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Sjögren, David. "Kärleksfullt tilltal, kvarsittning eller kroppsaga: En modellgenererande undersökning om korrektionsmedel i 1800-talets folkskolereglementen". Nordic Journal of Educational History 5, n. 2 (17 dicembre 2018): 37–66. http://dx.doi.org/10.36368/njedh.v5i2.117.
Testo completoAbstract (sommario):
Compassionate Corrections, Detention or Corporal Punishment: A Model-Generating Study on Correctional Methods in Nineteenth Century Comprehensive School BylawsThis article aims to develop a systematising model to analyse correction and punishment in the nineteenth century elementary school in Sweden. The model is used to identify and compare the different forms of correction, to systematise mutual relationships between milder corrections and more harsh punishments, and to find patterns between faults and correction. The model is also used to systematically identify how expressions about correction and punishment change over time. The model is developed on the basis of normative material, which regulated how to maintain order in classrooms.
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Allerup, P., e H. Madsen. "On the Correction of Liquid Precipitation". Hydrology Research 17, n. 4-5 (1 agosto 1986): 237–50. http://dx.doi.org/10.2166/nh.1986.0016.
Testo completoAbstract (sommario):
The paper discusses a bi-linear statistical model for correcting aerodynamic errors, earlier presented by Allerup and Madsen, 1980. Further data from Finland, USA and Australia testing the model will be presented. A simplification of the bi-linear model in order to cover different gauge types and varying measuring levels will be demonstrated. The simplification will extend the applicability of the correction model when implemented into automatic correction systems. The paper will discuss the problems of fit by the simplified model and attention will be given to physical interpretation of the mathematical structure in the model. Besides aerodynamic errors, wetting losses influence the correction values. It will be demonstrated how these effects cause too large corrections for small amounts of precipitation and too small corrections for large amounts.
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Hoang, Tuan G., Peter Behrenbruch e Phil Do Huu. "Correction of laboratory gas permeability measurements using Klinkenberg-type correction models". APPEA Journal 57, n. 1 (2017): 171. http://dx.doi.org/10.1071/aj16064.
Testo completoAbstract (sommario):
Routine laboratory permeability measurements require both overburden correction and in the case of lower permeability gas measurements also Klinkenberg-type correction, accounting for slippage of gas when flowing through a porous medium. These corrections are necessary for obtaining representative permeability values for dynamic simulation. The objective of this paper is to determine the most suitable technique for determining representative, equivalent reservoir permeability. Laboratory permeability is routinely measured using different types of gases, most often helium and air, less often liquid. Single phase permeability measurements should be independent of the measuring fluid. However, laboratory permeability measurements using gas tend to overestimate sample permeability due to gas slippage. This effect was first reported by Klinkenberg (1941). Influencing factors are type of gas, mean experimental pressure and rock properties. The so called ‘Square-root model’ (Florence et al. 2007) accounts for all of these factors and is an extension of Klinkenberg’s original equation. The applicability of the Square-root model and earlier Klinkenberg-type models of Jones and Owens (1979) and Sampath and Keighin (1981) for correcting single-point laboratory gas permeability measurements are investigated on a comparative basis. Furthermore, Klinkenberg-type corrections are best made after overburden correction. The study presented involves a parametric approach of the gas slippage influencing factors, in addition to a comparison of alternative formulations. In comparing various Klinkenberg-type corrections, it is shown that the Square-root model compares most favourably and is most suitable for correcting laboratory data in the absence of specific measurements, as validated by comparison with laboratory deduced measurements. Datasets from the Asia-Pacific region and elsewhere are used to exemplify the methodology.
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Pozdnyakov, Yuri, Zoryana Skybinska, Tetiana Gryniv, Igor Britchenko, Peter Losonczi, Olena Magopets, Oleksandr Skybinskyi e Nataliya Hryniv. "Comparative analysis of models for adjustment procedure in assets value independent evaluation performed by comparative approach". Eastern-European Journal of Enterprise Technologies 6, n. 13 (114) (28 dicembre 2021): 80–93. http://dx.doi.org/10.15587/1729-4061.2021.248011.
Testo completoAbstract (sommario):
This paper addresses the field of economic measurements of the value of assets, carried out by the methods of independent expert evaluation. The mathematical principles of application, within a comparative methodical approach, of additive and multiplicative models for correcting the cost of single indicator of compared objects have been considered. The differences of mathematical basis of the compared models were analyzed. It has been shown that the ambiguity in the methodology of correction procedure requires studying the advantages and disadvantages of known models, as well as the justification and elaboration of recommendations for their application. Possible forms of correction representation using several alternative units of measurement have been defined; formulas for their interconnection have been built. Analytic expressions have been derived that mathematically describe the algorithms for performing the evaluation correction procedure using various forms of correction representation. The influence of the correction execution model on the characteristics of uncertainty in the independent evaluation result has been analyzed. The scope of two possible types of correction introduction models has been determined. A specific numerical example was used to demonstrate the methodological advantages of using a multiplicative model when summarizing percentage corrections. The independence of the correction result on the sequence of correction introduction has been confirmed. It is proposed to use the selected measure of partial corrections as a criterion for the adequacy of the correction introduction model. It is proved that the result of the independent expert evaluation depends on the chosen model and does not depend on the sequence of correction introduction. The reported study results are important in terms of theory and practice since they make it possible to improve the accuracy and reliability of the result of independent expert evaluation.
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Heineck, Jan, Alexandre Serra, Cornelius Haupt e Stefan Rammelt. "Accuracy of Corrective Osteotomies in Fibular Malunion: A Cadaver Model". Foot & Ankle International 30, n. 8 (agosto 2009): 773–77. http://dx.doi.org/10.3113/fai.2009.0773.
Testo completoAbstract (sommario):
Background: While incorrect length of a fibular fracture reduction can be measured by plain radiographs, accurate imaging of rotational deformities requires computed tomography (CT). Operative correction of fibular malrotation has not been accurately measured. The aim of this study was to evaluate the accuracy of operative correction of fibular malrotation. Materials and Methods: Six pairs of formalin-fixed, lower leg cadaver specimens had shortening with additional internal or external rotation induced by segmental fibular resection and plate fixation. The deformity was measured by CT. Two experienced surgeons performed standardized corrective operations on six specimens each. The postoperative results were measured by CT. Results: The mean overall accuracy for correction of malrotation was 1.58 degrees (SD = 0.8 degrees). There were no significant differences between the two surgeons performing the corrections. Conclusion: The accuracy of operative correction of malrotation in this cadaver model is in accordance with the requirements reported in clinical studies. Clinical Relevance: Considering the error margin for CT analysis, correction within 5 to 10 degrees seems practical.
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van Giersbergen, Noud P. A. "BARTLETT CORRECTION IN THE STABLE AR(1) MODEL WITH INTERCEPT AND TREND". Econometric Theory 25, n. 3 (giugno 2009): 857–72. http://dx.doi.org/10.1017/s0266466609090690.
Testo completoAbstract (sommario):
Bartlett corrections are derived for testing hypotheses about the autoregressive parameter ρ in the stable (a) AR(1) model, (b) AR(1) model with intercept, (c) AR(1) model with intercept and linear trend. The correction is found explicitly as a function of ρ. In the models with deterministic terms, the correction factor is asymmetric in ρ. Furthermore, the Bartlett correction is monotonically increasing in ρ and tends to infinity when ρ approaches the stability boundary of + 1. Simulation results indicate that the Bartlett corrections are useful in controlling the size of the likelihood ratio statistic in small samples, although these corrections are not the ultimate panacea.
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DelSole, Timothy, Mei Zhao, Paul A. Dirmeyer e Ben P. Kirtman. "Empirical Correction of a Coupled Land–Atmosphere Model". Monthly Weather Review 136, n. 11 (1 novembre 2008): 4063–76. http://dx.doi.org/10.1175/2008mwr2344.1.
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Abstract This paper investigates empirical strategies for correcting the bias of a coupled land–atmosphere model and tests the hypothesis that a bias correction can improve the skill of such models. The correction strategies investigated include 1) relaxation methods, 2) nudging based on long-term biases, and 3) nudging based on tendency errors. The last method involves estimating the tendency errors of prognostic variables based on short forecasts—say lead times of 24 h or less—and then subtracting the climatological mean value of the tendency errors at every time step. By almost any measure, the best correction strategy is found to be nudging based on tendency errors. This method significantly reduces biases in the long-term forecasts of temperature and soil moisture, and preserves the variance of the forecast field, unlike relaxation methods. Tendency errors estimated from ten 1-day forecasts produced just as effective corrections as tendency errors estimated from all days in a month, implying that the method is trivial to implement by modern standards. Disappointingly, none of the methods investigated consistently improved the random error variance of the model, although this finding may be model dependent. Nevertheless, the empirical correction method is argued to be worthwhile even if it improves only the bias, because the method has only marginal impacts on the numerical speed and represents forecast error in the form of a tendency error that can be compared directly to other terms in the tendency equations, which in turn provides clues as to the source of the forecast error.
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Hoque, Mohammed Mainul, Norbert Jakowski e Jens Berdermann. "Positioning performance of the NTCM model driven by GPS Klobuchar model parameters". Journal of Space Weather and Space Climate 8 (2018): A20. http://dx.doi.org/10.1051/swsc/2018009.
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Users of the Global Positioning System (GPS) utilize the Ionospheric Correction Algorithm (ICA) also known as Klobuchar model for correcting ionospheric signal delay or range error. Recently, we developed an ionosphere correction algorithm called NTCM-Klobpar model for single frequency GNSS applications. The model is driven by a parameter computed from GPS Klobuchar model and consecutively can be used instead of the GPS Klobuchar model for ionospheric corrections. In the presented work we compare the positioning solutions obtained using NTCM-Klobpar with those using the Klobuchar model. Our investigation using worldwide ground GPS data from a quiet and a perturbed ionospheric and geomagnetic activity period of 17 days each shows that the 24-hour prediction performance of the NTCM-Klobpar is better than the GPS Klobuchar model in global average. The root mean squared deviation of the 3D position errors are found to be about 0.24 and 0.45 m less for the NTCM-Klobpar compared to the GPS Klobuchar model during quiet and perturbed condition, respectively. The presented algorithm has the potential to continuously improve the accuracy of GPS single frequency mass market devices with only little software modification.
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Moga, Nikolay. "Working model of a physical education based spastic movement disorder correction system aimed at tender age children". International Journal of Pedagogy, Innovation and New Technologies 6, n. 2 (30 dicembre 2019): 123–32. http://dx.doi.org/10.5604/01.3001.0013.6849.
Testo completoAbstract (sommario):
The article describes modern modeling of physical rehabilitation processes for persons with musculoskeletal system disorders, and reveals a significant deficiency of this aspect in modern rehabilitation systems. Most of the developments in this field are based on practical, empirical experience of rehabilitation activities for a specific category of children. This is understandable but does not prevent mistakes in the strategy and tactics of long-term physical rehabilitation. It is necessary to have clear conceptual guidelines for the most effective process of physical rehabilitation concerning tender age children with spastic movement disorders. This can be achieved by pre-modeling the system of adaptive physical education of babies with spastic paresis. A structured and logically constructed model construction of the rehabilitation system includes four effective blocks: monitoring of physical development and spastic motor disorders (I), which is itself divided into medical, pedagogical, psychological; corrective measures (II) strategies and tactics, including a general correction program for the typological subgroup of children with spastic paresis and an individual correction program for normalizing the motor status of a particular child; correction of motor disorders of spastic type (III), which provides the means and methods of correctional physical education of tender age children with spastic motor disorders. The latter include: game, hypercorrection, contraindications, sufficient repetition of exercises, objectivity, and individual load differentiation; control and correction of the correction process (IV), which provides for permanent control over the components of the motor rehabilitation system, starting with the monitoring of physical development and ending with the peculiarities of the work correction process by means of physical education. Intra-system relations between all components of the working model are envisaged, and the priority of individual components of a perspective modeled system is considered. The model provides an invariant component of the system of adaptive physical education, universal for different children with spastic syndrome, as well as a variational component, which provides differentiation and individualization of corrective tactics for each specific child and its peculiarities of psychophysical development. The pre-designed working model of the correction system of movement disorders spastic forms of tender age children by physical education means will be tested in the process of forming a pedagogical experiment, which will make the necessary corrections both in the structural construction of this general rehabilitation system and in the substantive filling of its internal components.
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Danforth, Christopher M., Eugenia Kalnay e Takemasa Miyoshi. "Estimating and Correcting Global Weather Model Error". Monthly Weather Review 135, n. 2 (1 febbraio 2007): 281–99. http://dx.doi.org/10.1175/mwr3289.1.
Testo completoAbstract (sommario):
Abstract The purpose of the present study is to explore the feasibility of estimating and correcting systematic model errors using a simple and efficient procedure, inspired by papers by Leith as well as DelSole and Hou, that could be applied operationally, and to compare the impact of correcting the model integration with statistical corrections performed a posteriori. An elementary data assimilation scheme (Newtonian relaxation) is used to compare two simple but realistic global models, one quasigeostrophic and one based on the primitive equations, to the NCEP reanalysis (approximating the real atmosphere). The 6-h analysis corrections are separated into the model bias (obtained by time averaging the errors over several years), the periodic (seasonal and diurnal) component of the errors, and the nonperiodic errors. An estimate of the systematic component of the nonperiodic errors linearly dependent on the anomalous state is generated. Forecasts corrected during model integration with a seasonally dependent estimate of the bias remain useful longer than forecasts corrected a posteriori. The diurnal correction (based on the leading EOFs of the analysis corrections) is also successful. State-dependent corrections using the full-dimensional Leith scheme and several years of training actually make the forecasts worse due to sampling errors in the estimation of the covariance. A sparse approximation of the Leith covariance is derived using univariate and spatially localized covariances. The sparse Leith covariance results in small regional improvements, but is still computationally prohibitive. Finally, singular value decomposition is used to obtain the coupled components of the correction and forecast anomalies during the training period. The corresponding heterogeneous correlation maps are used to estimate and correct by regression the state-dependent errors during the model integration. Although the global impact of this computationally efficient method is small, it succeeds in reducing state-dependent model systematic errors in regions where they are large. The method requires only a time series of analysis corrections to estimate the error covariance and uses negligible additional computation during a forecast. As a result, it should be suitable for operational use at relatively small computational expense.
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Guimin Huang, Guimin Huang, e Maolin Li Guimin Huang. "An Errors Correction Model for the Errors of Non-word and Real-word in English Composition". 電腦學刊 33, n. 1 (febbraio 2022): 138–50. http://dx.doi.org/10.53106/199115992022023301013.
Testo completoAbstract (sommario):
<p>In the procedure from composing English, it is inevitable to face the phenomenon of word writing errors. In recent years, English composition automatic correcting system has attracted much attention. However, the precision of the existing word errors correcting system is vague generalization. So as to move forward the accuracy of checking and correcting word errors, this paper designs a word errors correction model based on natural language processing technology. This model designs phoneme matching method based on an improved IDM algorithm, and combined with a non-word input errors correction method based on character distance. The accuracy of correcting non-word errors in this model reached 86.5%. The study also proposes a real-word errors correction method, which is implemented basing on the real-word confusion set and combining the binary statistical model and the GloVe word vector model, improving the real-word errors correction method based on feature annotation of the real-word confusion set, with an accuracy of 77.9%. </p> <p> </p>
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Schultz, Craig A., Stephen C. Myers, James Hipp e Christopher J. Young. "Nonstationary Bayesian kriging: A predictive technique to generate spatial corrections for seismic detection, location, and identification". Bulletin of the Seismological Society of America 88, n. 5 (1 ottobre 1998): 1275–88. http://dx.doi.org/10.1785/bssa0880051275.
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Abstract Seismic characterization works to improve the detection, location, and identification of seismic events by correcting for inaccuracies in geophysical models. These inaccuracies are caused by inherent averaging in the model, and, as a result, exact data values cannot be directly recovered at a point in the model. Seismic characterization involves cataloging reference events so that inaccuracies in the model can be mapped at these points and true data values can be retained through a correction. Application of these corrections to a new event requires the accurate prediction of the correction value at a point that is near but not necessarily coincident with the reference events. Given that these reference events can be sparsely distributed geographically, both interpolation and extrapolation of corrections to the new point are required. In this study, we develop a closed-form representation of Bayesian kriging (linear prediction) that incorporates variable spatial damping. The result is a robust nonstationary algorithm for spatially interpolating geophysical corrections. This algorithm extends local trends when data coverage is good and allows for damping (blending) to an a priori background mean when data coverage is poor. Benchmark tests show that the technique gives reliable predictions of the correction value along with an appropriate uncertainty estimate. Tests with travel-time residual data demonstrate that combining variable damping with an azimuthal coverage criterion reduces the large errors that occur with more classical linear prediction techniques, especially when values are extrapolated in poor coverage regions. In the travel-time correction case, this technique generates both seismic corrections along with uncertainties and can properly incorporate model error in the final location estimate. Results favor the applicability of this nonstationary algorithm to other types of seismic corrections such as amplitude and attenuation measures.
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M. Hull, Robert. "Capital Structure Model (CSM): correction, constraints, and applications". Investment Management and Financial Innovations 15, n. 1 (14 marzo 2018): 245–62. http://dx.doi.org/10.21511/imfi.15(1).2018.21.
Testo completoAbstract (sommario):
This paper extends the Capital Structure Model (CSM) research by performing the following tasks. First, a correction is offered on the corporate tax rate adjustment found in the break-through concept of the levered equity growth rate (gL) given by Hull (2010). This correction is important because gL links the plowback-payout and debt-equity choices and so its accuracy is paramount. Second, this paper introduces a retained earnings (RE) constraint missing from the CSM growth research when a firm finances with internal equity. The RE constraint governs the plowback-payout and debt-equity choices through the interdependent relation between RE and interest payments (I). Third, a by-product of the RE constraint is a second constraint that governs a no-growth situation so that I does not exceed the available cash flows. Fourth, with the gL correction and two constraints in place, updated applications of prior research and new applications are provided. These applications reveal lower gain to leverage (GL) values than previously reported with more symmetry around the optimal debt-to-equity ratio (ODE) while minimizing steep drop-offs in firm value. For larger plowback ratios, the optimal debt level choice can change. The new constraints serve to point out the need for further research to incorporate external financing within the CSM framework.
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Suzuki, Hirofumi, Hiroaki Iwashita, Takuya Takagi, Keisuke Goto, Yuta Fujishige e Satoshi Hara. "Explainable and Local Correction of Classification Models Using Decision Trees". Proceedings of the AAAI Conference on Artificial Intelligence 36, n. 8 (28 giugno 2022): 8404–13. http://dx.doi.org/10.1609/aaai.v36i8.20816.
Testo completoAbstract (sommario):
In practical machine learning, models are frequently updated, or corrected, to adapt to new datasets. In this study, we pose two challenges to model correction. First, the effects of corrections to the end-users need to be described explicitly, similar to standard software where the corrections are described as release notes. Second, the amount of corrections need to be small so that the corrected models perform similarly to the old models. In this study, we propose the first model correction method for classification models that resolves these two challenges. Our idea is to use an additional decision tree to correct the output of the old models. Thanks to the explainability of decision trees, the corrections are describable to the end-users, which resolves the first challenge. We resolve the second challenge by incorporating the amount of corrections when training the additional decision tree so that the effects of corrections to be small. Experiments on real data confirm the effectiveness of the proposed method compared to existing correction methods.
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Niu, Dongsheng, e Lingyun Hou. "Comparison Study on Different Compressibility Modifications of Turbulence Model in Supersonic Combustion Simulation". Advances in Mechanical Engineering 6 (1 gennaio 2014): 238250. http://dx.doi.org/10.1155/2014/238250.
Testo completoAbstract (sommario):
Supersonic combustion in two-model scramjet combustors of hydrogen and hydrocarbon fuel was, respectively, simulated using the in-house two-dimensional compressible, turbulent, and reacting flow code. Three kinds of compressibility modifications, namely, the dilatational compressibility, structural compressibility, and shock unsteadiness corrections, were incorporated into the k-ω shear stress transport (SST) model, respectively. In addition, the case that employs all the three corrections simultaneously was also performed to evaluate the coupling effect of these individual corrections. The steady laminar flamelet model was adopted to simulate the interaction between turbulence and chemical kinetics. The calculation results using compressibility modifications are in good agreement with experiments, validating the effectiveness and accuracy of the turbulent modification model. Results show that the dilatational compressibility correction model has good versatility in all conditions. The structural compressibility correction model demonstrates the best correction effect in near wall region but has no significant effect in the central flow field. The correction effect of the shock unsteadiness compressibility correction model is sensitive and proportional to the strength of shock wave. Moreover, the coupling case gives the most remarkable correction effect in most situations, indicating that the overlying effect may improve the prediction accuracy.
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Shabbott, Britne A., e Robert L. Sainburg. "Differentiating Between Two Models of Motor Lateralization". Journal of Neurophysiology 100, n. 2 (agosto 2008): 565–75. http://dx.doi.org/10.1152/jn.90349.2008.
Testo completoAbstract (sommario):
This study was designed to differentiate between two models of motor lateralization: “feedback corrections” and dynamic dominance. Whereas the feedback correction hypothesis suggests that handedness reflects a dominant hemisphere advantage for visual-mediated correction processes, dynamic dominance proposes that each hemisphere has become specialized for distinct aspects of control. This model suggests that the dominant hemisphere is specialized for controlling task dynamics, as required for coordinating efficient trajectories, and the nondominant hemisphere is specialized for controlling limb impedance, as required for maintaining stable postures. To differentiate between these two models, we examined whether visuomotor corrections are mediated differently for the nondominant and dominant arms. Participants performed targeted reaches in a virtual reality environment in which visuomotor rotations occurred in two directions that elicited corrections with different coordination requirements. The feedback correction model predicts a dominant arm advantage for the timing and accuracy of corrections in both directions. Dynamic dominance predicts that correction timing and accuracy will be similar for both arms, but that interlimb differences in the quality of corrections will depend on the coordination requirements, and thus, direction of corrections. Our results indicated that correction time and accuracy did not depend on arm. However, correction quality, as reflected by trajectory curvature, depended on both arm and rotation direction. Nondominant trajectories were systematically more curvilinear than dominant trajectories for corrections with the highest coordination requirement. These results support the dynamic dominance hypothesis.
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P, Woodburne, Zhao Y, Raehsler R e Sohng S. "The Dynamic Phillips Curve Revisited: An Error Correction Model". International Journal of Advances in Management and Economics 1, n. 5 (2 settembre 2012): 01–04. http://dx.doi.org/10.31270/ijame/01/05/2012/01.
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Crawford, William, Sergey Frolov, Justin McLay, Carolyn A. Reynolds, Neil Barton, Benjamin Ruston e Craig H. Bishop. "Using Analysis Corrections to Address Model Error in Atmospheric Forecasts". Monthly Weather Review 148, n. 9 (25 agosto 2020): 3729–45. http://dx.doi.org/10.1175/mwr-d-20-0008.1.
Testo completoAbstract (sommario):
Abstract This paper illustrates that analysis corrections, when applied as a model tendency term, can be used to improve nonlinear model forecasts and are consistent with the hypothesis that they represent an additive 6-h accumulation of model error. Comparison of mean analysis corrections with observational estimates of bias further illustrates the fidelity with which mean analysis corrections capture the model bias. While most previous implementations have explored the use of analysis corrections to correct forecast biases in short-range forecasts, this is the first implementation of the correction method using both a seasonal mean and random analysis correction for medium-range forecasts (out to 10 days). Overall, the analysis correction–based perturbations are able to improve forecast skill in ensemble and deterministic systems, especially in the first 5 days of the forecast where bias and RMSE in both lower-tropospheric temperature and 500 hPa geopotential height are significantly improved across all experiments. However, while the method does provide some significant improvement to forecast skill, some degradation in bias can occur at later lead times when the average bias at analysis time trends toward zero over the length of the forecast, leading to an overcorrection by the analysis correction–based additive inflation (ACAI) method. Additionally, it is shown that both the mean and random component of the ACAI perturbations play a role in adjusting the model bias, and that the two components can have a complicated and sometimes nonlinear interaction.
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Kim, Mingyu, e Jeongrae Kim. "Predicting IGS RTS Corrections Using ARMA Neural Networks". Mathematical Problems in Engineering 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/851761.
Testo completoAbstract (sommario):
An autoregressive moving average neural network (ARMANN) model is applied to predict IGS real time service corrections. ARMA coefficients are determined by applying a neural network to IGS02 orbit/clock corrections. Other than the ARMANN, the polynomial and ARMA models are tested for comparison. An optimal order of each model is determined by fitting the model to the correction data. The data fitting period for training the models is 60 min. and the prediction period is 30 min. The polynomial model is good for the fitting but bad for the prediction. The ARMA and ARMANN have a similar level of accuracies, but the RMS error of the ARMANN is smaller than that of the ARMA. The RMS error of the ARMANN is 0.046 m for the 3D orbit correction and 0.070 m for the clock correction. The difference between the ARMA and ARMANN models becomes significant as the prediction time is increased.
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Allerup, P., H. Madsen e F. Vejen. "A Comprehensive Model for Correcting Point Precipitation". Hydrology Research 28, n. 1 (1 febbraio 1997): 1–20. http://dx.doi.org/10.2166/nh.1997.0001.
Testo completoAbstract (sommario):
Wind induced errors in precipitation measurements result in systematic deficits, which are particularly large when the precipitation falls as snow combined with high wind speed. The actual magnitude of the deficit can amount to more than half of the true precipitation. In order to correct for these deficits, newly developed statistical models for solid and mixed precipitation are presented; together with a correction model for liquid precipitation presented earlier, a comprehensive system of correction models is now available. Statistical errors on the corrections are estimated.
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Brautović, Mato. "Corrections Practice in the Croatian Online Media: Between Legislation and Tradition". Drustvena istrazivanja 30, n. 4 (27 dicembre 2021): 785–806. http://dx.doi.org/10.5559/di.30.4.07.
Testo completoAbstract (sommario):
Economic, technological and societal trends have switched the model of (online) journalism so that it is focused on the immediacy and volume that has resulted in a lower level of accuracy. To retain a critical function in a democracy, that model needs a corresponding error correction practice. In this study, we used content analysis to investigate how the Croatian online media correct errors, and how their correction practices differ according to the types of online media. The results demonstrate that errors in action or meaning (N = 217) were 67.8% of all errors, that the most common way of correcting errors was by posting an independent note about an error that was linked to the article (59%, N = 188), and that the correction notes were linked to uncorrected articles in 85.1% (N = 159) of cases. The findings showed that the only statistically significant difference between traditional and online media were the correction labelling practice and the location of the corrections.
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Rocheta, Eytan, Jason P. Evans e Ashish Sharma. "Can Bias Correction of Regional Climate Model Lateral Boundary Conditions Improve Low-Frequency Rainfall Variability?" Journal of Climate 30, n. 24 (dicembre 2017): 9785–806. http://dx.doi.org/10.1175/jcli-d-16-0654.1.
Testo completoAbstract (sommario):
Global climate model simulations inherently contain multiple biases that, when used as boundary conditions for regional climate models, have the potential to produce poor downscaled simulations. Removing these biases before downscaling can potentially improve regional climate change impact assessment. In particular, reducing the low-frequency variability biases in atmospheric variables as well as modeled rainfall is important for hydrological impact assessment, predominantly for the improved simulation of floods and droughts. The impact of this bias in the lateral boundary conditions driving the dynamical downscaling has not been explored before. Here the use of three approaches for correcting the lateral boundary biases including mean, variance, and modification of sample moments through the use of a nested bias correction (NBC) method that corrects for low-frequency variability bias is investigated. These corrections are implemented at the 6-hourly time scale on the global climate model simulations to drive a regional climate model over the Australian Coordinated Regional Climate Downscaling Experiment (CORDEX) domain. The results show that the most substantial improvement in low-frequency variability after bias correction is obtained from modifying the mean field, with smaller changes attributed to the variance. Explicitly modifying monthly and annual lag-1 autocorrelations through NBC does not substantially improve low-frequency variability attributes of simulated precipitation in the regional model over a simpler mean bias correction. These results raise questions about the nature of bias correction techniques that are required to successfully gain improvement in regional climate model simulations and show that more complicated techniques do not necessarily lead to more skillful simulation.
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Huang, K. D., Ding Hua Zhang, Fang Long Zha e M. J. Li. "Integrated Method of Enhancing Image Quality for FPD-Based Cone-Beam Computed Tomography". Key Engineering Materials 474-476 (aprile 2011): 1277–82. http://dx.doi.org/10.4028/www.scientific.net/kem.474-476.1277.
Testo completoAbstract (sommario):
The main factors of impacting Cone-Beam Computed Tomography (CBCT) image quality and their causes were studied, and an integrated method of enhancing CBCT image quality was proposed according to the Digital Radiography (DR) imaging model. First, the original polychromatic X-ray was filtered into quasi-monochromatic X-ray by the filter plate of copper-tungsten alloy, in order to improve the quality of the original projection images. Then, the integrated artifact corrections for projection images were processed on the order of dark field correction, gain non-uniformity correction, scatter correction and beam hardening correction, to avoid the one-sidedness of only correcting a certain kind of artifact. Experimental results show that the method can almost eliminate the main artifacts of CBCT system and improve image clarity and signal to noise ratio.
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Dajles, Andres, e Joseph Cavanaugh. "Probabilistic Pairwise Model Comparisons Based on Bootstrap Estimators of the Kullback–Leibler Discrepancy". Entropy 24, n. 10 (18 ottobre 2022): 1483. http://dx.doi.org/10.3390/e24101483.
Testo completoAbstract (sommario):
When choosing between two candidate models, classical hypothesis testing presents two main limitations: first, the models being tested have to be nested, and second, one of the candidate models must subsume the structure of the true data-generating model. Discrepancy measures have been used as an alternative method to select models without the need to rely upon the aforementioned assumptions. In this paper, we utilize a bootstrap approximation of the Kullback–Leibler discrepancy (BD) to estimate the probability that the fitted null model is closer to the underlying generating model than the fitted alternative model. We propose correcting for the bias of the BD estimator either by adding a bootstrap-based correction or by adding the number of parameters in the candidate model. We exemplify the effect of these corrections on the estimator of the discrepancy probability and explore their behavior in different model comparison settings.
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Sharika, K. M., Arjun Ramakrishnan e Aditya Murthy. "Control of Predictive Error Correction During a Saccadic Double-Step Task". Journal of Neurophysiology 100, n. 5 (novembre 2008): 2757–70. http://dx.doi.org/10.1152/jn.90238.2008.
Testo completoAbstract (sommario):
We explored the nature of control during error correction using a modified saccadic double-step task in which subjects cancelled the initial saccade to the first target and redirected gaze to a second target. Failure to inhibit was associated with a quick corrective saccade, suggesting that errors and corrections may be planned concurrently. However, because saccade programming constitutes a visual and a motor stage of preparation, the extent to which parallel processing occurs in anticipation of the error is not known. To estimate the time course of error correction, a triple-step condition was introduced that displaced the second target during the error. In these trials, corrective saccades directed at the location of the target prior to the third step suggest motor preparation of the corrective saccade in parallel with the error. To estimate the time course of motor preparation of the corrective saccade, further, we used an accumulator model (LATER) to fit the reaction times to the triple-step stimuli; the best-fit data revealed that the onset of correction could occur even before the start of the error. The estimated start of motor correction was also observed to be delayed as target step delay decreased, suggesting a form of interference between concurrent motor programs. Taken together we interpret these results to indicate that predictive error correction may occur concurrently while the oculomotor system is trying to inhibit an unwanted movement and suggest how inhibitory control and error correction may interact to enable goal-directed behaviors.
26
Yuen, Ka-Veng. "Efficient Model Correction Method with Modal Measurement". Journal of Engineering Mechanics 136, n. 1 (gennaio 2010): 91–99. http://dx.doi.org/10.1061/(asce)em.1943-7889.0000068.
Testo completo
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Haerter, J. O., S. Hagemann, C. Moseley e C. Piani. "Climate model bias correction and the role of timescales". Hydrology and Earth System Sciences 15, n. 3 (28 marzo 2011): 1065–79. http://dx.doi.org/10.5194/hess-15-1065-2011.
Testo completoAbstract (sommario):
Abstract. It is well known that output from climate models cannot be used to force hydrological simulations without some form of preprocessing to remove the existing biases. In principle, statistical bias correction methodologies act on model output so the statistical properties of the corrected data match those of the observations. However, the improvements to the statistical properties of the data are limited to the specific timescale of the fluctuations that are considered. For example, a statistical bias correction methodology for mean daily temperature values might be detrimental to monthly statistics. Also, in applying bias corrections derived from present day to scenario simulations, an assumption is made on the stationarity of the bias over the largest timescales. First, we point out several conditions that have to be fulfilled by model data to make the application of a statistical bias correction meaningful. We then examine the effects of mixing fluctuations on different timescales and suggest an alternative statistical methodology, referred to here as a cascade bias correction method, that eliminates, or greatly reduces, the negative effects.
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Dong, Chun Lai. "The Comparative Analysis and Research of the Correction Model on Troposphere Delay". Applied Mechanics and Materials 166-169 (maggio 2012): 960–63. http://dx.doi.org/10.4028/www.scientific.net/amm.166-169.960.
Testo completoAbstract (sommario):
This paper briefly describes the troposphere delay correction model, It developed a software using the real-time calculation of the troposphere delay corrections modified value. Based on the concept of sensitivity, Respectively on temperature, atmospheric pressure and high Angle variation, drawing analyzes correction effect of three correct model (Hopfield, Saastamoinen and Black), making a reasonable choice model of beneficial conclusion.
29
Haerter, J. O., S. Hagemann, C. Moseley e C. Piani. "Climate model bias correction and the role of timescales". Hydrology and Earth System Sciences Discussions 7, n. 5 (8 ottobre 2010): 7863–98. http://dx.doi.org/10.5194/hessd-7-7863-2010.
Testo completoAbstract (sommario):
Abstract. It is well known that output from climate models cannot be used to force hydrological simulations without some form of preprocessing to remove the existing biases. In principle, statistical bias correction methodologies act on model output so the statistical properties of the corrected data match those of the observations. However the improvements to the statistical properties of the data are limited to the specific time scale of the fluctuations that are considered. For example, a statistical bias correction methodology for mean daily values might be detrimental to monthly statistics. Also, in applying bias corrections derived from present day to scenario simulations, an assumption is made of persistence of the bias over the largest timescales. We examine the effects of mixing fluctuations on different time scales and suggest an improved statistical methodology, referred to here as a cascade bias correction method, that eliminates, or greatly reduces, the negative effects.
30
Adhitama, Rifki, Aditya Wijayanto e Dwi Mustika Kusumawardani. "Analisis Tingkat Kesiapan Pengguna Sistem Informasi Koreksi Essay Otomatis Berbasis Web Menggunakan Model Technology Readiness Index (TRI)". J. Sistem Info. Bisnis 11, n. 2 (23 gennaio 2022): 161–67. http://dx.doi.org/10.21456/vol11iss2pp161-167.
Testo completoAbstract (sommario):
During the pandemic, the learning model directly impacts both students and teachers, especially in evaluating and correcting assignments to measure student learning. Evaluation and correction of the learning process at both the high school and high school and university levels are generally carried out multiple-choice examinations during this pandemic. Many tools can be used to carry out multiple-choice assessments. The essay assessment is usually done manually and takes a long time because the lecturer has to make corrections one by one. On the other hand, information retrieval is a concept that can be used to build an automatic essay correction information system so that the correction of essay questions can be done quickly and efficiently, as in multiple-choice works. The automatic essay correction information system is a relatively new technology, especially for its plural use in this pandemic. A new technology that will be applied in a plural manner requires a measurement. One of the measurements that can be used is the Technology Readiness Index (TRI). TRI is used because it can measure the readiness and tendency of users to implement an information system. The case study in this research was conducted at the Faculty of Informatics (FIF) Telkom Institute of Technology Purwokerto (ITTP). The TRI measurement of the automatic essay correction information system carried out at FIF produces a TRI of 3.27. This value is between 2.90 and 3.51 (2.90 ≤ TRI ≤ 3.51). Consisted of an optimism value of 1.01, and innovativeness value of 0.52, a discomfort value of 0.55, and an insecurity value of 1.19.
31
Guner, Feyyaz, J. V. R. Prasad, Chengjian He e David Peters. "Fidelity Enhancement of a Multirotor Dynamic Inflow Model via System Identification". Journal of the American Helicopter Society 67, n. 2 (1 aprile 2022): 1–17. http://dx.doi.org/10.4050/jahs.67.022009.
Testo completoAbstract (sommario):
Multirotor analytical dynamic inflow models in the literature, such as pressure potential superposition inflow model or velocity potential superposition inflow model (VPSIM), have been shown to capture the fundamental inflow interference effects between the rotors. Some of the differences in inflow predictions seen between these analytic models and high-fidelity wake models are attributed to missing real flow effects such as wake distortion, contraction, decay, swirl, etc. As such, correction terms are needed in the analytically derived multirotor finite-state inflow models, because of the potential flow and rigid wake assumptions they are based on, in order to capture some of the missing real flow effects in them. This paper develops a systematic methodology for arriving at the needed correction terms in the VPSIM through comparisons of its inflow predictions with those of a viscous vortex particle model (VVPM). Also, a procedure is developed to assess the relative importance of individual real flow effects and the associated corrections needed for improving the overall fidelity of the VPSIM. The developed methodology is applied to the Harrington coaxial rotor using its geometric and aerodynamic data from the literature. It is shown that the addition of swirl coupling correction terms to the VPSIM significantly improves its correlations with the VVPM. Further, it is shown that the required corrections are reasonably insensitive to thrust sharing ratio conditions between the rotors.
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Tippett, Michael K., Anthony G. Barnston, David G. DeWitt e Rong-Hua Zhang. "Statistical Correction of Tropical Pacific Sea Surface Temperature Forecasts". Journal of Climate 18, n. 23 (1 dicembre 2005): 5141–62. http://dx.doi.org/10.1175/jcli3581.1.
Testo completoAbstract (sommario):
Abstract This paper is about the statistical correction of systematic errors in dynamical sea surface temperature (SST) prediction systems using linear regression approaches. The typically short histories of model forecasts create difficulties in developing regression-based corrections. The roles of sample size, predictive skill, and systematic error are examined in evaluating the benefit of a linear correction. It is found that with the typical 20 yr of available model SST forecast data, corrections are worth performing when there are substantial deviations in forecast amplitude from that determined by correlation with observations. The closer the amplitude of the uncorrected forecasts is to the optimum squared error-minimizing amplitude, the less likely is a correction to improve skill. In addition to there being less “room for improvement,” this rule is related to the expected degradation in out-of-sample skill caused by sampling error in the estimate of the regression coefficient underlying the correction. Application of multivariate [canonical correlation analysis (CCA)] correction to three dynamical SST prediction models having 20 yr of data demonstrates improvement in the cross-validated skills of tropical Pacific SST forecasts through reduction of systematic errors in pattern structure. Additional beneficial correction of errors orthogonal to the CCA modes is achieved on a per-gridpoint basis for features having smaller spatial scale. Until such time that dynamical models become freer of systematic errors, statistical corrections such as those shown here can make dynamical SST predictions more skillful, retaining their nonlinear physics while also calibrating their outputs to more closely match observations.
33
McCubbine, J. C., W. E. Featherstone e J. F. Kirby. "Fast-Fourier-based error propagation for the gravimetric terrain correction". GEOPHYSICS 82, n. 4 (1 luglio 2017): G71—G76. http://dx.doi.org/10.1190/geo2016-0627.1.
Testo completoAbstract (sommario):
We have identified a gap in the literature on error propagation in the gravimetric terrain correction. Therefore, we have derived a mathematical framework to model the propagation of spatially correlated digital elevation model errors into gravimetric terrain corrections. As an example, we have determined how such an error model can be formulated for the planar terrain correction and then be evaluated efficiently using the 2D Fourier transform. We have computed 18.3 billion linear terrain corrections and corresponding error estimates for a 1 arc-second ([Formula: see text]) digital elevation model covering the whole of the Australian continent.
34
Zhang, Yaoxin, e Yafei Jia. "Velocity Correction Coefficients in Pressure Correction–Type Model". Journal of Hydraulic Engineering 145, n. 6 (giugno 2019): 06019008. http://dx.doi.org/10.1061/(asce)hy.1943-7900.0001604.
Testo completo
35
Gou, Wei, e Zheng Chen. "Think Twice: A Post-Processing Approach for the Chinese Spelling Error Correction". Applied Sciences 11, n. 13 (23 giugno 2021): 5832. http://dx.doi.org/10.3390/app11135832.
Testo completoAbstract (sommario):
Chinese Spelling Error Correction is a hot subject in the field of natural language processing. Researchers have already produced many great solutions, from the initial rule-based solution to the current deep learning method. At present, SpellGCN, proposed by Alibaba’s team, achieves the best results of which character level precision over SIGHAN2013 is 98.4%. However, when we apply this algorithm to practical error correction tasks, it produces many false error correction results. We believe that this is because the corpus used for model training contains significantly more errors than the text used for model correcting. In response to this problem, we propose performing a post-processing operation on the error correction tasks. We employ the initial model’s output as a candidate character, obtain various features of the character itself and its context, and then use a classification model to filter the initial model’s false error correction results. The post-processing idea introduced in this paper can apply to most Chinese Spelling Error Correction models to improve their performance over practical error correction tasks.
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Pan, Lin, Fei Guo e Fujian Ma. "An Improved BDS Satellite-Induced Code Bias Correction Model Considering the Consistency of Multipath Combinations". Remote Sensing 10, n. 8 (28 luglio 2018): 1189. http://dx.doi.org/10.3390/rs10081189.
Testo completoAbstract (sommario):
The satellite-induced systematic biases were identified to exist in the code observations from BeiDou navigation satellite system (BDS) satellites using multipath (MP) combinations. The current correction model for satellite-induced code bias (SICB) does not take into account the consistency of MP combinations, which limits the accuracy of the developed model. Both the cycle slips and different tracking of a satellite at different stations can affect the absolute values of MP combinations, although the variations remain unchanged. An improved SICB piecewise linear correction model as a function of elevations is proposed. We estimate the model parameters for each frequency and for each satellite. The single-difference of MP combinations in the domain of elevation angles is carried out to remove the unknown ambiguities and stable hardware delays so that the SICB modeling is free of the effects of MP combination inconsistency. In addition, a denser elevation node separation of 1°, rather than the 10° usually employed by the traditional model, is used to describe the more precise SICB variations. The SICB corrections show significant differences among orbit types and frequency bands. The SICB variations have much less effect on Inclined Geosynchronous Orbit (IGSO) satellites than on Medium Earth Orbit (MEO) satellites for the regional BDS (BDS-2). The B1 signal has the largest SICB corrections, which can be up to 0.9 m close to zenith for BDS-2 MEO satellites, and the B2 signal follows. After adding the SICB corrections to the code observations, the elevation-dependent code biases vanish, and we can obtain improved code observations. After applying the improved SICB correction model, the root mean square (RMS) values of MP combination time series are reduced by 7%, 6% and 2%, and 18%, 14% and 5% on the B1, B2 and B3 frequencies for the BDS-2 IGSO and MEO satellites, respectively. For comparison, we also establish the traditional SICB correction model. With the traditional SICB correction model, the corresponding RMS MP combinations are smaller than those of uncorrected MP series, but slightly larger than those of corrected MP series using the improved SICB correction model. To validate the effectiveness and correctness of our proposed model, single-frequency precise point positioning (PPP) processing with BDS-2 MEO and IGSO satellites is conducted. An accuracy improvement of 24%, 19% and 89%, and 7%, 7% and 6% for the single-frequency PPP applying the improved SICB corrections over the case without SICB corrections and the case using the traditional SICB corrections in east, north and vertical directions is achieved, respectively. Although only centimeter-level SICB variations could be observed for the two legacy signals B1 and B3 and the three new navigation signals B1C, B2a and B2b transmitted by the satellites of global BDS demonstration system (BDS-3S), we still establish an effective SICB correction model on the B1 and B3 frequencies for BDS-3S IGSO satellites, and the RMS MP combinations are reduced by 1–4% after applying the improved SICB corrections.
37
ZHANG, XIANG-HONG, YI-ZAO WU e JIANG-FENG WANG. "TURBULENCE MODELS FOR ACCURATE AEROTHERMAL PREDICTION IN HYPERSONIC FLOWS". Modern Physics Letters B 24, n. 13 (30 maggio 2010): 1345–48. http://dx.doi.org/10.1142/s021798491002358x.
Testo completoAbstract (sommario):
Accurate description of the aerodynamic and aerothermal environment is crucial to the integrated design and optimization for high performance hypersonic vehicles. In the simulation of aerothermal environment, the effect of viscosity is crucial. The turbulence modeling remains a major source of uncertainty in the computational prediction of aerodynamic forces and heating. In this paper, three turbulent models were studied: the one-equation eddy viscosity transport model of Spalart-Allmaras, the Wilcox k -ω model and the Menter SST model. For the k -ω model and SST model, the compressibility correction, press dilatation and low Reynolds number correction were considered. The influence of these corrections for flow properties were discussed by comparing with the results without corrections. In this paper the emphasis is on the assessment and evaluation of the turbulence models in prediction of heat transfer as applied to a range of hypersonic flows with comparison to experimental data. This will enable establishing factor of safety for the design of thermal protection systems of hypersonic vehicle.
38
Kaupužs, J., R. V. N. Melnik e J. Rimšāns. "Corrections to finite-size scaling in the φ4 model on square lattices". International Journal of Modern Physics C 27, n. 09 (agosto 2016): 1650108. http://dx.doi.org/10.1142/s0129183116501084.
Testo completoAbstract (sommario):
Corrections to scaling in the two-dimensional (2D) scalar [Formula: see text] model are studied based on nonperturbative analytical arguments and Monte Carlo (MC) simulation data for different lattice sizes L ([Formula: see text]) and different values of the [Formula: see text] coupling constant [Formula: see text], i.e. [Formula: see text], 1, 10. According to our analysis, amplitudes of the nontrivial correction terms with the correction–to–scaling exponents [Formula: see text] become small when approaching the Ising limit ([Formula: see text]), but such corrections generally exist in the 2D [Formula: see text] model. Analytical arguments show the existence of corrections with the exponent [Formula: see text]. The numerical analysis suggests that there exist also corrections with the exponent [Formula: see text] and, perhaps, also with the exponent about [Formula: see text], which are detectable at [Formula: see text]. The numerical tests provide an evidence that the structure of corrections to scaling in the 2D [Formula: see text] model differs from the usually expected one in the 2D Ising model.
39
Ding, Aoshuang, Xiaodong Ren, Xuesong Li e Chunwei Gu. "Numerical Investigation of Turbulence Models for a Superlaminar Journal Bearing". Advances in Tribology 2018 (2018): 1–14. http://dx.doi.org/10.1155/2018/2841303.
Testo completoAbstract (sommario):
With rotating machineries working at high speeds, oil flow in bearings becomes superlaminar. Under superlaminar conditions, flow exhibits between laminar and fully developed turbulence. In this study, superlaminar oil flow in an oil-lubricated tilting-pad journal bearing is analyzed through computational fluid dynamics (CFD). A three-dimensional bearing model is established. CFD results from the laminar model and 14 turbulence models are compared with experimental findings. The laminar simulation results of pad-side pressure are inconsistent with the experimental data. Thus, the turbulence effects on superlaminar flow should be considered. The simulated temperature and pressure distributions from the classical fully developed turbulence models cannot correctly fit the experimental data. As such, turbulence models should be corrected for superlaminar flow. However, several corrections, such as transition correction, are unsuitable. Among all the flow models, the SST model with low-Re correction exhibits the best pressure distribution and turbulence viscosity ratio. Velocity profile analysis confirms that a buffer layer plays an important role in the superlaminar boundary layer. Classical fully developed turbulence models cannot accurately predict the buffer layer, but this problem can be resolved by initiating an appropriate low-Re correction. Therefore, the SST model with low-Re correction yields suitable results for superlaminar flows in bearings.
40
Chen, Yu-Jie, Shi-Lin Li, Yu-Zhu Chen, Wen-Du Li e Wu-Sheng Dai. "Gravitational constant model and correction". Journal of Mathematical Physics 63, n. 11 (1 novembre 2022): 112503. http://dx.doi.org/10.1063/5.0095583.
Testo completoAbstract (sommario):
We construct a model for considering the quantum correction of the gravitational constant. In the model, the gravitational constant originates from a coupling between the gravitational field and a scalar field. If the scalar field, as it should be in the real physical world, is a quantum field, the gravitational constant will have a quantum correction. The quantum correction, generally speaking, varies with spacetime coordinates. Therefore, the gravitational constant is no longer a constant. In different spacetime, the quantum correction is different, for the coupling in different spacetime is different. As a result, the gravitational constant in different spacetime is different, though the difference is only at the quantum level. We calculate the quantum correction of the gravitational constant in the Schwarzschild spacetime, the H3 (Euclidean AdS3) spacetime, the H3/ Z spacetime, the universe model, the de Sitter spacetime, and the Rindler spacetime.
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Rashdan, M. "Covariant Equation of State for Two Colliding Nuclear Matters in the Relativistic Meson Field Theory". International Journal of Modern Physics E 06, n. 01 (marzo 1997): 151–59. http://dx.doi.org/10.1142/s021830139700010x.
Testo completoAbstract (sommario):
The relativistic mean field theory (linear and nonlinear) models are extended to the case of two colliding nuclear matters, relevant to heavy ion scattering and reactions. The effect of vacuum corrections is taken into account through the relativistic Hartree approximation. The Fermi sea is assumed to consist of two colliding Lorentz elongated spheres. A relativistic covariant Pauli correction is considered for the overlap case. This relativistic Pauli correction is found to be very important due to its dependence on the effective nucleon mass which strongly depends on the model equation of state. It is found that by increasing the velocity the energy per baryon increases and saturates at higher densities. The increase in the energy per baryon at low density (the region of no overlap) is much larger than that at high density (the region of large overlap), due to Pauli correction effects. The saturation density of the nonlinear model is shifted to larger values than that of the linear model. Vacuum corrections effects are found to reduce largely te overlap region.
42
Mohasseb, M., A. El-Rabbany, O. Abd El-Alim e R. Rashad. "DGPS Correction Prediction Using Artificial Neural Networks". Journal of Navigation 60, n. 2 (20 aprile 2007): 291–301. http://dx.doi.org/10.1017/s0373463307004158.
Testo completoAbstract (sommario):
This paper focuses on modelling and predicting differential GPS corrections transmitted by marine radio-beacon systems using artificial neural networks. Various neural network structures with various training algorithms were examined, including Linear, Radial Biases, and Feedforward. Matlab Neural Network toolbox is used for this purpose. Data sets used in building the model are the transmitted pseudorange corrections and broadcast navigation message. Model design is passed through several stages, namely data collection, preprocessing, model building, and finally model validation. It is found that feedforward neural network with automated regularization is the most suitable for our data. In training the neural network, different approaches are used to take advantage of the pseudorange corrections history while taking into account the required time for prediction and storage limitations. Three data structures are considered in training the neural network, namely all round, compound, and average. Of the various data structures examined, it is found that the average data structure is the most suitable. It is shown that the developed model is capable of predicting the differential correction with an accuracy level comparable to that of beacon-transmitted real-time DGPS correction.
43
Chetry, Binod, Jibitesh Dutta e Wompherdeiki Khyllep. "Thermodynamics of scalar field models with kinetic corrections". International Journal of Modern Physics D 28, n. 15 (novembre 2019): 1950163. http://dx.doi.org/10.1142/s0218271819501633.
Testo completoAbstract (sommario):
In this work, we compare the thermodynamical viability of two types of noncanonical scalar field models with kinetic corrections: the square kinetic and square root kinetic corrections. In modern cosmology, the generalized second law of thermodynamics (GSLT) plays an important role in deciding thermodynamical compliance of a model as one cannot consider a model to be viable if it fails to respect GSLT. Hence, for comparing thermodynamical viability, we examine the validity of GSLT for these two models. For this purpose, by employing the Unified first law (UFL), we calculate the total entropy of these two models in apparent and event horizons. The validity of GSLT is then examined from the autonomous systems as the original expressions of total entropy are very complicated. Although, at the background level, both models give interesting cosmological dynamics, however, thermodynamically we found that the square kinetic correction is more realistic as compared to the square root kinetic correction. More precisely, the GSLT holds for the square kinetic correction throughout the evolutionary history except only during the radiation epoch where the scalar field may not represent a true description of the matter content. On the other hand, the square root kinetic model fails to satisfy the GSLT in major cosmological eras.
44
Moheimani, S. O. Reza. "Model Correction for Sampled-Data Models of Structures". Journal of Guidance, Control, and Dynamics 24, n. 3 (maggio 2001): 634–37. http://dx.doi.org/10.2514/2.4760.
Testo completo
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Zhu, Rong-Fei, Tai-Fu Feng e Hai-Bin Zhang. "The QCD corrections of the process h → ηbZ". Modern Physics Letters A 33, n. 15 (20 maggio 2018): 1830008. http://dx.doi.org/10.1142/s0217732318300082.
Testo completoAbstract (sommario):
We investigate the 125 GeV Higgs boson decay to a pseudoscalar quarkonium [Formula: see text] and [Formula: see text] boson. We calculate the quantum chromodynamics (QCD) one-loop corrections to the branching ratio of the process, [Formula: see text], both in the Standard Model (SM) and in the two Higgs double models (THDM). Adding the QCD one-loop corrections, the branching ratio of [Formula: see text] in the SM is [Formula: see text]. The relative correction of that QCD one-loop level relative to the tree level of [Formula: see text] is around 76% in the SM. Similarly, the relative correction in the THDM also can be around 75%. The key parameter, [Formula: see text], can affect the relative correction in the THDM.
46
Kiros, Atakilti Brhanu, e Petros Ukbagergis Aray. "Tigrigna language spellchecker and correction system for mobile phone devices". International Journal of Electrical and Computer Engineering (IJECE) 11, n. 3 (1 giugno 2021): 2307. http://dx.doi.org/10.11591/ijece.v11i3.pp2307-2314.
Testo completoAbstract (sommario):
This paper presents on the implementation of spellchecker and corrector system in mobile phone devices, such as a smartphone for the low-resourced Tigrigna language. Designing and developing a spell checking for Tigrigna language is a challenging task. Tigrigna script has more than 32 base letters with seven vowels each. Every first letter has six suffixes. Word formation in Tigrigna depends mainly on root-and-pattern morphology and exhibits prefixes, suffixes, and infixes. A few project have been done on Tigrigna spellchecker on desktop application and the nature of Ethiopic characters. However, in this work we have proposed a systems modeling for Tigrigna language spellchecker, detecting and correction: a corpus of 430,379 Tigrigna words has been used. To indication the validity of the spellchecker and corrector model and algorithm designed, a prototype is developed. The experiment is tested and accuracy of the prototype for Tigrigna spellchecker and correction system for mobile phone devices achieved 92%. This experiment result shows clearly that the system model is efficient in spellchecking and correcting relevant suggested correct words and reduces the misspelled input words for writing Tigrigna words on mobile phone devices.
47
Заневський, І. П., e Л. Г. Заневська. "Ruffier test model taking into account an age of the patient". Teorìâ ta Metodika Fìzičnogo Vihovannâ, n. 2 (30 giugno 2013): 17–27. http://dx.doi.org/10.17309/tmfv.2013.2.1013.
Testo completoAbstract (sommario):
There are presented the results of the comparative analysis of the existing methods of correcting the values of Ruffier index for the children teenagers. The model of the correction of the value of Ruffier index and the model of the correction of the gradation of the estimations of Ruffier test taking into account an age of the patient are proposed. It is shown that the parameter of the correction of the value of Ruffier index and gradations of the estimations of the corresponding test must be a relationship of the standard pulse rate in the state of calmness, accepted for the age class of patient, to the standard pulse rate of adult person. The corresponding model of the estimation of the functional state of the cardiovascular system of persons of school age showed a statistically significal (p < 0,001) correction of the value of Ruffier index and the gradation of the levels of health relatively to the conventional model for the adult, which is recommended. The quantitative assessment of the consequences of correction in the distribution of students on levels and groups of health is represented.
48
Bohn, Theodore J., Mergia Y. Sonessa e Dennis P. Lettenmaier. "Seasonal Hydrologic Forecasting: Do Multimodel Ensemble Averages Always Yield Improvements in Forecast Skill?" Journal of Hydrometeorology 11, n. 6 (1 dicembre 2010): 1358–72. http://dx.doi.org/10.1175/2010jhm1267.1.
Testo completoAbstract (sommario):
Abstract Multimodel techniques have proven useful in improving forecast skill in many applications, including hydrology. Seasonal hydrologic forecasting in large basins represents a special case of hydrologic modeling, in which postprocessing techniques such as temporal aggregation and time-varying bias correction are often employed to improve forecast skill. To investigate the effects that these techniques have on the performance of multimodel averaging, the performance of three hydrological models [Variable Infiltration Capacity, Sacramento/Snow-17, and the Noah land surface model] and two multimodel averages [simple model average (SMA) and multiple linear regression (MLR) with monthly varying model weights] are examined in three snowmelt-dominated basins in the western United States. These evaluations were performed for both simulating and forecasting [using the Ensemble Streamflow Prediction (ESP) method] monthly discharge, with and without monthly bias corrections. The single best bias-corrected model outperformed the multimodel averages of raw models in both retrospective simulations and ensemble mean forecasts in terms of RMSE. Forming an MLR multimodel average from bias-corrected models added only slight improvements over the best bias-corrected model. Differences in performance among all bias-corrected models and multimodel averages were small. For ESP forecasts, both bias correction and multimodel averaging generally reduced the RMSE of the ESP ensemble means at lead times of up to 6 months in months when flow is dominated by snowmelt, with the reduction increasing as lead time decreased. The primary reason for this is that aggregating simulated streamflows from daily to monthly time scales increases model cross correlation, which in turn reduces the effectiveness of multimodel averaging in reducing those components of model error that bias correction cannot address. This effect may be stronger in snowmelt-dominated basins because the interannual variability of winter precipitation is a common input to all models. It was also found that both bias correcting and multimodel averaging using monthly varying parameters yielded much greater error reductions than methods using time-invariant parameters.
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Bordoy, Roger, e Paolo Burlando. "Bias Correction of Regional Climate Model Simulations in a Region of Complex Orography". Journal of Applied Meteorology and Climatology 52, n. 1 (gennaio 2013): 82–101. http://dx.doi.org/10.1175/jamc-d-11-0149.1.
Testo completoAbstract (sommario):
AbstractThis study presents a method to correct regional climate model (RCM) outputs using observations from automatic weather stations. The correction applies a nonlinear procedure, which recently appeared in the literature, to both precipitation and temperature on a monthly basis in a region of complex orography. To assess the temporal stability of such a correction, the correcting parameters of each variable are investigated using different time periods within the observational record. The RCM simulations used in this study to evaluate the bias-correction method are the publicly available “Reg-CM3” experiments from the Ensemble-Based Predictions of Climate Changes and Their Impacts (ENSEMBLES) project. They provide daily precipitation and temperature time series on a raster with spatial resolution of 0.22°. The analysis is performed in the Rhone catchment, located in southwestern Switzerland and characterized by highly complex orography. The results show that the nonlinear bias correction increases dramatically the accuracy not only of the RCM mean daily precipitation and temperature but also of values across the entire domain of the probability distribution. Moreover, the correction parameters seem to be reasonably independent from the sample used for their calibration, especially in the case of temperature. The good performance of the method over the considered mountainous region during the evaluation period points to the suitability of this technique for correcting RCM biases regardless of the stationarity of the climate and, therefore, also for future climate and in regions characterized by marked orography.
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Carlucci, Lorenzo, John Case e Sanjay Jain. "Learning correction grammars". Journal of Symbolic Logic 74, n. 2 (giugno 2009): 489–516. http://dx.doi.org/10.2178/jsl/1243948324.
Testo completoAbstract (sommario):
AbstractWe investigate a new paradigm in the context of learning in the limit, namely, learningcorrection grammarsfor classes ofcomputably enumerable (c.e.)languages. Knowing a language may feature a representation of it in terms oftwogrammars. The second grammar is used to make corrections to the first grammar. Such a pair of grammars can be seen as a single description of (or grammar for) the language. We call such grammarscorrection grammars. Correction grammars capture the observable fact that peopledocorrect their linguistic utterances during their usual linguistic activities.We show that learning correction grammars for classes of c.e. languages in theTxtEx-mode(i.e., converging to a single correct correction grammar in the limit) is sometimes more powerful than learning ordinary grammars even in theTxtBc-model (where the learner is allowed to converge to infinitely many syntactically distinct but correct conjectures in the limit). For eachn≥ 0. there is a similar learning advantage, again in learning correction grammars for classes of c.e. languages, but where we compare learning correction grammars that maken+ 1 corrections to those that makencorrections.The concept of a correction grammar can be extended into the constructive transfinite, using the idea of counting-down from notations for transfinite constructive ordinals. This transfinite extension can also be conceptualized as being about learning Ershov-descriptions for c.e. languages. Forua notation in Kleene's general system (O, <o) of ordinal notations for constructive ordinals, we introduce the concept of anu-correction grammar, whereuis used to bound the number of corrections that the grammar is allowed to make. We prove a general hierarchy result: ifuandvare notations for constructive ordinals such thatu<ov. then there are classes of c.e. languages that can beTxtEx-learned by conjecturingv-correction grammars but not by conjecturingu-correction grammars.Surprisingly, we show that—above “ω-many” corrections—it is not possible to strengthen the hierarchy:TxtEx-learningu-correction grammars of classes of c.e. languages, whereuis a notation inOforanyordinal, can be simulated byTxtBc-learningw-correction grammars, wherewis any notation for the smallest infinite ordinalω.