Results 31 to 40 of about 5,511,845 (178)

Limit cycles for Singular Perturbation Problems via Inverse Integrating Factor

Boletim da Sociedade Paranaense de Matemática, 2008
In this paper singularly perturbed vector fields X_{varepsilon} defined in R^2 are discussed. The main results use the solutions of the linear partial differential equation X_{varepslion}V = div(X_{varepslion})V to give conditions for the existence of limit cycles converging to a singular orbit with respect to the Hausdorff distance.
Llibre, Jaume, Medrado, João C.R., Da Silva, Paulo R.   +2 more
openaire   +5 more sources

Secondary Data Analytics of Aquaporin Expression Levels in Glioblastoma Stem-Like Cells

Cancer Informatics, 2015
Glioblastoma is the most common brain tumor in adults in which recurrence has been attributed to the presence of cancer stem cells in a hypoxic microenvironment.
Raphael D. Isokpehi, Katharina C. Wollenberg Valero, Barbara E. Graham, Maricica Pacurari, Jennifer N. Sims, Udensi K. Udensi, Kenneth Ndebele   +6 more
doaj   +1 more source

Existence of an inverse integrating factor, center problem and integrability of a class of nilpotent systems

Chaos, Solitons & Fractals, 2012
We characterize the nilpotent systems whose lowest degree quasi-homogeneous term is (y,σxn)T, σ=±1, having a formal inverse integrating factor. We prove that, for n even, the systems with formal inverse integrating factor are formally orbital equivalent to (x˙,y˙)T=(y,xn)T. In the case n odd, we give a formal normal form that characterizes them.
Algaba Durán, Antonio, García García, Cristóbal, Reyes Columé, Manuel   +2 more
openaire   +3 more sources

An Enhanced Reptile Search Algorithm for Inverse Modeling of Unsaturated Seepage Parameters in Clay Core Rockfill Dam Using Monitoring Data during Operation

Mathematics
The seepage characteristics of clay core walls are crucial for the seepage safety of core rockfill dams, with the permeability coefficient in the unsaturated zone being nonlinear.
Zhangxin Huang, Zhenzhong Shen, Liqun Xu, Yiqing Sun   +3 more
doaj   +1 more source

Research on Optimization of Control Strategy for Energy Storage Systems Considering Battery State of Charge

发电技术
ObjectivesDistributed energy storage systems exhibit slow state of charge (SOC) equalization and low current distribution accuracy due to inconsistency in the SOC and capacity among battery cells.
WANG Mingqi, XIA Xiangyang, ZHAO Xiaoyue, HUANG Ru, DENG Hualong, LIU Daifei, CAI Yukuan   +6 more
doaj   +1 more source

Risk Quantification and Analysis of Coupled Factors Based on the DEMATEL Model and a Bayesian Network

Applied Sciences, 2019
With the developing of high integrations in large scale systems, such as aircraft and other industrial systems, there are new challenges in safety analysis due to the complexity of the mission process and the more complicated coupling characteristic of ...
Jian Jiao, Mengwei Wei, Yuan Yuan, Tingdi Zhao   +3 more
doaj   +1 more source

Food-specific IgG antibodies and body mass index: multivariate analysis of clinical correlations in underweight populations

Frontiers in Immunology
BackgroundThis study investigates the relationship between food-specific IgG antibodies and nutritional status in underweight populations, addressing a critical gap in existing research focused predominantly on obesity.
Yao-Chi Zeng, Cui-Yu Li, Xiao-Li Song, Shu-Fen Huang, Yi Xie, Juan Zeng, Rui Yuan   +6 more
doaj   +1 more source

Modifiable risk factors that mediate the effect of educational attainment on the risk of stroke: a network Mendelian randomization study

Molecular Brain, 2023
Background Stroke is a common cerebrovascular disease with great danger to public health. Educational inequality is a universal issue that influences populations’ stroke risk.
Bangbei Wan, Ning Ma, Zhi Zhou, Weiying Lu   +3 more
doaj   +1 more source

Local analytic integrability for a class of degenerate planar vector fields

Advanced Nonlinear Studies
Using the normal form theory and the existence of an algebraic inverse integrating factor we characterize the local analytic integrability of the systems whose quasi-homogeneous leading term is a1y3+a2x3y,b1x5+b2x2y2 $\left({a}_{1}{y}^{3}+{a}_{2}{x}^{3}y,
Algaba Antonio, Reyes Manuel, Giné Jaume   +2 more
doaj   +1 more source

Feedback methods for inverse simulation of dynamic models for engineering systems applications [PDF]

, 2011
Inverse simulation is a form of inverse modelling in which computer simulation methods are used to find the time histories of input variables that, for a given model, match a set of required output responses.
David J. Murray-Smith, Murray-Smith, D.J.   +1 more
core   +1 more source