarsal bone), 8.3% (III metacarpal bone), 8.4% (femur). Abstract 13 The average bone stiffness took the following order: III metatarsal bone (35.1 kg/mm) <III metacarpus (41.5 kg/mm) <femur (60.5 kg/mm). This indicator did not differ between the groups of pigs fed at different intensity, except for the metacarpal bone, which was more stiffer in pigs fed aa libitum (P<0.05). The femur of animals fed ad libitum showed a tendency (P<0.09) to be more stiffer and a force of 4.5 kg required for its displacement by 1 mm. Breed differences in stiffness were found for the femur (P <0.05) and III metacarpal bone (P <0.05). For femur, the highest value of this indicator was found in Pietrain pigs (64.5 kg/mm), lower in pigs of 990 line (61.6 kg/mm) and the lowest in Duroc pigs (55.3 kg/mm). In turn, the 3rd metacarpal bone of Duroc and Pietrain pigs had similar stiffness (39.0 and 40.0 kg/mm respectively) and was smaller than that of line 990 pigs (45.4 kg/mm). The thickness of the cortical bone layer took the following order: III metatarsal bone (2.25 mm) <III metacarpal bone (2.41 mm) <femur (5.12 mm). The feeding system did not affect this indicator. Breed differences (P <0.05) for this trait were found only for the femur bone: Duroc (5.42 mm)> line 990 (5.13 mm)> Pietrain (4.81 mm). The cross sectional area of the examined bones was arranged in the following order: III metatarsal bone (84 mm2) <III metacarpal bone (90 mm2) <femur (286 mm2). The feeding system had no effect on the value of this bone trait, with the exception of the femur, which in animals fed the dosing system was 4.7% higher (P<0.05) than in pigs fed ad libitum. Breed differences (P<0.01) in the coross sectional area were found only in femur and III metatarsal bone. The value of this indicator was the highest in Duroc pigs, lower in 990 animals and the lowest in Pietrain pigs. The cortical index of individual bones was in the following order: III metatarsal bone (31.86) <III metacarpal bone (33.86) <femur (44.75). However, its value did not significantly depend on the intensity of feeding or the breed of pigs.
Book chapters on the topic "Weighted Differences Method"
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Zou, Junping, and Jiexian Wang. "Real-Time Estimation of GPS Satellite Clock Errors and Its Precise Point Positioning Performance." In Proceeding of 2021 International Conference on Wireless Communications, Networking and Applications, 823–30. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-19-2456-9_83.
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AbstractThe current stochastic model in GNSS processing is constructed based on the prior experience, for example the ratio of the weight of the pseudorange and phase observations is generally determined as 1:10000. These methods ignore the precision differences of the different GNSS receivers and observation space. In this paper, the standard deviation of differenced ionosphere-free pseudorange and phase observations is computed with dual-frequency observations and then the weight ratio of the pseudorange and phase observations is obtained using the computed standard deviation. This method is introduced in satellite clock estimating and the data is processed. The results show that the presented method is feasible, with which the accuracy of the estimated satellite clock results is improved. The estimated satellite clock results are further adopted in PPP and the positioning results of the 10 users validate that the estimated satellite clock, which uses the presented method, can accelerate the convergence of PPP compared with the traditional method.
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Zafar, Fiza, Alicia Cordero, and Juan Ramon Torregrosa. "A Family of Optimal Eighth Order Multiple Root Finders with Multivariate Weight Function." In Finite Difference Methods. Theory and Applications, 663–69. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-11539-5_78.
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Baeza, A., P. Mulet, and D. Zorío. "Weighted Extrapolation Techniques for Finite Difference Methods on Complex Domains with Cartesian Meshes." In SEMA SIMAI Springer Series, 243–59. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-32013-7_14.
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Makarov, V. L., and L. I. Demkiv. "Weight Uniform Accuracy Estimates of Finite Difference Method for Poisson Equation, Taking into Account Boundary Effect." In Lecture Notes in Computer Science, 92–103. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-00464-3_9.
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He, Zhanbo, Huiqiang Wang, Junyu Lin, Guangsheng Feng, Hongwu Lv, and Yibing Hu. "An Availability Evaluation Method of Web Services Using Improved Grey Correlation Analysis with Entropy Difference and Weight." In Communications in Computer and Information Science, 300–308. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-46248-5_37.
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Ludwig, R., T. K. D. Nguyen, H. Higuchi, and J. Henniger. "Modeling the transport of low molecular weight metal complexes across the liquid–liquid interface during extraction in a synthetic boundary cell by using the finite differences method." In Analytical Ultracentrifugation VII, 89–97. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/b98018.
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Bandera, Elisa V., Chi-Chen Hong, and Bo Qin. "Impact of Obesity and Related Factors in Breast Cancer Survivorship Among Hispanic Women." In Advancing the Science of Cancer in Latinos, 163–76. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-14436-3_14.
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AbstractBreast cancer is the leading cause of death among Hispanic women. The number of Hispanic breast cancer survivors is increasing because the US Hispanic population is fast-growing and breast cancer survival is improving. However, this vulnerable population has received little attention. Obesity and weight gain affect Hispanic and African American/Black women disproportionately. Obesity affects several factors relevant to cancer survivorship, including cancer treatment and patient-reported outcomes such as health-related quality of life (QoL). As a first step toward addressing these issues, a pilot study was conducted to assess the feasibility of assembling a cohort of Hispanic breast cancer survivors in New Jersey. Methods were similar to those used in the ongoing Women’s Circle of Health Follow-Up Study, a cohort of African American/Black breast cancer survivors in New Jersey. Hispanic breast cancer survivors were very interested and willing to participate. There were interesting differences in body mass index and central adiposity between Hispanic and African American/Black breast cancer survivors, but both groups had a high prevalence of body fatness and comorbidities. Hispanic breast cancer survivors had lower QoL, particularly obese women. More research is needed to understand survivorship needs in minority and medically underserved women after a breast cancer diagnosis.
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Yang, Wei-Jong, Cheng-Yu Lo, Pau-Choo Chung, and Jar Ferr Yang. "Weighted Module Linear Regression Classifications for Partially-Occluded Face Recognition." In Digital Image Processing - Advances and Applications [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.100621.
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Face images with partially-occluded areas create huge deteriorated problems for face recognition systems. Linear regression classification (LRC) is a simple and powerful approach for face recognition, of course, it cannot perform well under occlusion situations as well. By segmenting the face image into small subfaces, called modules, the LRC system could achieve some improvements by selecting the best non-occluded module for face classification. However, the recognition performance will be deteriorated due to the usage of the module, a small portion of the face image. We could further enhance the performance if we can properly identify the occluded modules and utilize all the non-occluded modules as many as possible. In this chapter, we first analyze the texture histogram (TH) of the module and then use the HT difference to measure its occlusion tendency. Thus, based on TH difference, we suggest a general concept of the weighted module face recognition to solve the occlusion problem. Thus, the weighted module linear regression classification method, called WMLRC-TH, is proposed for partially-occluded fact recognition. To evaluate the performances, the proposed WMLRC-TH method, which is tested on AR and FRGC2.0 face databases with several synthesized occlusions, is compared to the well-known face recognition methods and other robust face recognition methods. Experimental results show that the proposed method achieves the best performance for recognize occluded faces. Due to its simplicity in both training and testing phases, a face recognition system based on the WMLRC-TH method is realized on Android phones for fast recognition of occluded faces.
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Pereira, Rex Eugene. "Turning Browsers into Buyers." In Internet Marketing Research, 108–49. IGI Global, 2001. http://dx.doi.org/10.4018/978-1-878289-97-1.ch007.
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The chapter investigates the interaction effects between the search strategy of software agents and the consumer’s product class knowledge in the context of consumers seeking to purchase cars on the Internet. The research design used was a 2 x 4, between groups, completely randomized, two-factor, factorial design. The independent variables which were manipulated were product class knowledge (HIGH KNOWLEDGE, LOW KNOWLEDGE) and agent search strategy (elimination by aspects (EBA STRATEGY), weighted average method (WAD STRATEGY), profile building (PROFILE STRATEGY), simple hypertext (HYPERTEXT STRATEGY)). The dependent variables which were measured were satisfaction with the decision process (SATISFACTION), confidence in the decision (CONFIDENCE), trust in the agent’s recommendations (TRUST), propensity to purchase (PURCHASE), perceived cost savings (SAVINGS), and cognitive decision effort (EFFORT). Significant differences were found in the affective reactions of the subjects toward the agent/application depending on the level of product class knowledge possessed by the subjects. Subjects with high product class knowledge had more positive affective reactions towards agents/applications which used the WAD and EBA strategies as compared to the PROFILE strategy. Subjects with low product class knowledge had more positive affective reactions to agents/applications which used the PROFILE strategy as compared to the EBA and WAD strategies. When the systems were modified to increase the amount of information provided and to increase the degree of control provided to the subjects, their affective reactions to the agents/applications were found to be different from the original study. Subjects responded more positively to the previously “less preferred” strategy, thus weakening the interaction effect.
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FORNBERG, BENGT. "FAST GENERATION OF WEIGHTS IN FINITE DIFFERENCE FORMULAS." In Recent Developments in Numerical Methods and Software for ODEs/DAEs/PDEs, 97–123. WORLD SCIENTIFIC, 1992. http://dx.doi.org/10.1142/9789814335867_0006.
Full textConference papers on the topic "Weighted Differences Method"
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Hewamulla, K., HS Jayasena, and K. Guruge. "The impact of procurement method on construction time waste." In 10th World Construction Symposium. Building Economics and Management Research Unit (BEMRU), University of Moratuwa, 2022. http://dx.doi.org/10.31705/wcs.2022.73.
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Selection of the most appropriate procurement method for a proposed project is challenging because there are many factors to be evaluated in deciding. This study focuses on the impact of procurement method on construction time waste, and it was conducted to find how the time wastage varies according to the selected procurement route. Such knowledge is important in making better decisions when selecting a procurement method. Accordingly, the research aim was set to find the significant differences of time waste between traditional and design and build procurement methods. this research was conducted from a quantitative approach, deductive theory data collected through an online survey, and for data analysis using descriptive statistics. Twenty-two (22) number of time waste factors were identified through literature review. survey respondents weighted the significance of each factor between traditional and design and build procurement methods. Ten (10) factors caused significantly higher time waste in traditional method and none of the factors caused higher time waste in design and build method. Accordingly, the study concludes that time waste in traditional procurement is generally higher in traditional procurement method compared to design and build procurement method.
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Brown, Stephanie, and K. Blake Mitchell. "Development of a Fundamental and Operational Marksmanship Score based on Expert and Novice Marksmanship Data." In 13th International Conference on Applied Human Factors and Ergonomics (AHFE 2022). AHFE International, 2022. http://dx.doi.org/10.54941/ahfe1002425.
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Marksmanship is a primary contributor to the military’s quantification of Soldier lethality. Traditionally, Soldiers are graded using a standard marksmanship qualification task, assessing hit location and target distance. Additional components (e.g., weapon handling, timing) are not incorporated. This research developed a comprehensive marksmanship scoring method, focused on fundamental and operational marksmanship skills. A scoring index facilitates the understanding of the entire operational marksmanship process, from target detection to acquisition/engagement. Analysis of this tradespace helps improve training and can be utilized as a metric of performance for equipment evaluations. This novel scoring method includes all aspects of the marksmanship process divided into three components, including lethality (e.g., accuracy, precision, decision making), mobility (e.g., target acquisition time), and weapons handling (e.g., stability, trigger control). Utilizing marksmanship data from 16 Soldier volunteers (8 experts and 8 novices) on a static and dynamic shooting scenario, outcomes were normalized to distribute the variables’ two anchor scores. Weights were assigned to each metric that contributed to the combined scores. Weightings were determined utilizing a Student’s t-test pairwise comparison of means of the expert and novice scores for each metric. Components with highly statistically significant differences (p < .01) between the expert and novice were weighted more importantly and those with less difference (p < .05) were weighted less importantly. Weighted indices were applied to a marksmanship dataset of normally distributed skill level Infantry Soldiers (N = 46). This verification ensured that weightings created a normal distribution across the group, while assessing fundamentals and operational marksmanship skills. These new performance indices provide a single overarching score, representative of various aspects of marksmanship beyond simple shot coordinates, resulting in a performance metric that is easier for the end-user to comprehend. Future application of this scoring method are valuable for both training and acquisition test and evaluation performance assessments.
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Li, Wei, Tianzhao Yang, Xiao Wu, and Zhaoquan Yuan. "Learning Graph-based Residual Aggregation Network for Group Activity Recognition." In Thirty-First International Joint Conference on Artificial Intelligence {IJCAI-22}. California: International Joint Conferences on Artificial Intelligence Organization, 2022. http://dx.doi.org/10.24963/ijcai.2022/154.
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Group activity recognition aims to understand the overall behavior performed by a group of people. Recently, some graph-based methods have made progress by learning the relation graphs among multiple persons. However, the differences between an individual and others play an important role in identifying confusable group activities, which have not been elaborately explored by previous methods. In this paper, a novel Graph-based Residual AggregatIon Network (GRAIN) is proposed to model the differences among all persons of the whole group, which is end-to-end trainable. Specifically, a new local residual relation module is explicitly proposed to capture the local spatiotemporal differences of relevant persons, which is further combined with the multi-graph relation networks. Moreover, a weighted aggregation strategy is devised to adaptively select multi-level spatiotemporal features from the appearance-level information to high level relations. Finally, our model is capable of extracting a comprehensive representation and inferring the group activity in an end-to-end manner. The experimental results on two popular benchmarks for group activity recognition clearly demonstrate the superior performance of our method in comparison with the state-of-the-art methods.
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Tikhonov, Vadim S., Alexander I. Safronov, and Mikhail Ya Gelfgat. "Method of Dynamic Analysis for Rod-in-Hole Buckling." In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95059.
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The problem of a postbuckling dynamic behavior of weighted rod, which is inserted into an arbitrary profile hole with some clearance, under the axial compression load is considered. In practice, this analysis is important for calculation of the friction drag of the drillstring in inclined and horizontal wellbores. The mathematical model and numerical method of the rod-in-hole contact interaction are developed. The contact model is based on a nonlinear dependence of the normal-directed contact force on the depth of interpenetration of rod in hole. The tangential interaction of bodies with the contact surfaces is described using a model of “elastic-plastic” friction. The developed system of substantially nonlinear differential equations with partial derivatives of 3-D rod dynamics is approximated by the finite differences and integrated by the Runge-Kutta method. A simplified model for axial motion of rod is suggested to make the process of numerical integration faster. The results of numerical simulation of stress-deformed state of rod in horizontal, inclined and curved holes are presented. The results of numerical simulation are compared with the results of experiment. The effect of the friction factor on the rod buckling has been studied. The effect of local outside bulges of the drillstring on a postbuckling behavior of the drillstring is considered.
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Fenglin Wang, Qingfang Meng, Hong-Bo Xie, and Yuehui Chen. "Novel feature extraction method based on weight difference of weighted network for epileptic seizure detection." In 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2014. http://dx.doi.org/10.1109/embc.2014.6944317.
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Hu, Qingwei, Yanbin Xu, Ziqi Liu, Changbin Li, and Feng Dong. "Multiple Weighted Frequency-difference Method for Electrical Impedance Tomography." In 2021 IEEE International Instrumentation and Measurement Technology Conference (I2MTC). IEEE, 2021. http://dx.doi.org/10.1109/i2mtc50364.2021.9459818.
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Mann, Jonathan, Chris Currie, Jennifer Borg, and Norman Platts. "Further Development of Fatigue Crack Growth Expressions for Austenitic Stainless Steels in PWR Water and Additional Validation of the WTKR Method." In ASME 2020 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/pvp2020-21585.
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Abstract The primary water environment in a Pressurised Water Reactor (PWR) can have a significantly detrimental effect on the Fatigue Crack Growth (FCG) rates of Austenitic Stainless Steels. Expressions to describe FCG in these materials are provided in ASME Code Case N-809, which was based on results from tests performed under isothermal, simple waveform loading. A previous re-analysis of a much larger database of FCG results highlighted improvements to the N-809 model for nominally low carbon material grades. For non-isothermal and/or complex mechanical loading conditions, further improvements of the prediction of FCG rates were demonstrated by using the Weighted Temperature and K-Rate (WTKR) method. The combined use of improved FCG expressions and the WTKR method is expected to provide significant reductions in over-conservatism when used to assess plant-realistic loading transients. This paper describes the further development of revised expressions to describe the effect of PWR environments on FCG in austenitic stainless steels. The analysis is extended to a wider range of different types of stainless steel, including nominally high carbon 304 variants and 316-type materials. The analysis highlights that previously specified differences in FCG behaviour between nominally low and high carbon materials are minimal, and that 316-type materials exhibit improved performance in these environments. Further testing has also been performed using non-isothermal and complex waveform loading conditions, and these results are used as additional validation of the WTKR methodology.
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Lang, Fred D., and Tom Canning. "Determining HP-IP Turbine Seal Leakage." In ASME 2010 Power Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/power2010-27252.
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This paper presents a new method for determining turbine shaft seal leakages. Specifically the seals are those which flow from the High Pressure (HP) turbine to the Intermediate Pressure (IP) turbine when these machines share the same cylinder. This work began with the well-known Booth/Kautzmann Method, also known as an “Influence Test”. The work was instigated given that routine success of Booth/Kautzmann has not always been assured. This work promotes two major modifications. First, an improvement is advocated in which the contribution from seal flows is weighted based on source energies; i.e., use of a strictly defined thermodynamic boundary. This applies to isentropes and exergy differences. However, the use of weighted isentropes does not guarantee that Booth/Kautzmann will always work. Second, the use of a convergence parameter is advocated which normalizes the influence of differing Reheat flows. This convergence parameter leads to a consistently computed seal flow which is quite suitable for routine monitoring. The new technique has a remarkable ability to detect inconsistent data. Four case studies are presented: two conventional North American designs in which the HP seal is placed between the Governing Stage shell and 2nd HP stage group (termed the “Dummy Seal” or “N2 Packing” leakage); and two European designs in which the HP seal is exposed to turbine inlet conditions. Although several of these studies produced sharp convergences using Booth/ Kautzmann with weighted isentropes, this work places doubt on their reliability. Comments are offered on the technique’s use, data reduction procedures and on further development. A sample spreadsheet has been made available for use by power engineers.
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Hadady, Hanieh, Sage R. Hiibel, Doug Redelman, and Emil J. Geiger. "Use of a Separability Parameter for the Design of a High Frequency Dielectrophoresis Cell Sorter Device." In ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels collocated with the ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/icnmm2015-48528.
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We present a method to quantify and enhance separation of binary cells mixture in the microfluidic device using high frequency dielectrophoresis (>20 MHz). At these frequencies, the DEP response depends primarily on the dielectric properties of the cytoplasm. In order to achieve efficient separation, there must be a difference in the intrinsic dielectric properties of the populations to be sorted. For algae cells, the shift in high frequency dielectrophoresis response during lipid accumulation can be used as a basis of separation. We defined a separability parameter based on the expected difference in the dielectrophoresis responses of the algae cells. Chlamydomonas reinhardtii cells were cultured in regular media and then the same cells were cultured under nitrogenfree conditions to accumulate neutral (non-polar) lipids. Separability of microalgae cells with different lipid content via high frequency dielectrophoresis were investigated by a thin needle shaped electrodes patterned by standard photolithographic and wet etching procedures. Experimental separability factors were measured by estimation of relative lipid content with BODIPY 505/515 fluorescence dye and calculating the area-weighted intensity average of fluorescent images. Theoretical separability parameter was calculated using analytical analysis of single shell model by MATLAB. Theoretical and experimental separability parameters, as tools to determine the optimal separation method, were calculated for microalgae cells with different lipid content. This objective function was maximized in the range of 35–45 MHz for C. reinhardtii cells after 21 days of lipid accumulation in a static separation. In order to design a continuous cell sorter device, the theoretical separation factor was maximized based on differences in the magnitude or the direction of the DEP force.
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Currie, Chris, Andrew Morley, Norman Platts, Marius Twite, and Keith Wright. "Models for Calculating the Effect of Environment on Fatigue Life (Fen) for Complex Waveforms and/or Non-Isothermal Conditions." In ASME 2017 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/pvp2017-66030.
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Environmentally assisted fatigue of nuclear plant materials in the Pressurised Water Reactor (PWR) coolant environment is a phenomenon that has been extensively studied over the past 30 years. Methods for accounting for the PWR environment in an ASME III fatigue assessment are presented in NUREG/CR-6909. The deleterious effect of environment is described through a Fen factor dependent upon strain rate, temperature and the dissolved oxygen content of the water. The formulae which describe the Fen are based upon correlations observed in test data predominantly from tests conducted with constant temperature and strain rate (triangular or sawtooth loading). Actual loading histories encountered during service are far more complex, with both strain rate and temperature, and therefore Fen, varying through the cycle. NUREG/CR-6909 recommends a modified rate approach method for accounting for this, whereby the load cycle is broken up into a number of strain increments and then integrated to give the Fen for the cycle. There is a substantial and growing body of data for conditions in which the strain rate or temperature or both changes. The NUREG/CR-6909 modified rate approach does not generally perform well in describing the deleterious effect of environment in these complex conditions. In particular, the modified rate approach does not predict a difference in life when the temperature is varied in-phase or out-of-phase with the strain waveform, or when the slow portion of the strain rate is moved from the top to the bottom of the waveform. This paper presents new data from strain-controlled fatigue endurance testing of two casts of 304L with complex waveforms and temperature cycling. The paper then presents and compares a number of models for integrating the Fen through the cycle, including methods which weight Fen increments depending on position in the strain cycle. It is concluded that greater weighting on the environmental effect in the top of the cycle is necessary to describe the differences in life observed. This is further validated by a review of test data in the wider literature. An improved method is presented to account for the effects of the PWR environment on fatigue lives of austenitic stainless steel materials, which has similarities to the “Weighted K Rate” method previously presented by Rolls-Royce, PVP2016-63497, for environmentally assisted fatigue crack growth.
Reports on the topic "Weighted Differences Method"
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David, Gabrielle C. L., Patrick H. Trier, Ken M. Fritz, Steven L. Kichefski, Tracie-Lynn Nadeau, L. Allan James, Brian J. Topping, Wohl Ellen E., and Aaron Allen. National Ordinary High Water Mark Field Delineation Manual for Rivers and Streams : Interim Version. U.S. Army Engineer Reseach and Development Center, November 2022. http://dx.doi.org/10.21079/11681/46102.
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The ordinary high water mark (OHWM) defines the lateral extent of nontidal aquatic features in the absence of adjacent wetlands in the United States. The federal regulatory definition of the OHWM, 33 CFR 328.3(c)(7), states the OHWM is “that line on the shore established by the fluctuations of water and indicated by physical characteristics such as [a] clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.” This is the first manual to present a methodology for nationwide identification and delineation of the OHWM. A two-page data sheet and field procedure outline a weight-of-evidence (WoE) methodology to organize and evaluate observations at stream sites. This manual presents a consistent, science-based method for delineating the OHWM in streams. It also describes regional differences and challenges in identifying the OHWM at sites disturbed by human-induced or natural changes and illustrates how to use remote data to structure field inquiries and interpret field evidence using the principles of fluvial science. The manual demonstrates that, in many landscape settings, the OHWM may be located near the bankfull elevation.
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Balk, Ethan M., Kristin J. Konnyu, Wangnan Cao, Monika Reddy Bhuma, Valery A. Danilack, Gaelen P. Adam, Kristen A. Matteson, and Alex Friedman Peahl. Schedule of Visits and Televisits for Routine Antenatal Care: A Systematic Review. Agency for Healthcare Research and Quality (AHRQ), June 2022. http://dx.doi.org/10.23970/ahrqepccer257.
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Background. The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine plan a new evidence-based joint consensus statement to address the preferred visit schedule and the use of televisits for routine antenatal care. This systematic review will support the consensus statement. Methods. We searched PubMed®, Cochrane databases, Embase®, CINAHL®, ClinicalTrials.gov, PsycINFO®, and SocINDEX from inception through February 12, 2022. We included comparative studies from high-income countries that evaluated the frequency of scheduled routine antenatal visits or the inclusion of routine televisits, and qualitative studies addressing these two topics. We evaluated strength of evidence for 15 outcomes prioritized by stakeholders. Results. Ten studies evaluated scheduled number of routine visits and seven studies evaluated televisits. Nine qualitative studies also addressed these topics. Studies evaluated a wide range of reduced and traditional visit schedules and approaches to incorporating televisits. In comparisons of fewer to standard number of scheduled antenatal visits, moderate strength evidence did not find differences for gestational age at birth (4 studies), being small for gestational age (3 studies), Apgar score (5 studies), or neonatal intensive care unit (NICU) admissions (5 studies). Low strength evidence did not find differences in maternal anxiety (3 studies), preterm births (3 studies), and low birth weight (4 studies). Qualitative studies suggest that providers believe fewer routine visits may be more convenient for patients and may free up clinic time to provide additional care for patients with high-risk pregnancies, but both patients and providers had concerns about potential lesser care with fewer visits. In comparisons of hybrid (televisits and in-person) versus in-person only visits, low strength evidence did not find differences in preterm births (4 studies) or NICU admissions (3 studies), but did suggest greater satisfaction with hybrid visits (2 studies). Qualitative studies suggested patients and providers were open to reduced schedules and televisits for routine antenatal care, but importantly, patients and providers had concerns about quality of care, and providers and clinic leadership had suggestions on how to best implement practice changes. Conclusion. The evidence base is relatively sparse, with insufficient evidence for numerous prioritized outcomes. Studies were heterogeneous in the care models employed. Where there was sufficient evidence to make conclusions, studies did not find significant differences in harms to mother or baby between alternative models, but evidence suggested greater satisfaction with care with hybrid visits. Qualitative evidence suggests diverse barriers and facilitators to uptake of reduced visit schedules or televisits for routine antenatal care. Given the shortcomings of the evidence base, considerations other than proof of differences in outcomes may need to be considered regarding implications for clinical practice. New studies are needed to evaluate prioritized outcomes and potential differential effects among different populations or settings.
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Caulfield, Laura E., Wendy L. Bennett, Susan M. Gross, Kristen M. Hurley, S. Michelle Ogunwole, Maya Venkataramani, Jennifer L. Lerman, Allen Zhang, Ritu Sharma, and Eric B. Bass. Maternal and Child Outcomes Associated With the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC). Agency for Healthcare Research and Quality (AHRQ), April 2022. http://dx.doi.org/10.23970/ahrqepccer253.
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Objectives. The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) aims to safeguard the health of low-income, nutritionally at-risk pregnant and postpartum women and children less than 5 years old. This systematic review evaluates whether participation in WIC is associated with nutrition and health outcomes for women, infants, and children, and whether the associations vary by duration of participation or across subgroups. Because of major revisions to the WIC food package in 2009, we prioritized studies published since 2009 and included studies comparing outcomes before and after the 2009 food package change. Data sources. Using electronic publication databases, we conducted a literature search from January 2009 to September 2021 and a targeted search for selected outcomes from January 2000 to September 2021. Review methods. Paired team members independently screened search results, serially abstracted data, assessed risk of bias, and graded strength of evidence (SOE) using standard methods for observational studies. Results. We included 82 quantitative observational studies and 16 qualitative studies, with 49 studies comparing outcomes of WIC participants with WIC-eligible non-participants. WIC prenatal participation was associated with lower risk of three outcomes: preterm delivery (moderate SOE), low birth weight (moderate SOE), and infant mortality (moderate SOE). Prenatal WIC participation was associated with better maternal diet quality (low SOE), lower risk of inadequate gestational weight gain (low SOE), lower alcohol use in pregnancy (low SOE), and no difference in smoking (low SOE). Maternal WIC participation was associated with increased child preventive care and immunizations (each low SOE), and higher cognitive scores for children (low SOE). Child WIC participation was associated with better diet quality (moderate SOE), and greater intakes of 100 percent fruit juice, whole grain cereals, and age-appropriate milk (moderate SOE). Household WIC participation was associated with greater purchasing of healthy food groups (moderate SOE). Maternal WIC participation was not associated with breastfeeding initiation (moderate SOE). The evidence was insufficient for other outcomes related to maternal health and child growth. The evidence generally was insufficient on how WIC participation affects outcomes across subgroups. Conclusions. Maternal WIC participation was associated with improved birth outcomes, lower infant mortality, and better child cognitive development. WIC participation was associated with purchasing healthier foods and with improved diets for pregnant women and children. More research is needed on maternal health outcomes; food security; child growth, development, and academic achievement; and effectiveness of WIC in all segments of the eligible population.
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Andrawes, Bassem, Ernesto Perez Claros, and Zige Zhang. Bond Characteristics and Experimental Behavior of Textured Epoxy-coated Rebars Used in Concrete Bridge Decks. Illinois Center for Transportation, January 2022. http://dx.doi.org/10.36501/0197-9191/22-001.
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The deterioration of bridge decks is a problem typically associated with the corrosion of the reinforcing steel. This issue was partially controlled during the 1970s with the incorporation of the epoxy-coating protection system. However, research later demonstrated that the smooth surface resulting from the epoxy-coating application reduces most of the friction between the rebar and the surrounding concrete. Consequently, forces acting on the rib faces are reconfigured in such a way that the radial components increase, triggering the early development of cracks. To mitigate both the reduction of bonding and the formation of cracks, the Illinois Department of Transportation proposed a new type of coated bars: textured epoxy-coated (TEC) bars. Over the last few years, different projects have been executed to understand and improve the characteristics of TEC rebars. This report is a continuation of research performed at the University of Illinois Urbana-Champaign to evaluate the bond behavior of TEC bars. The experimental program starts by characterizing, qualitatively and quantitatively, the roughness of the TEC rebars. Next, their bond-slip interaction embedded in concrete is evaluated through pull-out tests. Finite element models of these tests are developed to validate the behavior observed as the textured reinforcement loses anchorage with concrete. Based on these results, the experimental program then aims to study the impact of the drying shrinkage, temperature change, and flexural demands on two large-scale bridge deck specimens reinforced, individually, with TEC and standard epoxy-coated bars. The results collected from both specimens using digital image correlation and strain gauges are compared to explore the differences exhibited by the traditional and the new type of reinforcement coatings in terms of stress distribution in bridge decks. Finally, given the specialized equipment and time-consuming procedure needed to calculate the roughness parameters of TEC bars, an empirical, weight-based approach is developed as a rapid method for assessing the rebars’ roughness on-site.
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Hovav, Ran, Peggy Ozias-Akins, and Scott A. Jackson. The genetics of pod-filling in peanut under water-limiting conditions. United States Department of Agriculture, January 2012. http://dx.doi.org/10.32747/2012.7597923.bard.
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Pod-filling, an important yield-determining stage is strongly influenced by water stress. This is particularly true for peanut (Arachishypogaea), wherein pods are developed underground and are directly affected by the water condition. Pod-filling in peanut has a significant genetic component as well, since genotypes are considerably varied in their pod-fill (PF) and seed-fill (SF) potential. The goals of this research were to: Examine the effects of genotype, irrigation, and genotype X irrigation on PF and SF. Detect global changes in mRNA and metabolites levels that accompany PF and SF. Explore the response of the duplicate peanut pod transcriptome to drought stress. Study how entire duplicated PF regulatory processes are networked within a polyploid organism. Discover locus-specific SNP markers and map pod quality traits under different environments. The research included genotypes and segregating populations from Israel and US that are varied in PF, SF and their tolerance to water deficit. Initially, an extensive field trial was conducted to investigate the effects of genotype, irrigation, and genotype X irrigation on PF and SF. Significant irrigation and genotypic effect was observed for the two main PF related traits, "seed ratio" and "dead-end ratio", demonstrating that reduction in irrigation directly influences the developing pods as a result of low water potential. Although the Irrigation × Genotype interaction was not statistically significant, one genotype (line 53) was found to be more sensitive to low irrigation treatments. Two RNAseq studies were simultaneously conducted in IL and the USA to characterize expression changes that accompany shell ("source") and seed ("sink") biogenesis in peanut. Both studies showed that SF and PF processes are very dynamic and undergo very rapid change in the accumulation of RNA, nutrients, and oil. Some genotypes differ in transcript accumulation rates, which can explain their difference in SF and PF potential; like cvHanoch that was found to be more enriched than line 53 in processes involving the generation of metabolites and energy at the beginning of seed development. Interestingly, an opposite situation was found in pericarp development, wherein rapid cell wall maturation processes were up-regulated in line 53. Although no significant effect was found for the irrigation level on seed transcriptome in general, and particularly on subgenomic assignment (that was found almost comparable to a 1:1 for A- and B- subgenomes), more specific homoeologous expression changes associated with particular biosynthesis pathways were found. For example, some significant A- and B- biases were observed in particular parts of the oil related gene expression network and several candidate genes with potential influence on oil content and SF were further examined. Substation achievement of the current program was the development and application of new SNP detection and mapping methods for peanut. Two major efforts on this direction were performed. In IL, a GBS approach was developed to map pod quality traits on Hanoch X 53 F2/F3 generations. Although the GBS approach was found to be less effective for our genetic system, it still succeeded to find significant mapping locations for several traits like testa color (linkage A10), number of seeds/pods (A5) and pod wart resistance (B7). In the USA, a SNP array was developed and applied for peanut, which is based on whole genome re-sequencing of 20 genotypes. This chip was used to map pod quality related traits in a Tifrunner x NC3033 RIL population. It was phenotyped for three years, including a new x-ray method to phenotype seed-fill and seed density. The total map size was 1229.7 cM with 1320 markers assigned. Based on this linkage map, 21 QTLs were identified for the traits 16/64 weight, kernel percentage, seed and pod weight, double pod and pod area. Collectively, this research serves as the first fundamental effort in peanut for understanding the PF and SF components, as a whole, and as influenced by the irrigation level. Results of the proposed study will also generate information and materials that will benefit peanut breeding by facilitating selection for reduced linkage drag during introgression of disease resistance traits into elite cultivars. BARD Report - Project4540 Page 2 of 10
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Bonfil, David J., Daniel S. Long, and Yafit Cohen. Remote Sensing of Crop Physiological Parameters for Improved Nitrogen Management in Semi-Arid Wheat Production Systems. United States Department of Agriculture, January 2008. http://dx.doi.org/10.32747/2008.7696531.bard.
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To reduce financial risk and N losses to the environment, fertilization methods are needed that improve NUE and increase the quality of wheat. In the literature, ample attention is given to grid-based and zone-based soil testing to determine the soil N available early in the growing season. Plus, information is available on in-season N topdressing applications as a means of improving GPC. However, the vast majority of research has focused on wheat that is grown under N limiting conditions in sub-humid regions and irrigated fields. Less attention has been given to wheat in dryland that is water limited. The objectives of this study were to: (1) determine accuracy in determining GPC of HRSW in Israel and SWWW in Oregon using on-combine optical sensors under field conditions; (2) develop a quantitative relationship between image spectral reflectance and effective crop physiological parameters; (3) develop an operational precision N management procedure that combines variable-rate N recommendations at planting as derived from maps of grain yield, GPC, and test weight; and at mid-season as derived from quantitative relationships, remote sensing, and the DSS; and (4) address the economic and technology-transfer aspects of producers’ needs. Results from the research suggest that optical sensing and the DSS can be used for estimating the N status of dryland wheat and deciding whether additional N is needed to improve GPC. Significant findings include: 1. In-line NIR reflectance spectroscopy can be used to rapidly and accurately (SEP <5.0 mg g⁻¹) measure GPC of a grain stream conveyed by an auger. 2. On-combine NIR spectroscopy can be used to accurately estimate (R² < 0.88) grain test weight across fields. 3. Precision N management based on N removal increases GPC, grain yield, and profitability in rainfed wheat. 4. Hyperspectral SI and partial least squares (PLS) models have excellent potential for estimation of biomass, and water and N contents of wheat. 5. A novel heading index can be used to monitor spike emergence of wheat with classification accuracy between 53 and 83%. 6. Index MCARI/MTVI2 promises to improve remote sensing of wheat N status where water- not soil N fertility, is the main driver of plant growth. Important features include: (a) computable from commercial aerospace imagery that include the red edge waveband, (b) sensitive to Chl and resistant to variation in crop biomass, and (c) accommodates variation in soil reflectance. Findings #1 and #2 above enable growers to further implement an efficient, low cost PNM approach using commercially available on-combine optical sensors. Finding #3 suggests that profit opportunities may exist from PNM based on information from on-combine sensing and aerospace remote sensing. Finding #4, with its emphasis on data retrieval and accuracy, enhances the potential usefulness of a DSS as a tool for field crop management. Finding #5 enables land managers to use a DSS to ascertain at mid-season whether a wheat crop should be harvested for grain or forage. Finding #6a expands potential commercial opportunities of MS imagery and thus has special importance to a majority of aerospace imaging firms specializing in the acquisition and utilization of these data. Finding #6b on index MCARI/MVTI2 has great potential to expand use of ground-based sensing and in-season N management to millions of hectares of land in semiarid environments where water- not N, is the main determinant of grain yield. Finding #6c demonstrates that MCARI/MTVI2 may alleviate the requirement of multiple N-rich reference strips to account for soil differences within farm fields. This simplicity will be less demanding of grower resources, promising substantially greater acceptance of sensing technologies for in-season N management.
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Driving Confidence in a Connected Vehicle Environment: A Case Study of Expressway Work Zone. SAE International, December 2020. http://dx.doi.org/10.4271/2020-01-5210.
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At present, how the application of connected vehicle technology will affect drivers’ driving psychology needs to be explored. As an important part of driving psychology, driving confidence can guide drivers to operate calmly when facing a complex traffic environment, which has an important impact on reducing accident rates and improving traffic efficiency. Based on the driving behavior data in the expressway work zone under a connected vehicle environment, this study mainly analyzed the difference between the psychological characteristics of drivers with warning information or without warning information when facing the work zone ahead. Firstly, based on driving simulation technology, the expressway work zone scene in a connected vehicle environment was designed, and the on-board human-machine interface was used to provide warning information of the work zone ahead. Secondly, the difference of drivers’ driving confidence in psychology when driving with or without warning information was analyzed by using the characteristics of average vehicle spatiotemporal diagram and gas pedal angle. Finally, a method of quantifying driving confidence was proposed, which used a kind of objective weighting method to get the weights between different indicators. Based on this method, drivers’ degree of driving confidence under two conditions was calculated. The results showed that connected vehicle technology could affect drivers’ driving confidence in psychology when facing the work zone ahead. In the connected vehicle environment, 82.9% of drivers’ degree of driving confidence would increase, and the average degree of driving confidence with warning information was 10.9% higher than that without warning information.