scholarly journals Availability Analysis of Hybrid Systems Consisting of Main Units and Cold Standby Processors

2021 ◽  
Author(s):  
Ibrahim Yusuf ◽  
Nafisatu Muhammad Usman ◽  
Saminu Iliyasu Bala
Keyword(s):  
Hybrid Systems ◽  
Numerical Experiments ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Critical Parameters ◽  
System Parameters ◽  
First Order ◽  
Availability Analysis ◽  
Linear Differential ◽  
Partial Rank Correlation

The present paper studies availability of four hybrid systems configured as series-parallel systems. Each system or configuration consisting of main units and their corresponding processors. Configuration I consist of three processors is a 2-out-of-3 unit connected to 2-out-of-3 processors, Configuration II is a 2-out-of-3 unit connected to 2-out-of-4 processors, Configuration III is a 2-out-of-4 unit connected to 2-out-of-4 processors while Configuration IV is a 2-out-of-4 unit connected to 2-out-of-3 processors. The failure and repair times of units and their processors are assumed to be exponentially distributed. Explicit expressions for steady state availability are developed for each system using first order linear differential difference equations and validated by performing numerical experiments. Analysis of the effect of various system parameters on availability was performed. Graphical illustrations are given to highlight important results. The systems are ranked based on their availability and found that Configuration IV is better. Sensitivity analysis on the model’s outcomes are performed using partial rank correlation coefficients (PRCC) to determine the most critical parameters leading to increase (decrease) in the value of availability.

scholarly journals Quantifying the dose-dependent impact of intracellular amyloid beta in a mathematical model of calcium regulation in xenopus oocyte

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0246116
Author(s):  
Joseph Minicucci ◽  
Molly Alfond ◽  
Angelo Demuro ◽  
David Gerberry ◽  
Joe Latulippe
Keyword(s):  
Mathematical Model ◽  
Amyloid Beta ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Dependent Manner ◽  
Partial Rank Correlation ◽  
Dose Dependent ◽  
Detrimental Impact ◽  
Oligomeric Forms

Alzheimer’s disease (AD) is a devastating illness affecting over 40 million people worldwide. Intraneuronal rise of amyloid beta in its oligomeric forms (iAβOs), has been linked to the pathogenesis of AD by disrupting cytosolic Ca2+ homeostasis. However, the specific mechanisms of action are still under debate and intense effort is ongoing to improve our understanding of the crucial steps involved in the mechanisms of AβOs toxicity. We report the development of a mathematical model describing a proposed mechanism by which stimulation of Phospholipase C (PLC) by iAβO, triggers production of IP3 with consequent abnormal release of Ca2+ from the endoplasmic reticulum (ER) through activation of IP3 receptor (IP3R) Ca2+ channels. After validating the model using experimental data, we quantify the effects of intracellular rise in iAβOs on model solutions. Our model validates a dose-dependent influence of iAβOs on IP3-mediated Ca2+ signaling. We investigate Ca2+ signaling patterns for small and large iAβOs doses and study the role of various parameters on Ca2+ signals. Uncertainty quantification and partial rank correlation coefficients are used to better understand how the model behaves under various parameter regimes. Our model predicts that iAβO alter IP3R sensitivity to IP3 for large doses. Our analysis also shows that the upstream production of IP3 can influence Aβ-driven solution patterns in a dose-dependent manner. Model results illustrate and confirm the detrimental impact of iAβOs on IP3 signaling.

scholarly journals HUMAN POPULATION EFFECTS ON THE ULSOOR LAKE FISH SURVIVAL

2018 ◽  
Vol 26 (04) ◽  
pp. 603-632 ◽  
Author(s):  
PANKAJ KUMAR TIWARI ◽  
IULIA MARTINA BULAI ◽  
FRANCESCA BONA ◽  
EZIO VENTURINO ◽  
ARVIND KUMAR MISRA
Keyword(s):  
Human Population ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Organic Pollution ◽  
Fish Population ◽  
Fish Mortality ◽  
Human Populations ◽  
Sewage Farm ◽  
Fish Survival ◽  
Partial Rank Correlation

In this paper, we introduce a model to study the effects of human populations on fish survival in aquatic media. Directly, this occurs by fishing. Indirectly instead this is related to other human actions that lead to organic pollution and consequently low dissolved oxygen(DO) levels, thereby harming the aquatic fauna. Mathematically, we consider various nonlinear processes involving human population, organic pollutants, bacteria, DO and fish population. In the present study, our aim is to investigate the effect of depleted level of DO on the survival of fish populations in such an aquatic system. The case study in consideration is represented by the Ulsoor lake, Bengaluru, India. Into it, huge amounts of sewage were discharged and resulted in reduction of DO level and massive fish mortality. Equilibria are analyzed for feasibility and stability, substantiated via numerical simulations. Global sensitivity analysis identifies the important parameters having a significant impact on the fish population. The Partial Rank Correlation Coefficients (PRCCs) values of fish population in the lake with respect to input parameters of the system show that the growth rate of humans in the lake watershed has maximum negative correlation while the growth in the fish population due to DO has maximum positive correlation with the density of fish population in the lake. The results show that increase in human population may decrease fish population in the system to very low values. However, by controlling additional dissolved organic loads coming from domestic sewage, farm waste and many other sources, the level of DO can be brought back to values that allow fish survival. Maintaining it at these levels would preserve the ecosystem.

Best Estimate Analysis of Maanshan PWR LBLOCA by TRACE Coupling With DAKOTA

2014 ◽  
Author(s):  
Jung-Hua Yang ◽  
Jong-Rong Wang ◽  
Hao-Tzu Lin ◽  
Chunkuan Shih
Keyword(s):  
Power Plant ◽  
Input Data ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Best Estimate ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant ◽  
Probability Calculation ◽  
Partial Rank Correlation ◽  
Limiting Values

This research is focused on the Large Break Loss of Coolant Accident (LBLOCA) analysis of the Maanshan power plant by TRACE-DAKOTA code. In the acceptance criteria for Loss of Coolant Accidents (LOCAs), there are two accepted analysis methods: conservative methodology and best estimate methodology. Compared with conservative methodology, the best estimate and realistic input data with uncertainties to quantify the limiting values i.e., Peak Cladding Temperature (PCT) for LOCAs analysis. By the conservative methodology, the PCTCM (PCT calculated by conservative methodology) of Maanshan power plant LBLOCA calculated is 1422K. On the other hand, there are six key parameters taken into account in the uncertainty analysis in this study. In PCT95/95 (PCT of 95/95 confidence level and probability) calculation, the PCT95/95 is 1369K lower than the PCTCM (1422K). In addition, the partial rank correlation coefficients between input parameters and PCT indicate that accumulator pressure is the most sensitive parameter in this study.

scholarly journals A mathematical model for Dengue and Chikungunya in Mexico

2017 ◽  
Author(s):  
Nohemí Báez-Hernández ◽  
Mauricio Casas-Martínez ◽  
Rogelio Danis-Lozano ◽  
Jorge X. Velasco-Hernández
Keyword(s):  
Rank Correlation ◽  
Correlation Coefficients ◽  
Negative Influence ◽  
Positive Influence ◽  
Vector Population ◽  
Secondary Infections ◽  
Biting Rate ◽  
Reproduction Numbers ◽  
Partial Rank Correlation ◽  
Parameter Values

AbstractWe present a model that incorporates two co-circulating viral diseases, Dengue and Chikungunya, where we allow secondary infections from either of the two diseases. We only consider one vector population, Ae. aegypti since in the Mexican region where we set our scenarios, only this species has been reported to transmit both viruses. We estimate the basic reproduction number and perform numerical simulations for different scenarios where we may observe coexistence of Dengue and Chikungunya; we also compare the results of the model with Dengue and Chikungunya data from Mexico 2015 and we obtain a good model fit. To complete our findings we perform a sensitivity analysis, and calculate the partial rank correlation coefficients (PRCCs) to determine the parameter values influence on the reproduction numbers and predict fate of the diseases.We show that R0 for each one of the viruses is highly sensitive to the mosquito biting rate and the transmission rates for both diseases with positive influence and the average lifespan of mosquito along with the human recovery rate with negative influence on both diseases. Our results are consistent with those of previous authors.

scholarly journals Prevention and Control of Tuberculosis Relying on a Tuberculosis Dynamic Model Based on the Cases of American

2020 ◽  
Author(s):  
Yan Wu ◽  
Meng Huang ◽  
Ximei Wang ◽  
Yong Li ◽  
Lei Jiang ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Prevention And Control ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Latin Hypercube Sampling ◽  
The Sustainable Development ◽  
United State ◽  
Partial Rank Correlation ◽  
And Control ◽  
Protection Period

Abstract Background: Tuberculosis (TB) which is a preventable and curable disease, is claimed as the second largest number of fatalities and there are 9,025 cases reported in the United State in 2018. Many researches have done a lot of research and achieved remarkable results, but TB is also a serious problem for human being.The study is a further exploration. Methods: In the paper, we propose a new dynamic model to study the transmission dynamics of TB, then use global differential evolution and local sequential quadratic programming (DESQP) optimization algorithm to estimate parameters of the model. Finally, we use Latin hypercube sampling (LHS) and partial rank correlation coefficients (PRCC) to analyze the influence of parameters on the basic reproduction number (R0) and the total infectious (including the diagnosed, undiagnosed and incomplete treatment infectious), respectively. Results: By the research, the basic reproduction is computed as 2.3597 which means TB will be epidemic in US. The diagnosed rate is 0.6082 which means the undiagnosed will be diagnosed after 1.6442 years. The diagnosed will be recovered with an average of 1.9912 years, especially, some diagnosed will end the treatment after 1.7550 years, for some reasons. By the study, it’s shown that there are 2.4% of the recovered will be reactivated and 13.88% of the newborn will be vaccination. However, the immunity will be lose after about 19.6078 years. Conclusion: Through the results of this study, we give some suggestions to help prevent and control the TB epidemic in the United State, such as prolonging the protection period of the vaccine by developing new and more effective vaccines to prevent TB, using the chemoprophylaxis for incubation patients to prevent their conversion into active TB; raising people’s awareness of prevention and control of TB and treatment after illness; isolation treatment for the infected to reduce the spread of TB. According to the latest report, in the announcement came at the first WHO Global Ministerial Conference on Ending Tuberculosis in the Sustainable Development Era, we predict that it’s difficult to control TB in 2030.

scholarly journals The relationship between balance ability and walking ability using the Berg Balance Scale in people with transfemoral amputation

2019 ◽  
Vol 43 (4) ◽  
pp. 396-401 ◽  
Author(s):  
Yuji Azuma ◽  
Takaaki Chin ◽  
Yasushi Miura
Keyword(s):  
Rank Correlation ◽  
Correlation Coefficients ◽  
Berg Balance Scale ◽  
Walking Ability ◽  
Transfemoral Amputation ◽  
Balance Scale ◽  
Spearman’S Rank Correlation ◽  
Balance Ability ◽  
Partial Rank Correlation ◽  
The Relationship

Background: Few reports have examined the relationship between balance ability and walking ability in people with transfemoral amputation using the Berg Balance Scale. Objectives: To assess the construct validity (known groups discrimination, convergent validity, and floor/ceiling effects) of Berg Balance Scale for people with transfemoral amputation. Study design: Cross-sectional study Methods: Thirty people with transfemoral amputation participated (age: 54 ± 19 years; range: 18–78 years). Outcome measures (Berg Balance Scale, Timed Up & Go test, Six-Minute Walk Test, and use of ambulatory aids) were compared between the groups requiring and not requiring ambulatory aids by the Mann–Whitney U test, Student’s t-test or Welch’s t-test. Correlations were assessed using Spearman’s rank correlation coefficients and age-corrected Spearman’s partial rank correlation coefficients. Results: The group using ambulatory aids had a significantly lower Berg Balance Scale score (41 ± 5 vs 52 ± 3). Berg Balance Scale score was correlated with Timed Up & Go test, use of aids, and Six-Minute Walk Test using Spearman’s rank correlation coefficients (r =−0.85, p < 0.0001; r =−0.82, p < 0.0001; r = 0.81, p < 0.0001) and age-corrected partial rank correlation coefficients (r =−0.66, p < 0.0001; r =−0.56, p = 0.0017; r = 0.57, p = 0.0012). No ceiling effect of Berg Balance Scale was observed. Conclusions: Balance ability in people with transfemoral amputation could be evaluated using Berg Balance Scale and is correlated with walking ability. Clinical relevance In clinical practice, using Berg Balance Scale for people with transfemoral amputation may adequately enable us to discriminate different groups based on walking ability from the perspective of balance ability. When walking ability is evaluated as low, the improvement of walking ability may be evaluated by Berg Balance Scale improvement during rehabilitation.

Dependencies between maternal and fetal autonomic tone

2019 ◽  
Vol 47 (3) ◽  
pp. 323-330 ◽  
Author(s):  
Janine Zöllkau ◽  
Eva-Maria Dölker ◽  
Alexander Schmidt ◽  
Uwe Schneider ◽  
Dirk Hoyer
Keyword(s):  
Heart Rate ◽  
Gestational Age ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Surrogate Data ◽  
Autonomic Tone ◽  
Autonomic Activation ◽  
Diagnostic Window ◽  
Partial Rank Correlation ◽  
Synchronous Monitoring

Abstract Background Disturbances in maternal physiology can cause changes in the fetal condition that may lead to impaired fetal development. Synchronous monitoring of cardiac autonomic tone via the assessment of the fetal and maternal heart rate (HR) and heart rate variability (HRV) may provide an appropriate diagnostic window. Methods Partial rank correlation coefficients between the maternal and fetal HR and HRV indices were calculated and verified by testing surrogate data in 315 magnetocardiographic (MCG) recordings from 141 healthy women pregnant with singleton fetuses [18+6 to 39+2 weeks gestational age (WGA)]. We assessed maternal self-perceived depression, anxiety and stress by means of the Depression, Anxiety, Stress Scales self-reporting instrument (DASS42G) questionnaire. Results The maternal HRV correlated positively with the fetal HRV, but negatively with the fetal HR. Correlation was |r|<0.2 in state-independent and gestational age (GA) <32 weeks, but |r|>0.2 in active sleep and GA ≥32 weeks. The DASS42G results correlated with the maternal HRV and HR, while the fetal HR and HRV were not influenced. Conclusion Correlations between maternal and fetal autonomic activation were statistically confirmed. They depend on the GA and active fetal state. As far as healthy subjects are concerned, maternal self-perceived stress, anxiety or depression is mirrored in maternal but not in fetal autonomic tone.

scholarly journals Some reliability characteristics of a linear consecutive 2-out-of-4 system connected to 2-out-of-4 supporting device for operation

2018 ◽  
Vol 7 (1) ◽  
pp. 135
Author(s):  
Yusuf Ibrahim ◽  
Bashir Yusuf ◽  
Mansur Babagana ◽  
Baffa Sani ◽  
Muhammad Auwal Lawan
Keyword(s):  
Busy Period ◽  
Repairable System ◽  
Profit Function ◽  
Order Linear Differential Equation ◽  
System Parameters ◽  
First Order ◽  
Reliability Characteristics ◽  
Linear Differential ◽  
Supporting Device ◽  
System Operating

This paper presents the Markov model for the reliability analysis of a linear consecutive 2-out-of-4 repairable system operating with the help of a linear consecutive 2-out-of-4 external supporting device. The system is analyzed using first order linear differential equation to develop the explicit expression for steady-state availability, busy period and profit function. Based on assumed numerical values given to system parameters, graphical illustrations are given to highlight important results. In addition, the effect of failure and repair on availability and profit are researched.

scholarly journals A Preliminary Study on Dependence of Mercury Distribution on the Degree of Coalification in Ningwu Coalfield, Shanxi, China

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3119
Author(s):  
Yinjiao Su ◽  
Xuan Liu ◽  
Yang Teng ◽  
Kai Zhang
Keyword(s):  
Linear Correlation ◽  
Bituminous Coal ◽  
Rank Correlation ◽  
Correlation Coefficients ◽  
Chemical Extraction ◽  
Mercury Distribution ◽  
Sequential Chemical Extraction ◽  
Average Proportion ◽  
Total Proportion ◽  
The Relationship

Mercury (Hg) is a toxic trace element emitted from coal conversion and utilization. Samples with different coal ranks and gangue from Ningwu Coalfield are selected and investigated in this study. For understanding dependence of mercury distribution characteristics on coalification degree, Pearson regression analysis coupled with Spearman rank correlation is employed to explore the relationship between mercury and sulfur, mercury and ash in coal, and sequential chemical extraction method is adopted to recognize the Hg speciation in the samples of coal and gangue. The measured results show that Hg is positively related to total sulfur content in coal and the affinity of Hg to different sulfur forms varies with the coalification degree. Organic sulfur has the biggest impact on Hg in peat, which becomes weak with increasing the coalification degree from lignite to bituminous coal. Sulfate sulfur is only related to Hg in peat or lignite as little content in coal. However, the Pearson linear correlation coefficients of Hg and pyritic sulfur are relatively high with 0.479 for lignite, 0.709 for sub-bituminous coal and 0.887 for bituminous coal. Hg is also related to ash content in coal, whose Pearson linear correlation coefficients are 0.504, 0.774 and 0.827 respectively, in lignite, sub-bituminous coal and bituminous coal. Furthermore, Hg distribution is directly depended on own speciation in coal. The total proportion of F2 + F3 + F4 is increased from 41.5% in peat to 87.4% in bituminous coal, but the average proportion of F5 is decreased from 56.8% in peat to 12.4% in bituminous coal. The above findings imply that both Hg and sulfur enrich in coal largely due to the migration from organic state to inorganic state with the increase of coalification degree in Ningwu Coalfield.

Interspike interval dependency from arterial chemoreceptors

1985 ◽  
Vol 59 (5) ◽  
pp. 1566-1570 ◽  
Author(s):  
D. F. Donnelly ◽  
W. F. Nolan ◽  
E. J. Smith ◽  
R. E. Dutton
Keyword(s):  
Carotid Body ◽  
Interspike Interval ◽  
Correlation Coefficients ◽  
Feedback System ◽  
Serial Dependence ◽  
Control Series ◽  
First Order ◽  
System Operating ◽  
Poisson Type

The carotid body impulse generator has been previously characterized as a Poisson-type random process. We examined the validity of this characterization by analyzing sinus nerve spike trains for interspike interval dependency. Fifteen single chemoreceptive afferents were recorded in vivo under hypoxic-hypercapnic conditions, and approximately 1,000 consecutive interspike intervals for each fiber were timed and analyzed for serial dependence. The same set of intervals placed in shuffled order served as a control series without serial dependence. The original spike interval trains showed significantly negative first-order serial correlation coefficients and less variability in joint interval distributions than did the shuffled interval trains. These results suggest that the chemoreceptor afferent train is not random and may reflect a negative feedback system operating within the carotid body that limits variation about a mean frequency.

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