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Exploration of Long-term CD4 Profile in HIV Patients Under HAART at Mizan-Tepi University Teaching Hospital and Tepi General Hospital, South Western Ethiopia 埃塞俄比亚西南部米赞-特皮大学教学医院和特皮总医院接受HAART治疗的HIV患者长期CD4谱的探索
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-09-15 DOI: 10.11648/J.PAMJ.20200905.12
S. Andargie, Assaye Belay Gelaw
Currently, because of the wide availability and free service of HAART, HIV/AIDS related morbidity and mortality has decreased significantly. However, patients accessing antiretroviral treatment (ART) programmes in sub-Saharan Africa frequently have very advanced immunodeficiency and various reserches suggest that such patients may have diminished capacity for CD4 cell count recovery. The objective of this study was to investigate the long-term effect of highly active antiretroviral therapy on the CD4 lymphocyte count of HIV-infected Patients. Subjects from the multicenter HAART Program cohort (from Mizan-Tepi University Teaching Hospital and Tepi General Hospital), aged 18 years or older and had an ART treatment start date in between February 1, 2017 to January 31, 2019 were enrolled in the present study and followed for a maximum of 3 years. Liner mixed model with nested random effect were used to model the longitudianl CD4 count over time. The data reveal robust CD4 responses to ART that are continual over several years. Being under HAART for long period and having baseline CD4 count greater than 150 were positively associated with CD4 increment over time while starting ART at late stage (Stage 3 or 4) and being male are negatively assocted with CD4 increment over time. These study show strong and repetitive CD4 response to ART among patients remaining on therapy. Earlier HIV diagnosis and initiation of ART could significantly progress patient outcomes in the study area.
目前,由于HAART的广泛提供和免费服务,与艾滋病毒/艾滋病有关的发病率和死亡率已显著下降。然而,在撒哈拉以南非洲,接受抗逆转录病毒治疗(ART)规划的患者往往具有非常严重的免疫缺陷,各种研究表明,这些患者的CD4细胞计数恢复能力可能降低。本研究的目的是探讨高活性抗逆转录病毒治疗对hiv感染患者CD4淋巴细胞计数的长期影响。来自多中心HAART项目队列的受试者(来自Mizan-Tepi大学教学医院和Tepi综合医院),年龄在18岁或以上,ART治疗开始日期在2017年2月1日至2019年1月31日之间,被纳入本研究,最长随访3年。采用嵌套随机效应的线性混合模型来模拟CD4随时间的纵向计数。数据显示,CD4细胞对抗逆转录病毒治疗的反应持续数年。长期接受HAART治疗和基线CD4计数大于150与CD4随时间的增加呈正相关,而在晚期(第3或第4阶段)开始ART治疗和男性与CD4随时间的增加呈负相关。这些研究表明,在继续接受抗逆转录病毒治疗的患者中,CD4细胞对抗逆转录病毒治疗有强烈和重复的反应。在研究地区,早期的HIV诊断和开始抗逆转录病毒治疗可以显著改善患者的预后。
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引用次数: 0
A 2-Stage Implicit Runge-Kutta Method Based on Heronian Mean for Solving Ordinary Differential Equations 基于Heronian均值的二阶隐式龙格-库塔法求解常微分方程
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-09-09 DOI: 10.11648/j.pamj.20200905.11
A. S. Olaniyan, Omolara Fatimah Bakre, M. A. Akanbi
In recent times, the use of different types of mean in the derivation of explicit Runge-Kutta methods had been on increase. Researchers have explored explicit Runge-Kutta methods derivation by using different types of mean such as geometric mean, harmonic mean, contra-harmonic mean, heronian mean to name but a few; as against the conventional explicit Runge-Kutta methods which was viewed as arithmetic mean. However, despite efforts to improve the derivation of explicit Runge-Kutta methods with use of other types of mean, none has deemed it fit to extend this notion to implicit Runge-Kutta methods. In this article, we present the use of heronian mean as a basis for the construction of implicit Runge-Kutta method in a way of improving the conventional method which is arithmetic mean based. Numerical results was conducted on ordinary differential equations which was compared with the conventional two-stage fourth order implicit Runge-Kutta (IRK4) method and two-stage third order diagonally implicit Runge-Kutta (DIRK3) method. The results presented confirmed that the new scheme performs better than these numerical methods. A better Qualitative properties using Dalquist test equation were established.
近年来,在显式龙格-库塔方法的推导中,越来越多地使用不同类型的平均值。研究者利用几何均值、调和均值、反调和均值、赫伦均值等不同类型的均值,探索了显式龙格-库塔方法的推导;而传统的显式龙格-库塔方法被视为算术平均值。然而,尽管人们努力使用其他类型的均值来改进显式龙格-库塔方法的推导,但没有人认为它适合将这一概念扩展到隐式龙格-库塔方法。本文在改进传统的基于算术平均的方法的基础上,提出了用赫氏平均作为构造隐式龙格-库塔方法的基础。对常微分方程进行了数值计算,并与传统的两阶段四阶隐式龙格-库塔法(IRK4)和两阶段三阶对角隐式龙格-库塔法(DIRK3)进行了比较。结果表明,新方案的性能优于现有的数值方法。利用Dalquist检验方程建立了较好的定性性质。
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引用次数: 2
Common Fixed Point for Two Multivalued Mappings on Proximinal Sets in Regular Modular Space 正则模空间中邻近集上两个多值映射的公共不动点
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-08-10 DOI: 10.11648/j.pamj.20200904.12
N. Faried, H. A. Ghaffar, S. Hamdy
In 2010, Chistyakov, V. V., defined the theory of modular metric spaces. After that, in 2011, Mongkolkeha, C. et. al. studied and proved the new existence theorems of a fixed point for contraction mapping in modular metric spaces for one single-valued map in modular metric space. Also, in 2012, Chaipunya, P. introduced some fixed point theorems for multivalued mapping under the setting of contraction type in modular metric space. In 2014, Abdou, A. A. N., Khamsi, M. A. studied the existence of fixed points for contractive-type multivalued maps in the setting of modular metric space. In 2016, Dilip Jain et. al. presented a multivalued F-contraction and F-contraction of Hardy-Rogers-type in the case of modular metric space with specific assumptions. In this work, we extended these results into the case of a pair of multivalued mappings on proximinal sets in a regular modular metric space. This was done by introducing the notions of best approximation, proximinal set in modular metric space, conjoint F-proximinal contraction, and conjoint F-proximinal contraction of Hardy-Rogers-type for two multivalued mappings. Furthermore, we give an example showing the conditions of the theory which found a common fixed point of a pair of multivalued mappings on proximinal sets in a regular modular metric space. Also, the applications of the obtained results can be used in multiple fields of science like Electrorheological fluids and FORTRAN computer programming as shown in this communication.
2010年,Chistyakov, V. V.定义了模度量空间理论。之后,2011年Mongkolkeha, C.等研究并证明了模度量空间中一个单值映射在模度量空间中收缩映射不动点的存在性新定理。Chaipunya, P.(2012)也引入了模度量空间中缩型集合下的多值映射的不动点定理。2014年,Abdou, A. A. N., Khamsi, M. A.研究了模度量空间下缩型多值映射不动点的存在性。2016年,Dilip Jain等人提出了模度量空间中具有特定假设的多值f -收缩和hardy - rogers型f -收缩。在这项工作中,我们将这些结果推广到正则模度量空间中近端集合上的一对多值映射。通过引入两个多值映射的最佳逼近、模度量空间中的近端集、联合f -近端收缩和hardy - rogers型的联合f -近端收缩的概念来实现。在此基础上,给出了正则模度量空间中近集上的一对多值映射存在公共不动点的条件。此外,所获得的结果可以应用于多个科学领域,如电流变流体和FORTRAN计算机编程,如本通信所示。
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引用次数: 1
An Accelerated Accuracy-enhanced Randomized Singular Value Decomposition for Factorizing Matrices with Low-rank Structure 低秩结构矩阵分解的加速精度增强随机奇异值分解
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-07-28 DOI: 10.11648/j.pamj.20200904.11
Joseph Roger Arhin, Francis Sam, K. Coker, Toufic Seini
Big data has in recent years gained ground in many scientific and engineering problems. It seems to some extent prohibitive for traditional matrix decomposition methods (i.e. QR, SVD, EVD, etc.) to handle such large-scale problems involving data matrix. Many researchers have developed several algorithms to decompose such big data matrices. An accuracy-enhanced randomized singular value decomposition method (referred to as AE-RSVDM) with orthonormalization recently becomes the state-of-the-art to factorize large data matrices with satisfactory speed and accuracy. In our paper, low-rank matrix approximations based on randomization are studied, with emphasis on accelerating the computational efficiency on large data matrices. By this, we accelerate the AE-RSVDM with modified normalized power iteration to result in an accelerated version. The accelerated version is grounded on a two-stage scheme. The first stage seeks to find the range of a sketch matrix which involves a Gaussian random matrix. A low-dimensional space is then created from the high-dimensional data matrix via power iteration. Numerical experiments on matrices of different sizes demonstrate that our accelerated variant achieves speedups while attaining the same reconstruction error as the AE-RSVDM with orthonormalization. And with data from Google art project, we have made known the computational speed-up of the accelerated variant over the AE-RSVDM algorithm for decomposing large data matrices with low-rank form.
近年来,大数据在许多科学和工程问题上取得了进展。传统的矩阵分解方法(QR、SVD、EVD等)似乎在一定程度上难以处理这种涉及数据矩阵的大规模问题。许多研究人员已经开发了几种算法来分解这种大数据矩阵。一种精度增强的随机奇异值分解方法(简称AE-RSVDM)是近年来以令人满意的速度和精度分解大型数据矩阵的最新方法。本文研究了基于随机化的低秩矩阵逼近,重点是提高大数据矩阵的计算效率。在此基础上,采用改进的归一化功率迭代对AE-RSVDM进行加速,得到加速版本。加速版基于两阶段方案。第一阶段寻求找到包含高斯随机矩阵的草图矩阵的范围。然后通过幂次迭代从高维数据矩阵创建一个低维空间。在不同大小的矩阵上进行的数值实验表明,我们的加速变体在获得与正规一化AE-RSVDM相同的重构误差的同时实现了加速。通过谷歌艺术项目的数据,我们已经知道了加速变体在分解具有低秩形式的大数据矩阵时比AE-RSVDM算法的计算速度。
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引用次数: 0
Some Separate Quasi-Asymptotics Properties of Multidimensional Distributions and Application 多维分布的几个独立拟渐近性质及其应用
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-07-14 DOI: 10.11648/J.PAMJ.20200903.13
N. Stojanović
Quasi-asymptotic behavior of functions as a method has its application in observing many physical phenomena which are expressed by differential equations. The aim of the asymptotic method is to allow one to present the solution of a problem depending on the large (or small) parameter. One application of asymptotic methods in describing physical phenomena is the quasi-asymptotic approximation. The aim of this paper is to look at the quasi-asymptotic properties of multidimensional distributions by extracted variable. Distribution T(x0,x) from S'(Ṝ+1×Rn) has the property of the separability of variables, if it can be represented in form T(x0,x)=∑φi(x0)ψi (x) where distributions, φi(x0) from S'(Ṝ1) and ψi from S(Rn), x0 from Ṝ1+ and x is element Rn different values of do not depend on each other. Distribution T(x0,x) the element S'(Ṝ+1×Rn) is homogeneous and of order α at variable x0 is element Ṝ1+ and x=x1,x2,…,xn from Rn if for k>0 it applies that T(kx0,kx)=kα T(x0,x). The method of separating variables is one of the most widespread methods for solving linear differential equations in mathematical physics. In this paper, the results by V. S Vladimirov are used to present the proof of the basic theorems, regarding the quasi-asymptotic behavior of multidimensional distributions by a singular variable, with the application of quasi-asymptotics to the solution of differential equations.
函数的拟渐近行为作为一种方法,在观察许多用微分方程表示的物理现象时有其应用。渐近方法的目的是允许人们根据大(或小)参数给出问题的解。渐近方法在描述物理现象中的一个应用是拟渐近逼近。本文的目的是通过抽取变量来研究多维分布的拟渐近性质。S'(Ṝ+1×Rn)中的分布T(x0,x)具有变量可分性,如果它可以表示为T(x0,x)=∑φi(x0)ψi (x)其中分布φi(x0)来自S'(Ṝ1)和ψi来自S(Rn), x0来自Ṝ1+和x是元素Rn的不同值不依赖于彼此。分布T(x0,x)元素S'(Ṝ+1×Rn)是齐次的,在变量x0处的α阶是元素Ṝ1+,x =x1,x2,…,xn,如果k>0,适用于T(kx0,kx)=kα T(x0,x)。分离变量法是数学物理中最常用的求解线性微分方程的方法之一。本文利用V. S . Vladimirov的结果,给出了关于多维分布的奇异变量拟渐近性的基本定理的证明,并将拟渐近性应用于微分方程的解。
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引用次数: 0
Investor’s Optimal Strategy with and Without Transaction Cost Under Ornstein-Uhlenbeck and Constant Elasticity of Variance (CEV) Models Via Exponential Utility Maximization 基于指数效用最大化的Ornstein-Uhlenbeck和Constant Elasticity of Variance (CEV)模型下投资者有交易成本和无交易成本的最优策略
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-07-04 DOI: 10.11648/J.PAMJ.20200903.12
S. Ihedioha, Nanle Tanko Danat, A. Buba
In this work, we studied the optimal investment problem of an investor who had exponential utility preference and traded two assets; (1) a risky asset which price dynamics was governed by the Constant Elasticity of variance (CEV) model and (2) a risk-free asset which price system followed the Ornstein-Uhlenbeck model. We employed the maximum principle of dynamic programming to obtain the Hamilton-Jacobi-Bellman (H-J-B) equation on which the first principle and the elimination of variable dependency were applied to get the closed-form of the investor’s optimal strategies. Two scenarios where the Brownian motions correlated and where they did not correlate were investigated. Also considered were the cases of when transaction cost was involved and when transaction cost was not involved. This lead to six cases that among the results obtained was that the investor has an optimal investment strategy that requires more amount of money for investment when the Brownian motions do not correlate and there is transaction cost than when the Brownian motions correlate and there is no transaction.
本文研究了具有指数效用偏好的投资者交易两种资产的最优投资问题;(1)风险资产,其价格动态受恒定弹性方差(CEV)模型控制;(2)无风险资产,其价格系统遵循Ornstein-Uhlenbeck模型。利用动态规划的极大值原理得到了Hamilton-Jacobi-Bellman (H-J-B)方程,在该方程上应用第一原理和变量相关性消去得到了投资者最优策略的封闭形式。研究了布朗运动相关和不相关的两种情况。还考虑了何时涉及交易成本和何时不涉及交易成本的情况。这导致了6种情况,在得到的结果中,投资者有一个最优的投资策略,即当布朗运动不相关且有交易成本时,比当布朗运动相关且没有交易时需要更多的资金进行投资。
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引用次数: 2
A New Analysis of Approximate Solutions for Numerical Integration Problems with Quadrature-based Methods 数值积分问题近似解的一种新分析方法
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-06-20 DOI: 10.11648/J.PAMJ.20200903.11
Mir Md. Moheuddin, Muhammad Abdus Sattar Titu, Saddam Hossain
In this paper, we mainly propose the approximate solutions to solve the integration problems numerically using the quadrature method including the Trapezoidal method, Simpson’s 1/3 method, and Simpson’s 3/8 method. The three proposed methods are quite workable and practically well suitable for solving integration problems. Through the MATLAB program, our numerical solutions are determined as well as compared with the exact values to verify the higher accuracy of the proposed methods. Some numerical examples have been utilized to give the accuracy rate and simple implementation of our methods. In this study, we have compared the performance of our solutions and the computational attempt of our proposed methods. Moreover, we explore and calculate the errors of the three proposed methods for the sake of showing our approximate solution’s superiority. Then, among these three methods, we analyzed the approximate errors to prove which method shows more appropriate results. We also demonstrated the approximate results and observed errors to give clear idea graphically. Therefore, from the analysis, we can point out that only the minimum error is in Simpson’s 1/3 method which will beneficial for the readers to understand the effectiveness in solving the several numerical integration problems.
本文主要提出了用正交法求解积分问题的近似解,包括梯形法、辛普森1/3法和辛普森3/8法。所提出的三种方法均具有较强的可操作性和实用性,适用于求解积分问题。通过MATLAB程序,确定了我们的数值解,并与精确值进行了比较,验证了所提方法具有较高的精度。一些数值算例说明了我们的方法的准确率和简单实现。在这项研究中,我们比较了我们的解决方案的性能和我们提出的方法的计算尝试。此外,我们还对这三种方法的误差进行了探讨和计算,以显示我们的近似解的优越性。然后,在这三种方法中,我们分析了近似误差,以证明哪种方法的结果更合适。我们还演示了近似结果和观察到的误差,以图形形式给出清晰的概念。因此,从分析中我们可以指出,Simpson的1/3方法只有最小的误差,这有利于读者了解在解决几个数值积分问题时的有效性。
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引用次数: 0
Cohomology Operations andπ-Strongly Homotopy Commutative Hopf Algebra 上同调运算与π-强同伦交换Hopf代数
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-04-23 DOI: 10.11648/J.PAMJ.20200902.12
C. Tcheka
Steenrod operations are cohomology operations that are themselves natural transformations between cohomology functors. There are two distinct types of steenrod operations initially constructed by Norman Steenrod and called Steenrod squares and reduced p-th power operations usually denoted Sq and pi respectively. Since their creation, it has been proved that these operations can be constructed in the cohomology of many algebraic structures, for instance in the cohomology of simplicial restricted Lie algebras, the cohomology of cocommutative Hopf algebras and the homology of infinite loop space. Later on J. P. May developped a general algebraic setting in which all the above cases can be studied. In this work we consider a cyclic group π of oder a fixed prime p and combine theπ-strongly homotopy commutative Hopf algebra structure to the May’s approach with the aim to build these natural transformations on the Hochschild cohomology groups. Moreover we give under some conditions a link of these natural transformations with the Gerstenhaber algebra structure.
Steenrod运算是上同调运算,它本身是上同调函子之间的自然变换。steenrod运算有两种不同的类型,最初是由Norman steenrod构造的,称为steenrod平方和降p次幂运算,通常分别表示为Sq和pi。自它们被创造以来,已经证明了这些运算可以构造在许多代数结构的上同调上,例如简单限制李代数的上同调、协交换Hopf代数的上同调和无限环空间的上同调上。后来,j.p. May发展了一个一般的代数集合,在这个集合中可以研究上述所有情况。本文考虑一个序为固定素数p的循环群π,并将π-强同伦交换Hopf代数结构与May方法结合起来,目的是在Hochschild上同调群上建立这些自然变换。并在一定条件下给出了这些自然变换与Gerstenhaber代数结构的联系。
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引用次数: 0
Comparison of Numerical Methods for System of First Order Ordinary Differential Equations 一阶常微分方程组数值方法的比较
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-04-14 DOI: 10.11648/J.PAMJ.20200902.11
Jemal Demsie Abraha
In this paper three numerical methods are discussed to find the approximate solutions of a systems of first order ordinary differential equations. Those are Classical Runge-Kutta method, Modified Euler method and Euler method. For each methods formulas are developed for n systems of ordinary differential equations. The formulas explained by these methods are demonstrated by examples to identify the most accurate numerical methods. By comparing the analytical solution of the dependent variables with the approximate solution, absolute errors are calculated. The resulting value indicates that classical fourth order Runge-Kutta method offers most closet values with the computed analytical values. Finally from the results the classical fourth order is more efficient method to find the approximate solutions of the systems of ordinary differential equations.
本文讨论了求一阶常微分方程组近似解的三种数值方法。分别是经典龙格-库塔法、修正欧拉法和欧拉法。对于每种方法,都给出了n个常微分方程组的公式。通过实例说明了这些方法所解释的公式,以确定最准确的数值方法。通过对因变量解析解与近似解的比较,计算了绝对误差。结果表明,经典的四阶龙格-库塔方法与计算的解析值最接近。最后,从结果来看,经典四阶方法是求解常微分方程组近似解的更有效方法。
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引用次数: 2
SDA-COVID-19: Social Distancing App for COVID-19 Track and Control (Preprint) SDA-COVID-19: COVID-19跟踪和控制社交距离应用程序(预印本)
IF 0.2 Q4 MATHEMATICS Pub Date : 2020-04-04 DOI: 10.2196/preprints.19120
Evon M. O. Abu-Taieh, Issam Alhadid, Ali Zolait, Jeihan M. Abu-Tayeh
UNSTRUCTURED COVID-19 is a highly contagious and lethal virus-based disease. Social distancing is the only way to stop the virus from spreading. In this context, the researchers suggest a social distancing application named SDA-COVID-19. The suggested App (SDA-COVID-19) will help individuals maintain social distancing by the exchange of data among phones about potentially infected and/or contaminated people with COVID-19, with whom an individual socialized or came in contact, whereby, an individual will be alerted if a COVID-19 infected person is in close proximity. Two versions are suggested for SDA-COVID-19 one is Service-Oriented and the other is Bluetooth oriented.
COVID-19是一种高度传染性和致命性的基于病毒的疾病。保持社交距离是阻止病毒传播的唯一途径。在这种情况下,研究人员提出了一种名为SDA-COVID-19的社交距离应用程序。建议的应用程序(SDA-COVID-19)将通过在手机之间交换与个人社交或接触过的潜在感染和/或感染COVID-19的人的数据来帮助个人保持社交距离,从而在COVID-19感染者靠近时向个人发出警报。sda - covid建议有两个版本,一个面向服务,一个面向蓝牙。
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引用次数: 0
期刊
Italian Journal of Pure and Applied Mathematics
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