scholarly journals Contributions to the Normalized Correlation and the Mean Squares Metric

2006 ◽  
Author(s):  
Marius Staring
Keyword(s):  
Source Code ◽  
Computation Time ◽  
Convergence Properties ◽  
Random Subset ◽  
Speed Up ◽  
The Mean ◽  
The Cost

This document describes contributions on the NormalizedCorrelationImageToImageMetric and the MeanSquaresImageToImageMetric of the Insight Toolkit ITK . For the first metric a two time speed-up can be achieved by rewriting the code to loop only once over the fixed image. This is instead of the two times that is used in the current ITK code. The reduction in computation time comes at the cost of an additional storage of a parameters array. For both metric we have implemented the option to use only a random subset of the fixed image voxels for calculating the metric value and its derivatives. This reduces the computation time (substantially), while convergence properties are maintained. This paper is accompanied with the source code.

scholarly journals Towards a High Order Convergent ALE-SPH Scheme with Efficient WENO Spatial Reconstruction

Water ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2432
Author(s):  
Rubén Antona ◽  
Renato Vacondio ◽  
Diego Avesani ◽  
Maurizio Righetti ◽  
Massimiliano Renzi
Keyword(s):  
Source Code ◽  
High Order ◽  
Moving Least Squares ◽  
Arbitrary Lagrangian Eulerian ◽  
Convergence Properties ◽  
Spatial Reconstruction ◽  
Speed Up ◽  
Sph Algorithm ◽  
The One ◽  
Convergence Of The Scheme

This paper studies the convergence properties of an arbitrary Lagrangian–Eulerian (ALE) Riemann-based SPH algorithm in conjunction with a Weighted Essentially Non-Oscillatory (WENO) high-order spatial reconstruction, in the framework of the DualSPHysics open-source code. A convergence analysis is carried out for Lagrangian and Eulerian simulations and the numerical results demonstrate that, in absence of particle disorder, the overall convergence of the scheme is close to the one guaranteed by the WENO spatial reconstruction. Moreover, an alternative method for the WENO spatial reconstruction is introduced which guarantees a speed-up of 3.5, in comparison with the classical Moving Least-Squares (MLS) approach.

An inertial modified algorithm for solving variational inequalities

2020 ◽  
Vol 54 (1) ◽  
pp. 163-178 ◽  
Author(s):  
Dang Van Hieu ◽  
Pham Kim Quy
Keyword(s):  
Hilbert Spaces ◽  
Lipschitz Constant ◽  
Inertial Effects ◽  
Convergence Properties ◽  
Pseudomonotone Operators ◽  
Lipschitz Continuous ◽  
Strong Pseudomonotonicity ◽  
Computational Performance ◽  
Speed Up ◽  
The Cost

The paper deals with an inertial-like algorithm for solving a class of variational inequality problems involving Lipschitz continuous and strongly pseudomonotone operators in Hilbert spaces. The presented algorithm can be considered a combination of the modified subgradient extragradient-like algorithm and inertial effects. This is intended to speed up the convergence properties of the algorithm. The main feature of the new algorithm is that it is done without the prior knowledge of the Lipschitz constant and the modulus of strong pseudomonotonicity of the cost operator. Several experiments are performed to illustrate the convergence and computational performance of the new algorithm in comparison with others having similar features. The numerical results have confirmed that the proposed algorithm has a competitive advantage over the existing methods.

scholarly journals Resection-Intersection Bundle Adjustment Revisited

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ruan Lakemond ◽  
Clinton Fookes ◽  
Sridha Sridharan
Keyword(s):  
Computer Vision ◽  
Computation Time ◽  
Bundle Adjustment ◽  
Convergence Properties ◽  
Network Modelling ◽  
Essential Components ◽  
Comparable Accuracy ◽  
The Cost ◽  
Over Time ◽  
Sparse Bundle Adjustment

Bundle adjustment is one of the essential components of the computer vision toolbox. This paper revisits the resection-intersection approach, which has previously been shown to have inferior convergence properties. Modifications are proposed that greatly improve the performance of this method, resulting in a fast and accurate approach. Firstly, a linear triangulation step is added to the intersection stage, yielding higher accuracy and improved convergence rate. Secondly, the effect of parameter updates is tracked in order to reduce wasteful computation; only variables coupled to significantly changing variables are updated. This leads to significant improvements in computation time, at the cost of a small, controllable increase in error. Loop closures are handled effectively without the need for additional network modelling. The proposed approach is shown experimentally to yield comparable accuracy to a full sparse bundle adjustment (20% error increase) while computation time scales much better with the number of variables. Experiments on a progressive reconstruction system show the proposed method to be more efficient by a factor of 65 to 177, and 4.5 times more accurate (increasing over time) than a localised sparse bundle adjustment approach.

Design and development of manually operated gladiolus planter

2018 ◽  
Vol 5 (01) ◽  
Author(s):  
TAPAN K. KHURA ◽  
H. L. KUSHWAHA ◽  
SATISH D LANDE ◽  
PKSAHOO . ◽  
INDRA L . KUSHWAHA
Keyword(s):  
Coefficient Of Variation ◽  
Field Capacity ◽  
Power Source ◽  
Forward Speed ◽  
Cereal Crop ◽  
Maximum Coefficient ◽  
Coefficient Of Uniformity ◽  
The Mean ◽  
The Cost ◽  
Immense Potential

Floriculture is an age-old farming activity in India having immense potential for generating selfemployment and income to farmers. However, the cost of cultivation of flower is high as compared to cereal crop. Level of mechanization for different field operations is one but foremost reason for the higher cost of cultivation. As most of the Indian farmers are marginal and small, a need for manually operated gladiolus planter was felt. The geometric properties of gladiolus corm were determined for designing the seed metering system and seed hopper of the planter. The planter was evaluated in the field when pulled by two persons as a power source and guided by a person. The coefficient of variation and highest deviation from the mean spacing was observed as 12.93% and 2.65cm respectively. The maximum coefficient of uniformity of 90.59% was observed for a nominal corm spacing of 15cm at 0.56 kmh-1 forward speed. An average MISS percentage was observed as 2.65 and 2.25 for nominal corm spacing of 15 and 20 cm. The multiple index was zero for two levels corm spacing and forward speed of operation. The QFI was found in the range of 97.2 and 97.9 percent. The average field capacity of the planter was observed as 0.02 hah-1.The average draft requirement of the planter was found as 821 ± 50.3 N.

scholarly journals Seasonal Influenza and Low Flu Vaccination Coverage as Important Factors Modifying the Costs and Availability of Hospital Services in Poland: A Retrospective Comparative Study

2021 ◽  
Vol 18 (10) ◽  
pp. 5173
Author(s):  
Robert Susło ◽  
Piotr Pobrotyn ◽  
Lidia Brydak ◽  
Łukasz Rypicz ◽  
Urszula Grata-Borkowska ◽  
...  
Keyword(s):  
Influenza Season ◽  
Influenza Infection ◽  
Hospital Staff ◽  
University Hospital ◽  
Control Group ◽  
Admission Rates ◽  
Risk Of Death ◽  
The Mean ◽  
Retrospective Comparative Study ◽  
The Cost

Introduction: Influenza infection is associated with potential serious complications, increased hospitalization rates, and a higher risk of death. Materials and Methods: A retrospective comparative analysis of selected indicators of hospitalization from the University Hospital in Wroclaw, Poland, was carried out on patients with confirmed influenza infection in comparison to a control group randomly selected from among all other patients hospitalized on the respective wards during the 2018–2019 influenza season. Results: The mean laboratory testing costs for the entire hospital were 3.74-fold higher and the mean imaging test costs were 4.02-fold higher for patients with confirmed influenza than for the control group; the hospital expenses were additionally raised by the cost of antiviral therapy, which is striking when compared against the cost of a single flu vaccine. During the 2018–2019 influenza season, influenza infections among the hospital patients temporarily limited the healthcare service availability in the institution, which resulted in reduced admission rates to the departments related to internal medicine; the mean absence among the hospital staff totaled approximately 7 h per employee, despite 7.3% of the staff having been vaccinated against influenza at the hospital’s expense. Conclusions: There were significant differences in the hospitalization indicators between the patients with confirmed influenza and the control group, which markedly increased the hospital care costs in this multi-specialty university hospital.

The cost of a general stochastic epidemic

1972 ◽  
Vol 9 (02) ◽  
pp. 257-269 ◽  
Author(s):  
J. Gani ◽  
D. Jerwood
Keyword(s):  
Recursive Equation ◽  
Stieltjes Transform ◽  
Stochastic Epidemic ◽  
The Mean ◽  
The Cost ◽  
Mean Cost ◽  
General Stochastic

This paper is concerned with the cost Cis = aWis + bTis (a, b > 0) of a general stochastic epidemic starting with i infectives and s susceptibles; Tis denotes the duration of the epidemic, and Wis the area under the infective curve. The joint Laplace-Stieltjes transform of (Wis, Tis ) is studied, and a recursive equation derived for it. The duration Tis and its mean Nis are considered in some detail, as are also Wis and its mean Mis . Using the results obtained, bounds are found for the mean cost of the epidemic.

scholarly journals Comparison of the costs of HPV testing through community health campaigns versus home-based testing in rural Western Kenya: a microcosting study

BMJ Open ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. e033979
Author(s):  
Easter Elizabeth Olwanda ◽  
James G Kahn ◽  
Yujung Choi ◽  
Jessica Yasmine Islam ◽  
Megan Huchko
Keyword(s):  
Community Health ◽  
Outcome Measures ◽  
Health Campaigns ◽  
Capital Goods ◽  
Western Kenya ◽  
Home Based ◽  
Registration Number ◽  
The Mean ◽  
The Cost ◽  
Mean Cost

ObjectivesTo estimate the cost of human papillomavirus (HPV)-based screening through community health campaigns (CHCs) and home-based testing.SettingCHCs and home-based testing in six communities in rural Western Kenya.ParticipantsCHCs and home-based screening reached 2297 and 1002 women aged 25–65 years, respectively.Outcome measuresOutcome measures were overall cost per woman screened achieved through the CHCs and home-based testing and the cost per woman for each activity comprising the screening intervention.ResultsThe mean cost per woman screened through CHCs and home-based testing were similar, at $37.7 (range $26.4–$52.0) and $37.1 (range $27.6–$54.0), respectively. For CHCs, personnel represented 49% of overall cost, supplies 25%, services 5% and capital goods 23%. For home-based testing, these were: personnel 73%, supplies 25%, services 1% and capital goods 2%. A greater number of participants was associated with a lower cost per participant.ConclusionsThe mean cost per woman screened is comparable for CHC and home-based testing, with differences in type of input. The CHCs generally reached more eligible women in the six communities, whereas home-based strategies more efficiently reached populations with low screening rates.Trial registration numberNCT02124252.

Optimal stationary strategies in leavable Markov decision processes

1990 ◽  
Vol 27 (01) ◽  
pp. 134-145
Author(s):  
Matthias Fassbender
Keyword(s):  
Transition Probabilities ◽  
Practical Applications ◽  
Stationary Strategies ◽  
Countable State ◽  
Markov Decision ◽  
Bias Optimality ◽  
The Mean ◽  
Optimal Stationary Strategies ◽  
The Cost ◽  
Reward Criterion

This paper establishes the existence of an optimal stationary strategy in a leavable Markov decision process with countable state space and undiscounted total reward criterion. Besides assumptions of boundedness and continuity, an assumption is imposed on the model which demands the continuity of the mean recurrence times on a subset of the stationary strategies, the so-called ‘good strategies'. For practical applications it is important that this assumption is implied by an assumption about the cost structure and the transition probabilities. In the last part we point out that our results in general cannot be deduced from related works on bias-optimality by Dekker and Hordijk, Wijngaard or Mann.

scholarly journals Addition of Flucytosine to Fluconazole for the Treatment of Cryptococcal Meningitis in Africa: A Multicountry Cost-effectiveness Analysis

2019 ◽  
Vol 70 (1) ◽  
pp. 26-29 ◽  
Author(s):  
Tinevimbo Shiri ◽  
Angela Loyse ◽  
Lawrence Mwenge ◽  
Tao Chen ◽  
Shabir Lakhi ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Cost Effectiveness ◽  
Cryptococcal Meningitis ◽  
Cost Effective ◽  
Immunodeficiency Virus ◽  
The Mean ◽  
The Cost ◽  
The Impact ◽  
Costing Analysis ◽  
Very High

Abstract Background Mortality from cryptococcal meningitis remains very high in Africa. In the Advancing Cryptococcal Meningitis Treatment for Africa (ACTA) trial, 2 weeks of fluconazole (FLU) plus flucytosine (5FC) was as effective and less costly than 2 weeks of amphotericin-based regimens. However, many African settings treat with FLU monotherapy, and the cost-effectiveness of adding 5FC to FLU is uncertain. Methods The effectiveness and costs of FLU+5FC were taken from ACTA, which included a costing analysis at the Zambian site. The effectiveness of FLU was derived from cohorts of consecutively enrolled patients, managed in respects other than drug therapy, as were participants in ACTA. FLU costs were derived from costs of FLU+5FC in ACTA, by subtracting 5FC drug and monitoring costs. The cost-effectiveness of FLU+5FC vs FLU alone was measured as the incremental cost-effectiveness ratio (ICER). A probabilistic sensitivity analysis assessed uncertainties and a bivariate deterministic sensitivity analysis examined the impact of varying mortality and 5FC drug costs on the ICER. Results The mean costs per patient were US $847 (95% confidence interval [CI] $776–927) for FLU+5FC, and US $628 (95% CI $557–709) for FLU. The 10-week mortality rate was 35.1% (95% CI 28.9–41.7%) with FLU+5FC and 53.8% (95% CI 43.1–64.1%) with FLU. At the current 5FC price of US $1.30 per 500 mg tablet, the ICER of 5FC+FLU versus FLU alone was US $65 (95% CI $28–208) per life-year saved. Reducing the 5FC cost to between US $0.80 and US $0.40 per 500 mg resulted in an ICER between US $44 and US $28 per life-year saved. Conclusions The addition of 5FC to FLU is cost-effective for cryptococcal meningitis treatment in Africa and, if made available widely, could substantially reduce mortality rates among human immunodeficiency virus–infected persons in Africa.

Optimized Mooring Line Simulation Using a Hybrid Method Time Domain Scheme

2014 ◽  
Author(s):  
Niels Hørbye Christiansen ◽  
Per Erlend Torbergsen Voie ◽  
Jan Høgsberg ◽  
Nils Sødahl
Keyword(s):  
Hybrid Method ◽  
Time Domain ◽  
Computation Time ◽  
Mooring Line ◽  
Mooring Lines ◽  
Fem Model ◽  
Input Variables ◽  
The Time Domain ◽  
The Cost ◽  
Short Time

Dynamic analyses of slender marine structures are computationally expensive. Recently it has been shown how a hybrid method which combines FEM models and artificial neural networks (ANN) can be used to reduce the computation time spend on the time domain simulations associated with fatigue analysis of mooring lines by two orders of magnitude. The present study shows how an ANN trained to perform nonlinear dynamic response simulation can be optimized using a method known as optimal brain damage (OBD) and thereby be used to rank the importance of all analysis input. Both the training and the optimization of the ANN are based on one short time domain simulation sequence generated by a FEM model of the structure. This means that it is possible to evaluate the importance of input parameters based on this single simulation only. The method is tested on a numerical model of mooring lines on a floating off-shore installation. It is shown that it is possible to estimate the cost of ignoring one or more input variables in an analysis.

Sign in / Sign up

Export Citation Format

Share Document