Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1760189
D. Zoran, Vahid Parvaneh, Nabil Mlaiki, N. Hussain, S. Radenović
Abstract We introduce some generalizations of contractions for multi-valued mappings and establish some fixed point theorems for multi-valued mappings in b -metric spaces. Our results generalize and extend several known results in b-metric spaces. Some examples are included which illustrate the cases when new results can be applied while old ones cannot.
{"title":"On some new generalizations of Nadler contraction in b-metric spaces","authors":"D. Zoran, Vahid Parvaneh, Nabil Mlaiki, N. Hussain, S. Radenović","doi":"10.1080/25742558.2020.1760189","DOIUrl":"https://doi.org/10.1080/25742558.2020.1760189","url":null,"abstract":"Abstract We introduce some generalizations of contractions for multi-valued mappings and establish some fixed point theorems for multi-valued mappings in b -metric spaces. Our results generalize and extend several known results in b-metric spaces. Some examples are included which illustrate the cases when new results can be applied while old ones cannot.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1760189","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47712474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1721401
Lea Anzagra, S. Sarpong, Suleman Nasiru
Abstract The quest to generate distributions with more desirable and flexible properties for the modeling of data has led to an intense focus on the development of new families that are generalizations of existing distributions by researchers. A new family of distributions called the chen generated family is developed in this study. Its statistical properties such as the quantile, moments, incomplete moments, stochastic ordering and order statistics are derived by using the method of maximum likelihood, estimators for the parameters of the new family are developed. Three special distributions, Chen Burr III, Chen Kumaraswamy and Chen Weibull, are proposed from the new family, though it can generalize other distributions. A demonstration of the usefulness of the new family is performed using real dataset.
为了生成具有更理想和更灵活的数据建模属性的分布，研究人员强烈关注现有分布的新家族的发展。本文发展了一种新的分布族，称为陈生成族。利用极大似然方法推导了其分位数、矩量、不完全矩量、随机有序量和有序统计量等统计性质，并给出了新族参数的估计量。虽然它可以推广其他分布，但从新族中提出了三个特殊分布，Chen Burr III, Chen Kumaraswamy和Chen Weibull。使用真实数据集演示了新家族的有用性。
{"title":"Chen-G class of distributions","authors":"Lea Anzagra, S. Sarpong, Suleman Nasiru","doi":"10.1080/25742558.2020.1721401","DOIUrl":"https://doi.org/10.1080/25742558.2020.1721401","url":null,"abstract":"Abstract The quest to generate distributions with more desirable and flexible properties for the modeling of data has led to an intense focus on the development of new families that are generalizations of existing distributions by researchers. A new family of distributions called the chen generated family is developed in this study. Its statistical properties such as the quantile, moments, incomplete moments, stochastic ordering and order statistics are derived by using the method of maximum likelihood, estimators for the parameters of the new family are developed. Three special distributions, Chen Burr III, Chen Kumaraswamy and Chen Weibull, are proposed from the new family, though it can generalize other distributions. A demonstration of the usefulness of the new family is performed using real dataset.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1721401","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42527480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1815949
Ghodratallah Fasihi Ramandia, H. Ghahremani-Gol
Abstract In this paper, it has been proved that if a 3-dimensional cosymplectic manifold admits a Yamabe soliton, then either is locally flat or the potential field is a contact vector field. Some special potential vector fields of Yamabe solitons on 3-dimensional cosymplectic manifolds have been considered and some other results have been obtained. Also, for general -dimensional case, it will be shown that if an cosymplectic manifold admits a contact Yamabe soliton structure, then is a cosymplectic manifold. Finally, an example of Yamabe soliton on a 3-dimensional cosymplectic manifold is provided.
{"title":"Yamabe solitons on 3-dimensional cosymplectic manifolds","authors":"Ghodratallah Fasihi Ramandia, H. Ghahremani-Gol","doi":"10.1080/25742558.2020.1815949","DOIUrl":"https://doi.org/10.1080/25742558.2020.1815949","url":null,"abstract":"Abstract In this paper, it has been proved that if a 3-dimensional cosymplectic manifold admits a Yamabe soliton, then either is locally flat or the potential field is a contact vector field. Some special potential vector fields of Yamabe solitons on 3-dimensional cosymplectic manifolds have been considered and some other results have been obtained. Also, for general -dimensional case, it will be shown that if an cosymplectic manifold admits a contact Yamabe soliton structure, then is a cosymplectic manifold. Finally, an example of Yamabe soliton on a 3-dimensional cosymplectic manifold is provided.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1815949","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42008538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1805871
M. Tahir, G. Zaman, Syed Inayat Ali Shah
Abstract In this article, we prolate, the coinfection mathematical model for the implication of optimal control. Here the model (Tahir, 0004) AIDS/HIV/TB is extended for an optimal control purpose, and for sensitivity analysis of the dominant parameters involved in infection. For this purpose, initially, we apprized the threshold number of the concern model. Then the sensitivity analysis is discussed for dominant parameters which mostly spread infection in population. Moreover, simulation is shown in simple graph and area graph which shows the effected area of any population in any community by using Matlab programming. Here our mission is to minimize the coinfection problem from any community. Also we defined six control variables with different schemes to control and minimized infection. In the last section, numerical simulation is presented in a new way by Runge-Kutta method of order four, and Matlab programming which is with and without control or vaccination for the concern model.
{"title":"Evaluation and control estimation strategy for three acting play diseases with six control variables","authors":"M. Tahir, G. Zaman, Syed Inayat Ali Shah","doi":"10.1080/25742558.2020.1805871","DOIUrl":"https://doi.org/10.1080/25742558.2020.1805871","url":null,"abstract":"Abstract In this article, we prolate, the coinfection mathematical model for the implication of optimal control. Here the model (Tahir, 0004) AIDS/HIV/TB is extended for an optimal control purpose, and for sensitivity analysis of the dominant parameters involved in infection. For this purpose, initially, we apprized the threshold number of the concern model. Then the sensitivity analysis is discussed for dominant parameters which mostly spread infection in population. Moreover, simulation is shown in simple graph and area graph which shows the effected area of any population in any community by using Matlab programming. Here our mission is to minimize the coinfection problem from any community. Also we defined six control variables with different schemes to control and minimized infection. In the last section, numerical simulation is presented in a new way by Runge-Kutta method of order four, and Matlab programming which is with and without control or vaccination for the concern model.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1805871","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42431561","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1766797
H. Mehravaran, R. Allahyari, Hojjatollah Amiri Kayvanloo
Abstract The paper deals with the achievements of introducing the notion of F-cone metric spaces over Fréchet algebra as a generalization of F-cone metric spaces over a Banach algebra, -cone metric spaces over a Banach algebra, and -cone metric spaces over a Banach algebra. First, we study some of its topological properties. Next, we define a generalized Lipschitz for such spaces. Also, we investigate some fixed points for mappings satisfying such conditions in the new framework. Subsequently, as an application of our results, we provide an example. Our work generalizes some well-known results in the literature.
{"title":"F-cone metric spaces over Fréchet algebra","authors":"H. Mehravaran, R. Allahyari, Hojjatollah Amiri Kayvanloo","doi":"10.1080/25742558.2020.1766797","DOIUrl":"https://doi.org/10.1080/25742558.2020.1766797","url":null,"abstract":"Abstract The paper deals with the achievements of introducing the notion of F-cone metric spaces over Fréchet algebra as a generalization of F-cone metric spaces over a Banach algebra, -cone metric spaces over a Banach algebra, and -cone metric spaces over a Banach algebra. First, we study some of its topological properties. Next, we define a generalized Lipschitz for such spaces. Also, we investigate some fixed points for mappings satisfying such conditions in the new framework. Subsequently, as an application of our results, we provide an example. Our work generalizes some well-known results in the literature.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1766797","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49555209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1857915
G. Srinivasa Rao, K. Rosaiah, C. R. Naidu
Abstract This paper aims to develop a multiple deferred state sampling plan for a time-truncated life test if the lifetime of the item follows exponentiated half logistic distribution. The optimal parameters of the proposed plan, such as the number of successive lots required for making the decision whether to accept or reject the current lot, sample size, the rejection and acceptance numbers are obtained using two points approach. The implementation of the proposed plan is illustrated with examples. Tables are constructed for various combinations of consumer’s and producer’s risks. Comparison is also made with existing sampling plans under exponentiated half logistic distribution.
{"title":"Design of multiple-deferred state sampling plans for exponentiated half logistic distribution","authors":"G. Srinivasa Rao, K. Rosaiah, C. R. Naidu","doi":"10.1080/25742558.2020.1857915","DOIUrl":"https://doi.org/10.1080/25742558.2020.1857915","url":null,"abstract":"Abstract This paper aims to develop a multiple deferred state sampling plan for a time-truncated life test if the lifetime of the item follows exponentiated half logistic distribution. The optimal parameters of the proposed plan, such as the number of successive lots required for making the decision whether to accept or reject the current lot, sample size, the rejection and acceptance numbers are obtained using two points approach. The implementation of the proposed plan is illustrated with examples. Tables are constructed for various combinations of consumer’s and producer’s risks. Comparison is also made with existing sampling plans under exponentiated half logistic distribution.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1857915","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49441055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1857577
S. Azami, S. H. Fatemi
Abstract In this paper, we get two compactness results for complete manifolds by applying a (sub-) elliptic second-order differential operator on distance functions. The first is an extension of a theorem of Galloway and gets an upper estimate for the diameter of the manifold and the second is an extension of a theorem of Ambrose.
{"title":"Some compactness results by elliptic operators","authors":"S. Azami, S. H. Fatemi","doi":"10.1080/25742558.2020.1857577","DOIUrl":"https://doi.org/10.1080/25742558.2020.1857577","url":null,"abstract":"Abstract In this paper, we get two compactness results for complete manifolds by applying a (sub-) elliptic second-order differential operator on distance functions. The first is an extension of a theorem of Galloway and gets an upper estimate for the diameter of the manifold and the second is an extension of a theorem of Ambrose.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1857577","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41815214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1853888
F. .. Adebola, O. Fasoranbaku, J. Kupolusi
Abstract Optimal design of experiment for logistic models has been examined and applied in a wide range of applications. The optimality of the designs is mostly determined by using general equivalence theorem with no attention paid to the extent at which the design can be useful for determining the predictive capability of the model. This paper addressed the predictive capability of optimal design model for two variable quadratic logistic regression model through prediction error variance(PEV). The PEV is a useful way to determining the predictive capability of a model in optimal design. The study used some initial guess parameters to represent any position of parameter in the design space through a simulation study of 10000 experimental runs. The design was optimal when the PEV value is less than one at nine equally weighted support points. The result of the analysis was able to identify the design that is good for prediction among all the designs obtained and conclude that prediction error variance should be used to test the stability of optimal design of experiment for two variable quadratic logistic models.
{"title":"On prediction error variance to determining optimal design for two variable quadratic logistic model","authors":"F. .. Adebola, O. Fasoranbaku, J. Kupolusi","doi":"10.1080/25742558.2020.1853888","DOIUrl":"https://doi.org/10.1080/25742558.2020.1853888","url":null,"abstract":"Abstract Optimal design of experiment for logistic models has been examined and applied in a wide range of applications. The optimality of the designs is mostly determined by using general equivalence theorem with no attention paid to the extent at which the design can be useful for determining the predictive capability of the model. This paper addressed the predictive capability of optimal design model for two variable quadratic logistic regression model through prediction error variance(PEV). The PEV is a useful way to determining the predictive capability of a model in optimal design. The study used some initial guess parameters to represent any position of parameter in the design space through a simulation study of 10000 experimental runs. The design was optimal when the PEV value is less than one at nine equally weighted support points. The result of the analysis was able to identify the design that is good for prediction among all the designs obtained and conclude that prediction error variance should be used to test the stability of optimal design of experiment for two variable quadratic logistic models.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1853888","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49302768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1829277
T. Mekonnen, G. Duressa
Abstract This paper deals with the numerical solution of singularly perturbed parabolic convection-diffusion problems with two small positive parameters multiplying the convection and diffusion terms. A parameter-uniform computational method is developed to solve these problems. The stability and consistency of the method are well established. Numerical experimentation is done and it is observed that the formulated method is stable, consistent and gives more accurate results than some methods exist in the literature.
{"title":"Computational method for singularly perturbed two-parameter parabolic convection-diffusion problems","authors":"T. Mekonnen, G. Duressa","doi":"10.1080/25742558.2020.1829277","DOIUrl":"https://doi.org/10.1080/25742558.2020.1829277","url":null,"abstract":"Abstract This paper deals with the numerical solution of singularly perturbed parabolic convection-diffusion problems with two small positive parameters multiplying the convection and diffusion terms. A parameter-uniform computational method is developed to solve these problems. The stability and consistency of the method are well established. Numerical experimentation is done and it is observed that the formulated method is stable, consistent and gives more accurate results than some methods exist in the literature.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1829277","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44566028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1080/25742558.2020.1750878
Jiabu Ye, D. Lai
Abstract Nonparametric tests are commonly used tests for two sample comparison in clinical studies. However, the estimation of treatment effects associated with the tests may not be obvious, especially under the covariate adjustment. In this article, we evaluated the effect of covariate adjustment on estimating treatment effects based on the Wilcoxon Rank Sum test, the van Elteren test, aligned rank test, and Jaeckel, Hettmansperger-McKean test through Monte Carlo simulations via mean square error and coverage probability. Based on the simulation, commonly used ANCOVA-based approach do not have good estimation of treatment effect when the covariate imbalance is severe. Aligned rank test seems perform well across most scenarios.
{"title":"Estimations of treatment effects based on covariate adjusted nonparametric methods","authors":"Jiabu Ye, D. Lai","doi":"10.1080/25742558.2020.1750878","DOIUrl":"https://doi.org/10.1080/25742558.2020.1750878","url":null,"abstract":"Abstract Nonparametric tests are commonly used tests for two sample comparison in clinical studies. However, the estimation of treatment effects associated with the tests may not be obvious, especially under the covariate adjustment. In this article, we evaluated the effect of covariate adjustment on estimating treatment effects based on the Wilcoxon Rank Sum test, the van Elteren test, aligned rank test, and Jaeckel, Hettmansperger-McKean test through Monte Carlo simulations via mean square error and coverage probability. Based on the simulation, commonly used ANCOVA-based approach do not have good estimation of treatment effect when the covariate imbalance is severe. Aligned rank test seems perform well across most scenarios.","PeriodicalId":92618,"journal":{"name":"Cogent mathematics & statistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25742558.2020.1750878","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44594725","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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