scholarly journals Investigation of error in evaluation of spectral statistical characteristics of numerical solution of stochastic dynamic system

2021 ◽  
pp. 60-65
Author(s):  
Yaroslav Beskrovnii ◽  
Oleksii Larin
Keyword(s):  
Confidence Interval ◽  
Dynamic System ◽  
Numerical Solution ◽  
Numerical Integration ◽  
Numerical Solutions ◽  
Stochastic Perturbation ◽  
Digital Processing ◽  
Statistical Characteristics ◽  
Stochastic Dynamic

In this paper, an algorithm for numerical simulations is developed for calculating a discrete dynamic system with a stochastic perturbation and an analysis of the quality of numerical solutions is carried out. For this, an algorithm for the numerical solution of a second-order differential equation with a stochastic right-hand side was developed and this algorithm was implemented as a program. The next step was to carry out a set of computational studies by varying the parameters of numerical integration with the subsequent assessment of their impact on the error and accuracy of simulations. To estimate the spectral density, the Welch periodogram method was used. To check the quality of simulations and assess the accuracy of solutions, it is proposed to compare the results of numerical integration and subsequent digital processing with analytical solutions that are known for the linear problem, given by the equation. As a result of the work, a comparative analysis of the dispersion of displacements relative to the lengths of signals from a different number of blocks was carried out, into which the signal is divided for the Welch method; the confidence interval of the error at different signal lengths and the confidence interval of the error with a different number of blocks at a certain signal length. Comparison of the variance with a different number of blocks showed that with a signal length of 30 s and from 90 s, there is a slight scatter of the variance values within an error of ± 5%.

scholarly journals Quantitative Trait Loci: A Meta-analysis

Genetics ◽  
2000 ◽  
Vol 155 (1) ◽  
pp. 463-473
Author(s):  
Bruno Goffinet ◽  
Sophie Gerber
Keyword(s):  
Quantitative Trait Loci ◽  
Confidence Interval ◽  
Quantitative Trait ◽  
Meta Analysis ◽  
Trait Loci ◽  
Akaike Criterion ◽  
Using Data

Abstract This article presents a method to combine QTL results from different independent analyses. This method provides a modified Akaike criterion that can be used to decide how many QTL are actually represented by the QTL detected in different experiments. This criterion is computed to choose between models with one, two, three, etc., QTL. Simulations are carried out to investigate the quality of the model obtained with this method in various situations. It appears that the method allows the length of the confidence interval of QTL location to be consistently reduced when there are only very few “actual” QTL locations. An application of the method is given using data from the maize database available online at http://www.agron.missouri.edu/.

scholarly journals A fractional order epidemic model for the simulation of outbreaks of Ebola

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Weiqiu Pan ◽  
Tianzeng Li ◽  
Safdar Ali
Keyword(s):  
Numerical Solution ◽  
Root Mean Square ◽  
Fractional Order ◽  
Relative Error ◽  
Numerical Solutions ◽  
Real Data ◽  
Mean Square ◽  
Order Model ◽  
The Real ◽  
Fractional Orders

AbstractThe Ebola outbreak in 2014 caused many infections and deaths. Some literature works have proposed some models to study Ebola virus, such as SIR, SIS, SEIR, etc. It is proved that the fractional order model can describe epidemic dynamics better than the integer order model. In this paper, we propose a fractional order Ebola system and analyze the nonnegative solution, the basic reproduction number $R_{0}$ R 0 , and the stabilities of equilibrium points for the system firstly. In many studies, the numerical solutions of some models cannot fit very well with the real data. Thus, to show the dynamics of the Ebola epidemic, the Gorenflo–Mainardi–Moretti–Paradisi scheme (GMMP) is taken to get the numerical solution of the SEIR fractional order Ebola system and the modified grid approximation method (MGAM) is used to acquire the parameters of the SEIR fractional order Ebola system. We consider that the GMMP method may lead to absurd numerical solutions, so its stability and convergence are given. Then, the new fractional orders, parameters, and the root-mean-square relative error $g(U^{*})=0.4146$ g ( U ∗ ) = 0.4146 are obtained. With the new fractional orders and parameters, the numerical solution of the SEIR fractional order Ebola system is closer to the real data than those models in other literature works. Meanwhile, we find that most of the fractional order Ebola systems have the same order. Hence, the fractional order Ebola system with different orders using the Caputo derivatives is also studied. We also adopt the MGAM algorithm to obtain the new orders, parameters, and the root-mean-square relative error which is $g(U^{*})=0.2744$ g ( U ∗ ) = 0.2744 . With the new parameters and orders, the fractional order Ebola systems with different orders fit very well with the real data.

Effects of electromyographic biofeedback interventions for shoulder pain and function: Systematic review and meta-analysis

2021 ◽  
pp. 026921552199095
Author(s):  
Danilo Harudy Kamonseki ◽  
Letícia Bojikian Calixtre ◽  
Rodrigo Py Gonçalves Barreto ◽  
Paula Rezende Camargo
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Confidence Interval ◽  
Shoulder Pain ◽  
Meta Analysis ◽  
Quality Of Evidence ◽  
Electromyographic Biofeedback ◽  
Mean Differences ◽  
And Function

Objective: To systematically review the effectiveness of electromyographic biofeedback interventions to improve pain and function of patients with shoulder pain. Design: Systematic review of controlled clinical trials. Literature search: Databases (Medline, EMBASE, CINAHL, PEDro, CENTRAL, Web of Science, and SCOPUS) were searched in December 2020. Study selection criteria: Randomized clinical trials that investigated the effects of electromyographic biofeedback for individuals with shoulder pain. Patient-reported pain and functional outcomes were collected and synthesized. Data synthesis: The level of evidence was synthesized using GRADE and Standardized Mean Differences and 95% confidence interval were calculated using a random-effects inverse variance model for meta-analysis. Results: Five studies were included with a total sample of 272 individuals with shoulder pain. Very-low quality of evidence indicated that electromyographic biofeedback was not superior to control for reducing shoulder pain (standardized mean differences = −0.21, 95% confidence interval: −0.67 to 0.24, P = 0.36). Very-low quality of evidence indicated that electromyographic biofeedback interventions were not superior to control for improving shoulder function (standardized mean differences = −0.11, 95% confidence interval: −0.41 to 0.19, P = 0.48). Conclusion: Electromyographic biofeedback may be not effective for improving shoulder pain and function. However, the limited number of included studies and very low quality of evidence does not support a definitive recommendation about the effectiveness of electromyographic biofeedback to treat individuals with shoulder pain.

Transient Two-Dimensional Heat Conduction Problem With Partial Heating Near Corners

2016 ◽  
Author(s):  
Robert L. McMasters ◽  
Filippo de Monte ◽  
James V. Beck ◽  
Donald E. Amos
Keyword(s):  
Heat Conduction ◽  
Numerical Integration ◽  
Analytical Solutions ◽  
Numerical Solutions ◽  
Thermal Protection ◽  
Heat Conduction Problem ◽  
Separation Of Variables ◽  
Two Dimensional ◽  
Rectangular Region ◽  
Long Distance

This paper provides a solution for two-dimensional heating over a rectangular region on a homogeneous plate. It has application to verification of numerical conduction codes as well as direct application for heating and cooling of electronic equipment. Additionally, it can be applied as a direct solution for the inverse heat conduction problem, most notably used in thermal protection systems for re-entry vehicles. The solutions used in this work are generated using Green’s functions. Two approaches are used which provide solutions for either semi-infinite plates or finite plates with isothermal conditions which are located a long distance from the heating. The methods are both efficient numerically and have extreme accuracy, which can be used to provide additional solution verification. The solutions have components that are shown to have physical significance. The extremely precise nature of analytical solutions allows them to be used as prime standards for their respective transient conduction cases. This extreme precision also allows an accurate calculation of heat flux by finite differences between two points of very close proximity which would not be possible with numerical solutions. This is particularly useful near heated surfaces and near corners. Similarly, sensitivity coefficients for parameter estimation problems can be calculated with extreme precision using this same technique. Another contribution of these solutions is the insight that they can bring. Important dimensionless groups are identified and their influence can be more readily seen than with numerical results. For linear problems, basic heating elements on plates, for example, can be solved to aid in understanding more complex cases. Furthermore these basic solutions can be superimposed both in time and space to obtain solutions for numerous other problems. This paper provides an analytical two-dimensional, transient solution for heating over a rectangular region on a homogeneous square plate. Several methods are available for the solution of such problems. One of the most common is the separation of variables (SOV) method. In the standard implementation of the SOV method, convergence can be slow and accuracy lacking. Another method of generating a solution to this problem makes use of time-partitioning which can produce accurate results. However, numerical integration may be required in these cases, which, in some ways, negates the advantages offered by the analytical solutions. The method given herein requires no numerical integration; it also exhibits exponential series convergence and can provide excellent accuracy. The procedure involves the derivation of previously-unknown simpler forms for the summations, in some cases by virtue of the use of algebraic components. Also, a mathematical identity given in this paper can be used for a variety of related problems.

Analysis of Inventory Management in Reverse Supply Chain Using Stochastic Dynamic Programming Model

2008 ◽  
Author(s):  
Badr O. Johar ◽  
Surendra M. Gupta
Keyword(s):  
Dynamic Programming ◽  
Inventory Management ◽  
Reverse Logistics ◽  
Stochastic Dynamic Programming ◽  
Public Awareness ◽  
Financial Burden ◽  
Probabilistic Approach ◽  
Complex Nature ◽  
Stochastic Dynamic

Reverse logistics is a critical topic that has captured the attention of government, private entities and researchers in recent years. This increase in the concern was driven by current set of government regulations, increase of public awareness, and the attractive economic opportunities. Also, environmentalists have always demanded Original Equipment Manufacturers (OEMs) to be more involved and be responsible of their products at the end of its life cycle. However, the uncertainty in quality of items returned, and its quantity discourage OEMs from participating in such programs. Because of the unique problems associated and the complex nature of the reverse logistics activities, numerous studies have been carried out in this field. One of those crucial areas is inventory management of End-of-Life (EOL) products. The take back program could possibly bring financial burden to OEM if it is not managed well. Thus, an efficient yet cost effective system should be implemented to appropriately manage the overwhelming number of returns. Previously, we have analyzed the problem based on the assumption that the number of core products returned and disassembled parts and subassemblies are known in advance. In this paper, we introduce a probabilistic approach where different quality levels of for every component disassembled are considered and different probabilities of these qualities given the quality of the returned product. The model utilizes a multi-period stochastic dynamic programming in a disassembly line context to solve the problem, and generate the best option that will maximize the system total profit. A numerical example is given to illustrate the approach. Finally, directions for future research are suggested.

scholarly journals Effect of Hope-oriented group counseling on mental health of infertile women with failed IVF cycles: a randomized controlled trial

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Roya Rahimi ◽  
Shirin Hasanpour ◽  
Mojgan. Mirghafourvand ◽  
Khalil Esmaeilpour
Keyword(s):  
Mental Health ◽  
Confidence Interval ◽  
Group Counseling ◽  
Controlled Trial ◽  
Intervention Group ◽  
Mean Difference ◽  
Control Group ◽  
The Mean ◽  
And Control

Abstract Background Considering the prevalence of infertility in the community and the consequences of failure of infertility treatments on women’s mental health, interventions that can control stress, anxiety and depression in infertile women with a history of IVF failure will be very helpful. This study aimed to determine the effects of hope-oriented group counseling on mental health (primary outcome) and quality of life (QoL) (secondary outcome) of women with failed IVF cycles. Method This randomized controlled trial was conducted on 60 women with failed IVF cycles visiting Infertility Clinic at Al-Zahra Teaching Hospital of Tabriz- Iran. Participants were allocated to the intervention group (n = 30) and control group (n = 30) based on a randomized block design. Hope-oriented group counseling was provided to the intervention group in six 45–60 min sessions (once a week). The control group only received routine care to undergo another IVF cycle. The Depression Anxiety Stress Scale-21 (DASS-21) and the SF-12 Quality of Life Scale were filled out by interviewing the participants before the intervention and one week and one month after the intervention. After intervention 26 participants in each group were included in the analysis. Results There was no significant difference between the intervention and control groups in the socio-demographic profile of participants (P > 0.05). The post-intervention mean score of stress (adjusted mean difference = − 1.7, 95% confidence interval: − 3.2 to − 0.3, P = 0.018) and depression (adjusted mean difference = − 1.3, 95% confidence interval: − 4.7 to − 1.5, P < 0.001) was significantly lower in the intervention group compared to the control. Although the mean anxiety score was lower in the intervention group compared to the control, the difference between them was not statistically significant (adjusted mean difference = − 1.1, 95% confidence interval: − 2.6 to 0.4, P = 0.153). The mean score of QoL was significantly higher in the intervention group than that of the control group (adjusted mean difference = 6.9, 95% confidence interval: 5.1 to 8.8, P < 0.001). Conclusion Hope-oriented group counseling was effective in reducing stress and depression and improving QoL in women with failed IVF cycles. It is recommended to use this counseling approach, along with other methods, to improve the mental health of women with failed IVF cycles. Trial registration TCT Registration Number: TCTR 20191017003, registered on October 17, 2019.

Stochastic Dynamic Analysis and Reliability of a Vessel Rolling in Random Beam Seas

2015 ◽  
Vol 59 (02) ◽  
pp. 113-131
Author(s):  
Wei Chai ◽  
Arvid Naess ◽  
Bernt J. Leira
Keyword(s):  
Dynamic System ◽  
Markov Property ◽  
Planck Equation ◽  
Linear Filter ◽  
Stochastic Dynamic ◽  
Theoretical Principle ◽  
Pi Method ◽  
Beam Seas ◽  
Stochastic Dynamic Analysis ◽  
High Level

This article presents a four-dimensional (4D) path integration (PI) approach to study the stochastic roll response and reliability of a vessel in random beam seas. Specifically, a 4D Markov dynamic system is established by combing the single-degree-of freedom model used to represent the ship rolling behavior in random beam seas with a second-order linear filter used to approximate the stationary roll excitation moment. On the basis of the Markov property of the coupled 4D dynamic system, the response statistics of roll motion can be obtained by solving the Fokker-Planck equation of the dynamic system via the 4D PI method. The theoretical principle and numerical implementation of the current state of the art 4D PI method are presented. Moreover, the numerical robustness and accuracy of the 4D PI method are evaluated by comparing with the results obtained by the application of Monte Carlo simulation (MCS). The influence of the restoring terms and the damping terms on the stochastic roll response are investigated. Furthermore, based on the well-known Poisson assumption and the response statistics yielded by the 4D PI technique, evaluation of the reliability associated with high-level response is performed. The performance of the Poisson estimate for different levels of external excitations is evaluated by the versatile MCS technique.

scholarly journals Adjustment of oxygen use by means of pulse oximetry: an important tool for patient safety

2010 ◽  
Vol 8 (4) ◽  
pp. 449-455 ◽  
Author(s):  
Telma de Almeida Busch Mendes ◽  
Paola Bruno de Araújo Andreoli ◽  
Leny Vieira Cavalheiro ◽  
Claudia Talerman ◽  
Claudia Laselva
Keyword(s):  
Patient Safety ◽  
Quality Of Care ◽  
Physical Therapy ◽  
Confidence Interval ◽  
Pulse Oximetry ◽  
Patient Care ◽  
Physical Therapists ◽  
Severe Damage ◽  
Margin Of Error

ABSTRACT Objective: To assess patient's level of oxygenation by means of pulse oximetry, avoiding hypoxia (that causes rapid and severe damage), hyperoxia, and waste. Methods: Calculations were made with a 7% margin of error and a 95% confidence interval. Physical therapists were instructed to check pulse oximetry of all patients with prescriptions for physical therapy, observing the scheduled number of procedures. Results: A total of 129 patients were evaluated. Hyperoxia predominated in the sectors in which the patient was constantly monitored and hypoxia in the sectors in which monitoring was not continuous. Conclusions: Professionals involved in patient care must be made aware of the importance of adjusting oxygen use and the risk that non-adjustment represents in terms of quality of care and patient safety.

scholarly journals Unconditional Positive Stable Numerical Solution of Partial Integrodifferential Option Pricing Problems

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
M. Fakharany ◽  
R. Company ◽  
L. Jódar
Keyword(s):  
Option Pricing ◽  
Numerical Solution ◽  
Numerical Solutions ◽  
Stable Process ◽  
Integration Formula ◽  
Pricing Models ◽  
Integral Term ◽  
Pricing Problems ◽  
Stability And Consistency ◽  
Partial Integrodifferential Equation

This paper is concerned with the numerical solution of partial integrodifferential equation for option pricing models under a tempered stable process known as CGMY model. A double discretization finite difference scheme is used for the treatment of the unbounded nonlocal integral term. We also introduce in the scheme the Patankar-trick to guarantee unconditional nonnegative numerical solutions. Integration formula of open type is used in order to improve the accuracy of the approximation of the integral part. Stability and consistency are also studied. Illustrative examples are included.

Systematic Review and Meta-Analysis on Using Acupressure to Promote the Health of Older Adults

2019 ◽  
Vol 39 (10) ◽  
pp. 1144-1152 ◽  
Author(s):  
Meng-Chin Chen ◽  
Li-Yen Yang ◽  
Kuei-Min Chen ◽  
Hui-Fen Hsu
Keyword(s):  
Quality Of Life ◽  
Systematic Review ◽  
Older Adults ◽  
Health Promotion ◽  
Confidence Interval ◽  
Meta Analysis ◽  
Common Elements ◽  
The Common ◽  
Moderate Effect

Acupressure is noninvasive, safe, and appropriate for use among older adults. However, there remains little evidence of the common elements that contribute to the effectiveness of acupressure in promoting the health of older adults. A systematic review using meta-analysis was designed to examine the effects of acupressure on the health promotion in older adults. Studies published between 2012 and 2017 were searched for in 11 electronic databases. Acupressure was highly effective for improving sleep quality and cognitive functioning (0.85, 95% confidence interval [CI] = [0.49, 1.22]; 1.23, 95% CI = [0.88, 1.59]). A slight to moderate effect was found in alleviating constipation (0.37, 95% CI = [0.03, 0.71]), and a moderate effect was found for alleviating pain and improving quality of life (0.71, 95% CI = [0.09, 1.32]; 0.59 95% CI = [0.36, 0.82]).

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