scholarly journals Perturbation analysis of a variable M/M/1 queue: a probabilistic approach

2006 ◽  
Vol 38 (01) ◽  
pp. 263-283 ◽  
Author(s):  
Nelson Antunes ◽  
Christine Fricker ◽  
Fabrice Guillemin ◽  
Philippe Robert
Keyword(s):  
Power Series ◽  
Busy Period ◽  
Stationary Process ◽  
Probabilistic Approach ◽  
Power Series Expansion ◽  
Mean Value ◽  
Service Rate ◽  
The Mean ◽  
The Impact ◽  
Period Duration

In this paper, motivated by the problem of the coexistence on transmission links of telecommunications networks of elastic and unresponsive traffic, we study the impact on the busy period of an M/M/1 queue of a small perturbation in the service rate. The perturbation depends upon an independent stationary process (X(t)) and is quantified by means of a parameter ε ≪ 1. We specifically compute the two first terms of the power series expansion in ε of the mean value of the busy period duration. This allows us to study the validity of the reduced service rate approximation, which consists in comparing the perturbed M/M/1 queue with the M/M/1 queue whose service rate is constant and equal to the mean value of the perturbation. For the first term of the expansion, the two systems are equivalent. For the second term, the situation is more complex and it is shown that the correlations of the environment process (X(t)) play a key role.

scholarly journals Perturbation analysis of a variable M/M/1 queue: a probabilistic approach

2006 ◽  
Vol 38 (1) ◽  
pp. 263-283 ◽  
Author(s):  
Nelson Antunes ◽  
Christine Fricker ◽  
Fabrice Guillemin ◽  
Philippe Robert
Keyword(s):  
Power Series ◽  
Busy Period ◽  
Stationary Process ◽  
Probabilistic Approach ◽  
Power Series Expansion ◽  
Mean Value ◽  
Service Rate ◽  
The Mean ◽  
The Impact ◽  
Period Duration

In this paper, motivated by the problem of the coexistence on transmission links of telecommunications networks of elastic and unresponsive traffic, we study the impact on the busy period of an M/M/1 queue of a small perturbation in the service rate. The perturbation depends upon an independent stationary process (X(t)) and is quantified by means of a parameter ε ≪ 1. We specifically compute the two first terms of the power series expansion in ε of the mean value of the busy period duration. This allows us to study the validity of the reduced service rate approximation, which consists in comparing the perturbed M/M/1 queue with the M/M/1 queue whose service rate is constant and equal to the mean value of the perturbation. For the first term of the expansion, the two systems are equivalent. For the second term, the situation is more complex and it is shown that the correlations of the environment process (X(t)) play a key role.

scholarly journals Dietary acrylamide intake by potato crisps consumers: A case of Nairobi County

2020 ◽  
Vol 5 (1) ◽  
pp. 871-878
Author(s):  
George Ooko Abong ◽  
Jackline Akinyi Ogolla ◽  
Michael Wandayi Okoth ◽  
Bruno De Meulenaer ◽  
Jackson Ntongai Kabira ◽  
...  
Keyword(s):  
Probabilistic Approach ◽  
Mean Value ◽  
Mitigation Measures ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Potato Crisps ◽  
Flame Ionization ◽  
Consumption Data ◽  
Dietary Acrylamide ◽  
The Mean

AbstractThe levels of acrylamide intake because of potato crisps consumption remains unknown in Kenyan context. This study assessed the exposure to acrylamide because of consumption of potato crisps in Nairobi, Kenya. A cross-sectional survey was carried out among 315 crisps consumers in Nairobi, and consumption patterns were collected using a pre-tested structured 7-day recall questionnaire. A total of 43 branded and 15 unbranded potato crisps samples were purchased in triplicates of 100 g and acrylamide was quantified using a gas chromatograph with a flame ionization detector. Consumption data were combined with the data on acrylamide contents from which dietary acrylamide intake was calculated using a probabilistic approach based on @Risk TopRank 6 risk analysis software for excel. The mean estimated acrylamide intake was 1.57 µg/kg body weight (BW) per day while the 95th (P95) percentile was 5.1 µg/kg BW per day, with margins of exposures (MOE) being 197 and 61, respectively. The intake of acrylamide was significantly (P < 0.05) higher in unbranded crisps with a mean value of 2.26 and 95th percentile of 6.54 µg/kg BW per day, MOE being 137 and 47, respectively. There were extremely lower MOE indicating higher exposure to acrylamide by the consumers mainly because of the higher acrylamide contents in potato crisps, and hence the need for mitigation measures.

scholarly journals THE LUCK IN “TALENT VERSUS LUCK” MODELING

2020 ◽  
Vol 23 (03) ◽  
pp. 2050007
Author(s):  
SEAN ELVIDGE
Keyword(s):  
Mean Value ◽  
Maximum Amount ◽  
Random Numbers ◽  
Individual Parameter ◽  
Input Parameters ◽  
The Mean ◽  
Model Variability ◽  
The Impact ◽  
The Relationship

This paper further investigates the Talent versus Luck (TvL) model described by [Pluchino et al. Talent versus luck: The role of randomness in success and failure, Adv. Complex Syst. 21 (2018) 1850014] which models the relationship between ‘talent’ and ‘luck’ on the impact of an individuals career. It is shown that the model is very sensitive to both random sampling and the choice of value for the input parameters. Running the model repeatedly with the same set of input parameters gives a range of output values of over 50% of the mean value. The sensitivity of the inputs of the model is analyzed using a variance-based approach based upon generating Sobol sequences of quasi-random numbers. When using the model to look at the talent associated with an individual who has the maximum capital over a model run it has been shown that the choice for the standard deviation of the talent distribution contributes to 67% of the model variability. When investigating the maximum amount of capital returned by the model the probability of a lucky event at any given epoch has the largest impact on the model, almost three times more than any other individual parameter. Consequently, during the analysis of the model results one must keep in mind the impact that only small changes in the input parameters can have on the model output.

​Impact of Extreme Hot Environmental Temperature Period on Marker Enzymes of Carbohydrate Metabolism in Non-descript Sheep from Arid Tracts of Rajasthan

2021 ◽  
Author(s):  
Anandita Srivastava ◽  
Nalini Kataria
Keyword(s):  
Carbohydrate Metabolism ◽  
Environmental Temperature ◽  
Age Groups ◽  
Extreme Temperature ◽  
Mean Value ◽  
Marker Enzymes ◽  
Mean Values ◽  
The Mean ◽  
The Impact ◽  
Enzymes Of Carbohydrate Metabolism

Background: The present investigation was envisaged to find out the impact of extreme hot environmental temperature period (ETP) on marker enzymes of carbohydrate metabolism in male and female non-descript sheep of various age groups i.e. 4 to 13 months from arid tracts of Rajasthan. Glucose-6-phosphate dehydrogenase (G-6-PDH) and malate dehydrogenase (MDH) marker enzymes of carbohydrate metabolism were considered for study. Methods: During the period October 2016-June 2017 blood samples were collected to harvest sera for spectrophotometric method from 240 healthy animals selected from private slaughter house during moderate and extreme hot environmental temperature periods (ETPs). The mean values of markers attained during moderate ETP were reckoned as the control. It was 10.00 ± 0.10 UL-1 and 42.00±1.00 respectively. Conclusion: The mean value of MDH was significantly (p≤0.05) higher while G-6-PDH significantly (p≤0.05) lowers during extreme hot temperature in comparison to moderate period. Therefore, it could be concluded that variations in enzyme markers were associated with changes in environmental temperatures. Probably ETP were able to produce a profound effect on carbohydrate metabolism in sheep. Therfore it can be suggested that during the period of extreme temperature balanced ration must be provided to the animal along with proper management to decrease the severity of temperature impact.

KUALITAS HIDUP REMAJA YANG MENGALAMI DISMENORE DI SMK NEGERI 2 SUMEDANG

2018 ◽  
Vol 4 (2) ◽  
pp. 129
Author(s):  
Nadya Puspita Dewi ◽  
Tetti Solehati ◽  
Nur Oktavia Hidayati
Keyword(s):  
Quality Of Life ◽  
Sampling Technique ◽  
Mean Value ◽  
Social Dimension ◽  
Validity And Reliability ◽  
School Activities ◽  
Emotional Dimension ◽  
The Mean ◽  
The Impact

Dysmenorrhea is a pain before or during the menstrual period. The impact of dysmenorrhea are the disruption on physical function, emotional, social and school activities and disruption of quality of life. The study purpose is to detect the quality of life of adolescents with dysmenorrhea.The research method was a quantitative descriptive with total sampling technique to 195 students which selected using dysmenorrhea screening. The data were collected using the pediatric quality of life 4.0 generic module (PedsQL) teens report in Indonesian version which the validity and reliability have been tested. Analysis of data has been done to find out the mean value in each dimension and frequency distribution. The results showed that the mean value of the quality of life of adolescents with dysmenorrhea in general was 62,04 ± 8,15 and 51,8% was in the low. The mean value in physical dimension was 49,36 ± 9,19, emotional dimension was 57,62 ± 13,16, social dimension was 86,38 ± 13,28, and in the school dimension was 62,41 ± 14,77. The quality of life in high categories were in the emotional dimension (60,0%), social dimension (64,1%), and school dimension (60,5%). Meanwhile, the quality of life in low category was in the physical dimension (57,4%). It showed that the quality of life of adolescents with dysmenorrhea in SMK Negeri 2 Sumedang were low. It was recommended to the school and the health office in Sumedang district to provide the reproductive health education, specifically about the prevention and the treatment of dysmenorrhea on adolescents.  

Mindfulness and insomnia at pregnancy

2016 ◽  
Vol 33 (S1) ◽  
pp. s269-s269
Author(s):  
M. Marques ◽  
A.T. Pereira ◽  
E. Bento ◽  
S. Xavier ◽  
J. Azevedo ◽  
...  
Keyword(s):  
Anxiety Disorders ◽  
Pregnant Women ◽  
Mean Value ◽  
Inner Experience ◽  
The Mean ◽  
Competing Interest ◽  
Acting With Awareness ◽  
The Impact ◽  
Insomnia Symptoms ◽  
In Pregnancy

IntroductionThe impact of mindfulness in improving insomnia symptoms is documented in different samples (e.g. anxiety disorders; insomnia samples) and mindfulness based programs for pregnancy refer the association between mindfulness development and the reduction of insomnia symptoms/improvement of sleep.ObjectiveTo explore differences in the Facets Mindfulness Questionnaire-10 (FMQ-10; Azevedo et at. 2015), between sleep groups, in Portuguese pregnant women.MethodsFour hundred and nineteen pregnant women (mean age: 32.51 ± 4.759; weeks of gestation: 17.32 ± 4.803) answered the Facets Mindfulness Questionnaire-10 and the Insomnia Assessment Scale (IAS, Marques et al., 2015). Three sleep groups were created considering all the IAS items: good sleepers (no insomnia symptoms; no associated daily impairment); insomnia symptoms groups (one/more insomnia symptoms; no associated daily impairment; exclusion of other conditions/disorders explaining the symptoms); insomniacs (one/more insomnia symptoms; one/more daily associated impairment; exclusion of other conditions/disorders explaining the symptoms).ResultsThere were significant differences in the total FMQ-10 score, the F1/Nonjudging of inner experience and the F2/acting with awareness, between sleep groups [respectively, F (2.402) = 6,933; P = 0.001; F (2.406) = 10.243; P = 0.001; F (2.406) = 37.431; P = 0.002]. Tukey tests indicated that the mean total FMQ-10 and F1/Nonjudging of inner experience scores of good sleepers and insomnia symptoms group were significantly higher than of the insomniacs. The mean value of F2/acting with awareness in the good sleepers was significantly higher than of the insomniacs.ConclusionsIt seems important to develop mindfulness to improve sleep in pregnancy or reduce the impact of insomnia symptoms (common at pregnancy).Disclosure of interestThe authors have not supplied their declaration of competing interest.

A Study of Ecological Water Use Based on the Improved Tennant Method

2010 ◽  
Vol 113-116 ◽  
pp. 1504-1508 ◽  
Author(s):  
Jing Huan Tian ◽  
Ling Yu ◽  
Zhi Hong Zheng
Keyword(s):  
Water Use ◽  
Traditional Method ◽  
Extreme Values ◽  
Mean Value ◽  
Improved Method ◽  
Existing Problems ◽  
Runoff Series ◽  
Tennant Method ◽  
The Mean ◽  
The Impact

To solve the existing problems arose in the Tennant method for estimating ecological water use in river course, a new methodology is proposed to replace the mean value by the median of runoff series in the Tenna nt formula. The motive is to eliminate the impact of some extreme values. Given runoff series of 47 years in Jiaokou reservoir of Zhangxi River, the traditional and the improved method were respectively applied to calculate the ecological water consumption in the river. The results show that the improved Tennant method is more reasonably than the traditional method.

scholarly journals On the Location of the Maximum of a Continuous Stochastic Process

2014 ◽  
Vol 51 (01) ◽  
pp. 152-161 ◽  
Author(s):  
Leandro P. R. Pimentel
Keyword(s):  
Stochastic Process ◽  
Brownian Motion ◽  
Stationary Process ◽  
Mean Value ◽  
Necessary Condition ◽  
Linear Perturbation ◽  
Short Article ◽  
Underlying Process ◽  
The Mean ◽  
Sufficient And Necessary Condition

In this short article we will provide a sufficient and necessary condition to have uniqueness of the location of the maximum of a stochastic process over an interval. The result will also express the mean value of the location in terms of the derivative of the expectation of the maximum of a linear perturbation of the underlying process. As an application, we will consider a Brownian motion with variable drift. The ideas behind the method of proof will also be useful to study the location of the maximum, over the real line, of a two-sided Brownian motion minus a parabola and of a stationary process minus a parabola.

scholarly journals Significant Effect of Project Based Learning Video on Students’ Listening Skill in Pandemic Situation

2021 ◽  
Vol 5 (2) ◽  
pp. 425
Author(s):  
Ni Wayan Febiyanti ◽  
Putu Kerti Nitiasih ◽  
Luh Gd Rahayu Budiarta ◽  
Ni Luh Putu Era Adnyayanti
Keyword(s):  
Standard Deviation ◽  
Quantitative Research ◽  
Listening Comprehension ◽  
Mean Value ◽  
Project Based Learning ◽  
School Students ◽  
Innovative Teaching ◽  
Listening Skill ◽  
The Mean ◽  
The Impact

Listening is one of the most important language skills to be learned by students. However, it is very difficult for teachers to teach these skills in learning during the Covid-19 pandemic. Teachers need innovative teaching techniques, one of which is using video media. This study aims to investigate the impact of using project-based learning videos on students' listening comprehension skills. The population in this study involved 4th grade elementary school students. The sample in this study used 40 grade 4 students from one intact class that were selected with a specific purpose. This research includes quantitative research with one group pretest-posttest design. The data collection instrument in this study used a listening comprehension test and a listening comprehension assessment rubric. The data collected were analyzed using descriptive and inferential statistical analysis. From the results of the study, it was found that the mean value of the group at the posttest was 86.85 which was greater than the mean value at the pretest, which was 75.75. The standard deviation on the pretest also shows a value of 5,678 and the standard deviation on the posttest is 3,180. From the results of statistical inferential analysis shows that the value of Sig. (2-tailed) is .000. and lower than Sig. levels (.05). Therefore, it can be concluded that there is a significant impact on the use of project-based learning videos on students' listening comprehension during the covid-19 pandemic.

scholarly journals The Impact of Strengthening Exercise on Dynamic Balance in Patients with Knee Osteoarthritis

2021 ◽  
Vol 15 (10) ◽  
pp. 3429-3431
Author(s):  
Shenbaga Subramanian Sundaram ◽  
Makesh Babu Subramanian ◽  
Riziq Allah Mustafa Gaowgeh ◽  
Mikhled Falah Maayah ◽  
Ziyad Neamatallah ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Dynamic Balance ◽  
Mean Value ◽  
Control Group ◽  
P Value ◽  
Strengthening Exercise ◽  
Significant Difference ◽  
The Mean ◽  
The Impact ◽  
Experimental Group

Background: Knee osteoarthritis is characterised clinically by usage-related pain and/or functional limitation. OA that is associated with physical dysfunction and decline in health-related quality of life caused the main disability worldwide and is expected to increase due to aging and obesity rates and further load on the population and health system. The strengthening exercises that normally used is knee flexion and extensions, isometric quadriceps exercise, isometric hamstring exercise, and sit to stand to improve the balance. Objectives: is to find out the impact of Strengthening exercise on Balance in patients with knee Osteoarthritis Study Design: Quasi experimental study Methods: Fifty-six (n=56) of knee OA patients were involved in this study by judgemental sampling design. Researcher will first demonstrate and explain the Y-balance tools testing procedure based on Plisky and colleagues study. Participants are given to practice six trials before the formal testing, stated that SEBT have a significant learning effect and found that the reaching distances reached the longest distance after six trials and then will be constant. Results: Independent t-test shows significant difference in only anterior direction. In the experimental group the mean value is 69.83 with a SD of 11.62 while in the control group the mean value is 63.51 with a SD of 11.36; p-value of .045 and t-value of 2.056. In postero-lateral directions result shows there is no significant difference, experimental group the mean value is 91.10 with a SD of 9.74 while in control group mean value is 90.88 with SD value of 12.68; p-value of .947 and t-value of .067. Result of postero-medial shows no significant difference too, in experimental group the mean value of 95.16 with SD of 10.92 while in control group the mean value is 93.40 with SD of 8.20; p=value of .501 and t-value of .678. Conclusion: This study has proven strengthening exercise using YBT improved only anterior direction of YBT but no significant difference in postero-lateral and postero-medial direction. Key Words: Knee Osteoarthritis, Strengthening exercise, Dynamic Balance, Star excursion test

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